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Comparisons of higher-order-aberrations following hyperopic small incision lenticule extraction, hyperopic laser-assisted in situ keratomileusis and lenticule implantation for correction of hyperopia

Journal paper
Liu YC, Wen XX, Teo E, Williams GP, Chan LN and Mehta JS
Transl Vis Sci Technol. 2018 Apr; 7(2): 15. Published online 2018 Mar 29. doi: 10.1167/tvst.7.2.15
Publication year: 2018

Abstract

PURPOSE:

To compare the postoperative higher-order-aberrations (HOAs) after hyperopic small incision lenticule extraction (SMILE), hyperopic laser-assisted in situ keratomileusis (LASIK), and lenticule implantation for correction of hyperopia.

Methods

Eighteen monkeys were divided to six groups: +2.00 D and +4.00 D hyperopic SMILE, +2.00 D and +4.00 D hyperopic LASIK (n = 6 eyes for each), and lenticule implantation with a −2.00 D and −4.00 D lenticule (n = 3 eyes for each). The corneal HOAs were evaluated preoperatively and 3-month postoperatively.

Results

At 3-month postoperatively, the spherical aberrations significantly increased toward negative direction in all +4.00 D groups (all P < 0.05). There was a significant change toward more negative values in the third-order vertical coma in the SMILE +4.00 D and LASIK +4.00 D groups (P = 0.026 and P = 0.036, respectively). There were also significant changes in the third-order horizontal trefoil (P = 0.034) and oblique secondary astigmatism (P = 0.012) in the LASIK +4.00 D group. In the eyes that underwent +4.00 D lenticule implantation, the fourth-order horizontal quatrefoil significantly increased (P = 0.029). In low hyperopia correction (+2.00 D), treatment with lenticule implantation tended to have less changes in HOAs, compared to the other two groups.

Conclusions

In hyperopic SMILE, hyperopic LASIK or lenticule implantation surgery, significant induction of third- and fourth-order HOAs were seen in moderate hyperopia correction but not in low hyperopia correction. In low hyperopia treatment, lenticule implantation might offer a favorable trend in the aspect of HOAs.

Translational Relevance

The results provided the knowledge of surgically induced HOAs and understanding of the effects of surgery in different types of hyperopic correction.

Keywords: higher-order- aberrations, hyperopia, SMILE, LASIK, lenticule implantation

Hyperopic Refractive Correction by LASIK, SMILE or lenticule reimplantation in a Non-Human Primate Model

Journal paper
Williams GP and Wu B (joint first authors), Liu YC, Teo E, Chan LN, Yam G, Tan D and Mehta JS
PLoS One. 2018; 13(3): e0194209.
Publication year: 2018

Abstract

Hyperopia is a common refractive error, apparent in 25% of Europeans. Treatments include spectacles, contact lenses, laser interventions and surgery including implantable contact lenses and lens extraction. Laser treatment offers an expedient and reliable means of correcting ametropia. LASIK is well-established however SMILE (small-incision lenticule extraction) or lenticule implantation (derived from myopic laser-correction) are newer options. In this study we compared the outcomes of hyperopic LASIK, SMILE and lenticule re-implantation in a primate model at +2D/+4D treatment. While re-implantation showed the greatest regression, broadly comparable refractive results were seen at 3-months with SMILE and LASIK (<1.4D of intended), but a greater tendency to regression in +2D lenticule reimplantation. Central corneal thickness showed greater variation at +2D treatment, but central thickening during lenticule reimplantation at +4D treatment was seen (-17± 27μm LASIK, -45 ± 18μm SMILE and 28 ± 17μm Re-implantation; p <0.01) with expected paracentral thinning following SMILE. Although in vivo confocal microscopy appeared to show higher reflectivity in all +4D treatment groups, there were minimal and inconsistent changes in inflammatory responses between modalities. SMILE and lenticule re-implantation may represent a safe and viable method for treating hyperopia, but further optimization for lower hyperopic treatments is warranted.

iovs sep 2017

Performing reliable lens capsulotomy in the presence of corneal edema with a femtosecond laser

Journal paper
Williams GP, George BL, Wong YR, Yam G, Seah XY, Ang M, Tay SC and Mehta JS
Investigative Ophthalmology and Visual Science 2017 58(11):4490-4498
Publication year: 2017

Abstract

Purpose:

To determine the effects of the Ziemer LDV Z8 liquid interface femtosecond laser platform during capsulotomy under different energy settings in the presence of corneal edema.

Methods:

Cadaveric porcine eyes (n = 36) employed at less than 6 and greater than 24 post enucleation hours to simulate clear/edematous corneas, underwent capsulotomy with the Ziemer LDV Z8 femtosecond laser (5-mm diameter, energy 90%, 130%, or 150%). Lens capsules were removed for evaluation by scanning electron microscopy and rupture strengths determined by the single column universal testing system. Following ethical approval, 23 patients had lens capsules removed during routine cataract surgery following manual or Z8 capsulotomy and subjected to TUNEL assay.

Results:

There was no difference in edge morphology or rupture strength (120, 113, and 118 mN at increasing energy, P = 0.42) in the clear cornea. Only 50% of capsulotomies succeeded at 90% energy in an edematous cornea, improving with increased energy (75% completion at 130%, 100% at 150%). Rupture strength in edematous corneas was not significantly different at 112, 133, and 114 mN for 90%, 130%, and 150%, respectively (P = 0.3). In human samples, increased TUNEL-positive cells were seen at 130% energy, but not at 150% (0.0 manual vs. 0.2 [90%] vs. 2.1 [130%] vs. 0.6 [150%], P < 0.05).

Conclusions:

Because of the low energy delivered by a femtosecond nanojoule platform, even incremental increases in energy appeared to have minimal effect on lens capsule morphology and strength and negligible influence on cell death. Furthermore, increasing energy appeared to enhance consistency and the ability to complete a capsulotomy in an edematous cornea.

Differential nerve regeneration by human corneal stromal keratocytes and stromal fibroblasts

Journal paper
Yam G, Williams GP, Lee X-W, Setiawan M, Yusoff ZBM, Htoon HM, Zhou L, Fuest M, Mehta JS
Scientific Reports 2017 28;7:45396. doi: 10.1038/srep45396.
Publication year: 2017

Abstract

Laser refractive surgeries reshape corneal stroma to correct refractive errors, but unavoidably affect corneal nerves. Slow nerve regeneration and atypical neurite morphology cause desensitization and neuro-epitheliopathy. Following injury, surviving corneal stromal keratocytes (CSKs) are activated to stromal fibroblasts (SFs). How these two different cell types influence nerve regeneration is elusive. Our study evaluated the neuro-regulatory effects of human SFs versus CSKs derived from the same corneal stroma using an in vitro chick dorsal root ganglion model. The neurite growth was assessed by a validated concentric circle intersection count method. Serum-free conditioned media (CM) from SFs promoted neurite growth dose-dependently, compared to that from CSKs. We detected neurotrophic and pro-inflammatory factors (interleukin-8, interleukin-15, monocyte chemoattractant protein-1, eotaxin, RANTES) in SFCM by Bio-Plex Human Cytokine assay. More than 130 proteins in SFCM and 49 in CSKCM were identified by nanoLC-MS/MS. Proteins uniquely present in SFCM had reported neuro-regulatory activities and were predicted to regulate neurogenesis, focal adhesion and wound healing. Conclusively, this was the first study showing a physiological relationship between nerve growth and the metabolically active SFs versus quiescent CSKs from the same cornea source. The dose-dependent effect on neurite growth indicated that nerve regeneration could be influenced by SF density.

Corneal lenticule storage prior to re-implantation

Journal paper
Liu YC and Williams GP (joint first authors), George BL, Soh YQ, Seah XY, Peh GS, Yam GH and Mehta JS
Molecular Vision 2017 (in press)
Publication year: 2017

Abstract

Purpose: To explore the optimal lenticule storage conditions that maintain lenticule integrity and clarity.

Methods: A total of 99 lenticules obtained from myopic patients undergoing small incision lenticule extraction (SMILE) were divided into four combinations for short-term storage conditions: PBS, Dulbecco’s Modified Eagle’s Medium (DMEM), Optisol GS, or anhydrous glycerol. Two thirds of the lenticules were further stored for 4 weeks under eight different conditions. Clarity evaluation with transmittance measurements, cell-death assays with terminal deoxynucleotidyl transferase-mediated nick end labeling assay (TUNEL), collagen fibril spacing and necrotic response assessed with transmission electron microscopy (TEM), and immunohistochemistry analysis for human leukocyte antigens (HLAs) and CD45 for immunogenicity, and matrix metalloproteinase (MMP)-2 for keratocyte response, were undertaken at baseline, 48 h (short term), and 4 weeks (long term).

Results: The TUNEL and immunogenicity results were comparable among the groups. The mean percentage of TUNEL-positive cells across all groups was 24.3% ± 11.8% and 62.9% ± 20.7% at the 48 h and 4 week time points, respectively. HLA-ABC+, HLA-DR+, and CD45+ cells were extremely rare, and MMP-2 expression ranged from non-detectable to minimal, under all conditions at all time points. Transmittance at 4 weeks was significantly different among groups with the greatest maintenance of clarity seen in the lenticules stored initially in DMEM at 4 °C for 48 h followed by cryopreservation in serum-free medium or glycerol at 4 °C followed by storage at room temperature. At TEM analysis at 4 weeks, the lenticules cryopreserved in liquid nitrogen, regardless of storage solutions, had significantly narrower inter-fibrillar distance than controls, while glycerol-preserved lenticules, at either room temperature or −80 °C, maintained the inter-fibrillar distance.

Conclusions: Clarity, structural integrity, and low immunogenicity under various conditions, at 4 °C or room temperature for short-term storage, offer encouragement for lenticule storage. It can be undertaken without access to s specialized and potentially expensive laboratory setup at least within the first 48 h before transportation to larger facilities for long-term storage.

An International Ocular Surface Disease Scoring System (OSDISS): Defining Activity and Damage by A Delphi Consultation

Journal paper
Mathewson P and Williams GP (joint first authors), Hodson J, Watson S and Rauz S
Ocular Surface 2017 Jan;15(1):97-111
Publication year: 2017

Abstract

PURPOSE:

Unifying terminology for the description of ocular surface disease (OSD) is vital for determining treatment responses and ensuring robust clinical trial outcomes. To date, there are no agreed parameters describing ‘activity’ and ‘damage’ phases of disease.

METHODS:

A working group of international experts in OSD, oculoplastics, and uveitis from a range of backgrounds (university, teaching, district general and private hospitals) participated in a modified Delphi consensus-building exercise (October 31, 2011 to March 20, 2015). Two steering group meetings took place in which factors based upon published literature were discussed and supplemented with anonymous web-based questionnaires to refine clinical indices according to ‘activity’ (reversible changes resulting directly from the inflammatory process) and/or ‘damage’ (persistent, >6 months duration) changes resulting from previously active disease that are cumulative and irreversible).

RESULTS:

The recommended set of clinical parameters for the assessment of OSD encompasses 68 clinical indices and 22 ancillary grading tools (in parenthesis) subdivided by anatomical domain as follows: 4(4) tear-film, eyelid 21(3), 17(3) conjunctiva, 15(10) cornea and 11(2) Anterior Chamber/Sclera. Of these; 17(2) were considered as measures of clinical activity, 27(3) as damage, 1(8) as measures of both activity and damage. Twenty-three clinical descriptors and 9 tools did not reach the threshold for inclusion into the main standard set. These were defined as ‘second tier’ parameters for use in special clinical settings.

CONCLUSION:

These core parameters provide the first description of ‘activity’ and ‘damage’ relevant to OSD and provide a platform for the future development of scoring scales for each parameter.

KEYWORDS:

Delphi process; conjunctiva; cornea; disease activity; disease damage; disease scoring; disease staging; ocular surface disease

The effects of a low-energy, high frequency liquid optic interface system during femtosecond laser on lens capsulotomy

Journal paper
Williams GP, George BL, Wong YR, Seah XY, Ang HP, Loke MKA, Tay SC and Mehta JS
Scientific Reports 2016;6:24352. doi: 10.1038/srep24352
Publication year: 2016

Abstract

The introduction of femtosecond laser assisted cataract surgery (FLACS) is a paradigm changing approach in cataract surgery, the most commonly performed surgical procedure. FLACS has the potential to optimize the creation of an anterior lens capsulotomy, a critical step in accessing the cataractous lens. The merits of using a laser instead of a manual approach include a potentially more circular, consistent, and stronger aperture. In this study we demonstrated for the first time in both a porcine and human experimental setting that with a low energy, high repetition FLACS system, that a circular, smooth and strong capsulotomy was achievable. While there was no demonstrable difference in the resistance to rupture before or after the removal of the nucleus, larger capsulotomies had an increase in tensile strength. The LDV Z8 system appeared to create circular, rupture-resistant and smooth capsulotomies in both porcine and more importantly human globes.

 

 

Periodontitis prevalence and serum antibody reactivity to periodontal bacteria in primary Sjögren’s syndrome: a pilot study

Journal paper
Lugonja B, Yeo E, Milward MR, Wilson D, Dietrich T, Chapple ILC, Rauz S, Williams G, Barone F, de Pablo P, Buckley CD, Hamburger J, Richards A, Poveda-Gallego A, Scheel-Toellner D and Bowman S
Journal of Clinical Peridontology 2016 Jan;43(1):26-33. doi: 10.1111/jcpe.12485
Publication year: 2016

Abstract

AIMS:

The aims of this study were as follows: (i) To assess the prevalence of periodontitis among patients with primary Sjögren’s syndrome (pSS) and comparator groups of patients with rheumatoid arthritis (RA) and osteoarthritis (OA). (ii) To perform a pilot study to compare serum antibody responses to 10 oral/periodontal bacteria in these patient groups and a historical comparator group of patients with periodontitis.

MATERIALS AND METHODS:

Standard clinical periodontal assessments were performed on 39 pSS, 36 RA and 23 OA patients and “In-house” antibody ELISAs for serum antibodies against 10 oral/periodontal bacteria were performed in these groups.

RESULTS:

Forty-six percent of the pSS group, 64% of the RA group and 48% of the OA group had moderate/severe periodontitis. These frequencies did not reach statistical significance between groups. Raised antibody levels to Prevotella denticola were found in the pSS, RA and periodontitis groups compared to the OA group. Significant between group differences were seen for Aggregatibacter actinomycetemcomitans, Prevotella intermedia and Campylobacter showae. None of these differences were specifically associated with pSS.

CONCLUSION:

This study showed no increase in periodontitis in pSS patients. Although the P. denticola data are of interest, identifying bacterial triggering factors for pSS will likely require alternative strategies including modern techniques such as microbiome analysis.

KEYWORDS:

Sjogren’s; bacterial reactivity; periodontitis

Conjunctival neutrophils and progressive scarring in Ocular Mucous Membrane Pemphigoid

Journal paper
Williams GP. Nightingale P, Southworth HS, Denniston AKO, Tomlins PJ, Turner S, Hamburger J, Bowman SJ, Curnow SJ and Rauz S
Investigative Ophthalmology and Visual Science 2016 57 (13), 5457-5469
Publication year: 2016

Abstract

Purpose:

Ocular mucous membrane pemphigoid (OcMMP) is a rare autoimmune disorder resulting in progressive conjunctival fibrosis and ocular surface failure leading to sight loss in up to 50%. This study was designed to optimize an ocular surface sampling technique for identification of novel biomarkers associated with disease activity and/or progressive fibrosis.

Methods:

Fifty-seven patients with OcMMP underwent detailed examination of conjunctival inflammation and fibrosis using fornix depth measurement. Ocular surface impression cytology (OSIC) to sample superior bulbar conjunctiva combined with flow cytometry (OSIC-flow) profiled infiltrating leukocytes. Profiles were compared with healthy controls (HC) and disease controls (primary Sjögren’s syndrome, pSS). Thirty-five OcMMP patients were followed every 3 months for 12 months.

Results:

Overall neutrophils were elevated in OcMMP eyes when compared to pSS or HC (109 [18%] neutrophils/impression [NPI]; 2 [0.2%]; 6 [0.8%], respectively [P < 0.0001]) and in OcMMP patients with no visible inflammation when compared with HC (44.3 [7.9%]; 5.8 [0.8%]; P < 0.05). At 12 months follow-up, 53% of OcMMP eyes progressed, and this was associated with baseline conjunctival neutrophilia (P = 0.004). As a potential biomarker, a value of 44 NPI had sensitivity, specificity, and positive predictive values of 75%, 70%, and 73%, respectively. Notably, eyes with no visible inflammation and raised conjunctival neutrophils were more likely to progress and have a greater degree of conjunctival shrinkage compared to those without raised neutrophils.

Conclusions:

These data suggest that OSIC-flow cytometric analyses may facilitate repeated patient sampling. Neutrophils may act as a biomarker for monitoring disease activity, progressive fibrosis, and response to therapy in OcMMP even when the eye appears clinically uninflamed.

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Comparison of intraocular pressure changes with liquid or flat applanation interfaces in a femtosecond laser platform

Journal paper
Williams GP, Ang HP, George BL, Liu YC, Peh G, Izquierdo L, Tan DT and Mehta JS
Scientific Reports 2015;5:14742. doi: 10.1038/srep14742. IF 5.6, C 2.
Publication year: 2015

Abstract

Cataract surgery is the most common surgical procedure and femtosecond laser assisted cataract surgery (FLACS) has gained increased popularity. FLACS requires the application of a suction device to stabilize the laser head and focus the laser beam accurately. This may cause a significant escalation in intra-ocular pressure (IOP), which poses potential risks for patients undergoing cataract surgery. In this study we aimed to assess the effect of the Ziemer LDV Z8 femtosecond cataract machine on IOP. We demonstrated through a porcine model that IOP was significantly higher with a flat interface but could be abrogated by reducing surgical compression and vacuum. Pressure was lower with a liquid interface, and further altering angulation of the laser arm could reduce the IOP to 36 mmHg. A pilot series in patients showed comparable pressure rises with the porcine model (30 mmHg). These strategies may improve the safety profile in patients vulnerable to high pressure when employing FLACS with the Ziemer LDV Z8.

A comparison of different operating systems for femtosecond lasers in cataract surgery

Journal paper
Wu BM, Williams GP, Tan A, Mehta JS
Journal of Ophthalmology 2015. Article ID 616478 doi:10.1155/2015/616478
Publication year: 2015

Abstract

The introduction of femtosecond lasers is potentially a major shift in the way we approach cataract surgery. The development of increasingly sophisticated intraocular lenses (IOLs), coupled with heightened patient expectation of high quality postsurgical visual outcomes, has generated the need for a more precise, highly reproducible and standardized method to carry out cataract operations. As femtosecond laser-assisted cataract surgery (FLACS) becomes more commonplace in surgical centers, further evaluation of the potential risks and benefits needs to be established, particularly in the medium/long term effects. Healthcare administrators will also have to weigh and balance out the financial costs of these lasers relative to the advantages they put forth. In this review, we provide an operational overview of three of five femtosecond laser platforms that are currently commercially available: the Catalys (USA), the Victus (USA), and the LDV Z8 (Switzerland).

Neuron J is a rapid and reliable open source tool for evaluating corneal nerve density in Herpes Simplex Keratitis

Journal paper
Cottrell P, Ahmed S, James C, Hodson J, McDonnell P, Rauz S and Williams GP.
Investigative Ophthalmology and Visual Science 2014 6;55(11):7312-20
Publication year: 2014

Abstract

PURPOSE:

In vivo confocal microscopy (IVCM) demonstrates reduction in corneal sub-basal nerve density in herpes simplex keratitis (HSK). Image J is an open source image-analysis platform that can be combined with a nerve tracer, Neuron J. We sought to compare the reliability and speed of corneal nerve density quantification between these modalities and their relation to clinical damage.

METHODS:

A total of 16 eyes (14 patients) with chronic HSK was assessed clinically and by IVCM. Randomly ordered triplicate, representative images from the central cornea were presented to two masked observers and corneal sub-basal nerve density was measured using Image J/Neuron J. Agreement was quantified using intraclass correlation coefficients (ICC), Bland-Altman plots together with mean difference, and level of agreement (LoA).

RESULTS:

The median nerve density was measured at 7.1 mm/mm(2) (quartiles, 3.3-11.2), with Neuron-J demonstrating good intra-/interobserver agreement (ICC, 0.96-0.99; P < 0.001; mean difference, 0.1-1.4; LoA, <±3.3). Intraeye reliability was less consistent (mean difference, 1.7-2.3; LoA, ±8.8-9.8). Neuron J was highly comparable to Image J for both observers (ICC, 1.0; P < 0.001; mean difference, <0.2; LoA, ±<1.2) and significantly faster than Image J (median, 49 vs. 102 seconds, P < 0.001). Diminished nerve density was associated with corneal opacification and reduction in visual acuity (both P = 0.03).

CONCLUSIONS:

The IVCM combined with Neuron J affords objective, user-friendly, and fast quantification of corneal nerve damage in HSK. It provides semiobjective phenotyping of the sequelae of neurotrophic corneal damage and offers a potential tool for measuring vulnerability to relapse or additional infections. Further exploration in a larger longitudinal cohort is warranted.

KEYWORDS:

Herpes simplex; Image J; Neuron J; corneal nerve density

Defining the Limits of Normal Conjunctival Fornix Anatomy in a South Asian Population

Journal paper
Khan IJ, Ghauri A-J, Hodson J, Cottrell P, Edmunds MR, Evans S, Williams GP, Rauz S
Ophthalmology 2014 121(2):492-7
Publication year: 2014

Abstract

Purpose

Quantifying the extent of conjunctival fibrosis for documentation of progression in conjunctival scarring disease is a clinical challenge. Measurement of forniceal foreshortening facilitates monitoring of these disorders. This study aims (1) to define the limits of the normal human conjunctival fornices and how these alter with age and (2) to provide normative data for upper and lower fornix depths (FDs) and fornix intercanthal distance (FICD) within a healthy South Asian, racially distinct population.

Design

Epidemiologic, cross-sectional study.

Participants

A total of 240 subjects with national origins from South Asia, with no known ocular history and normal adnexal and conjunctival examination, aged 20 to 80 years.

Methods

An FICD modification of a custom-designed fornix depth measurer (FDM) was validated and used for measurement of both lower and upper FDs together with FICDs in 480 healthy eyes with no ocular comorbidities. Data were analyzed using repeated-measures analysis of variance and presented as means with 95% confidence intervals (CIs).

Main Outcome Measures

Mean lower and upper FDs and FICD for the entire cohort, stratified according to age decade and sex.

Results

For this South Asian population, the overall upper and lower FDs were 15.3 mm (95% CI, 14.9–15.6) and 10.9 mm (95% CI, 10.7–11.1), respectively, with FICD defined as 32.9 mm (95% CI, 32.5–33.4) (upper) and 31.7 mm (95% CI, 31.3–32.1) (lower). With increasing age, a progressive reduction of all measured parameters (P < 0.001) was noted, with female subjects having significantly shallower fornices (upper FD, P < 0.001; lower FD, P < 0.001; upper FICD, P = 0.081; and lower FICD, P = 0.015).

Conclusions

This is the first study to define the limits of normal upper FD and FICDs in any population group. Our study demonstrates sex variations and progressive conjunctival shrinkage with age. Although it provides important, objective data for normal forniceal anatomy, further study is recommended in other populations to confirm the generalizability of these data or to enable normal comparative datasets for the assessment of conjunctival scarring disorders among all anthropological groups.

Cytokine Production and Antigen Recognition by Human Mucosal Homing Conjunctival Effector Memory CD8+ T cells

Journal paper
Williams GP, Pachnio A, Long H, Rauz S and Curnow SJ
Investigative Ophthalmology and Visual Science 2014;55:8523–8530
Publication year: 2014

Abstract

Purpose.

Conjunctival epithelial T cells are dominated by CD3+CD56-TCRαβ+CD8αβ+ lymphocytes. In this study we explored the antigen experience status, mucosal homing phenotype, cytokine expression, and viral antigen recognition of conjunctival epithelial CD8+ T cells from healthy individuals.

Methods.

Following ocular surface impression cytology, conjunctival cells were recovered by gentle agitation and analyzed by flow cytometry for cell surface markers, cytokine production (stimulated by phorbol 12-myristate 13-acetate [PMA]/ionomycin), and Epstein-Barr virus (EBV)/cytomegalovirus (CMV) immunodominant epitope recognition using major histocompatibility complex (MHC) class I peptide tetramers.

Results.

In contrast to peripheral blood, conjunctival epithelial CD8+ T cells were dominantly CD45RACCR7 effector memory cells, and the vast majority expressed the mucosal homing integrin αEβ7. Conjunctival memory CD8+ T cells maintained effector functions with the ability to secrete IFN-γ and expression of Granzyme B, although they expressed significantly reduced amounts per cell compared to peripheral blood T cells. Interestingly, herpetic virus-specific CD8+ T cells recognizing epitopes derived from EBV and CMV could be detected in the conjunctival cells of healthy virus carriers, although they were generally at lower frequencies than in the peripheral blood of the same donor. Virus-specific conjunctival CD8+ T cells were dominated by CD45RACCR7 effector memory cells that expressed αEβ7.

Conclusions.

These data demonstrate that the majority of conjunctival epithelial CD8+ T cells are mucosal homing αEβ7+ effector memory T cells, which can recognize viral epitopes and are capable of secreting Granzyme B and IFN-γ.

Keywords: CD8+ T cell, conjunctiva, impression cytology, infection

Cortisol biosynthesis in the human ocular surface innate immune response

Journal paper
Susarla R, Liu L, Walker EA, Bujalska IJ, Al-Salem J, Williams GP, Sreekantam S, Taylor AE, Tallouzi M, Southworth HS, Murray PI, Wallace GR and Rauz S
PLOS One 2014 Apr 15;9(4)
Publication year: 2014

Abstract

Innate immune responses have a critical role in regulating sight-threatening ocular surface (OcS) inflammation. While glucocorticoids (GCs) are frequently used to limit tissue damage, the role of intracrine GC (cortisol) bioavailability via 11-beta-hydroxysteroid dehydrogenase type 1 (11β-HSD1) in OcS defense, remains unresolved. We found that primary human corneal epithelial cells (PHCEC), fibroblasts (PHKF) and allogeneic macrophages (M1, GM-CSF; M2, M-CSF) were capable of generating cortisol (M1>PHKF>M2>PHCEC) but in corneal cells, this was independent of Toll-like receptor (TLR) activation. While PolyI∶C induced maximal cytokine and chemokine production from both PHCEC (IFNγ, CCL2, CCL3, and (CCL4), IL6, CXCL10, CCL5, TNFα) and PHKF (CCL2, IL-6, CXCL10, CCL5), only PHKF cytokines were inhibited by GCs. Both Poly I∶C and LPS challenged-corneal cells induced M1 chemotaxis (greatest LPS-PHKF (250%), but down-regulated M1 11β-HSD1 activity (30 and 40% respectively). These data were supported by clinical studies demonstrating reduced human tear film cortisol∶cortisone ratios (a biomarker of local 11β-HSD1 activity) in pseudomonas keratitis (1∶2.9) versus healthy controls (1∶1.3; p<0.05). This contrasted with putative TLR3-mediated OcS disease (Stevens-Johnson Syndrome, Mucous membrane pemphigoid) where an increase in cortisol∶cortisone ratio was observed (113.8∶1; p<0.05). In summary, cortisol biosynthesis in human corneal cells is independent of TLR activation and is likely to afford immunoprotection under physiological conditions. Contribution to ocular mucosal innate responses is dependent on the aetiology of immunological challenge.

Elevation of conjunctival epithelial neutrophils in Ocular Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis

Journal paper
Williams GP, Tomlins PJ, Denniston AKO, Southworth HS, Sreeknatham S, Curnow SJ and Rauz S
Investigative Ophthalmology and Visual Science 2013 54 (7) pp. 4578-4585
Publication year: 2013

Abstract

Purpose.

Ocular complications related to Stevens-Johnson Syndrome (SJS)–Toxic Epidermal Necrolysis (TEN) may persist and progress after resolution of systemic disease. This is thought to be related in part to persistent ocular innate-immune signaling. In this study, our aim was to characterize infiltrative conjunctival cellular profiles during acute (<12 months) and chronic (>12 months) disease.

Methods.

Consecutive patients presenting with SJS-TEN over a 12-month period were followed for 1 year. Detailed clinical examination and conjunctival impression cell recovery was analyzed by flow cytometry for the presence of intraepithelial leukocytes and compared with healthy controls (n = 21).

Results.

Ten patients were recruited of whom six had acute disease and five were classified as TEN (SCORTEN = 1, n = 4). Conjunctival inflammation was graded as absent/mild in a total of nine patients; but despite this, evidence of fornix shrinkage was observed in nine subjects. This inversely correlated with disease duration (P < 0.05). A reduction in percentage of CD8αβ+ T cells compared with controls (80% vs. 57%; P < 0.01) was associated with a corresponding increase in the number/percentage of CD45INTCD11b+CD16+CD14 neutrophils (186 vs. 3.4, P < 0.01, 31% vs. 0.8%, P < 0.001). Neutrophils inversely correlated with disease duration (r = −0.71, P = 0.03), yet there was no absolute change in the CD8αβ+ or neutrophil populations during the study period (P = 1.0).

Conclusions.

These data highlight that a neutrophilic infiltrate is present in mildly inflamed or clinically quiescent conjunctival mucosa in patients with ocular SJS-TEN, where neutrophil numbers inversely correlate with disease duration. Neutrophil persistence endorses the hypothesis of an unresolved innate-inflammatory process that might account for disease progression.

Keywords: SJS, TEN, neutrophils, innate immunity

Ulcerative keratitis following particulate elemental gold deposition

Journal paper
Raj A, Williams GP, Hawksworth NR
Journal of Ocular Pharmacology and Therapeutics 2012;28(3):323-5
Publication year: 2012

Abstract

PURPOSE:

To describe a case of 68-year-old male industrial chemist who received a chemical injury after a gold/amine compound exploded causing bilateral eye injuries. No apparent long-term problems were anticipated. After cataract extraction 40 years later, he developed a localized ulcerative keratitis adjacent to embedded gold in the cornea.

METHODS:

To describe the clinical features, management, and outcomes.

RESULTS:

Successful treatment with topical hydrocortisone was achieved. Subsequently, 3 further episodes of ulcerative keratitis were treated with topical steroid therapy without need for systemic immunosuppression. A systemic vasculitic/autoimmune screen was normal.

DISCUSSION:

Ocular chrysiasis is well recognized after systemic gold administration and is normally considered inert, but in this case exogenous gold deposition might have been a contributing factor to very localized and repeated episodes of stromal erosion in this man, many years after the original injury. To the best of our knowledge this is the first such reported case.

jrsm

Post-phacoemulsification Cytomegalovirus Corneal Endotheliitis: Diagnostic and Management Approaches

Journal paper
Ghauri AJ, Williams GP, Shah S, Murray PI, Rauz S
JRSM Short Reports 2012 3(6):42
Publication year: 2012

Quantitative polymerase chain reaction is essential in diagnosing and monitoring cytomegalovirus endotheliitis. Treatment with long-term anti-virals and endothelial surgery can offer successful visual rehabilitation.

Incidence, Presenting Features and Diagnosis of Cicatrising Conjunctivitis in the United Kingdom

Journal paper
Radford C, Rauz S, Williams GP, Saw VP and Dart JKD
Eye 2012 26 (9) pp. 1199-208.
Publication year: 2012

Abstract

PURPOSE:

Cicatrising conjunctival disorders are uncommon, and are difficult to diagnose and manage. This study was designed to assess the annual incidence and underlying diagnosis of patients with cicatrising conjunctivitis (CC) within the United Kingdom.

METHODS:

Clinical data of newly diagnosed cases of CC were reported via the British Ophthalmological Surveillance Unit at diagnosis and at 12 months follow-up.

RESULTS:

A total of 50 (61%) ocular mucous membrane pemphigoid (OcMMP), 16 (20%) Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS-TEN) and 16 (20%) other causes of CC, equating to an incidence of 0.8, 0.2, and 0.2 per million, respectively, were reported. Although diagnosis of SJS-TEN was usually within a median of 7 days of symptom-onset, that for OcMMP and other CC was a median 225 days for both. At diagnosis, 64/163 (39%) eyes had moderate/severe conjunctival inflammation, and 102/164 (62%) had symblepharon formation. Although 43/82 (52%) patients were commenced on immunosuppression or had this therapy modified, at follow-up there was an increase in the number of symblepharon, despite control of inflammation (P<0.001). Mortality only occurred in the SJS-TEN group (4/16 (25%)).

CONCLUSION:

CC has a substantial morbidity and for non-SJS-TEN causes, diagnosis is frequently delayed. The proportion of patients given immunosuppressive therapy to prevent disease progression may be less than optimal. These data highlight the need for developing patient access to specialist-designated centres with expertise in CC.

The dominant human conjunctival epithelial CD8αβ+ T cell population is maintained with age but the number of CD4+ T cells increases

Journal paper
Williams GP, Denniston AKO, Oswal KS, Tomlins PJ, Barry RJ, Rauz S and Curnow SJ
Age 2012 34(6):1517-1528
Publication year: 2012

Abstract

The conjunctiva is a highly specialized ocular mucosal surface that, like other mucosa, houses a number of leukocyte populations. These leukocytes have been implicated in age-related inflammatory diseases such as dry-eye, but their phenotypic characteristics remain largely undetermined. Existing literature provides rudimentary data from predominantly immunohistochemical analyses of tissue sections, prohibiting detailed and longitudinal examination of these cells in health and disease. Using recovered cells from ocular surface impression cytology and flow cytometry, we examined the frequency of leukocyte subsets in human conjunctival epithelium and how this alters with age. Of the total CD45+ leukocyte population within the conjunctival epithelium, 87% [32–99] (median) [range] comprised lymphocytes, with 69% [47–90] identified as CD3 + CD56- T cells. In contrast to peripheral blood, the dominant conjunctival epithelial population was TCRαβ + CD8αβ + (80% [37–100]) with only 10% [0-56%] CD4+ cells. Whilst a significant increase in the CD4+ population was seen with age (r = 0.5; p < 0.01) the CD8+ population remained unchanged, resulting in an increase in the CD4:CD8 ratio (r = 0.5;p < 0.01). IFNγ expression was detectable in 18% [14–48] of conjunctival CD4+ T cells and this was significantly higher among older individuals (<35 years, 7[4–39] vs. >65 years, 43[20–145]; p < 0.05). The elevation of CD4+ cells highlights a potentially important age-related alteration in the conjunctival intra-epithelial leukocyte population, which may account for the vulnerability of the aging ocular surface to disease.

Keywords: Aging, T cell, Lymphocyte, Conjunctiva, Mucosa

Aqueous Humor Suppression of Dendritic Cell Function Helps Maintain Immune Regulation in the Eye during Human Uveitis

Journal paper
Denniston AKO, Tomlins PJ, Williams GP, Kottoor S, Khan I, Oswal S, Salmon M, Wallace GR, Rauz S, Murray PI and Curnow SJ
Investigative Ophthalmology and Visual Science 2012 53 (2) pp. 888-896
Publication year: 2012

Abstract

PURPOSE:

Noninfectious uveitis is characterized by a dysregulated inflammatory or immune response in the eye. It is unclear whether this represents a failure of immune privilege or an overwhelming inflammatory drive that has exceeded the capacity of regulatory mechanisms that are still functioning. The authors investigated immune regulation in the human eye during intraocular inflammation (uveitis) and its impact on dendritic cell (DC) function and subsequent T-cell responses.

METHODS:

Myeloid DCs were isolated from the aqueous humor (AqH) and peripheral blood of patients with active uveitis and characterized by flow cytometry. The effect of uveitis AqH was interrogated in an in vitro model of peripheral blood monocyte-derived DCs from healthy controls.

RESULTS:

Myeloid DCs isolated from uveitic AqH were characterized by elevated major histocompatibility complex classes I and II (MHC I/II), but reduced CD86 compared with matched peripheral blood DCs. Exposure of peripheral blood monocyte-derived DCs from healthy controls to the inflammatory AqH supernatant recapitulated this phenotype. Despite interferon gamma (IFNγ)-dependent upregulation of MHC I, inflammatory AqH was overall suppressive to DC function, with reduced CD86 expression and diminished T-cell responses. This suppressive effect was equal to or greater than that induced by noninflammatory AqH, but was glucocorticoid independent (in contrast to noninflammatory AqH).

CONCLUSIONS:

These data indicate that the ocular microenvironment continues to regulate DC function during uveitis, despite IFNγ-driven upregulation of MHC expression, supporting the hypothesis that immune regulation within the eye is maintained during inflammation.

journal ophthalmology june 2011

Validation of a Fornix Depth Measurer - A Putative Tool for the Assessment of Progressive Cicatrising Conjunctivitis’

Journal paper
Williams GP, Saw VP, Saeed T, Evans ST, Cottrell P, Curnow SJ, Nightingale P, Rauz S
British Journal of Ophthalmology 2011 Jun;95(6):842-7
Publication year: 2011

Abstract

Background/aims

Documentation of conjunctival forniceal foreshortening in cases of progressive cicatrising conjunctivitis (PCC) is important in ascertaining disease stage and progression. Lower fornix shortening is often documented subjectively or semi-objectively, whereas upper forniceal obliteration is seldom quantified. Although tools such as fornix depth measurers (FDMs) have been described, their designs limit upper fornix measurement. The purpose of this study was to custom-design a FDM to evaluate the upper fornix and to assess variability in gauging fornix depth.

Methods

A polymethylmethacrylate FDM was constructed using industry-standard jewellery computer software and machinery. Two observers undertook a prospective independent evaluation of central lower fornix depth in a heterogeneous cohort of patients with clinically normal and abnormal conjunctival fornices both subjectively and by using the FDM (in mm). Upper central fornix depth was also measured. Agreement was assessed using Bland–Altman plots.

Results

Fifty-one eyes were evaluated. There was 100% intraobserver agreement to within 1 mm for each observer for lower fornix measurement. The mean difference in fornix depth loss using the FDM between observer 1 and 2 was 1.19%, with 95% confidence of agreement (±2SD) of −15% to +20%. In total, 86% (44/51) of measurements taken by the two observers agreed to within 10% of total lower fornix depth (ie, ±1 mm) versus only 63% (32/51) of the subjective measurements. Mean upper fornix difference was 0.57 mm, with 95% confidence of agreement of between −2 and +3 mm.

Conclusions

This custom-designed FDM is well tolerated by patients and shows low intraobserver and interobserver variability. This enables repeatable and reproducible measurement of upper and lower fornix depths, facilitating improved rates of detection and better monitoring of progression of conjunctival scarring.

Keywords: Conjunctiva, inflammation, diagnostic tests/investigations, treatment medical
jrsm

Rheumatoid corneal melt: autoimmunity or infection?

Journal paper
Williams GP, Denniston AKO, Elamanchi SR and Rauz S
JRSM Short Reports 2011 4;2(1):1
Publication year: 2011

Evaluation of early and late presentation of patients with ocular mucous membrane pemphigoid to two major tertiary referral hospitals in the United Kingdom

Journal paper
Williams GP, Radford C, Nightingale P, Dart JKD and Rauz S
Eye 2011 Sep;25(9):1207-18
Publication year: 2011

Abstract

Purpose

Ocular mucous membrane pemphigoid (OcMMP) is a sight-threatening autoimmune disease in which referral to specialists units for further management is a common practise. This study aims to describe referral patterns, disease phenotype and management strategies in patients who present with either early or established disease to two large tertiary care hospitals in the United Kingdom.

Patients and Methods

In all, 54 consecutive patients with a documented history of OcMMP were followed for 24 months. Two groups were defined: (i) early-onset disease (EOD:<3years, n=26, 51 eyes) and (ii) established disease (EstD:>5years, n=24, 48 eyes). Data were captured at first clinic visit, and at 12 and 24 months follow-up. Information regarding duration, activity and stage of disease, visual acuity (VA), therapeutic strategies and clinical outcome were analysed.

Results

Patients with EOD were younger and had more severe conjunctival inflammation (76% of inflamed eyes) than the EstD group, who had poorer VA (26.7%=VA<3/60, P<0.01) and more advanced disease. Although 40% of patients were on existing immunosuppression, 48% required initiation or switch to more potent immunotherapy. In all, 28% (14) were referred back to the originating hospitals for continued care. Although inflammation had resolved in 78% (60/77) at 12 months, persistence of inflammation and progression did not differ between the two phenotypes. Importantly, 42% demonstrated disease progression in the absence of clinically detectable inflammation.

Conclusions

These data highlight that irrespective of OcMMP phenotype, initiation or escalation of potent immunosuppression is required at tertiary hospitals. Moreover, the conjunctival scarring progresses even when the eye remains clinically quiescent. Early referral to tertiary centres is recommended to optimise immunosuppression and limit long-term ocular damage.

Keywords: cicatrising conjunctivitis, conjunctival scarring, progression, immunosuppression
journal of immunology Jan 11

Endogenous cortisol & TGF-beta in human aqueous humour contribute to ocular immune privilege by regulating dendritic cell function

Journal paper
Denniston AK, Kottoor SH, Khan I, Oswal K, Williams GP, Abbott J, Wallace GR, Salmon M, Rauz S, Murray PI and Curnow SJ
Journal of Immunology 2011 186(1):305-11
Publication year: 2011

Abstract

Aqueous humor (AqH) has been shown to have significant immunosuppressive effects on APCs in animal models. We wanted to establish whether, in humans, AqH can regulate dendritic cell (DC) function and to identify the dominant mechanism involved. Human AqH inhibited the capacity of human peripheral blood monocyte-derived DC to induce naive CD4(+) T cell proliferation and cytokine production in vitro, associated with a reduction in DC expression of the costimulatory molecule CD86. This was seen both for DC cultured under noninflammatory conditions (immature DC) and for DC stimulated by proinflammatory cytokines (mature DC). DC expression of MHC classes I/II and CD83 was reduced (mature DC only). Myeloid DC from peripheral blood were similarly sensitive to the effects of human AqH, but only under inflammatory conditions. The addition of α-melanocyte stimulating hormone and vasoactive intestinal peptide did not cause significant inhibition at physiological levels. However, the addition of exogenous cortisol at physiological levels recapitulated the AqH-induced reduction in CD86 and inhibition of DC-induced T cell proliferation, and blockade of cortisol in AqH partially reversed its suppressive effects. TGF-β2 had an additional effect with cortisol, and although simultaneous blockade of cortisol and TGF-β2 in AqH reduced its effectiveness, there was still a cortisol- and TGF-β-independent component. In humans, AqH regulates DC maturation and function by the combined actions of cortisol and TGF-β2, a pathway that is likely to contribute to the maintenance of immune privilege in the eye.

jrsm

Machiavelli and the EWTD

Journal paper
Denniston AKO and Williams GP
JRSM E Letter 2009;
Publication year: 2009

The use of intracameral phenylephrine in the management of Intra-Operative Floppy Iris Syndrome following Doxazosin

Journal paper
Williams GP, Tsaloumas MD
Eye 2008 Aug;22(8):1094
Publication year: 2008

Sir,

We read with interest the findings of Dhingra et al.1 Further reports on the problems of intraoperative floppy-iris syndrome (IFIS), associated with doxazosin have been described. The most recent (n=31) finding is that 37% of patients taking doxazosin had features of IFIS.2 However, larger series indicate that the problem is uncommon and less severe than for the α1A-antagonist tamsulosin.3, 4, 5 An observational study by Cheung et al3 of 1689 patients undergoing cataract surgery found that 9 out of 42 patients using doxazosin had incomplete IFIS. Nguyen et al4 found that out of 375 patients with IFIS taking an α1-antagonist, six were using doxazosin. This was also reflected by the experience of Chadha et al5 who found that 1 patient out of 48 using doxazosin developed incomplete IFIS.

However, we also recently encountered two patients using doxazosin with resultant moderate IFIS during cataract surgery. The first patient was a 76-year-old Caucasian male using 8 mg doxazosin po od for hypertension. The second was a 72-year-old Asian male taking 4 mg of doxazosin po od for benign prostatic hypertrophy. In both cases, there was incomplete pupil dilatation (5 mm for first patient and 6 mm for the second) and iris undulation was noted after initial wound construction. We successfully utilised dilute intracameral phenylephrine (as described by Gurbaxani and Packard6) to prevent iris prolapse and maintain pupil size during phacoemulsification. Surgery was completed successfully without complication.

Both patients were noted to be taking an α1-antagonist preoperatively and the possibility of IFIS was anticipated. Undoubtedly, this influenced the decision to utilise intracameral phenylephrine early as a means of preventing intraoperative complications. Atthough our subjective grading of moderate IFIS (like Dhingra et al1) appears more severe than the experience of larger series, we agree that the possibility of well-described intraoperative complications should be anticipated. Among the numerous management options available, we found that the use of intracameral phenylephrine offered a quick and effective method for preventing further problems.

Severe, permanent orbital disease in Herpes Zoster Ophthalmicus

Journal paper
Dhingra S, Williams G, Pearson A
Orbit 2008;27(4):325-7
Publication year: 2008

Abstract

A 63-year-old man with HZO presented with involvement of cranial nerves II, III, IV, V, and VI, with proptosis, raised intraocular pressure, and chemosis. With the aid of orbital imaging, a diagnosis of orbital apex inflammation secondary to HZO was confirmed, and he was treated with intravenous acyclovir and oral steroids. Despite this, he made a minimal recovery at eight months following presentation. Severe, irreversible orbital disease may develop following HZO, and an ischemic vasculitis may play a role in the pathogenesis of the disease.

Transient Horner syndrome associated with hypertension

Journal paper
Williams GP, Lukaris A, Hawksworth NR
Eye. 2007 Jan;21(1):139-40
Publication year: 2007

Sir,

A 46-year-old man presented with a droopy left upper-lid associated with headache, facial, and neck pain. He was otherwise well and a nonsmoker.

Examination revealed 2 mm of left ptosis, anisocoria (see Figure 1) and facial anhidrosis. Acuity was 6/4 in each eye. The blood pressure was markedly elevated (250/140). He had hypertensive retinopathic changes but ocular and systemic examinations were otherwise unremarkable. Although index of suspicion for carotid artery dissection was low, urgent ultrasound Doppler’s of the carotid/vertebral circulations and computed tomography scanning with contrast of the head/neck were performed and excluded this possibility.

A weak adrenaline solution (1 : 1000) was instilled to ascertain if a preganglionic or postganglionic Horner’s was present. This resulted in no change in pupil size, confirming a preganglionic lesion or central Horner’s syndrome.

Chest radiography and electrocardiography revealed cardiomegaly and left ventricular hypertrophy. He was referred to the medical team for further investigation/management. Subsequent echocardiography confirmed left ventricular hypertrophy. He was found to have elevated serum lipids and creatinine (at 164 μmol/l). All other investigations were normal. Hypertension and hypercholesterolaemia were controlled medically and Aspirin commenced.

Although the presence of a Horner’s syndrome was irrefutable on clinical grounds (Figure 1), full pharmacological testing with 4% cocaine eyedrops (unavailable in ‘out of hours’ practice), would have completed the investigations.1 After 1 month, the central Horner’s syndrome had completely resolved. Our patient had sustained a transient ischaemic attack affecting the preganglionic neuron in the ocular sympathetic chain. Given the absence of brainstem signs we suspect the lesion was near the posterolateral hypothalamus, the origin of the ocular sympathetic chain. This area is supplied by small vessels known as the posteriomedial penetrating arteries, which arise variably from the Circle of Willis, posterior and middle cerebral arteries. Treatment involves modification of the cardiovascular risk profile—as in this case.

Although hypertension has been described with Horner syndrome, this was in relation to carotid dissection.2 This is a life-threatening emergency which may manifest in numerous ways in association with Horner syndrome.3 To our knowledge this is the first reported case of transient central Horner syndrome associated with hypertension.

bjo jul 2007

Social Impact of Visual Impairment

Journal paper
Williams GP, Pathak-Ray V, Austin M.
British Journal of Ophthalmology 2007;91:986
Publication year: 2007

We read with interest the extended report by Hassell et al about the adverse effect of quality of life in mild visual impairment (<6/12) and worse. Their demonstration of the impact of age‐related macular degeneration on quality‐of‐life indices is an important illustration of the difficulties experienced by visually impaired people.

We have reported a similar experience in West Glamorgan (Wales, UK). Our study was comprised of 66 patients registered as blind/partially sighted (59.1% because of age‐related macular degeneration). The demographic characteristics mirrored this study (mean age 81.33 (SD 9.87) years; 69.7% female). We used an alternative index to the impact of vision impairment (IVI) questionnaire, the National Eye Institute visual function questionnaire (NEI‐VFQ 25). This has similar categories, including general health, general vision, ocular pain, near activities, distance activities, social functioning, mental health, role difficulties, dependency, colour vision and peripheral vision.

Hassell et al showed a statistically significant restriction in leisure and work, social and consumer interaction, and household and personal care difficulties between those with a mild/moderate impairment and those with severe impairment. This was our experience in the analogous categories of social functioning (NEI‐VFQ score 36.49% for the blind vs 50% for the partially sighted; p<0.001) and dependency (NEI‐VFQ score 30.07% for the blind vs 46.98% for the partially sighted; p<0.001). Furthermore, percentage scores in our study were <50% for all categories except general health, ocular pain and colour vision for blind and partially sighted people. None of the studies that have used the NEI‐VFQ to determine the extent of visual function, have previously demonstrated mean scores as low as in our study., Hassell et al have, therefore, shown a worse quality of life in severely visually impaired people (<6/60), and also reinforced the important fact that all people with visual impairment experience difficulties.

A second interesting finding in their paper was the absence of correlation between duration of visual impairment and adaptation. We found that the NEI‐VFQ scores for those living alone were better than those for individuals living with someone for numerous categories including near vision activities (20.9% vs 15.3%, p = 0.03), distant vision activities (27.9% vs 20.1%, p = 0.056) and dependency (46.3 vs 31.4%, p = 0.004; Williams GP, Pathak‐Ray V and Austin MW, unpublished data, 2001).

This may imply that living alone forces people to adapt. We interpreted this finding with caution, however, as a number of people “living with someone” resided in a nursing/residential home. This may have occurred as a result of living alone, causing difficulties with coping in the first instance.

Finally, the paper by Hassell et al was undertaken before people had received low vision services. Depressingly, our study found that there was incomplete delivery of formal low visual aid assessment (n = 44, 66%); 70% of these people found the aids to be of use. We, therefore, agree with Hassell et al referral to low visual services should be considered, and adequate delivery and support is required for it to be effective.

'Quality of life and visual rehabilitation: an observational study of low vision in three general practices in West Glamorgan

Journal paper
Williams GP, Pathak-Ray V, Austin M, Lloyd AP, Millington IM and Bennett A
Eye 2007 Apr 21(4):522-527
Publication year: 2007

Abstract

AIM:

To survey low vision in an urban population and assess impact on quality of life, rehabilitation and support.

METHODS:

In a cross-sectional population survey, 66 patients were identified from databases of three general practices and surveyed by investigator administered questionnaire. Main outcome measures were ocular diagnoses, (US) National Eye Institute Visual Function-Questionnaire (NEI-VFQ) scores assessing visual and nonvisual disability, eligibility for, awareness and receipt of rehabilitation and support.

RESULTS:

Of 24,420 individuals on the lists of the three study practices, we found 101 registered as blind or partially sighted (prevalence 0.41%). A total of 66 patients participated with ocular diseases of age-related macular degeneration 39 (59%), glaucoma 11 (17%), diabetic retinopathy two (3%), retinitis pigmentosa two (3%), and 12 (18%) ‘others’. Better eye visual acuity was counting fingers or worse in 32 (48.5%). NEI-VFQ scores were poor-overall mean 41.5% (SD 23.5). In all, 80% had a social services home visit with one-third of these still in contact. In all, 66% had undergone a low vision aid assessment and 57.6% of these used their aid. The awareness and receipt of benefits arising from registration as visually impaired were lower than for other supportive measures available for reasons unrelated to vision. None had a guide dog.

CONCLUSIONS:

We found expected patterns of low vision but poorer levels of function and support that may reflect age and deprivation in a population failed by the current systems for identification, registration, and rehabilitation based on legislation overtaken by demographic change and social provision independent of visual status.

bjo sept 2007

Early pathological features of the cornea in Toxic Epidermal Necrolysis

Journal paper
25. Williams GP, Mudhar HS, Leyland M
British Journal of Ophthalmology 2007; 91: 1129-1132
Publication year: 2007

Abstract

Aim

To describe the early pathological changes in the cornea during toxic epidermal necrolysis (TEN).

Method

Demonstration of histological features of sequential corneal samples taken during management of complications of TEN in a young adult.

Results

Early vacuolation of basal keratinocytes and late infiltration of the cornea with CD 8 lymphocytes were observed. These changes are similar to those found in cutaneous TEN and may represent weakening of the stromal–epithelium interface with resultant recurrent erosion and chronic inflammation.

Conclusions

Similar changes were found in avascular corneal tissue to those previously described in skin. The initial insult may be traumatic. We propose that a cytokine‐mediated response contributes to the initial insult, either in response to and/or by accelerating severe inflammation. This precedes a cytotoxic infiltration which may exacerbate episodes of recurrent erosion. This provides a new insight into the mechanism of disease in the cornea following TEN.

Stevens‐Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are rare, life‐threatening mucocutaneous blistering disorders. TEN is the more severe manifestation with a mortality rate of 34%. The immunological pathogenesis has been previously reported in the skin.,,,, There are few pathological data regarding the early corneal changes, however. We report the histological features of sequential corneal samples taken during management of complications of TEN in a young adult.

Serratia marcescens endophthalmitis secondary to pneumonia

Journal paper
Williams G, Morris B, Hope D and Austin M
Eye. 2006 Nov;20(11):1325-6
Publication year: 2006

Sir,

A 56-year-old female was admitted to ITU with postoperative pneumonia secondary to Serratia marcescens treated with Imipenem 750 mg b.i.d. i.v. She underwent bowel resection for Crohn’s disease 1 week prior to her pneumonia. A month later, she arrested and became comatosed despite resuscitation. She deteriorated, developing renal failure requiring haemofiltration. S. marcescens was grown from sputum and blood cultures and Teicoplanin 400 mg b.i.d. i.v. was started. After 24 h, she developed an acute right red eye.

On examination, there was an afferent pupillary defect, corneal oedema, and hypopyon. There was no fundal view (Figure 1). Examination of her left eye was unremarkable. A diagnosis of endogenous endophthalmitis was suspected and a vitreous tap performed with Ceftazidime 2.25 mg, Vancomycin 1 mg, and Amphotericin 5 μg given intravitreally. In addition, she was given hourly G Cefuroxime 5% and G Gentamicin 1.5%. S. marcescens sensitive to Ceftazidime was isolated from her vitreous and a repeated intravitreal injection of Ceftazidime and Vancomycin were given 72 h later. There was little ocular or systemic improvement and despite aggressive treatment she eventually died of multiple organ failure. An autopsy was declined.

Endogenous endophthalmitis (EE) accounts for 10% of all endophthalmitis.1 Fungi are the most common causal pathogen2 followed by bacteria.1, 3 Risk factors include systemic immunosuppression, sepsis, major surgery, indwelling catheters, and prolonged antibiotic therapy.2 The overall prognosis is poor with useful vision preserved in only 40%, 6 and 7–15% patients die from septicaemia.4, 5

Identifying the underlying cause is paramount. Conjunctival swabs poorly reflect intrinsic eye infection and vitreous tap/biopsy6 should be performed and intravitreal antibiotics administered.

S. marcescens is multiresistant Gram-negative bacillus that can produce a red pigment causing a pink hypopyon.7 To our knowledge, this is the first reported case of S. marcescens pneumonia as a primary source for EE (the lung is the most common site for these pathogens8). Despite appropriate systemic and intravitreal antibiotics, the visual outcome was poor and the patient eventually died. As the incidence of EE (especially Gram-negative infections) appears to be rising,3 then this aggressive organism may become a more common cause for this devastating condition.