EDTA chelation for symptomatic band keratopathy: results and recurrence.

PurposeTo identify causes of symptomatic band keratopathy, and assess the results and long-term recurrence rates following chelation with topical ethylene-diamine-tetra-acetic acid (EDTA).Patients and methodsA retrospective review of surgical logbooks identified patients managed by EDTA chelation for symptomatic band keratopathy from 2009 to 2015.ResultsWe identified 108 cases; 89 case notes were available for analysis. Most cases of band keratopathy were idiopathic (36%). The most commonly identified underlying diagnosis was long-term topical glaucoma therapy (27%). Median presenting visual acuity was 6/18 (range 6/6-NPL) with the visual axis affected in 97.8% of cases. Treatment involved corneal epithelium removal, recurrent application of topical EDTA, and subsequent debridement. The mean duration of the operation was 20 min (range 10-45). Mean initial follow-up time was 40 days, and the visual axis was clear in 97.8%. Visual acuity was maintained or improved in 79.8%, with 13.5% improving by two lines or more. The mean length of follow-up was 581 days (median 374, maximum 2438). Twenty-five eyes (28.1%) showed localised recurrence of calcium with a mean time of 546 days (median 374), but only four cases required repeat EDTA chelation. The median time between operations was 430 days. Thirty-two per cent of the recurrence cases were associated with hypotony or chronic presence of silicone oil.ConclusionsChelation of calcium with topical EDTA is a safe and effective treatment for band keratopathy. Visual acuity improves in most eyes and while the rate of recurrence is moderate, the need for retreatment is low (4.5% overall).

Multiplex PCR testing requires a robust multi-disciplinary strategy to effectively manage identified cases of chlamydial conjunctivitis.

INTRODUCTION: Implementation of an in-house polymerase chain reaction (PCR) multiplex assay by West of Scotland Specialist Virology Centre to improve sample processing means all viral eye swabs are now routinely tested for Adenovirus, Herpes simplex, Varicella and Chlamydia. Concern was raised regarding subsequent management and sexual health attendance for Chlamydia-positive patients identified in eye casualty. METHODS: A retrospective review of virology results identified 76 Chlamydia-positive patients from 1914 eye swabs (4%) from May 2007 to April 2008. Of these results, 12 originated from Glasgow eye casualty and available clinical notes were cross-referenced with the sexual health network (Sandyford). RESULTS: Identified issues included no documentation of implications of testing, poor communication of positive results and poor referral pathways to sexual health for assessment; all leading to inadequate management. A shared care network was created to address these issues. A designated sexual health advisor was identified to improve sexual health referral, specialist assessment, standardised management and contact tracing. Re-audit showed more consistent follow-up. CONCLUSION: New PCR technology has resulted in a shared care approach to address corresponding implications of testing. Effective communication with a structured protocol and a central point of contact has improved follow-up and ensures appropriate best practice management of chlamydial conjunctivitis.

Free radicals and the pH of topical glaucoma medications: a lifetime of ocular chemical injury?

INTRODUCTION: Preservatives in ophthalmic preparations are known to cause ocular surface damage. Excipients can also contribute to oxidative stress in the compromised ocular surface. We evaluated commonly used topical glaucoma medications to ascertain pH levels and the intrinsic presence of free radicals. METHODS: Samples of 27 topical glaucoma preparations were analysed for total free radical presence using a Randox Kit for total antioxidant status. Analytical grade indicator paper was used to ascertain pH levels. RESULTS: Free radical concentrations for these 27 glaucoma preparations ranged from 0 to 4.54 mmol/l, with a median value of 0.66 mmol/l (mean value of 0.662 mmol/l, SD 0.839). Levels of pH ranged from 4.0 to 7.4, with a median value of 6.5 (mean 6.252, SD 0.826). There was no evidence of a direct correlation between these two variables (r=0.232, P=0.275). CONCLUSION: This study is the first to document the range of pH and concentrations of free radicals intrinsically present in commonly used glaucoma medications. Long-term exposure to preservatives, free radicals, and pH levels could all contribute to ocular surface damage. The effect of excipients could be responsible for patient intolerance when changing products in the compromised ocular surface.

The importance of informed consent in patients with wet age-related macular degeneration considering intravitreal anti-vascular endothelial growth factor treatments.

Retinal pigment epithelial (RPE) tears are now a documented potential complication following the intravitreal injection of anti-vascular endothelial growth factor (VEGF) treatments for neovascular age-related macular degeneration. Patients are often not well consented regarding this risk and thus we retrospectively analyzed the data from all of our patients undergoing this treatment over a six month period. Our findings highlighted the fact that the three patients (out of thirty) who had developed this RPE tear complication were initially all diagnosed with a pigment epithelial detachment (which is a type of macular degeneration in question). Therefore, we have adjusted our informed consent procedure such that all patients with "wet" macular degeneration and especially those with pigment epithelial detachments are now fully consented regarding the risks of the intravitreal treatment, which could potentially damage their vision further.

Topical mitomycin C chemotherapy in the management of ocular surface neoplasia: a 10-year review of treatment outcomes and complications.

INTRODUCTION: The use of topical mitomycin C (MMC) has gained popularity in the management of ocular surface neoplasia. The aim of this study is to determine outcomes and complications following such treatment. METHODS: This study is a retrospective review of patients treated with topical MMC for ocular surface neoplasia, including primary acquired melanosis (PAM), melanoma, corneal-conjunctival intraepithelial neoplasia (CCIN), squamous cell carcinoma (SCC) and sebaceous gland carcinoma (SGC). Data regarding diagnosis, short- and long-term outcomes, and short- and long-term complications, were recorded. RESULTS: 58 patients were identified, with a mean age of 63 years and mean follow-up of 36 months. 21 received MMC as primary therapy and 37 as surgical adjuvant. The regimen was 0.04% MMC four times a day for 3 weeks on, 3 weeks off, 3 weeks on, with topical steroid and lubricants throughout. Initial clinical response was either partial or complete in 93%. Overall, 26% developed recurrent disease at a mean of 13 months post treatment. Recurrence rates by pathology were 20% PAM, 25% melanoma, 0% CCIN, 67% SCC and 57% SGC. Short-term complications occurred in 52%, but only 7% required treatment cessation. Long-term complications such as persisting keratoconjunctivitis, epiphora and corneal problems, occurred in 31%. CONCLUSION: The results confirm the effectiveness of topical MMC chemotherapy in the management of ocular surface neoplasia. Self-limiting short-term complications were common; however, limbal stem cell deficiency appears to be a significant long-term complication of treatment, occurring in 12%.

Observation of the in vivo movement of host keratocytes into donor tissue following corneal graft; a novel technique.

BACKGROUND/AIMS: The cornea is a highly cellular structure that exists in a dynamic state of cell loss, renewal and replacement. The limbus contains corneal epithelial stem cells. The progenitor or stem cell of the keratocyte remains poorly defined. The authors sought to investigate the in vivo movement of corneal stromal and epithelial cells using a chromosome in situ hybridisation (CISH) technique on human tissue. METHODS: Four explanted sex-mismatched human corneal buttons were studied using the CISH technique to identify corneal epithelial and keratocyte cells containing the Y chromosome. Keratocyte identity and lack of infiltrating inflammatory cells were confirmed by immunohistochemistry. The sex mismatch of donor (XX) and host (XY) suggested any identified Y chromosomes cells were of host origin having migrated into the donor tissue. RESULTS: Host corneal epithelial cells were identified in all four buttons, and corneal stromal keratocytes were present in three of the four specimens in the central corneal area. CONCLUSION: Defining the corneal cell movements and the location of the progenitor or stem cells has important clinical implications. This study has successfully used the CISH technique to demonstrate the in vivo centripetal movement of corneal stromal keratocytes and epithelial cells. The CISH technique may allow further investigation of the corneal stromal dynamics using archival tissue.

Comment on "An analytic solution of capillary rise restrained by gravity" by N. Fries and M. Dreyer.

The porous medium model of Green and Ampt, describing flow in porous media, appeared earlier than the capillary model of Washburn, although both lead to mathematically identical models. Here, the model of Green and Ampt was related to the Washburn model by an examination of the parameters involved in each. Fries et al. [N. Fries, M. Dreyer, J. Colloid Interface Sci. 320 (2008) 259-263] presented an explicit solution to this model. This solution is identical to the explicit solution of the Green and Ampt model presented earlier by Barry et al. [D.A. Barry, J.-Y. Parlange, G.C. Sander, M. Sivaplan, J. Hydrol. 142 (1993) 29-46].

Comment on "The effect of evaporation on the wicking of liquids into a metallic weave" by N. Fries, K. Odic, M. Conrath and M. Dreyer.

A recent paper reported capillary rise and evaporation experiments in metallic wicks, as well as a mathematical model. The authors found a consistent discrepancy between the model predictions and data: The model over-predicted the capillary height rise by about 20%. The model used assumes that the porous medium is either fully wet or dry, an assumption that is particularly unsuited to evaporation from the wick surface. An alternative variable-saturation model is proposed that provides a possible explanation for the 20% discrepancy reported by the authors.