Or iginal s tud y Novel removal of corneal epithelium
Autumn 2021 • Vol 16 | No 2 SA Ophthalmology Journal
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Alcohol cotton bud technique for removal of corneal epithelium at the slit lamp in corneal crosslinking S Ballim MBChB, FC Ophth(SA), MMed Ophth(UKZN); Honorary lecturer, School of Clinical Medicine, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa ORCID: https://orcid.org/ 0000-0001-5088-0606 S Mahomed MBChB, MMed(PHM), PhD(PHM); Senior lecturer, School of Laboratory Medicine and Medical Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa ORCID: https://orcid.org/0000-0001-7095-9186 Corresponding author: Dr Shaheer Ballim, Postnet Suite 247, Private Bag X10, Musgrave Road, Durban, 4062, South Africa; tel: +27 31 2075450; email: shaheerballim@gmail.com
Abstract Aim: To describe the procedure and patient outcomes of a novel technique for the removal of corneal epithelium during corneal crosslinking. Methods: This is a retrospective case series of patients who underwent epithelium-off corneal crosslinking for keratoconus using a new technique to remove the corneal epithelium at a private ophthalmology clinic. Demographic and clinical data, keratometry, rate of epithelial healing, degree of corneal haze and incidence of any complications were recorded over a median follow-up period of 36 weeks. The corneal epithelium was removed at the slit lamp under topical anaesthesia. A cotton bud dampened in 70% alcohol facilitated easy and non-traumatic removal of the epithelium in an 8–9 mm diameter for subsequent corneal crosslinking. Results: Thirty-six eyes of 23 patients had crosslinking using this technique. The median number of days to epithelial closure was three (range two to six). Of the 27 eyes not lost to follow-up, 23 eyes (85.19%) showed decrease or stability (within 1 dioptre) of Kmax. The procedure did not inhibit the effect of corneal crosslinking for keratoconus. Fifteen eyes (55.55%) showed
Introduction
Corneal crosslinking is an important aspect in the management of patients with keratoconus. The procedure has been shown to prevent progression of the disease, and in some cases improve vision, by strengthening and stiffening the cornea.1 The most effective technique includes removal of the corneal epithelium as part of the procedure. 2 The standard Dresden protocol involves epithelial removal of the central 7 mm. 3 The corneal epithelium has shown to be a significant barrier to the corneal absorption of hydrophilic molecules such as riboflavin.4 Removal of the epithelium therefore markedly improves uptake of riboflavin into the corneal stroma in preparation for ultraviolet radiation in corneal crosslinking. Various techniques and instruments have been reported for removal of the
improvement in visual acuity, 11 eyes (40.70%) showed stability of visual acuity, and one eye (3.70%) showed deterioration in visual acuity by one line or more. There was one case of sterile corneal infiltrates (2.78%); no other complications were noted. All patients found the procedure acceptable in terms of patient experience and comfort. The technique used minimal resources and time. Conclusion: The findings of this study suggest that this novel technique may be provide a safe and effective method for removing corneal epithelium before corneal crosslinking. Keywords: corneal epithelium removal, keratoconus, crosslinking, resource-constrained Funding: No financial support was received by any of the authors for performing this research. Conflict of interest: The authors have no conflicts of interest to declare.
corneal epithelium. These instruments include a blunt spatula,1,5 a blunt knife,6 and an ophthalmic scalpel.7,8 The use of specialised instruments has also been reported such as an Amoils epithelial scrubber/brush, and an Epi Clear device (Orca Surgical).9-11 The choice of instrument is often based on the surgeon’s preference. Corneal epithelium can also be removed with ablative laser as in transepithelial photorefractive keratectomy.12-14 Some of these instruments, and the chemical solutions used, are not easily available in resource-constrained settings. In South Africa, there are no standard guidelines to indicate how the corneal epithelium should be removed. Anecdotal reports include manual removal with a blunt instrument, spatula or blade; and use of 20% ethyl alcohol solution in a ring or well to soak the epithelium before removal
with a cotton bud or microsponge. The technique described in this research was originally necessitated in the context of a public health sector eye clinic in South Africa due to a lack of easily available equipment and consumables, together with the challenge of a high disease burden of keratoconus. The technique was found to be safe, cost-effective and timeefficient (author’s anecdotal experience). The technique was then successfully implemented in private practice. The aims of the study are to describe a novel technique for the removal of corneal epithelium at the slit lamp during corneal crosslinking, to audit the safety and efficacy of the technique and to describe patient outcomes.
Materials and methods
This retrospective observational
