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Up Front | Feb 2009

Complications of Refractive Surgery

The sixth article in this series focuses on the execution and management of laser surgery.

This series of articles follows the nine modules of the University of Ulster's 1-year E-learning program. The first year of the course explores theory, followed by the second year of affiliated research projects. In this article, we discuss considerations of laser surgery, including dry eye after LASIK, intraocular pressure (IOP) measurement after corneal refractive surgery, complications of corneal refractive surgery, complications of phakic IOLs, and complications of refractive lens exchange.

WEEK 1
Dr. Dartt reviewed the causes and incidence of dry eye after LASIK, addressing the issue of hinge location as a possible factor. Additionally, he stressed that corneal nerves are equally distributed around the circumference of the cornea. The treatment of post-LASIK dry eye, the mainstays being unpreserved artificial tears, topical cyclosporine, and in severe cases, punctal plugs, were discussed. A clinical case of a 48-year-old man with monocular -7.00 D myopia and dry eye was presented, and most participants agreed that refractive lens exchange could be offered to avoid dry eye.

Dr. Cunliffe and Professor Shah delivered a lecture on IOP measurement after refractive surgery. IOP evaluation is altered by corneal thinning and changes in corneal viscoelastic properties, making inference of the correction factor difficult. The issue of refractive surgery in patients with ocular hypertension was also introduced in the clinical case of a patient with bilateral -6.00 D myopia, corneal thickness of 530 µm, well-controlled ocular hypertension, and normal optic discs and visual field. Participants decided that ocular hypertension was not an absolute contraindication for corneal refractive surgery, provided that appropriate follow-up occurs.

WEEK 2
Professor Alió introduced retinal complications associated with refractive surgery, discussing retinal detachments, neovascular membranes, and lacquer cracks. The risks were also considered with regard to phakic IOL implantation and clear lens extraction. Dr. Aylward delivered a lecture on the preoperative assessment of refractive surgery candidates and examination techniques, prophylaxis of retinal complications, and management options for preexisting retinal diseases.

Students discussed the case of a 28-year-old secretary with a bilateral refractive error of -17.00 D who became contact-lens intolerant. Posterior vitreous detachment occurred in the right eye 2 years ago, and two small atrophic holes within an area of lattice degenerations were evident in both eyes. The patient had a family history of retinal detachment. Participants debated possible treatment options and associated risks. Other discussions included the prophylaxis of asymptomatic retinal degenerations prior to refractive surgery and the preoperative use of dilated fundoscopy.

WEEK 3
Dr. Gartry addressed intra- and postoperative complications of LASIK, highlighting the management of microstriae. In one case, despite UCVA of 20/20, the patient complained of imperfect vision 3 months after LASIK for -3.00 D; microstriae were visible on retroillumination. All participants concluded that management should be conservative because of the patient's good visual activity. Relifting the flap 3 months after LASIK may not solve the problem.

A case in which a 1-mm nest of epithelial ingrowth was not causing visual disturbances was the subject of another discussion. Careful follow-up was recommended, with flap-lifting advised only in case of enlargement or visual symptoms.

In a third discussion, a patient referred 1 month after PRK with latest-generation laser treatment for -3.00 -3.00 X 180° was presented. The patient now has 6/6- with -1.50 D, no haze, and no epithelial irregularities. Tangential topography demonstrated a regular central steepening (Figure 1). The differential diagnosis of this case was discussed, especially ectasia versus central island. Observations in favor of a diagnosis of central island included the location (not inferior as in most ectasias) and the regular shape, despite the fact that central islands are rare with modern laser platforms. An Orbscan (Bausch & Lomb, Rochester, New York) evaluation of posterior surface was recommended with subsequent follow-up to further clarify the clinical picture, given that central islands tend to improve whereas ectasia tends to worsen.

WEEK 4
Dr. Leccisotti discussed corneal grafting after complicated refractive surgery, reviewing the classification of procedures. The current approach is to use lamellar grafting whenever possible. Deep anterior lamellar keratoplasty (DALK) and other similar techniques should be used to treat severe irregular astigmatism and ectasia, thus sparing the endothelium and notably reducing the risk and the severity of rejection. Posterior lamellar keratoplasty is emerging as the favored technique to replace damaged endothelium, with the benefits of a closed-globe surgery and the avoidance of high post-keratoplasty astigmatism.

The following case was presented: A 55-year-old man underwent bilateral radial and astigmatic keratotomy 20 years ago for bilateral refraction of -10.00 D. In his right eye, visual acuity was 6/12 with +1; in the left, it was 6/9 with +1 (Figure 2). The patient complained of blurred vision in his right eye and is contact-lens intolerant. Participants reviewed the therapeutic options, including better contact lens fitting and DALK.

Iris complications induced by angle-supported phakic IOLs were reviewed in two discussions. In the first, diplopia caused by a large peripheral iridectomy was presented, the only solution being suturing of the iridectomy with 10-0 Prolene. In the second, the management of a 35-year-old woman with bilateral phakic IOL implantation in right and left eyes (-8 and -6, respectively) was discussed. She had forme fruste keratoconus and a pachymetry of 480 µm. Three years after implantation, iris atrophy and pupil ovalization were evident in both eyes (Figure 3). The patient was willing to keep the IOLs, as she hated glasses and had always been unable to wear contacts. All participants agreed that IOLs should be explanted to prevent further iris damage and the development of angular synechiae.

Antonio Leccisotti, MD, PhD, is a Visiting Professor at the School of Biomedical Sciences, University of Ulster, Coleraine, Northern Ireland, and Director of the Ophthalmic Department, Casa di Cura Rugani, Siena, Italy. Dr. Leccisotti states that he has no financial interest in the products or companies mentioned. He may be reached at tel: +39 335 8118324; fax: +39 0577 578600; e-mail: leccisotti@libero.it.

Colm McAlinden, BSc (Hons), MCOptom, is an optometrist currently undertaking a PhD in refractive surgery with the School of Biomedical Sciences, University of Ulster, Coleraine, Northern Ireland. Mr. McAlinden states that he has no financial interest in the products or companies mentioned. Mr. McAlinden may be reached at: e-mail: colm.mcalinden@gmail.com.

Damien McConville, MSc, MBCS, FHEA, is a Learning Technologist at the Institute of Lifelong Learning, University of Ulster. Mr. McConville states that he has no financial interest in the products or companies mentioned. He may be reached at tel: +44 0 2890368537; e-mail: d.mcconville@ulster.ac.uk.

Johnny E. Moore, FRCOphth, PhD, is a Visiting Professor at the School of Biomedical Sciences, University of Ulster, Coleraine, Northern Ireland, and Department of Ophthalmology, Mater Hospital, Belfast Hospital Trust Northern Ireland, and Director of Leeson Eye Institute, Dublin, Ireland. Dr. Moore states that he has no financial interest in the products or companies mentioned. He may be reached at tel: +353 0 16674778; e-mail: johnnymoorebal@gmail.com.

Tara Moore, PhD, NTF, is a Course Director and Senior Lecturer at the School of Biomedical Sciences, University of Ulster, Coleraine, Northern Ireland. Dr. Moore states that she has no financial interest in the products or companies mentioned. She may be contacted at tel: +44 0 7793226873; e-mail: t.moore@ulster.ac.uk.

Sunil Shah, FRCOphth, FRCSEd, FBCLA, is a Visiting Professor at the School of Biomedical Sciences, University of Ulster, Coleraine, UK, Visiting Professor at the School of Life & Health Sciences, Aston University, Birmingham, UK, Medical Director, Midland Eye Institute, Solihull, UK, Consultant Ophthalmic Surgeon, Heart of England Foundation Trust, Birmingham, UK, and Consultant Ophthalmic Surgeon, Birmingham & Midland Eye Centre, Birmingham, UK. Dr. Shah states that he has no financial interest in the products or companies mentioned. He may be reached at tel: +441217112020; fax: +441217114040; e-mail: sunilshah@doctors.net.uk.

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