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R B Vajpayee, Corneal & Cataract Surgery, Centre for Eye Research Australia, University of Melbourne, 32 Gisborne Street, East Melbourne, Victoria 3002, Australia; [email protected]
Corneal ectatic dystrophies with peripheral thinning are difficult to treat as the routine techniques of contact lens fitting and corneal transplantation often do not achieve optimum visual results. These conditions include keratoglobus with generalised corneal thinning and pellucid marginal degeneration (PMD) with corneal thinning involving the periphery of the cornea within 1–2 mm from the limbus.1 This extreme thinness of the cornea involving the periphery makes the surgical management of these cases challenging. A standard keratoplasty is difficult and usually results in suboptimal optical results.2 Other surgical techniques which have been tried in these cases include large diameter or eccentric penetrating keratoplasty, epikeratoplasty, large-diameter lamellar keratoplasty, corneal wedge resection, crescentic lamellar grafts and corneoscleroplasty.2–6 We had previously reported a single-stage surgical technique of central lamellar graft with peripheral intralamellar tuck in a patient of keratoglobus.7 In the present study, we report our experience with this technique, which has now been referred to as “Tuck In” Lamellar Keratoplasty (TILK), in 12 cases of corneal ectasias involving both central and peripheral parts of cornea.
PATIENTS AND METHODS
Twelve eyes of 12 consecutive patients with central corneal ectasias and peripheral corneal involvement requiring surgical intervention were selected from the Cornea services of our centre. These included eight patients of combined keratoconus and PMD and four patients of keratoglobus. Informed consent was obtained from the subjects, and Institutional Review Board approval was obtained. The cases of keratoconus and pellucid marginal degeneration were diagnosed with the help of clinical history, slit-lamp evaluation, videokeratography findings and ultrasonic pachymetry findings. Rabinowitz criteria were used for the initial diagnosis of keratoconus. The severity of keratoconus and PMD was evaluated based on keratometry values. All patients were contact lens intolerant and had best corrected visual acuity (BCVA) ⩽20/120 with nine patients (75%) having BCVA ⩽20/200. At initial presentation, a detailed ocular examination was performed, which included assessment of visual acuity, refraction, keratometry, nine-point ultrasonic pachymetry (Sonogage, Cleveland, OH), videokeratography (Bausch & Lomb, Rochester, NY), endothelial cell count (Topcon SP 2000P), applanation tonometry and a dilated fundus examination. The intraocular pressure was adjusted according to...