Natural history of central topographic islands following excimer laser photorefractive keratectomy
In: Journal of cataract and refractive surgery, Jg. 22 (1996), Heft 9, S. 1151-1158
academicJournal
- print, 21 ref
Zugriff:
Purpose: To assess the incidence and natural history of central corneal topographic islands following excimer laser photorefractive keratectomy (PRK) and photoastigmatic refractive keratectomy (PARK). Setting: A dedicated corneal diseases and refractive surgery unit within a National Health Service Trust ophthalmology unit in the United Kingdom. Methods: Corneal topographic analysis was performed in a prospective study of 100 eyes of 75 consecutive patients who had PRK. All PRK/PARK excimer laser photorefractive procedures were performed by two surgeons observing a standardized protocol using a VISX 20/20 excimer laser. Mean preoperative myopic error was 5.54 diopters (D) ± 3.44 (SD). Corneal topographic analysis was performed on all eyes preoperatively, 1 week postoperatively, and monthly thereafter for a minimum of 6 months or until central islands, if present, resolved. All patients had a minimum 12 months follow-up. Results: Postoperatively, 29 eyes (29%) demonstrated central corneal topographic islands of greater than 3.00 D topographic power by computerized videokeratography (CVK). All central islands were identified in the first 4 weeks postoperatively. In all cases the differential dioptric power, created by the central islands within the ablation zone, decreased rapidly; within 6 months, 26 (90%) central islands had fully resolved without further treatment, and the remaining 3 (10%) resolved within 1 year of photorefractive surgery. The occurrence of central islands was related to higher preoperative myopic spherical equivalent (P =.01), greater attempted laser correction (P =.01), and greater projected depth of ablation (P =.01) (Student's two-tailed t-test). Conclusions: Central corneal topographic islands occurred in a significantly higher proportion of eyes having excimer laser photorefractive surgery than previously believed. The islands were associated with decreased unaided vision, reduced best spectacle-corrected acuity, and other troublesome visual symptoms; however, the central islands, along with their associated visual effects, usually resolved without surgical intervention within 6 months postoperatively.
Titel: |
Natural history of central topographic islands following excimer laser photorefractive keratectomy
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Autor/in / Beteiligte Person: | MCGHEE, C. N. J ; BRYCE, I. G |
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Zeitschrift: | Journal of cataract and refractive surgery, Jg. 22 (1996), Heft 9, S. 1151-1158 |
Veröffentlichung: | New York, NY: Elsevier Science, 1996 |
Medientyp: | academicJournal |
Umfang: | print, 21 ref |
ISSN: | 0886-3350 (print) |
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