Long-term Results of Phototherapeutic Keratectomy (o-PTK) with 193 nm Excimer Laser for Macular Corneal Dystrophy
Hafner A., Seitz B., Langenbucher A., Naumann G. O. H.
Department of Ophthalmology, Universiy of Erlangen
Purpose: To investigate the functional and morphological long-term outcome of o-PTK for macular corneal dystrophy.
Method: Out of a total of 317 PTKs, between 6/1994 and 10/1998 10 consecutive o-PTKs (5 OD, 5 OS) were performed in eyes with superficial opacities caused by macular dystrophy. The intended laser ablation depth after epithelial debridement and pannectomy varied from 20 to 100 µm. We used the slit-scanning-mode with a repetition rate of 20/s or 25/s and a pulse rate of 1774 ± 502 (976 - 2422). In most cases a 6,0 mm metall mask was used to protect peripheral Bowman`s layer.
Results: Mean follow-up was 4.5 ± 3.1 (maximum 8.7) years. Best-corrected visual acuity increased from preoperatively 0.3 ± 0.2 to 0.5 ± 0.2, initially. The mean spherical equivalent increased from -0.9 ± 1.1 D preoperatively to -0.4 ± 1.8 D postoperatively. Likewise, mean keratometric central power decreased from 44.5 ± 0.7 D preoperatively to 42.5 ± 0.6 D postoperatively. During follow-up we saw recurrences in 7 eyes. The mean time period without recurrences was 3.3 ± 0.5 years. The earliest recurrence was seen after 0.8 years. In 6 eyes a penetrating keratoplasty was performed. In none of the transplants a recurrence was observed up to now (mean follow-up after penetrating keratoplasty: 0.5 to 4.2 years). The maximum follow-up of the other 3 eyes without documen
Zurück | Back