[Phototherapeutic keratectomy for recurrent corneal erosion syndrome (e-PTK). Report on 116 consecutive interventions].
OBJECTIVE
Patients with recurrent corneal erosion syndrome can suffer both psychologically and socially due to excessive pain. After the failure of conservative treatment, conventional surgical interventions, such as anterior stromal puncture have been suggested. The purpose of this study was to assess the morphological and functional results of minimally invasive excimer laser phototherapeutic keratectomy (e-PTK) for treatment of recurrent corneal erosion syndrome and in particular, to evaluate the cumulative recurrence rate.


METHODS
Between July 1990 and January 2001, 116 e-PTKs have been performed mostly in the acute stage of the disease in this single center study. In 15 eyes an unsuccessful PTK had previously been performed elsewhere. Reasons for the erosion included trauma ( n=80), Cogan's epithelial dystrophy ( n=14), bullous keratopathy ( n=2), and in 20 cases no cause could be detected. A manually guided spot profile was applied in 99 cases (pulse energy 10 mJ, repetition rate 2/s or 3/s, 66-330 pulses). In 17 cases a scanning slit procedure was applied (intended ablation per scan 1 microm, repetition rate 20/s, 447-1,017 pulses). The broad deepithelialisation of Bowman's layer was treated with defocussed overlapping laser pulses.


RESULTS
Complete epithelial closure was achieved after an average of 2.3+/-1.3 (median 2) days, the mean follow-up was 2.2+/-1.6 years with a maximum of 5.6 years. Best corrected visual acuity increased from 0.6+/-0.4 preoperatively to 0.9+/-0.3 postoperatively. The keratometric central power remained constant (preoperative 43.0+/-2.2 D (diopters), postoperative 43.3+/-1.9 D). The median keratometric astigmatism remained constant at 1.0 D. Only in 2 patients was an iatrogenic, not completely reversible irregular astigmatism of more than 2 D induced during the learning curve. The spherical equivalent did not change significantly (-1.0+/-3.3 D preop., -1.1+/-3.4 D postop.). In 9 eyes (7.8%) a recurrent epithelial defect occurred after 2-24 (average 8+/-6) months. The cumulative 1-year recurrence rate was 6.5%, the 2-year recurrence rate was 11.5%, the 3-, 4-, and 5-year recurrence rates were all 13.6%.


CONCLUSIONS
For recurrent corneal erosion syndrome, e-PTK performed with low pulse energy and low number of pulses can be considered an effective treatment modality to achieve a fast and mostly durable epithelial closure. Even after broad removal of the loose epithelium, change of refraction or induction of an irregular astigmatism with visual loss seems to be the exception.
Seitz
B
B
Augenklinik mit Poliklinik der Universität Erlangen-Nürnberg, Germany. berthold.seitz@augen.imed.uni-erlangen.de
Langenbucher
A
A
Hafner
A
A
Kus
M M
MM
Naumann
G O H
GO
D000328:Adult; D000368:Aged; D001251:Astigmatism / Q000209:etiology; D003316:Corneal Diseases / Q000175:diagnosis / Q000473:pathology / Q000601:surgery*; D019573:Epithelium, Corneal / Q000473:pathology; D005260:Female; D006801:Humans; D054018:Lasers, Excimer; D008297:Male; D008875:Middle Aged; D018903:Photorefractive Keratectomy; D011183:Postoperative Complications / Q000209:etiology; D012008:Recurrence; D012029:Refraction, Ocular / Q000502:physiology; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology