Abstract
Abstract: :
Purpose: No paper has demonstrated the details of surgical procedure of excimer laser phototherapeutic keratectomy (PTK) in Gelatinous Drop-like Corneal Dystrophy (GDCD). To establish optimal surgical procedure for the GDCD by PTK. Methods: Four eyes of 3 patients with GDCD were studied. Both patients were diagnosed as GDCD by clinical findings and molecular genetic analysis. Four eyes had had surgeries of keratectomy, lamellar keratoplasty, keratoepithelioplasty and penetrating keratoplasty previously however, they had developed recurrences. In 2 recurred corneas with severe surface irregularities and dense scarring, scraping in protruded area manually with Beaver blade #5700 and then, PTK were performed without surface smoothing material. A VISX 20/20 Star2 excimer laser calibrated at 100mJ/cm2, 193nm, and 5Hz was used and set for the circle PTK ablation program. Ablation depth was from 30 and 70 µm respectively. In 2 recurred corneas with severe surface irregularities and light scarring, scraping of surface layer was performed but not PTK. Observation period is from 3 months to 39 months. Results: Visual acuity was improved from 20/600 to 20/300 and from 20/200 to 20/50 in 2 corneas with scraping and PTK and, from20/1000 to 20/200 and from 20/2000 to 20/600 in 2 corneas with scraping without PTK. Conclusions: GDCD develops severe surface irregularities therefore, direct ablation with excimer laser on the surface of the cornea produces more surface irregularities. Because, no optimum surface smoothing materials for PTK has been developed yet, in recurred GDCD cornea with severe surface irregularities, surface layer (epithelial layer and degenerated Bowman's membrane) should be removed manually and then, PTK is performed without surface smoothing material. In recurred cornea with light scarring, scraping of surface layer should be performed but not PTK.
Keywords: cornea: clinical science • laser • degenerations/dystrophies