[Histological study of gelatinous drop-like dystrophy following excimer laser phototherapeutic keratectomy].
OBJECTIVE
Investigation of effects of excimer laser phototherapeutic keratectomy (PTK) on gelatinous drop-like dystrophy.


OBJECTIVE
The patient was a 28-year-old woman with gelatinous drop-like dystrophy. She had a history of penetrating keratoplasty and underwent PTK for recurrent lesions by spot mode several times. Finally her sight deteriorated and she underwent lamellar keratoplasty. We divided the corneal specimen into 2 halves, the non-ablated area and the ablated area. The corneal specimens were investigated histologically.


RESULTS
Light microscopy showed a decrease in thickness of the epithelial layer, absence of Bowman's layer, and amyloid positive materials at the subepithelial layer in both areas. Electronmicroscopy showed irregularly arranged amyloid fibrils in the subepithelial layer of the non-ablated area. In the ablated area, two different types of amyloid fibrils were identified. In the middle and deep stromal layer, the collagen lamellar structure was intact and keratocytes were normal in both areas.


CONCLUSIONS
In the subepithelial layer, two different types of amyloid fibrils were identified in the ablated area. These findings might show that the original disease was affected by excimer laser ablation. In the middle and deep stromal layer, collagen lamellar structure was intact and keratocytes were normal in both areas. These findings suggest that PTK has less effect on the tissue beneath the ablated area, indicating that PTK is a useful and safe technique to remove corneal opacities.
Ito
M
M
Department of Ophthalmology, Nihon University School of Medicine, Japan.
Takahashi
J
J
Sakimoto
T
T
Sawa
M
M
D000328:Adult; D003317:Corneal Dystrophies, Hereditary / Q000473:pathology* / Q000601:surgery*; D005260:Female; D006801:Humans; D054018:Lasers, Excimer; D018903:Photorefractive Keratectomy