Anterior stromal puncture in bullous keratopathy - A clinicopathologic study

Purpose. We report our experience of anterior stromal puncture (ASP) in sym ptomatic chronic corneal edema patients awaiting penetrating keratoplasty ( PK) and hypothesize the mechanism of action of ASP in bullous keratopathy ( BK). Methods. We reviewed the medical records of 28 patients with BK who un derwent ASP between November 1996 and September 1999 with at least I month of follow-up. In all these patients, approximately 200 punctures were given with a bent 26-gauge needle sparing the peripheral cornea. Patients were e xamined on days 1 and 7, 1 month, and every 3 months after the procedure. T he symptoms, corneal findings, and visual acuity of the patients at last fo llow-up were noted and compared with the preprocedure findings. For 11 pati ents who underwent PK, histopathologic study of corneal buttons was perform ed and a clinicopathologic correlation was attempted. Results. Of the 28 pa tients, there were 15 men and 13 women with a mean age of 61.1 years, The c linical diagnosis was pseudophakic BK in 11 (39.3%), aphakic BK in 11 (39.3 %), Fuchs' dystrophy in 4 (14.3%), failed graft in 1 (3.6%), and chronic co rneal edema of unknown etiology in 1 (3.6%). The follow-up ranged from 1 to 33 months with a mean of 9.5 +/- 7.5 months. Symptomatic relief was noted in all. Twenty patients (71.4%) had complete relief, whereas eight patients (28.6%) experienced mild symptoms such as tearing and occasional pain, Vis ual acuity improved in 7 patients (25%), decreased in 12 (42.8%), and remai ned the same in 9 (32.4%). Objective evidence of scarring after ASP was not ed in all patients. Complete regression of epithelial bullae and epithelial edema was found in 10 (35.7%) and partial regression in 18 (62.25%) patien ts. There was no progression or appearance of new blood vessels except in o ne patient (3.6%). Histologically, puncture marks and superficial stromal s carring were noted in all corneal buttons. Adhesion of epithelium with vary ing degrees of subepithelial fibrosis was seen in six, whereas in the remai ning five buttons, there was complete denudation of the epithelium. Vascula rization was seen in five and inflammation in two buttons. Clinicopathologi c correlation revealed that symptomatic patients had persistent edema and l oose adhesion of the epithelium to the stroma, resulting in detachment. Con clusions. ASP is a simple, safe, and cost-effective outpatient procedure fo r symptomatic relief in patients with BK. The possibility of decreased visu al acuity after the procedure should be explained to all patients. Although ASP promoted subepithelial fibrosis in all cases, its subsequent adhesion is variable and probably has clinical relevance. Further studies could be d irected toward identifying specific mediators that promote epithelial-strom al interaction and firm anchoring of epithelium to the underlying stroma.