Long-standing bullous keratopathy is associated with peripheral conjunctivalization and limbal deficiency

To investigate whether peripheral corneal neovascularization in bullous keratopathy (BK) is due to conjunctivalization, a sign of limbal stem cell deficiency.

Observational case-control study.

Sixteen BK patients.

Patients were divided into 2 groups: BK without peripheral neovascularization [NV(-) group; 5 patients, 5 eyes] and BK with neovascularization [NV(+) group; 11 patients, 13 eyes]. Evidence of conjunctivalization was evaluated by periodic acid-Schiff staining of impression cytology samples from the peripheral vascularized cornea. The 2 groups' durations of disease also were compared. Penetrating keratoplasty (PK) was performed in all 16 cases, and the 2 groups' durations of reepithelialization after PK were compared.

Presence of goblet cells using impression cytology, duration of BK, and duration of postoperative reepithelialization.

Goblet cells were found on the peripheral corneal surface in all eyes in the NV(+) group. However, all eyes in the NV(-) group were negative for goblet cells (P<0.0001). Duration of disease was 14.4+/-5.4 months in the NV(-) group and 66.2+/-65.5 months in the NV(+) group (P = 0.030). Duration of postoperative epithelialization was 6.2+/-2.2 days in the NV(-) group and 28.8+/-36.5 days in the NV(+) group (P = 0.046).

Conjunctivalization of the peripheral cornea and delayed postoperative epithelialization in BK patients with NV suggest the presence of limbal stem cell deficiency in such patients. Patients with long-standing disease were found to be more prone to neovascularization. For this reason, early surgery may lead to a better surgical outcome.