Long-standing Bullous Keratopathy Is Associated with Peripheral Conjunctivalization and Limbal Deficiency
Presented in part at: Asia Pacific Society of Cornea and Refractive Surgery inaugural scientific meeting, March, 1998; Singapore.
Received 7 August 2005; accepted 17 January 2006. published online 26 April 2006.
Objective
To investigate whether peripheral corneal neovascularization in bullous keratopathy (BK) is due to conjunctivalization, a sign of limbal stem cell deficiency.
Design
Observational case–control study.
Participants
Sixteen BK patients.
Methods
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.
Main Outcome Measures
Presence of goblet cells using impression cytology, duration of BK, and duration of postoperative reepithelialization.
Results
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).
Conclusion
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.
1Department of Ophthalmology, Tokyo Dental College, Chiba, Japan.
2Department of Ophthalmology, School of Medicine, Keio University, Tokyo, Japan.
3Department of Ophthalmology, Kawasaki Municipal Hospital, Kawasaki, Japan.
4Cornea Center & Eye Bank, Tokyo Dental College, Chiba, Japan.
Correspondence and reprint requests to Yoji Takano, MD, Keio University, School of Medicine, Department of Ophthalmology, Shinanomachi: 35, Shinjuku-ku, Tokyo, Japan.
Manuscript no. 2005-741.
This study was supported by grants from the Japanese Ministry of Education, Culture, Sports, Science, and Technology, Tokyo, Japan; Medical School Faculty and Alumni Grants of the Keio University Medical Science Fund, Tokyo, Japan; and Hightech Research Center at Tokyo Dental College, Chiba, Japan.
1 Drs Uchino and Goto contributed equally to the work and therefore should be considered equivalent first authors.
ABSTRACT