Analysis of causes of bullous keratopathy in East China: a 10-year retrospective study

Abstract

Dear Editor Bullous keratopathy (BK) leads to decreased corneal transparency and ultimate loss of visual acuity [1]. According to the previous literatures, BK was one of the leading reasons for corneal transplantation [2–5], and Fuchs' dystrophy was most commonly seen in the etiology of BK [1–3]. However, Fuchs' dystrophy wasn’t the leading cause of BK in China. So we performed a retrospective study to explore the causes of BK in East China in the past 10 years. Medical records of inpatients diagnosed as BK treated in the Eye & ENT Hospital of Fudan University, one of the key eye centers in East China, between 1999 to 2008 were retrospectively reviewed, including demographic characteristics, cause of BK, preoperative conditions, associated disorders and surgery performed. A total of 249 eyes of 214 patients were reviewed in this study, composed of 85 females (39.7%) and 129 males (60.3%) aged from 13 to 86 years (mean 57.15±17.4 years). The leading cause of BK was intraocular surgery (130/249, 52.2%), among which 72.7% (94/130) of eyes were cataract surgery. The following reasons were glaucoma (50/249, 20.1%), ocular trauma (31/249, 12.4%), graft failure (13/ 249, 5.2%), herpes simplex keratitis (13/249, 5.2%), Fuchs' dystrophy (8/249, 3.2%) and laser iridotomy (LI) (4/249, 1.6%). Details of etiology are described in Table 1. As for the interval study, the percentage of BK caused by cataract surgery decreased gradually. In contrast, that induced by ocular trauma increased significantly, and the incidence of glaucoma-related BK was relatively steady in the past 10 years, shown in Fig. 1. Intraocular surgery was the leading cause of BK in East China, accounting for one half of the total cases. With the popularization of cataract surgery in China in the decade, the incidence of pseudophakic and aphakic bullous keratopathy increased dramatically. Interestingly, the percentage of BK due to cataract surgery showed an obvious decreasing trend in the recent 5 years, which may probably be attributed to better surgical techniques, improved intraocular lenses, and proper use of viscoelastics. Our result is similar to other researches [1, 2, 6]. Another finding of this study was that glaucoma caused 20.1% of BK in total cases. Further analysis showed that only six eyes with primary glaucoma developed BK, whereas 44 eyes were caused by secondary glaucoma, suggesting that the risk to develop BK increased dramatically once glaucoma coexisted with other ocular diseases such as ocular trauma and surgery. Even when not coexisting with glaucoma, ocular trauma still acted as the third leading cause of BK in this study. Patients of these cases were mainly young or middle-aged, acting as main workers in the families, which reminded us that much more attention should be paid to the trauma. LI used to be a recommended treatment for affected and contralateral eyes in acute angle-closure glaucoma [7]. Shimazaki et al. [8] reported a strikingly large number of LI-related BK in Japan. They supposed that the difference in the rate of LI-related BK between Japan and other Western countries was probably attributable to the difference in the prevalence of angle-closure glaucoma [9]. But in this This study was not supported by any funding. The authors indicate no financial conflict of interest. This study was carried out with approval of the Ophthalmology Department, Eye & ENT Hospital of Fudan University, Shanghai, People’s Republic of China, and conforms to the provisions of the Declaration of Helsinki. Xin Wang and Wentao Wang contributed equally to the study.