Background: To determine the etiology and morphological features of cataracts in a myopia-endemic area of Taiwan.
Methods: This retrospective case-controlled study comprised 332 patients (440 eyes) who underwent cataract-extraction surgery, 163 patients (220 eyes) constituting the presenile cataract study group, and 169 patients (220 eyes) constituting the senile cataract control group. Each group was divided into idiopathic, diabetic, and highly myopic subgroups. Age, gender, ocular and systemic comorbidities, and the types of cataract featured were recorded and analyzed. For the statistical analysis, chi 2 test was used.
Results: The mean ages of study subjects were 45.5 +/- 7.6 years for the presenile and 68.7 +/- 8.0 years for the senile cataract groups. We also observed a greater number of cataracts in highly myopic eyes of the presenile group (17.27%) compared to the senile group (0.90%) (p < 0.0001). The distribution of cataract types for the 3 presenile cataract subgroups revealed that nuclear sclerosis contributed most to presenile cataracts in highly myopic patients (p = 0.001), and correspondingly, the posterior subcapsular opacity contributed most in the idiopathic and diabetic cataract subgroups (p = 0.001).
Conclusions: We observed a greater number of cataracts from highly myopic eyes in the presenile group than in the senile group in southern Taiwan, a myopia-endemic area. Nuclear sclerosis contributed most to the presenile cataracts in the highly myopic subgroup.