Abstract
Purpose:
To identify anatomical parameters in a Kazakh population predisposing to the development of angle closure glaucoma.
Methods:
Data from healthy Kazakh (N= 98) and European origin subjects (N= 82) aged 20-75 yr were collected. Visual acuity, refraction, gonioscopy, ultrasound biometry of the anterior chamber, lens, vitreous, and axial length of the globe (BS-2000, Nidek, Japan), slit lamp examination, Anterior Segment ASOCT (Visante, Germany) were obtained. Anterior chamber parameters were measured.
Results:
On gonioscopy the frequency of narrow angle in Kazakhs was 57.6% vs 19% among European ethnicity. On gonioscopic exam ciliary body band was not visible in 57.6% of Kazakhs, but was visible in 74% of Europeans. On ASOCT in Kazakhs anterior chamber depth averaged 2.15 ± 0,05 mm vs European 3.0 ± 0,04 mm. By ASOCT frequency of narrow angles was higher in Kazakhs than Europeans (74% vs 15% respectively). Axial length in Kazakhs averaged 22.6 ± 0.1 mm vs European 23.4 ± 0.12 mm; and in Kazakhs anterior chamber depth was lower (mean 2.25 ± 0.05 mm) and the thickness of the lens was higher (mean 4.3 ± 0.07 mm) than European (p <0.05 vs European). In Kazakhs a crowded low profile anterior chamber angle lead to a significant decrease in anterior chamber depth (p <0.01) and narrowing angle (p <0.001).
Conclusions:
These findings identified statistically significant differences between Kazakh and European biometric measures. In particular, Kazakh eyes had a relatively shorter axial length, shallower angles and anterior chamber depth and a thicker lens. All these factors can contribute to a predisposition among Kazakhs to the occurrence of various forms of acute or progressive angle-closure glaucoma.