A comparative analysis of ocular biometry in acute and chronic presentations of primary angle-closure glaucoma

Purpose: Primary angle-closure glaucoma is the predominant form of glaucoma in the Asian population and is a leading cause of blindness. The objective of the study was to compare ocular biometric parameters among acute and chronic presentations of the disease. Materials and Methods: Sixty eyes of sixty patients diagnosed as having either acute (Group A) or chronic presentation (Group B) were studied. Those patients with a history of uniocular pain, headache, defective vision, along with high intraocular pressure (IOP 35 mmHg), shallow AC, and mid-dilated nonreactive pupil were classified as the acute variety. Chronic form was diagnosed in eyes with peripheral anterior synechiae of >180° with a chronically elevated IOP with disc and field changes. Patients with history of intraocular surgeries or trauma, secondary angle closure, active keratitis, or corneal opacities were excluded from the study. Contact ultrasonic biometry was used for measuring axial length, AC depth, and lens thickness. Lens-axial length factor (LAF) and relative lens position (RLP) were calculated. Statistical Analysis: Chi-square test and Independent sample t-test as applicable. Results: Group B patients were significantly older with a male predominance as compared to Group A. Lens thickness and LAF were significantly higher in Group A whereas axial length and AC depth were significantly lower in Group A (P < 0.001). RLP, keratometry, pachymetry, best-corrected visual acuity, and spherical equivalents were comparable in both groups. Conclusion: It is concluded that the mechanism of acute form of primary angle-closure disease can be explained by the ocular biometric parameters alone with possibility of some additional mechanism for the chronic presentation.