Abstract
Abstract: :
Purpose: To compare lens thickness, lens position and prevalence of lens opacity between affected and fellow eyes of subjects with acute primary angle closure (APAC). Methods: This was a prospective observational case series of 62 Asian subjects with APAC. Subjects who presented with APAC were treated with medical therapy followed by laser iridotomy in both eyes. Two weeks after iridotomy, central anterior chamber depth (ACD), lens thickness (LT) and axial length (AL) measurements were made in both eyes using ultrasound pachymetry. Lens position (LP) was defined as ACD + ½LT and relative lens position (RLP) was defined as LP/AL. A modified version of the Lens Opacity Classification III (LOCS III) system was used for grading lens opacity. This system grades nuclear color (NC), nuclear opalescence (NO), cortical (C) and posterior sub–capsular (PSC) cataract according to objective measures of color, density and area. Results: The 62 subjects were ethnic Chinese (89%), Malay (8%) or Indian (3%). Females comprised 63% of the sample and mean age was 60.2 ± 10.3 years. The mean lens thickness was 5.11 ± 0.57 mm and 5.10 ± 0.55 mm in affected and fellow eyes respectively (p=0.46) There was no significant difference in lens position (p=0.14) or relative lens position (p=0.08). Using paired tests, there was also no significant difference found for lens opacity grades, NO (p=0.58), NC (p=0.42), CO (p=0.77) and PSC (p=0.18) between attack and fellow eyes. Conclusions: Two weeks after APAC, there was no significant difference found in lens thickness, lens position or degree of lens opacity between affected and fellow eyes. The results suggest that factors other than these lens characteristics are significant in triggering APAC.
Keywords: clinical (human) or epidemiologic studies: risk factor assessment • cataract • depth