Ocular Biometric Characteristics of Chinese with History of Acute Angle Closure

Abstract

Purpose To investigate the biometric characteristics of Chinese patients with a history of acute angle closure (AAC). Methods In this clinic-based, retrospective, observational, cross-sectional study, biometric parameters of eyes were acquired from a general population of Chinese adults. The crowding value (defined as lens thickness (LT); central corneal thickness (CCT); anterior chamber depth (ACD)/axial length (AL)) was calculated for each patient. Logistic regression analysis was performed to identify risk factors for AAC. Receiver operating characteristic (ROC) curves were plotted, and biometric variables were compared to compile a risk assessment for AAC. Result This study included 1500 healthy subjects (2624 eyes, mean age of 66.54 ± 15.82 years) and 107 subjects with AAC (202 eyes, mean age of 70.01 ± 11.05 years). Eyes with AAC had thicker lens (P ≤ 0.001), shallower anterior chamber depth (P ≤ 0.001), and shorter axial length (P ≤ 0.001) than healthy eyes. Logistic regression analysis and ROC curve analysis indicated that a crowding value above 0.13 was a significant (P < 0.05) risk factor for the development of AAC. Conclusions Biometric parameters were significantly different between the eyes from the AAC group to the normal group. Ocular crowding value might be a new noncontact screening method to assess the risk of AAC in adults.

Comparison of uveal parameters between acute primary angle-closure eyes and fellow eyes in South Indian population

“…In a retrospective study by Niu et al . [ 22 ] in the Chinese population, where the ocular biometric parameters of eyes with APAC were compared with fellow eyes as well as with normal eyes, there was no difference in axial length between the APAC and fellow eyes, whereas APAC eyes had shorter axial length compared to the normal individuals. Similarly, Li et al .…”

Can ultrasonic biometric indices with optimal cut-offs be a potential screening tool for primary angle closure disease? A case-control study

“…We calculated the following composite indices: Lens position (LP)= ACD + 0.5 LT; Relative lens position (RLP) = (LP/AXL); Lens axial factor (LAF) =(LT/AXL)x 10; Simple crowding value (Cs)= (LT −ACD)/AXL. (19,20,31) A senior ophthalmologist (SSav) performed the gonioscopy. We used Goldmann's 3-mirror gonio-lens (Volk optics, Ohio, USA) under standardized conditions namely dim illumination, narrow slit beam with the patient's gaze in primary position.…”

“…(18) Previous studies have explored the association of the following biometric indices with a spectrum of PACD: anterior chamber depth (ACD), axial length (AXL), ACD/AXL, lens thickness (LT), lens axial factor (LAF), relative lens position (RLP) and simple crowding value(Cs). (16,19,20) With an appropriate cut-off point having optimal sensitivity and specificity, these indices can be used as potential surrogates to detect PACD. A few studies have determined these cut-off values among East Asian and Iranian populations.…”

“…A few studies have determined these cut-off values among East Asian and Iranian populations. (20)(21)(22)(23) Although certain studies from India have assessed few biometric indices, there is a lack of data on optimal cut-offs (discrimination thresholds) to differentiate individuals with and without PACD. (24,25) Given that genetic and environmental factors influence the ocular biometric parameters (26,27) and paucity of data in the Indian populace, we conducted a hospital-based case-control study in a coastal town of South India, with the following objectives 1.…”

Nanophthalmos-AssociatedMYRFGene Mutation Causes Ciliary Zonule Defects in Mice

“…Simple crowding value (calculated as (LT − ACD)/AL) was used to evaluate the crowding condition of the eye. 15…”