Qualitative and quantitative evaluation of acute angle-closure mechanisms

Abstract

BackgroundTo evaluate ocular biometric parameters in different subtypes of acute angle closure and compared to fellow eyes of AAC and PACS eyes.MethodsThis is a retrospective chart review study. A total of 167 eyes (96 patients) consisting of 71 AAC eyes, 71 fellow eyes of AAC, and 25 PACS eyes were recruited. All patients underwent ocular examination and biometry. The mechanism of AAC was confirmed by ultrasound biomicroscopy. We then subdivided AAC eyes into four subgroups: crowded-angle (CR), lens subluxation (LS) pupillary block (PB), and plateau iris syndrome (PL). Outcome variables included anterior chamber depth (ACD), lens thickness (LT), vitreal length (VL), axial length (AL), lens position and relative lens position (LP and RLP, respectively), and lens axial length factor (LAF).ResultsAmong the three groups, ACD was shallower in AAC eyes than fellow eyes of AAC and PACS eyes (p < 0.01 for both) and AAC eyes demonstrated a lesser LP and RLP. The LT, VL, AL, and LAF were not significantly different among the three groups. Among the four subgroups, LS displayed the most shallow ACD (p = 0.01). The lens position in PL was greater than in CR and LS (p < 0.05 and <0.01, respectively).ConclusionsAAC eyes had a more anterior lens position than fellow eyes and PACS eyes, though lens thickness did not differ among the groups. As such, an anterior lens position may offer more sensitive prognostication regarding future development of AAC compared to lens thickness.

Macular vessel density and foveal avascular zone parameters in patients after acute primary angle closure determined by OCT angiography

“…From a pathophysiological point of view, PACS and normal eyes are different even though they have the same RNFL thickness and VF. Usually, PACS eyes are recognized as having shallow anterior chambers and narrow anterior chambers with or without a short axial length 34 . Some people have evidenced that early glaucomatous damage involves the macula 35 .…”

Biometric indicators of eyes with occult lens subluxation inducing secondary acute angle closure

“…Ocular biometric parameters including ocular axial length (AL), central corneal thickness (CCT), aqueous depth (AD, depth from the endothelium of the cornea to the anterior surface of the lens), anterior chamber depth (ACD, depth from the epithelium of the cornea to the anterior surface of the lens, equal to CCT + AD), and lens thickness (LT) were recorded. Ultrasound biomicroscopy (UBM) were performedby an experienced ophthalmologist to evaluate the lens position as described in the literature [2]. The following formulas were used to assess the biometric chataracters of the patients.…”

“…Whenacute secondary angle closure is misdiagnosed as APAC, miotic agents might be administered, andtrabeculectomy may even beperformed. However, if correct diagnosis can be made before the surgery, appropriate treatmentswould be applied according to the patients' condition, thereby increasing the success rate of the surgery andthe recovery of visual function [2].…”

Biometric indicators of Eyes with Occult Lens Subluxation inducing Secondary Acute Angle Closure

“…When acute secondary angle closure is misdiagnosed as APAC, miotic agents would be administered, and trabeculectomy may even be performed. However, if correct diagnosis can be made before the surgery, appropriate treatments would be applied according to the patients' condition, thereby increasing the success rate of the surgery and the recovery of visual function [2].…”