Ophthalmology, November 2016
Teekhasaenee et al. proposed a new theory of the pathogenesis of true exfoliation syndrome (TEX). Further, they described the clinical spectrum of this syndrome as encompassing lens capsule lamellar separation and anterior zonular disruption as well as cataract and, often, pigment deposition.
Participants included 259 patients (424 eyes) with TEX, who ranged in age from 52 to 97 years (mean age, 75.2 ± 7.1 years). Of these, 11 patients had TEX associated with trauma (n = 1) or intense heat exposure (n = 10), while 248 patients had idiopathic TEX. Forty-nine patients were seen once and were lost to follow-up; the remaining 210 were seen every 3 months, with a mean follow-up of 9.6 ± 6.1 months (range, 3-50 months). At the initial visit, slit-lamp biomicroscopy, photography, and optical coherence imaging of the anterior capsule and zonules were performed. Photography was performed at all subsequent visits, with or without other imaging. The main outcome measures were detached membrane morphologic features, zonular defects, pigment deposition, glaucoma, phacodonesis, and cataract.
The condition was classified into 4 clinical stages: annular anterior capsule thickening with a distinct splitting margin (stage 1), an inward detached crescent flap lying on the anterior lens (stage 2), a floating and folding translucent membrane behind the iris (stage 3), and a broad membrane within the pupil (stage 4). Several stages could coexist in an eye.
All stages shared common histologic findings consisting of diffuse capsular lamellar separation and anterior zonular disruption. All patients developed cataract; 68.7% of patients had pigment deposition on the membrane; 10% had spontaneous phacodonesis; and 4.2% demonstrated secondary delamination.
The researchers identified capsularlamellar separation and anterior zonular disruption as the characteristic findings. The initial capsular splits occur along the insertions of disrupted anterior zonules, and the peeling progresses centrally in association with iris movement and aqueous flow. The authors concluded that aging, heat exposure, and trauma are risk factors for TEX.
The original article can be found here.