Posters

Vitreous volume enlargement (VE) syndrome and IOL position: new biomechanical model of the eye

Poster Details

First Author: P.Fedor USA

Co Author(s):                     

Abstract Details

Purpose:

To describe Vitreous Volume Enlargement syndrome (VE) based on Quantitative Ultrasound biomicroscopy (Q-UBM) and Anterior segment optical coherence tomography (AS-OCT) and its effect on IOL position.

Setting:

Cataract surgery referral private practice, Great Lakes Eye Consultants, Traverse City, Michigan, USA and MUS, Bratislava, Slovakia, EU

Methods:

VE syndrome is described in 15 eyes of 15 patients before and after cataract surgery. Quantitative UBM (Q-UBM) images are analyzed and interpreted based on new Fedor's biomechanical model of the eye. Two biomechanical barriers, the Lens-Ciliary membrane (LCM) and Iris membrane (IM) divide the eye in four basic compartments (K) – the anterior compartment (AK), intermediate compartment (IK), vitreous compartment (VK) and lens compartment (LK). The intraocular pressure can be different in each compartment: anterior intraocular pressure (AIP), intermediate intraocular pressure (IIP), vitreous intraocular pressure (VIP) and intralenticular pressure (ILP).

Results:

The intraocular lens is displaced in average 0.2 – 0.4 mm anteriorly in patients with vitreous volume enlargement syndrome (VE) that corresponds to 0.5 D to 1.0 D refractive shift. New system of quantitative AS analysis was developed defining 3 layers of AS: scleral spur, iris and ciliary apex layer. Scleral spur depth (RD), peripheral IPE depth (ID), ciliary apex depth (XD), and corresponding spur-to-spur (RTR), IPE-to-IPE (ITI), apex-to-apex (XTX) were defined. Ciliary angle (CA) and iris angle (IA) describe movement of ciliary-lens membrane (CLM) and iris membrane (IM) in a new biomechanical eye model.

Conclusions:

Quantitative UBM and Anterior segment OCT are suitable for quantitative analysis of the entire anterior segment including ciliary body area and provide complementary data. Q-UBM is suitable method to quantitatively analyze IOL position and anterior segment anatomy, diagnose VE syndrome and improve prediction of IOL position in small hyperopic eyes and biometric outliers.

Financial Disclosure:

None