Electron microscopy studies for opacified Intraocular lenses after glaucoma tube implants

Abstract

Purpose : Opacification of the implanted intraocular lens (IOL) is a rare but recognised complication after catarct surgery with implants. We report and study the opacification of hydrophilic IOLs following glaucoma drainage device implantation in a case series.

Methods : Our case-series included 2 cases of Rayner C-Flex and 2 Bausch and Lomb Akreos Adapt IOLs. The opacification occured average 2 years after the tube implant, 2 of which were Baerveldts tubes and 2 where Ahmed implants. Two lenses were explanted and analysed so far. The lenses were prepped and examined against a control IOL (out of the box) by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS).

Results : In both cases, the cross section showed deposits near anterior surface of the lens only. Deposits were confined to central area of anterior surfaceonly, and absent from outer edge. On SEM, deposits were 8-20 μm below the surface. No deposits were found on the surface of the lens. EDS analysis showed sub-anterior presence of both calcium and phosphorous in this region. There were no deposits other than the IOL polymer noticed in the inner or outermost areas of both IOLs. To compare, no deposits were demonstrated in either surfaces of a control out of the box IOL.

Some evidence was found suggesting pH change due to mitomycin C (MMC) penetration through a thin sclera in a myopic eye as a cause of the event

Conclusions : We are reporting 4 cases of IOL calcification after glaucoma tube implant, and hence analysing two explanted cases to date. Based on the finding, we discuss using MMC on high myopic patients as a possible caustive factor. Further studies on larger numbers are needed to further investigate this.

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.

 

SEM section showing deposits near anterior surface of lens only. Case 1

 

SEM micrograph highlighting areas of EDS analysis. Case 1