In Vivo Confocal Microscopy Analysis Of Effects Of Topical Preservative-free Timolol 0.1% Gel On Conjunctiva Changes

Abstract

Purpose: : To evaluate the effects at 1 year of preservative-free beta-blocker gel and preservative-containing beta-blocker eye drops on tear secretion and the eye surface.

Methods: : Forty patients with primary open-angle glaucoma or ocular hypertension were divided into two groups according to type of topical hypotensive therapy and compared with 20 healthy age-matched controls. Clinical tests (IOP, Schirmer I test, and lacrimal film break-up time BUT) and in vivo conjunctival confocal microscopy (IVCM) were performed in all patients at baseline and after 12 months. IVCM (HRT II Rostock Cornea Module; Heidelberg Engineering GmbH, Heidelberg, Germany) was performed after topical anaeshesia in the four cardinal locations and at the corresponding limbus to analyze conjunctiva cells.

Results: : A significant reduction in clinical scores (Schirmer I and BUT) was found between groups on topical hypotensive therapy and the control group. The clinical scores were significantly lower in the preserved beta-blocker medication group than in the preservative-free beta-blocker group. Intraepithelial goblet cell density was significantly lower in the preserved than in the preservative-free beta-blocker group (p<0.001) and controls (p<0.001). The epithelial layer was significantly more regular in the preserved beta blocker medication group than in the preservative-free beta-blocker group (p<0.001) and the control group (p<0.001).

Conclusions: : Based on our IVCM data, preservative-free beta-blocker gel induces less changes at ocular surface than preserved beta-blockers, a fact that should be considered to obtain less side effects and maximal adherence to treatment in a chronic condition such as glaucoma.

Keywords: conjunctiva • drug toxicity/drug effects • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)