Abstract
Purpose :
Corneal epithelial dryness or damage is more concerned in complicated proliferative diabetic retinopathy (PDR) surgery if using noncontact wide-angle viewing system. We designed a rigid contact lens to be used during surgery and performed a prospective, randomized, comparative study to analyze its protection of corneal epithelia.
Methods :
A thin and lightweight rigid contact lens was designed and constructed. The impact of the contact lens on the visualized fundus range was evaluated using a concrete eye model. Eighty two eyes of 74 patients with severe PDR were randomized to either the contact lens (CL) group, viscoelastic group (VIS), or balanced salt solution (BSS) group. Surgery time and corneal fluorescein staining score (FSS) postoperatively were mainly measured using one way analysis of variance (ANOVA) test.
Results :
In the eye model, a larger area of fundus was visualized with the use of our contact lens under the 128D (>80°) and 60D (45°) Resight lens compared to the 128D (76°) and 60D (42°) Resight lens alone. The mean surgery time was 51.36±8.06min,50.89±8.26min,and 55.46±9.14 in CL, VIS, and BSS group respectively (F=0.493,p=0.105). In four eyes of the BSS group, corneal epithelial layer was peeled because the serious dryness of the cornea could not maintain a clear fundus image. The FSS in BSS group was markedly higher than that of CL and VIS group 6 hours (7.22±3.81, 1.43±1.62, and 1.70±1.96 respectively, F=36.48, p<0.001), 1 day (5.33±3.40, 1.11±1.42 and 1.41±1.78 respectively, F=23.83, p<0.001), 3 days (3.33±2.02, 0.82±1.06 and 0.93±1.27 respectively; F=20.28, p<0.001), and 7 days (1.67±1.64, 0.50±0.80, and 0.63±0.93 respectively, F=6.865,p=0.002) postoperatively. There was no statistical significance of the FSS score between CL and Vis group at each follow-up endpoint.
Conclusions :
The contact lens we designed can slightly enlarger the visible fundus range and efficiently protect corneal epithelia from damage during vitrectomy in PDR patients.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.