Clinical and Biomolecular Analyses of Ocular Surface after Panretinal Photocoagulation Treatment in Patients with Proliferative Diabetic Retinopathy

Abstract

Purpose : To evaluate the effects of pan-retinal laser photocoagulation (PRP) on ocular surface in patients with proliferative diabetic retinopathy (PDR)

Methods : Thirty-eight patients with Type 2 diabetes mellitus and PDR who required PRP treatment were enrolled. Before, 1^st week, 1^st month, and 2^nd month after PRP, all patients underwent a comprehensive ophthalmic evaluation including Ocular Surface Disease Index (OSDI) questionnaire, corneal sensitivity, tear breakup time (BUT), corneal fluorescein staining, and Schirmer’s test with anesthesia. In addition, two conjunctival impression samples were taken, one sample was stained with periodic acid Schiff (PAS) and hematoxylin reagents to observe conjunctival epithelial cells and goblet cells, and the other sample was detected by real-time PCR assay to evaluate the expression of Intercellular Adhesion Molecule 1 (ICAM-1) and Signal transducer and activator of transcription 5 (STAT-5).

Results : A total of 38 patients were included in this study. The average age was 55.39±8.86 years and with a mean 9.42 ± 4.90 years diabetic course. The baseline HbA1c level of all patients was 6.54±1.34 (%). OSDI score slightly increased after treatment at 1^st week and 1^st month, but decreased to a level like pre-treatment at 2^nd month. However, no significant difference was observed. The changing magnitudes of corneal sensitivity across time were also flat and without significance. Schirmer’s test score firstly dropped at 1^st week and then increased to a level like pre-treatment at 2^nd month. The levels of BUT and Goblet cells number significantly dropped at 1^st week and 1^st month and then increased to the level like pre-treatment at 2^nd month. The corneal fluorescein staining score were significantly higher than pre-treatment at 1^st week and 1^st month, then decreased to a similar level to pre-treatment at 2^nd month. ICAM-1, STAT-5 expressions were maximumly high at 1^st week and then gradually decreased (all p < 0.05 compared to 1^st week).

Conclusions : PRP resulted in ocular surface damage and increased expression of specific non selective inflammatory markers, ICAM-1 and STAT-5, in PDR patients. These changes were similar to the pre-treatment state by the second month. Ocular surface protection and anti-inflammatory therapy should be considered after PRP treatment.

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.