Purpose:
To evaluate and compare corneal staining patterns of tripan blue(TB) versus rose bengal (RB) in patients with dry eye syndrome (DES). Secondary objectives included addressing patient’s comfort after instillation and to correlate disease severity with staining patterns.
Methods:
This was a prospective, randomized, comparative, crossover-fashioned study. Review Board and followed the Declaration of Helsinki. Patients were andomly selected from the external eye disease ambulatory, Department of ophthalmology of UNICAMP. Included in the study were patients with a previous diagnosis. Patients with any other ocular surface disorders, previous ocular surgery, contact lens wearers, and those who were using eyedrops other than lubricants were excluded. Demographics and clinical data were obtained. A questionnaire, the Ocular Surface Disease Index (OSDI), was used to classify disease severity. Two percent fluorescein drops were used to measure Break up time (BUT). Then, both 1% RB and 1% TB drops were applied. Patients were randomly divided in 2 groups, regarding dye instillation order (group 1: TB first; group 2: RB first). The second dye was applied 1 hour apart. An anesthetic drop preceded both. A staining score (van Bijsterveld scale) was used to evaluate the results. Staining scores for both RB and TB were compared between each other in both groups. The scores were also correlated to disease severity (measured by the OSDI score). Patient comfort to the colorant drop was evaluated by an objective questionnaire.
Results:
Fifty six eyes of 28 consecutive patients (22 females and 6 males) were included. There was no statistical difference between groups regarding disease severity, sex, or age. TB and RB showed good clinical correlation in both groups (group 1: P = 0.009 and group 2: P < 0.001). TB was better tolerated than RB. Overall, we found a low statistical correlation between disease severity and staining scores.
Conclusions:
Both TB and RB showed similar staining patterns. RB was found to provide greater patient discomfort. There was no correlation between disease severity (addressed by the ocular surface disease index questionnaire) and staining patterns (measured by the van Bijsterveld scale).
Keywords: cornea: tears/tear film/dry eye • cornea: surface mucins • cornea: epithelium