Purpose
To evaluate, in moderate to severe dry eye patients treated with topical corticosteroids, the in vivo laser scanning confocal microscopy (LSCM) corneal findings and their association with clinical response to treatment.
Methods
We consecutively recruited 50 patients with moderate to severe dry eye. Exclusion criteria were trauma or surgery in the previous 6 months, any systemic or ocular disease (other than dry eye) and any systemic or topical treatment (except artificial tears), ongoing or performed in the previous 3 months, with known effect on the ocular surface. Baseline and follow-up visits included Ocular Surface Disease Index (OSDI) questionnaire, full eye exam and LSCM study of central cornea (including superficial and basal epithelial cells density, anterior, posterior and activated keratocytes density, sub-basal dendritic cells density (DCD), and sub-basal nerves length and tortuosity). All patients were treated with loteprednol etabonate q.i.d. for 4 weeks. The follow-up visit was performed 30±2 days after the baseline. We compared clinical and confocal data obtained before and after treatment and looked for associations between baseline data and steroids-induced changes. Basing on the previously validated OSDI Minimal Clinically Important Difference, we re-analyzed the baseline findings comparing steroids responders to not-responders. Statistical analysis considered the worst eye.
Results
OSDI score and DCD significantly decreased after treatment (Paired samples t-test: 41.8±20.9 vs 52.3±20.7, P<0.01 and 64.3±45 vs 138.4±106.7cells/mm2, P<0.01, respectively). DCD baseline values showed significant correlations with both OSDI and DCD steroid-related changes (r=0.44, P<0.05 and r=0.70, P<0.01, respectively). Baseline mean DCD was significantly higher in responders to steroids compared to not-responders (Independent samples t-test: 164.1±109.2 vs 110.8±45.5; P<0.05).
Conclusions
In vivo confocal evaluation of DCD is effective in detecting steroid-related corneal inflammation changes. DCD baseline values are associated to symptoms' improvement after treatment. These promising preliminary data suggest the need for future studies, designed to test the predictive value of DCD for clinical response to steroids treatment.
Keywords: 486 cornea: tears/tear film/dry eye •
596 microscopy: confocal/tunneling •
557 inflammation