Is gabapentin effective in dry eye disease and neuropathic ocular pain?

This study aims to evaluate the efficacy of gabapentin treatment in dry eye disease (DED) and neuropathic ocular pain. Our study was performed with 72 patients. The painDETECT questionnaire was used for neuropathic pain screening. Patients who were thought to have severe DED according to ocular surface disease index (OSDI) questionnaire, Schirmer's test type 1 and tear break up time test results were treated with artificial tear and cyclosporine drops. Gabapentin treatment was also initiated in addition to artificial tear and cyclosporine drops treatments to the patients with neuropathic component and DED findings. We divided the patients into two groups: group 1 (n: 36), patients treated with artificial tear and cyclosporine drops and group 2 (n: 36), patients treated with artificial tear, cyclosporine drops and gabapentin. In the first evaluation, no significant differences were found between groups in terms of OSDI score, Schirmer's test result and TBUT. After the 6 weeks of treatment, in both groups OSDI score, Schirmer's test result and TBUT statistically significantly improved. OSDI score, Schirmer's test result and TBUT significantly improved after the 6 weeks of gabapentin treatment than artificial tear and cyclosporine treatment group (p < 0.001). Dry eye patients should be screened for neuropathic ocular pain symptoms and individualized treatment has to be applied. Our study showed that the use of gabapentin is effective in severe dry eye patients with neuropathic ocular pain.

Comparison of Corneal Layers and Anterior Sclera in Emmetropic and Myopic Eyes.

PURPOSE: The aim of this study was to compare the thickness of preocular tear film, corneal layers, and anterior sclera in patients with moderate to high myopia and emmetropia with anterior segment spectral domain optical coherence tomography. METHODS: This cross-sectional comparative study included 31 patients with high myopia and 31 emmetropic healthy controls. Patients with myopia had axial lengths ranging from 24 to 29 mm, whereas age-matched controls had axial lengths from 21 to 23.9 mm. Patients with myopia had refractive errors from -4.00 to -11.00 diopters spherical equivalent. Preocular tear film, corneal epithelium, Bowman layer, stroma, and Descemet membrane-endothelium complex were measured in the central cornea. Anterior scleral measurements were made at distances of 1, 3, and 5 mm from the limbus. Corneal-scleral thickness was measured with the anterior segment module of spectral domain optical coherence tomography. RESULTS: No statistically significant differences (P > 0.05) between patients with myopia and controls emerged regarding the thickness of preocular tear film, corneal epithelium, Bowman layer, corneal stroma, and Descemet membrane-endothelium complex. The anterior scleral thickness values of 1, 3, and 5 mm from the limbus were similar in both patients with myopia and control participants (P > 0.05). There were no significant correlations between central cornea stromal thickness and anterior scleral thickness in myopic participants (P > 0.05). CONCLUSIONS: The thickness of anterior wall structures and preocular tear film of patients with moderate to high myopia are not statistically different compared with those of healthy controls.

Effect of chronic smoking on lens nucleus as assessed by Pentacam HR lens densitometry in young adults.

OBJECTIVE: To evaluate the effects of chronic tobacco smoking on lens nucleus by Pentacam HR lens densitometry (LD) in young adults. DESIGN: Prospective cross-sectional case series. METHODS: Thirty subjects (23 M, 7 F) who were chronic cigarette smokers (≥10 cigarettes/day for at least 2 years) (group 1) and another 30 subjects (23 M, 7 F) who did not smoke (group 2), were included in this study. The patients were matched for age and sex between the groups. The exclusion criteria were any history of ocular surgery, any systemic disorders and any ocular diseases except for mild refractive disorders. Lens densitometry measurements were done with the Pentacam HR (Oculus, Wetzlar, Germany). The Schirmer test and pachymetry measurements were also performed. RESULTS: Mean age of the patients for both groups was 28.90 ± 8.20 years (range: 18-40 years). Mean lens densitometry (LD) measurements of Group 1 (chronic cigarette smoking group) were higher than those of Group 2 (control group) in all LD techniques; however only mean "peak" LD measurements showed a statistically significant difference between these two groups (Group 1: 8.67 ± 0.61, Group 2: 8.44 ± 0.70, p = 0.04). The mean Schirmer test value was 12.43 ± 5.60 mm in Group 1 and 13.00 ± 4.26 mm in Group 2 (p = 0.55). The mean central corneal thickness (CCT) value was 564.23 ± 34.61 µm in Group 1 and 550.47 ± 32.94 µm in Group 2 (p = 0.03). DISCUSSION: The Pentacam HR LD seems to be an important option for the evaluation of lens nucleus in young adults, because it gives objective and quantitative data. CONCLUSION: Although chronic smoking increases lens nucleus density in young adults, the effect is not statistically significant when compared with the control group.