Background: Meibomian gland dysfunction (MGD) is a common eye problem. Eyelid hygiene for MGD consists of warm compression, lid massage and lid scrubs. There have been reports of visual acuity changes after warm compression.
Objective: To compare visual acuity, corneal curvature, corneal astigmatism and refraction before and after MGD treatment with warm compression and lid scrubs.
Material and Method: The subjects, who were MGD patients at Rajavithi Hospital, were asked to do lid scrubs and warm compression using a gel pad at a controlled temperature of 35°C to 40°C for 10 minutes once daily. Visual acuity, corneal curvature, corneal astigmatism and refraction were measured before treatment, and at 4-week and 8-week visits.
Results: The data of 76 eyes from 38 patients were analyzed. Mean best corrected VA were 0.13+0.13, 0.14+0.12, 0.15+0.13 logMAR, at baseline, 4-week and 8-week visits, respectively. Mean flattest and steepest curvatures were 44.20+1.70, 45.09+1.72 at baseline, 44.11+1.63, 45.07+1.73 at 4-week visit, and 44.15+1.63, 45.04+1.67 diopters at 8-week visit. Mean astigmatism was -0.89+0.59 at baseline, -0.96+0.74 at 4-week visit and -0.89+0.69 diopters at 8-week visit. Spherical equivalence was 0.52+1.75, 0.60+1.83, 0.62+1.83 diopters at baseline, 4-week and 8-week visit, respectively. There were no statistically significant differences in visual acuity, corneal curvature, corneal astigmatism or refraction parameters at each visit. All patients reported no worsening in their vision, and some stated that they had better vision than before treatment.
Conclusion: There were no statistically significant changes in visual acuity, corneal curvature, corneal astigmatism or refraction following warm compression in subjects presenting with MGD.

Keywords: Corneal biomechanics, Warm compression, Meibomian gland dysfunction, Corneal curvature, Heat