Ophthalmology

Objectives: Refractive changes have been studied after muscle surgery in literature but most results are inconsistent. It has been postulated that changes in corneal tension after muscle surgery may cause a change in corneal curvature resulting in the change in refraction postoperatively. This study investigated changes in corneal topography and clinical refraction after horizontal rectus muscle surgery. Methods: Twenty-one eyes of 13 patients underwent horizontal rectus muscle surgery via limbal approach. Manifest refraction, cycloplegic refraction, and corneal topography were measured preoperatively, and postoperatively at day 1 and weeks 1, 2, 4 and 8. The proportion of subjects with at least 0.5 D change from preoperative measurements and the proportion of subjects that needed new prescription postoperative were also computed. Analysis of the results were done using the Friedman test to identify significant differences among measurements at different time periods with post-hoc analysis utilized to identify specific time periods with significant changes from preoperative measurements. Results: Mean corneal keratometry, horizontal, vertical, and oblique astigmatism, obtained topographically showed no significant difference from preoperative measurements. The statistically significant difference in corneal astigmatism in the recession group at day 1, week 4 and week 8 postoperatively was not confirmed when converted to power vectors in both vertical/horizontal (J0) and oblique (J45) astigmatism. Clinical refraction showed a transient myopic shift in spherical equivalent, statistically significant only on postoperative day 1 in the recession group. There was no statistically significant difference in clinical astigmatism. There was ≥ 0.5 D change in spherical equivalent in 60% in both study groups by the end of follow-up. The shift in J0 was more than 10% in the recession group. More than fifty percent (52.4%) needed new prescription for glasses. Conclusion No statistically significant change in corneal topography and clinical refraction following horizontal rectus muscle surgery were found. Patients should still be refracted at least 2 weeks postoperatively to check if there is a need for change in prescription glasses to improve alignment and/or improve vision.
Astigmatism ; Oculomotor Muscles ; Ophthalmologic Surgical Procedures ; Vision Tests ; Strabismus

Objectives: To describe the population of dry eye disease (DED) patients seen at the Philippine General Hospital (PGH) Dry Eye Clinic, and to compare the diagnosis, type, and severity of DED using Oculus Keratograph® 5M (Oculus GmbH, Wetzlar, Germany) with clinical diagnosis. Methodology: This was a single-center comparative, cross-sectional study. Newly-diagnosed DED patients were recruited for the dry eye group. A subset of healthy volunteers without DED was also recruited for the control group. The clinical data for both groups were collected, and the Ocular Surface Disease Index (OSDI) questionnaire was administered. Standard clinical dry eye testing and Keratograph testing were subsequently done. The PGH Dry Eye Clinic definitions were used to classify the types of dry eye. Results: Eighty (80) eyes of 40 patients per group were examined. For the dry eye group, the mean age and OSDI scores were significantly higher, while the average tear break up time (TBUT) was significantly lower. There was no significant difference in average basal secretion test (BST) and Schirmer 1 measurements between the two groups. 73% had evaporative type dry eye, while 27% had mixed type. Majority of the DED patients were females of >50 years old with mild evaporative type. Foreign body sensation was the most common symptom. Overall, there was poor agreement between clinical and Keratograph assessments of diagnosis and severity among patients in the dry eye group, but there was acceptable agreement when assessment was done in the control group. Conclusions DED patients at the PGH have similar characteristics to reported DED of other Asian populations. Evaporative or short TBUT type dry eye is the most frequently seen. Further formal validity study is needed for Oculus Keratograph® 5M to increase the value of its data to be included in routine dry eye screening.
Dry Eye Syndromes ; Philippines