Peripapillary retinal nerve fiber layer [RNFL] thickness measurements by topcon SD-OCT in myopic patients

Objective: To evaluate the effect of low-to-moderate myopia on peripapillary retinal nerve fiber layer [RNFL] thickness measured by Topcon SD optical coherence tomography [OCT]. Study Design: Cross-sectional study. Place and Duration of Study: Ophthalmology Department, Shifa Foundation Falahee Clinic, over a period of one year starting from June 2015

Methodology: A total of 43 eyes of 43 patients, having mild to moderate myopic refractive error, were enrolled in the study. Refractive error/spherical equivalent was calculated. RNFL thickness was obtained from all four peripapillary quadrants: temporal, superior, nasal, and inferior; and 12 sub-quadrants using Topcon SD OCT. Pearson correlation coefficients [r] were calculated to evaluate relationships between the RNFL thickness and spherical equivalent [SE] before and after adjustment for ocular magnification

Results: The study included 51.2% females and 48.8% males. Mean age was 30.9 +/- 6.45 years. Mean axial length was 24.25 +/- 0.91 mm. Mean SE was -3.25 +/- 1.93 DS. Mean of average RNFL thickness [with Littmann's correction] was 97.28 +/- 8.15 microm. Correlation analysis among all subjects showed that the average, mean nasal quadrant, upper nasal, and inferonasal sub-quadrant RNFL thickness had positive correlation with spherical equivalent [r = 0.31, p = 0.045]. However, correction of the magnification effect by applying Littmann formula eliminated this effect

Conclusion: In low-to-moderate myopia, RNFL measurements vary with refractive error of the eye. Since ocular magnification significantly affects the RNFL measurement, it should be considered in diagnosing glaucoma

Transient corneal edema after phacoemulsification

To determine the association between pre-operative and intra-operative factors leading to transient corneal edema after phacoemulsification. Cohort study. Department of Ophthalmology, Shifa Foundation Community Health Centre, Islamabad, from October 2011 to September 2012. Patients undergoing phacoemulsification and Intraocular Lens [IOL] implantation were enrolled in the study using consecutive non-probability sampling. Pre-operative risk factors including peripheral corneal degenerations, the type and density of cataract were documented. Surgical risk factors included the incision site, the type of intraocular lens, the phacotechnique and the phacopower time. Postoperatively the patients were assessed for corneal clarity and the degree of striate keratopathy. Statistical analysis was done using SPSS version 17. There were 43% male and 57% female patients [n = 182]. Mean age was 58.92 +/- 13.00 years [median and mode-60 years]. Factors which increased the risk of transient corneal edema after phacoemulsification included hypertension [p = 0.022], dense nuclear cataracts [p=0.006], divide and conquer technique [p = 0.008], duration of phacopower use [p < 0.001] and peripheral corneal degenerations [p < 0.001]. Patients with peripheral corneal degenerations and dense nuclear cataracts had significantly higher rates of postoperative corneal edema. Use of phaco-chop technique and less phaco-power time helps in decreasing corneal edema

Comparison of Ciprofloxacin 0.3% and Moxifloxacin 0.5% eye drops in bacterial corneal ulcers

To compare the effect of Ciprofloxacin 0.3% and Moxifloxacin 0.5% eye drops in bacterial corneal ulcers. Prospective randomized trial Ophthalmology department of Pakistan Institute of Medical Sciences, Islamabad. The total duration of the study was 18 months. 100 patients of bacterial corneal ulcers were randomly assigned to two treatment groups: A [Ciprofloxacin 0.3%] and B [Moxifloxacin 0.5%] for the treatment of bacterial corneal ulcers. The outcome measures included size of epithelial defect, size of infiltrate and reaction in anterior chamber on day 1, 2 and 3 and week 1, 2 and 3 after the initiation of treatment. They were compared between the two study groups using Student t test and Chi-square test. SPSS version 13 was used for data entry and analysis. The mean age of patients in Group A was 37.6 [+/- 9.7 SD] years and in Group B was 37.4 [+/- 9.2 SD] years. There were 34 [68%] female and 28[56%] male patients in group A and B respectively. There were significant differences in terms of size of infiltrate [p value 0.030] and reaction in anterior chamber [p value 0.002] between the two study groups. A non-significant difference was observed in size of epithelial defect between the two groups [p value 0.158 after 2 weeks]. Our study showed that Moxifloxacin 0.5% is superior to Ciprofloxacin 0.3% eye drops in treating bacterial corneal ulcers in adult patients