Comparison of preoperative prophylaxis with povidone-iodine (5%) and moxifloxacin (0.5%) versus povidone-iodine (5%) alone: a prospective study from India.

PURPOSE: To compare the effect of povidone-iodine (PI) 5% and moxifloxacin 0.5% solutions versus PI 5% solution alone on the conjunctival bacterial flora. METHODOLOGY: This is a comparative study in which the study population comprised adult patients scheduled for elective small incision cataract surgery. The eye to be operated (control eye) received topical moxifloxacin 0.5% drops 4 times, 1 day before surgery and 2 applications on the day of surgery. As placebo, the contralateral eye (study eye) received saline 0.90% drops as per the same schedule. Before surgery, on table, PI 5% was instilled in the conjunctival sac in both eyes. Conjunctival swabs were taken before initiation of therapy and 3 min after instillation of PI. RESULTS: Of the 96 pairs of eyes included in the study, conjunctival cultures before prophylaxis were similar between the two groups (p = 0.31), with 54 samples (56%) of the study group and 49 (51%) of the control group showing growth. With positive cultures reducing to 7 (14%) in the study group and 8 (16%) in the control group, both the prophylaxis methods appeared equally efficacious (p = 0.79). Both the groups showed a significant reduction in positive cultures following prophylaxis (p < 0.0001). CONCLUSIONS: PI 5% alone as preoperative prophylaxis was as effective as its combination therapy with moxifloxacin 0.5% in the reduction in conjunctival bacterial colonization.

Ixodidae - A rare cause of blepharitis.

Hard ticks are mainly responsible for more "tick-borne" diseases in humans when compared to soft ticks. Tick infestation of ocular and periocular tissues is rare. We report the case of a 61-year-old male with left upper eyelid edema with erythema and live parasite on the lid margin.

Serum magnesium in diabetic retinopathy: the association needs investigation.

BACKGROUND: Magnesium has an essential role in glucose metabolism, and hypomagnesaemia is common in diabetes mellitus. However, the relationship between serum magnesium and diabetic retinopathy is poorly understood. AIM: To determine the association between serum magnesium levels and retinopathy in type 2 diabetic patients with normal renal function and to correlate it with severity of retinopathy. METHODS: This cross-sectional observational study was conducted in a semi-urban tertiary-care teaching hospital. Clinicodemographic profile and serum magnesium levels were determined in patients with type 2 diabetes mellitus (DM) with (group 1) and without (group 2) retinopathy. Serum magnesium levels were correlated with the presence and severity of retinopathy. RESULTS: Of 104 type 2 DM patients, 50 had retinopathy. Younger age, longer duration of disease and poorer glycaemic control (p < 0.05) were found to be associated with retinopathy. The mean serum magnesium levels in patients with retinopathy and those without retinopathy were 1.63 ± 0.30 mg/dL and 1.76 ± 0.22 mg/dL, respectively (p = 0.029). Reduced serum magnesium was associated with elevated fasting sugars (p = 0.019) and female gender (p = 0.037). On comparative analysis of patients with sight-threatening diabetic retinopathy (STDR), non-STDR and no retinopathy by ANOVA test, patients with STDR had significantly lower serum magnesium (1.55 ± 0.33 mg/dL) (p = 0.031). CONCLUSION: Serum magnesium levels were lower in patients with diabetic retinopathy. Patients with STDR had lower serum magnesium compared with those without STDR. SUMMARY: Serum magnesium, studied extensively for its role in glucose metabolism, was found to be lower in patients with diabetic retinopathy compared with those without retinopathy. Sight-threatening diabetic retinopathy had significantly lower levels of serum magnesium.

Diurnal variation of central corneal thickness and intraocular pressure in eyes with pseudoexfoliation.

Purpose: Pseudoexfoliation syndrome (PXS) is an age related microfibrillopathy characterized by deposition of whitish flaky material over various ocular tissues. PXS eyes are known to have thinner corneas and thus can lead to an underestimation in intraocular pressure measurement. The purpose of this study was to find if there is any variation in central corneal thickness and intraocular pressure in PXS eyes and if there was any relationship between them. Methods: A prospective observational study was done on 141 eyes of 85 patients with PXS without glaucoma between November 2015 to April 2017 in the department of Ophthalmology in a tertiary hospital. CCT and IOP were measured by a handheld ultrasonic pachymeter (DGH Technology INC. Pachette 2, USA) and Goldmann applanation tonometer respectively at 4 different times during office hours. Results: A significant reduction of about 10 µm in mean CCT and 1.4 mmHg in mean IOP was noted over the 4 sessions which was statistically significant (P < 0.001). A significant correlation exists between IOP and CCT in PXS eyes at all times during the day (P < 0.001). Conclusion: The CCT measurements show significant thinning throughout the day, similar drop in IOP was also noted. Our study shows that there is a significant correlation between diurnal variation of CCT and IOP. Hence, it is prudent to measure CCT along with IOP at all times.

Microperimetry - A New Tool for Assessing Retinal Sensitivity in Macular Diseases.

INTRODUCTION: Macular disease is the leading cause of low vision in the Western world. Drusen and pigmentary irregularities are common among the rural Northern Indian population. The disease process leads to loss of central vision, metamorphopsia, macropsia or micropsia and colour vision defect. AIM: To study the retinal sensitivity changes in macular diseases using microperimetry. MATERIALS AND METHODS: It was an observational study, conducted in the Department of Ophthalmology at a rural tertiary care hospital. This study was started from December 2014 until June 2016, in all patients with macular disease above the age of 20 years attending the outpatient department. Microperimetry was done for 84 eyes of 52 patients with macular disease. Mean retinal Sensitivity (MS) and fixation stability was evaluated. The statistical analysis of mean retinal sensitivity, central 2° and 4° fixation was done by calculating the mean and standard deviation using 95% confidence interval. RESULTS: The range of age was between 20-81 years. Majority were 32 males (62%) and 20 females (38%). Out of the 84 eyes studied, majority of the macular disease were Age-Related Macular Degeneration (AMD) (50%). Rest 50% were other macular diseases. The mean retinal sensitivity (dB) shown by microperimetry was 10.83 in AMD, 9.12 in Cystoid Macular Oedema (CME), 10.34 in Epiretinal Membrane (ERM), 10.74 in Pigment Epithelial Detachment (PED), 8.96 in Central Serous Chorioretinopathy (CSCR), 6.43 in macular dystrophy, 7.15 in Lamellar Hole (LMH), 9.8 in Pseudomacular Hole (PMH), 3 in geographic atrophy, 11.1 in macular telangiectasia, 5.6 in Berlin oedema, 12.3 in macular scar and 15.2 in haemorrhage in macula. The study showed 64% of the eyes had stable 2° central fixation, 35% had relatively unstable fixation and 1% had unstable fixation. No significant correlation between retinal sensitivity and retinal thickness in AMD was found. CONCLUSION: This study shows that microperimetry can be a useful tool for objective evaluation of macular function and progression of the disease.

Comparative evaluation of applanation and indentation tonometers in a community ophthalmology setting in Southern India.

PURPOSE: Measurement of intraocular pressure (IOP) is one of the basic investigations in a general ophthalmic workup. In this study, we attempt to determine the agreement in the measurement of IOP obtained by Perkin's applanation tonometer, noncontact tonometer and Schiotz indentation tonometer in patients attending general ophthalmology OPD in a tertiary care centre in South India and its use in a community ophthalmology setting. METHODS: A cross-sectional analytical study in which IOP was measured in patients using the three tonometers. Central corneal thickness (CCT) was measured using Ultrasonic pachymetry. Bland Altman analysis was done to evaluate the agreement between instruments. RESULTS: 800 eyes of 400 patients were included in the study. By Bland Altman method, Schiotz indentation tonometer was found to have better correlation to IOP obtained by Perkin's applanation tonometer. Schiotz indentation tonometer was found to be most accurate when CCT was in the range of 501-550 µm and noncontact tonometer was found to be least accurate when CCT was greater than 600 microns. On comparing correlation at different age groups, both the methods had better correlation at <40 years age group. CONCLUSION: Both the tonometers showed a significant correlation with the gold standard technique (Perkin's applanation tonometer) over a range of IOP and CCT with the Schiotz tonometer better than the NCT. This study proves that Schiotz tonometer can be recommended as a reliable screening tool in community outreach ophthalmology services. The twin advantages of portability and availability make the Schiotz tonometer a popular choice among ophthalmology trainees and optometrists in a developing country like India.

Role of Optical Coherence Tomography in Assessing Anterior Chamber Angles.

INTRODUCTION: Gonioscopy is the gold standard in assessing anterior chamber angles. However, interobserver variations are common and there is a need for reliable objective method of assessment. AIM: To compare the anterior chamber angle by gonioscopy and Spectral Domain Optical Coherence Tomography (SD-OCT) in individuals with shallow anterior chamber. MATERIALS AND METHODS: This comparative observational study was conducted in a rural tertiary multi-speciality teaching hospital. A total of 101 eyes of 54 patients with shallow anterior chamber on slit lamp evaluation were included. Anterior chamber angle was graded by gonioscopy using the shaffer grading system. Angles were also assessed by SD-OCT with Trabecular Iris Angle (TIA) and Angle Opening Distance (AOD). Chi-square test, sensitivity, specificity, positive and negative predictive value to find correlation between OCT parameters and gonioscopy grading. RESULTS: Females represented 72.7%. The mean age was 53.93 ±8.24 years and mean anterior chamber depth was 2.47 ± 0.152 mm. Shaffer grade ≤ 2 were identified in 95(94%) superior, 42(41.5%) inferior, 65(64.3%) nasal and 57(56.4%) temporal quadrants. Cut-off values of TIA ≤ 22° and AOD ≤ 290 µm were taken as narrow angles on SD-OCT. TIA of ≤ 22° were found in 88(92.6%) nasal and 87(87%) temporal angles. AOD of ≤ 290 µm was found in 73(76.8%) nasal and 83(83%) temporal quadrants. Sensitivity in detecting narrow angles was 90.7% and 82.2% for TIA and AOD, while specificity was 11.7% and 23.4%, respectively. CONCLUSION: Individuals were found to have narrow angles more with SD-OCT. Sensitivity was high and specificity was low in detecting narrow angles compared to gonioscopy, making it an unreliable tool for screening.