Mean Amplitude of Diurnal Variation of Sub-Foveal Choroidal Thickness among Adults with Healthy Eyes Visiting Outpatient Department of a Tertiary Eye Care Centre.

Introduction: The choroid, particularly the choroidal vasculature, plays an important role in the pathophysiology of various ocular diseases. Diurnal variation in the thickness of the choroid has been reported in previous studies. This study aimed to find the mean amplitude of diurnal variation of sub-foveal choroidal thickness among adults with healthy eyes visiting the outpatient Department of a tertiary eye care centre. Methods: A descriptive cross-sectional study was conducted among adults with healthy eyes presenting to the outpatient Department of a tertiary eye care centre from 1 February 2023 to 3 June 2023 after obtaining ethical approval from the Institutional Review Committee. After a comprehensive medical eye examination, sub-foveal choroidal thickness measurement was performed using enhanced depth imaging optical coherence tomography at the baseline and subsequent interval afterwards. A convenience sampling method was used. The point estimate was calculated at a 95% Confidence Interval. Results: Among 60 eyes, the mean amplitude of the diurnal variation of subfoveal choroidal thickness was 35.16±14.08 microns (31.59-38.72, 95% Confidence Interval). The mean amplitude for the right eye was 36.30±14.08 microns, and for the left eye, it was 34.23±14.08 microns. Conclusions: The amplitude of diurnal variation of subfoveal choroidal thickness from this study was found to be similar to other studies done in international settings. Keywords: choroid; circadian rhythm; cross-sectional study; Ophthalmology.

Positive Microbiological Culture among Patients with Infective Keratitis Visiting the Cornea Unit of a Tertiary Care Centre.

Introduction: Keratitis is the infection and inflammation of the cornea. Microbial keratitis is a potentially sight-threatening corneal condition. The aim of this study was to find out the prevalence of positive microbiological culture among patients with infective keratitis visiting the Cornea Unit of a tertiary care centre. Methods: A descriptive cross-sectional study was conducted among patients with a clinical diagnosis of infective keratitis presenting to the Cornea Unit of a tertiary eye care centre from 16 October 2020 to 16 March 2021 after obtaining ethical approval from the Ethical Review Board. After slit-lamp examination, corneal scrapings were performed under aseptic conditions which were subjected to Gram stain, potassium hydroxide preparation and culture for bacterial and fungal pathogens. A convenience sampling method was used. The point estimate was calculated at a 95% Confidence Interval. Results: Among 428 patients, 337 (78.73%) (73.24-84.33, 95% Confidence Interval) had a positive microbiological culture. A total of 213 (49.76%) of enrolled samples had a prior history of ocular trauma. Aspergillus species 68 (20.17%) and Streptococcus species 33 (9.79%) were the most common organisms isolated from fungal and bacterial corneal ulcers respectively. Conclusions: The prevalence of positive microbiological culture among patients with infective keratitis from this study is similar to the pattern reported from similar settings. Keywords: corneal ulcer; keratitis; prevalence.

Normative Vascular Features on OCT Angiography in Healthy Nepalese Eyes.

Purpose: To establish normative data on morphological characteristics and quantitative parameters of Foveal Avascular Zone (FAZ) as well as their systemic and ocular associations using OCT angiography (OCT-A) in healthy Nepalese subjects. Patients and Methods: A prospective, cross-sectional, population-based study recruiting 210 healthy samples (420 eyes) aged 10 to 70 years was conducted. All the samples underwent detailed comprehensive eye examination followed by Optical Coherence Tomography Angiography (OCTA) and Enhanced Depth Imaging performed in each eye using Spectral Domain Optical Coherence Tomography. Foveal avascular zone area and vessel density in superficial and deep retinal plexus and Sub foveal Choroidal Thickness (SFCT) were evaluated. Ocular and systemic associations of these parameters were also studied in a multivariate analysis utilizing linear regression. Results: The mean superficial and deep FAZ area was 459.96 ± 124.75 µm (95% confidence interval [CI], 443.08-476.83) and 589.0 ± 141.39 µm (95% CL, 570.77-609.02), respectively. The vessel density in superficial capillary plexus was 54.03 ± 9.34% (95% CL, 53.98-54.11) while the vessel density in deep capillary plexus was 25.91 ± 38% (95% CL, 25.85-25.96). The mean SFCT in this study was 308.89 ± 68.87µm (95% CL, 299.64-318.14 µm). There was no statistically significant inter-eye difference in the FAZ parameters. Myopic eyes had smaller FAZ, lesser vessel density and thinner SFCT. Association was observed between superficial FAZ area and systolic blood pressure, and deep FAZ area and diastolic blood pressure. Conclusion: This study reports the normative data on FAZ parameters in healthy Nepalese subjects which can serve as references for interpreting these parameters in different retinal-choroidal diseases.

Blindness among Patients with Type II Diabetes Mellitus Presenting to the Outpatient Department of Ophthalmology of a Tertiary Care Centre: A Descriptive Cross-sectional Study.

Introduction: Diabetic retinopathy is a major microvascular complication of diabetes, and may progress to sight-threatening stages causing blindness with a consequent decrease in their quality of life. This study aimed to find out the prevalence of blindness among patients with type II diabetes mellitus attending the Outpatient Department of Ophthalmology of a tertiary care hospital. Methods: A descriptive cross-sectional study was conducted among patients with type II diabetes mellitus presenting to the Outpatient Department of Ophthalmology of a tertiary care centre from 2 August 2021 to 30 June 2022 after receiving ethical approval from the Institutional Review Committee (Reference number: 74/2021). Diabetic patients underwent detailed eye examination including vision, slit lamp biomicroscopy examination, and fundus evaluation with full pupil dilation. Convenience sampling method was used. Point estimate and 95% Confidence Interval were calculated. Results: Among 449 type II diabetic patients, blindness was seen in 17 (3.79%) (2.02-5.56, 95% Confidence Interval) patients. Among them, 1 (5.88%) had severe non-proliferative diabetic retinopathy, 3 (17.65%) had proliferative diabetic retinopathy and 8 (47.06%) had severe diabetic macular oedema. Conclusions:  The prevalence of blindness among patients with type II diabetes mellitus was less than in other studies conducted in similar settings. Screening and timely management of diabetic retinopathy could reduce the prevalence of blindness due to diabetic retinopathy. Keywords: blindness; diabetic retinopathy; prevalence.

Review on current concepts of myopia and its control strategies.

Myopia poses a significant burden on the healthcare system, economy and quality of life. It is an emerging global public health challenge and requires interventions to delay or stop onset and progression. With changing times and evidence, the concepts of myopia are changing along with the treatment and control strategies. Behavioural modifications including increased outdoors time and reduced near work, optical and pharmaceutical management options are reviewed. This paper presents a current overview on the concepts of myopia, and is expected to summarize updates on myopia control methods.