Publications by authors named "Bhim B Rai"
Multifocal functional tests are not routinely performed in diabetic retinopathy (DR) and diabetic macular edema (DME) management. We emphasise their importance and coin the term functional diabetic retinopathy (FDR). We reviewed current guidelines on management of DR/DME, and literature on diabetic retinal neurodegeneration (DRN) and functional deficits in DR/DME.
View Article and Find Full Text PDFPurpose: We conducted this study to determine the pattern and prevalence of retinal vein occlusion (RVO) in Bhutan to inform national health policy as no data has been compiled previously.
Methods: A retrospective cross-sectional survey was conducted over 3 years, including all new RVO cases. For patients with bilateral RVO, one eye was chosen randomly.
Visual field (VF) testing dates back to fifth century B.C. It plays a pivotal role in the diagnosis, management, and prognosis of retinal and neurological diseases.
View Article and Find Full Text PDFPurpose: To compare diagnostic power for different severities of age-related macular degeneration (AMD) of two-dimensional macular pigment optical densities (2D-MPOD) and spatially matched objective perimetry, with standard perimetry and best-corrected visual acuity (BCVA).
Methods: The ObjectiveField Analyser (OFA) provided objective perimetry, and a Heidelberg Spectralis optical coherence tomography (OCT) measured 2D-MPOD in AMD patients, both completed twice over 0.99 ± 0.
It is now clear that retinal neuropathy precedes classical microvascular retinopathy in diabetes. Therefore, tests that underpin useful new endpoints must provide high diagnostic power well before the onset of moderate diabetic retinopathy. Hence, we compare detection methods of early diabetic eye damage.
View Article and Find Full Text PDFPurpose: Retinal function beyond foveal vision is not routinely examined in the clinical screening and management of diabetic retinopathy although growing evidence suggests it may precede structural changes. In this study we compare optical coherence tomography (OCT) based macular structure with function measured objectively with the ObjectiveFIELD Analyzer (OFA), and with Matrix perimetry. We did that longitudinally in Type 2 diabetes (T2D) patients with mild Diabetic Macular Oedema (DMO) with good vision and a similar number of T2D patients without DMO, to evaluate changes in retinal function more peripherally over the natural course of retinopathy.
View Article and Find Full Text PDFPurpose: Ocular vascular diseases are common causes of visual impairment and blindness, for which anti-vascular endothelial growth factor (anti-VEGF) is the first-line therapy. Current study describes the profile of patients receiving intravitreal anti-VEGF injections (IVI), and gender variation in Bhutan. The study was designed to inform national health policy.
View Article and Find Full Text PDFPurpose: To determine the prevalence and severity of diabetic retinopathy (DR) at first presentation among diabetic patients attending national vitreoretinal (VR) services in Bhutan STUDY DESIGN: Retrospective cross-sectional study METHODS: We included all diabetic patients in Bhutan who presented for retinal evaluation for the first time over a 3-year period (2013-2016). Data including demography, clinical details, diagnostic tests, and clinical staging of DR were analyzed.
Results: A total of 843 diabetic patients, aged 57.
Background: Visual art can enhance wellbeing and quality-of-life; however, the experience of visual art for people with mild-to-moderate vision loss has not been examined.
Methods: Eight participants (6 females, 2 males; Mean age = 81 years, SD = 7.9, range 70-91 years; 4 with mild vision loss and 4 with moderate vision loss based on binocular visual acuity) completed a mixed-methods study comprising: a semi-structured interview on visual art experience; an eye examination; and questionnaires about visual functioning and quality-of-life.
Purpose: To inform national health policy, we quantified the pattern of neuro-ophthalmological disorders (NODs) presenting to the national vitreoretinal clinics in Bhutan.
Study Design: Retrospective cross-sectional study.
Methods: We reviewed all new NODs patients over three years.
Purpose: To study the power of an 80-second multifocal pupillographic objective perimetry (mfPOP) test tailored to the ETDRS grid to diagnose age-related macular degeneration (AMD) by Age-Related Eye Disease Study (AREDS) severity grade.
Design: Evaluation of a diagnostic technology.
Methods: We compared diagnostic power of acuity, ETDRS grid retinal thickness data, new 80-second M18 mfPOP test, and two wider-field 6-minute mfPOP tests (Macular-P131, Widefield-P129).
Objective: Previous work on temporally sparse multifocal methods suggests that the results are correlated with disability and progression in people with multiple sclerosis (PwMS). Here, we assess the diagnostic power of three cortically mediated sparse multifocal pupillographic objective perimetry (mfPOP) methods that quantified response-delay and light-sensitivity at up to 44 regions of both visual fields concurrently.
Methods: One high-spatial-resolution mfPOP method, P129, and two rapid medium-resolution methods, W12 and W20, were tested on 44 PwMS and controls.
Background: Medical services are still developing in Bhutan. There is no published national report on age-related macular degeneration (AMD). We therefore aim to determine the demographic characteristics and severity of AMD at first presentation among Bhutanese patients attending their recently inaugurated vitreoretinal (VR) clinics over a 3-year national survey, and to inform national health policy to develop suitable health program to prevent AMD-related blindness and visual impairment.
View Article and Find Full Text PDFPurpose: The purpose of this study was to compare central versus peripheral retinal sensitivities and delays in neovascular age-related macular degeneration (nAMD) using US Food and Drug Administration (FDA)-cleared multifocal pupillographic objective perimetry (mfPOP).
Methods: We recruited 18 patients with nAMD and commenced Pro re nata intravitreal anti- vascular endothelial growth factor (VEGF) injection. We compared macular (±15 degrees) and wide-field (±30 degrees) mfPOP variants.
Purpose: To compare per-region macular sensitivity and delay from objective perimetry with Matrix perimetry and retinal thickness in mild diabetic macular edema (DMO).
Methods: Thirty-three patients with type 2 diabetes (T2D) aged 59.2 ± 10.
Purpose: Patients with advanced age-related macular degeneration (AMD) may have preserved visual function despite significant retinal structural changes. We aimed to evaluate the relationships among retinal thickness, macular sensitivity, and visual acuity (VA) in advanced AMD.
Methods: We examined 43 eyes of 22 patients with advanced AMD (ages 66-93 years), prospectively recruited from the Canberra Hospital Ophthalmology Department.
Background: We conducted this study to report on the indications and types of retinal laser therapy (RLT) performed in Bhutan, knowing which is critical for proper planning and successful delivery of the services.
Methods: We reviewed the laser registers maintained in the laser rooms and vitreoretinal (VR) operating theatres (including paediatric cases managed under anaesthesia) over three years at the national and the two regional referral hospitals (RRHs). Intraoperative laser treatments (endolaser) were excluded.
Rural-urban differences in myopia prevalence among myopes presenting to Bhutanese retinal clinical services: a 3-year national study.
Graefes Arch Clin Exp Ophthalmol
March 2021
Purpose: To determine the prevalence and demographic characteristics of myopia among patients presenting to the national vitreo-retinal (VR) services in Bhutan.
Methods: The records of the VR clinic at the apex national referral centre, providing the only VR services in the country, were reviewed to identify all new myopia patients over three years. Thus, we surveyed all referrals nationally.
Background: Knowing the pattern and presentation of the diseases is critical for management strategies. To inform eye-care policy we quantified the pattern of vitreo-retinal (VR) diseases presenting at the national referral hospital in Bhutan.
Methods: We reviewed all new patients over three years from the retinal clinic of the Jigme Dorji Wangchuck National Referral Hospital.
Purpose: We examined patients presenting in a tertiary eye hospital in Nepal, focusing on information relevant to screening and management programs for vitreo-retinal (VR) disease.
Design: Retrospective, cross-sectional study.
Methods: We reviewed all patients presenting for the first time to the VR-clinic over 1 year.
Recovery dynamics of multifocal pupillographic objective perimetry from tropicamide dilation.
Graefes Arch Clin Exp Ophthalmol
January 2020
Purpose: To study the pupillary system by combining mydriasis and multifocal pupillographic objective perimetry (mfPOP). In particular, we explored how the dynamics of recovery differ for concurrently measured direct and consensual sensitivity, response delay, and signal-to-noise ratios (SNRs) for binocular mydriasis.
Methods: We recruited 26 normal participants, all with brown irides.
The magnitude and consequences of unrecorded alcohol consumption, defined as home brewed or clandestinely produced illicit liquor or surrogate alcoholic beverage has been little investigated in India. A significant portion of all alcohol consumed globally is unrecorded, therefore these consumers constitute a significant population. Sikkim, a province in Northeast India, lies in the foothills of the Himalayas.
View Article and Find Full Text PDFAim: To conduct a rapid assessment of avoidable blindness survey in Bhutan to obtain estimates of blindness, visual impairment, and cataract surgical coverage, outcomes and barriers among persons ≥50 years old.
Methods: A total of 82 clusters of 50 people ≥50 years were selected using probability proportionate to size sampling. Eligible participants were selected from households using compact segment sampling, and underwent ophthalmic examination for visual acuity, followed by penlight and direct ophthalmoscopy.