Macular Pigment Assessment in Indian Population Using Degree of Polarization Threshold: Impact of Diet on Macular Pigment Density.

Purpose: To determine macular pigment (MP) density scores in healthy Indians and examine correlations with demographic and lifestyle variables. Methods: We observed 484 Indians without an ocular pathology. Body mass index (BMI) and self-reported lifestyle factors (sunglasses usage, physical activity, and smoking) were noted. MP density was assessed as the threshold of perception of the shadow of their macular pigments on their retina using a new MP assessment tool (MP-eye). Lutein and zeaxanthin intake was assessed using a prevalidated questionnaire regionally designed for the Indian diet. Clusters of participants were created for statistical analysis based on MP-eye scores secondarily to detect any relevant effects in very low, low, medium, and high ranges of MPs. Results: Data analyzed included 235 males and 249 females with mean age of 36.1 ± 12.9 years (range, 14-72). The median MP-eye score was 6 (range, 0-10, with 10 being high). Most were non-smokers (413, 85.3%) and did not use sunglasses (438, 90.5%), and 314 (64.9%) had low physical activity. Diabetes was present in 62 participants (12.8%) and hypertension in 53 (10.9%). Advancing age (r = -0.209; P < 0.000) and BMI (r = -0.094; P = 0.038) had weak negative correlation with MP-eye scores. Hypertension was less prevalent (7/88) in the cluster with the highest median MP-eye score (P = 0.033). Dietary intake of MPs and other lifestyle factors did not correlate significantly with MP-eye score overall or when analyzed in clusters. Conclusions: MP-eye scores of an Indian population were normally distributed. Higher age, high BMI, and presence of hypertension were weakly associated with lower MP-eye scores. The impact of diet on MPs requires further evaluation. Translational Relevance: This normative regional database enables risk stratification of macular degeneration.

Real-world experience of full-thickness traumatic macular hole among young patients.

OBJECTIVE: To describe the demographics, clinical, and imaging characteristics, and visual outcomes in young patients with full-thickness traumatic macular hole (TMH). METHODS: This retrospective hospital-based study included patients with full-thickness TMH who presented between August 2010 and June 2021. Demographic data, clinical findings, and imaging characteristics were extracted from an electronic medical record system. Regression analyses were performed to determine significant associations among variables and to identify predictors of visual outcomes. RESULTS: 144 (0.005%) patients among 2,834,616 were diagnosed with Full thickness TMH. The majority of them were male (89.58%; odds ratio [OR] = 6.71) and the holes were unilateral. The mean age at presentation was 23.37 ± 8.19 years. Ball were the most common cause of injuries (22.22%), followed by stick (14.58%) and firecracker (12.50%). The mean LogMAR visual acuity (VA) at presentation was 1.18 ± 0.72, with 25.69% of eyes having VA < 20/400. The mean minimum hole diameter was 619.34 ± 336.16 µm. Sub-retinal fluid was present in 44.44%, followed by intraretinal fluid in 34.03% of eyes. Macular holes closed after vitrectomy in 66.67% of eyes, with mean final VA of 1.07 ± 0.85. Baseline VA was a strong predictor of final VA (R2 = 0.677; p = 0.000168). CONCLUSION: Traumatic macular hole is a unilateral condition with significant visual impairment that is mainly seen in males during the third decade of life. Surgery is successful in most cases but improvements in VA are modest.

Outcomes of vitreoretinal surgery in eyes with retinitis pigmentosa without retinal detachment.

PURPOSE: Outcomes of retinal detachment (RD) have been discussed in detail in many reports of patients with retinitis pigmentosa (RP). This study tries to understand the outcomes of vitreoretinal (VR) surgery for indications other than RD in the eyes with RP. METHODS: This is a retrospective study that includes clinical data from January 2013 to December 2021. Patients with RP who were treated with a VR surgical intervention were included in the study. The primary outcome of the study was to assess the changes in best-corrected visual acuity. RESULTS: Forty-four eyes of 40 patients with RP were included in the study. Nearly half of the eyes (43%, 19/44) presented from 1 month to 1 year after the onset of diminished vision, with or without floaters. The mean ± standard deviation (SD) best-corrected visual acuity (BCVA) at presentation was 1.30 ± 0.79 logMAR (20/400 ± 20/125). The major surgical indications were vitreous opacities (43.2%, 19/44) and subluxated/dislocated cataractous lenses (25%, 11/44). The median follow-up duration was 8 months (interquartile range (IQR): 1.5-27). Approximately 77% (34/44) of the eyes had improvement in vision. The mean postoperative BCVA at the last follow-up was 0.95 ± 0.73 logMAR (p-value: 0.03). CONCLUSIONS: Most eyes with RP recovered well after VR surgical interventions, with short-term improvements in visual acuity. It may be crucial to address the vitreous opacities and membranes as they hinder the residual central island of vision in RP. However, appropriate counselling is required regarding the progressive nature of retinal neuronal degeneration.

Clinical profile and demographic distribution of Stargardt disease phenotypes: An Electronic medical record-driven big data analytics from a multitier eye care network.

Purpose: To describe the demographics and clinical profile of Stargardt disease in patients presenting a multitier ophthalmology hospital network in India. Methods: This cross-sectional hospital-based study was performed among 2,834,616 new patients presenting between August 2010 and June 2021 in our network. Patients with a clinical diagnosis of Stargardt disease in at least one eye were included as cases. The data were collected using an electronic medical record system. Results: Overall, 1,934 (0.069%) patients were diagnosed with Stargardt disease. Most of the patients were male (63.14%). The most common age group at presentation was during the second decade of life, with 626 (31.87%) patients. The overall prevalence was higher in patients from a higher socioeconomic status (0.077%), in those presenting from the urban geography (0.079%), and in students (0.197%). Systemic history of hypertension was seen in 56 (2.85%) patients, while diabetes mellitus was seen in (2.49%) patients. Of the 3,917 eyes, 1,910 (48.76%) eyes had moderate visual impairment (>20/70-20/200) followed by severe visual impairment (>20/200 to 20/400) in 646 (16.49%) eyes. The most commonly associated retinal signs were retinal flecks in 1,260 (32.17%) eyes, followed by RPE changes in 945 (24.13%) eyes. The most documented investigations were autofluorescence (39.85%), followed by optical coherence tomography (23.90). Cataract surgery was the commonest performed surgical intervention in (0.66%) eyes, followed by intravitreal injection in 4 (0.10%) eyes. The family history of parent consanguinity marriage was reported by 212 (10.79%) patients. Conclusion: Stargardt disease was seen more commonly in males presenting during the second decade of life. It is predominantly a bilateral disease, with the majority of the eyes having moderate visual impairment.

Intraocular Microbiome in Diabetes and Diabetic Retinopathy: A Pilot Study.

INTRODUCTION: The objective of this study was to compare the microbiome in the aqueous humour and gut of people with diabetes mellitus (DM) with and without diabetic retinopathy (DR). METHODS: This was a prospective controlled study. The study included 17 people undergoing intraocular surgery in their naïve eyes. Stool samples were obtained in the perioperative period; aqueous humour samples of sufficient quantity were obtained in 12 people during intraocular surgery. Dietary information was obtained using a previously validated questionnaire. The gut and aqueous humour samples were assessed for microbiome using 16S rRNA gene sequencing coupled with QIIME and R software. RESULTS: Aqueous humour was analysed in 12 people: 4 each healthy controls, people with DM, and people with DR. There were minor differences at the phyla levels, but the aqueous humour microbiomes of healthy controls, DM, and DR formed three distinct clusters on heat map analysis with discriminatory genera. This genera-level clustering was more apparent for the intraocular than the gut microbiome. In people with DM and DR, we identified genera unique to the eye or the gut. There was a consistent reduction in the abundance of anti-inflammatory bacteria in people with DR than DM. CONCLUSIONS: There is a difference in intraocular and gut microbiome regardless of disease or health. Our preliminary findings indicate distinctive features of the intraocular microbiome in people with DR compared with those without it. While this distinctiveness appears more evident in aqueous humour than in the gut, it needs further confirmation with larger studies.

Observations on Six Rare Cases of Chorioretinitis Sclopetaria.

INTRODUCTION: Chorioretinitis sclopetaria (CS) is a rare consequence of ocular injury. Its association with open globe injury (OGI) and retinal detachment (RD) is controversial. This study evaluates patterns of chorioretinitis sclopetaria and its association with open globe injury and retinal detachment. CASE: This is an electronic review of records of a tertiary eye care institute of south India with descriptive analysis of six cases. Cases where fundus findings of chorioretinitis sclopetaria were available were included. Information regarding mode of injury, visual outcomes, follow up and causes of poor visual outcomes were obtained. Presence of open globe injury, retinal detachment, vitreous hemorrhage (VH) and orbital foreign body (FB) was also noted. Ultrasound scans of the eyeball were reviewed for presence of signs of chorioretinitis sclopetaria. OBSERVATIONS: All the injured patients were male (age range 23-52 years). Bullet and blast injuries were the modes of injury. The duration since injury to the last follow up ranged from 0.25 to 12 years. The final visual acuity was <20/200 in 3/6 cases. Open globe injury and retinal detachment was noted in one case each, while 3/5 cases had orbital foreign body. Extensive facial and neuro-surgery were required in 2/6 cases. Sonography showed signs of chorioretinitis sclopetaria in 2/3 cases where scans were available for review. CONCLUSIONS: Though manifestations of chorioretinitis sclopetaria evolve with time with visual improvement, final visual acuity is generally poor. Cases of chorioretinitis sclopetaria may have accompanying retinal detachment or open globe injury. Sonography should be evaluated with a high degree of suspicion for chorioretinitis sclopetaria in typical cases.

Optical Coherence Tomography Features of Ocular Cysticercosis: A Review of Literature With Observer Variation.

Ocular cysticercosis is a sparsely reported condition, requiring urgent management. The gold standard for diagnosis is an in toto extraction of the cyst with subsequent histopathology. The procedure can be demanding in contrast to the frequently adopted practice of in vivo cyst lysis. The latter, however, obviates a conventional biopsy. We reviewed published optical coherence tomography (OCT) images of ocular cysticercosis for their suitability to surrogate a conventional biopsy and identified commonly reported features. We also used triple masking and ascertained the observer agreement on identification of these features. We found that the features of the parasite are much more clearly discernible as compared with features of the involved ocular tissue itself. The hyperreflective cyst wall and scolex and the hyporeflective cyst cavity had the highest frequency and observer agreement among all the analyzed features, suggesting their use for diagnosis. We could match many of the OCT features with the previously reported histopathological findings, supporting the role of OCT as a diagnostic adjunct and a substitute for conventional biopsy. Conversely, features of the ocular tissue could be judged poorly with low observer agreement, suggesting poor prognostic ability of OCT. [Ophthalmic Surg Lasers Imaging Retina 2022;53:446-454.].

Unconventional avenues to decelerate diabetic retinopathy.

Diabetic retinopathy (DR) is an important microvascular complication of diabetes mellitus (DM), causing significant visual impairment worldwide. Current gold standards for retarding the progress of DR include blood sugar control and regular fundus screening. Despite these measures, the incidence and prevalence of DR and vision-threatening DR remain high. Given its slowly progressive course and long latent period, opportunities to contain or slow DR before it threatens vision must be explored. This narrative review assesses the recently described unconventional strategies to retard DR progression. These include gut-ocular flow, gene therapy, mitochondrial dysfunction-oxidative stress, stem cell therapeutics, neurodegeneration, anti-inflammatory treatments, lifestyle modification, and usage of phytochemicals. These therapies impact DR directly, while some of them also influence DM control. Most of these strategies are currently in the preclinical stage, and clinical evidence remains low. Nevertheless, our review suggests that these approaches have the potential for human use to prevent the progression of DR.

Jet stream related iatrogenic retinal breaks during vitreo-retinal surgery.

PURPOSE: To evaluate the causes of jet stream injury (JSI)-related iatrogenic retinal breaks (IRBs) during vitreoretinal surgery (VRS). METHODS: The precise surgical environment, which includes the indication and type of surgical procedure, retina status, details of instrumentation and fluidic parameters, and characteristics of the jet responsible for the IRB, was noted from case records. The nature of IRB and its healing and impact on anatomical and visual outcomes were analyzed. RESULTS: Five eyes of five patients with complete documentation of both the JSI and the IRB were included. Two cases were operated for macular hole, and one each for vitreous hemorrhage, retinal detachment, and endophthalmitis. One case had infusion-fluid-related JSI, while four developed it because of injection of surgical adjuncts (drugs, PFCL, and dye). JSI developed in two cases when the vitreous cavity was filled with fluid, while it was air-filled in three cases. In four cases, the fluid migrated into subretinal space, necessitating further maneuvers following which the breaks healed, but were directly responsible for vision loss in two cases. CONCLUSION: JSI related IRBs are rare but may be directly responsible for vision loss if they impact the macula. The balance between jet stream velocity, its distance from the retinal surface, the intervening media (vitreous cavity), and retinal health play an important role. It can occur because of both infusion as well as injection jets. Precautions must be taken in cases vulnerable to complications with suggested modifications in the surgical technique.

Correlation of vitreous chamber depth with ocular biometry in high axial myopia.

PURPOSE: The proportion of axial length (AL) occupied by vitreous chamber depth (VCD), or VCD:AL, consistently correlates to ocular biometry in the general population. Relation of VCD:AL to ocular biometry in high myopia is not known. The purpose of this study is to evaluate the relation of VCD and VCD:AL to ocular biometry of highly myopic eyes. METHODS: This was a cross-sectional retrospective study of records of 214 myopic eyes (<-1 D SE, aged 20-40 years) attending the refractive surgery services. High axial myopia was defined as AL >26.5 mm. Eyes with posterior staphyloma and myopic maculopathy were excluded. Records were assessed for measurements of AL, central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT), white to white diameter (WTW), and vitreous chamber depth (VCD). Groups were formed based on increasing AL, while the sum of CCT, ACD, and LT was recorded as anterior segment depth (AS). The main outcome measure was the correlation of VCD and VCD:AL to ocular biometry. A comparison was also performed based on of degree of axial myopia. RESULTS: Mean age of the patients was 27.0 ± 5.2 years. VCD showed a very strong correlation with AL (R = 0.98, P < 0.001) but did not correlate to any anterior parameter. VCD:AL showed moderate negative relation with AS (R = -0.43, P < 0.001) and ACD (R = -0.3, P < 0.001), while it had a weakly negative relation with LT (R = -0.18, P = 0.006). VCD:AL showed strong negative relation (R > ~0.7) with AS in all individual groups of AL. Among anterior parameters, WTW showed the most consistent relation with ocular biometry. CONCLUSION: VCD:AL is a better correlate of ocular biometry in high myopia as compared to VCD. However, the correlation is weaker than that noted by previous studies done on the general population. Longitudinal studies of VCD:AL in the younger age group is recommended.

Development of Diabetic retinopathy screening guidelines in South-East Asia region using the context, challenges, and future technology.

OBJECTIVE: To formulate guidelines for screening of diabetic retinopathy (DR) for the World Health Organization (WHO) South-East Asia Region (SEAR) aligned with the current infrastructure and human resources for health (HRH). DESIGN: A consultative group discussion of technical experts of the International Agency for the Prevention of Blindness (IAPB) from SEAR. PARTICIPANTS: IAPB country chairs and DR technical experts from SEAR countries. METHODS: Data related to DR in SEAR was collected from published literature on available DM and DR guidelines and the participating experts. The 10 SEAR countries (the Democratic Republic of Korea was not included for lack of sufficient data) were divided into 3 resource levels (low, medium, and high) based on gross national income/per capita, cataract service indicators (cataract surgical rate and cataract surgical service), current infrastructure and available HRH. Two countries each were assigned to low (Myanmar, Timor-Leste) and high resource (India, Thailand) levels, and the remaining 6 countries (Bangladesh, Bhutan, Indonesia, Maldives, Nepal, Sri Lanka) were assigned the medium resource level. The DR care system was divided into 3 levels of care (essential, recommended, and desirable) and 3 levels of service delivery (primary, secondary, and tertiary). MAIN OUTCOME MEASURES: Primary, secondary, and tertiary level guidelines for screening of DR. RESULTS: Nine WHO SEAR countries participated in the formulation of the new country-specific DR screening guidelines. The DR screening recommendations were: advocacy at the community level, visual acuity measurement, and non-mydriatic fundus photography at the primary level, comprehensive eye examination and retinal laser at the secondary level, and intravitreal therapy and vitrectomy at the tertiary level. The systemic care of DM and hypertension are recommended at all levels commiserating with their care capabilities. CONCLUSIONS: The DR guidelines for the SEAR region are the first region-specific and resource-aligned recommendations for comprehensive DR care in each country of the region. In the future, the new technological advances in retinal camera technology, teleophthalmology, and artificial intelligence should be included within the structure of the public DR care system.

Selfie fundus imaging for diabetic retinopathy screening.

BACKGROUND: Regular screening for retinopathy and timely intervention reduces blindness from diabetes by 90%. Screening is currently dependent on the interpretation of images captured by trained technicians. Inherent barriers of accessibility and affordability with this approach impede widespread success of retinopathy screening programs. Herein, we report our observations on the potential of a novel approach, Selfie Fundus Imaging (SFI), to enhance diabetic retinopathy screening. METHODS: The study was undertaken over a two-month period during COVID 19 lockdown. 60 diabetic patients participated in the study. Retinal images were captured using three different approaches, handheld smartphone-based photographs captured by patients themselves after a short video-assisted training session (SFI group), and smartphone-based photographs captured by a trained technician and photographs taken on desktop conventional digital fundus camera (Gold standard). Sensitivity and kappa statistics was determined for retinopathy and macular oedema grading. FINDINGS: Mean age of the study participants was 52.4 years ± 9.8 years and 78% were men. Of 120 images captured using SFI, 90% were centred-gradable, 8% were decentred-gradable and 2% were ungradable. 82% patients captured the image within a minute (majority by 31-45 s). The sensitivity of SFI to detect diabetic retinopathy was 88.39%. Agreement between SFI grading and standard fundus photograph grading was 85.86% with substantial kappa (0.77). For the detection of diabetic macular oedema, the agreement between SFI images and standard images was 93.67, with almost perfect kappa (0.91). CONCLUSION: Fundus images were captured by patients using SFI without major difficulty and were comparable to images taken by trained specialist. With greater penetrance, advances, and availability of mobile photographic technology, we believe that SFI would positively impact the success of diabetic retinopathy screening programs by breaking the barriers of availability, accessibility, and affordability. SFI could ensure continuation of screening schedules for diabetic retinopathy, even in the face a highly contagious pandemic.

Management of a misidentified and misnumbered intraocular glass foreign body with an endoscope in a case of endophthalmitis.

An endoscope is a useful adjunct for the retinal surgeon to overcome haze of a compromised anterior segment. It allows early surgery in trauma and infections which translates to better results. Intraocular glass foreign body is a challenging condition, demanding highly skilled surgical expertise. We present endoscopic removal of an intraocular foreign glass body in a badly traumatised and infected eye. The surgical challenge was accentuated by an imaging misdiagnosis of 'twin metallic foreign bodies'.

Training of nonophthalmologists in diabetic retinopathy screening.

The burden of diabetes mellitus (DM) and diabetic retinopathy (DR) is at alarming proportions in India and around the globe. The number of people with DM in India is estimated to increase to over 134 million by 2045. Screening and early identification of sight-threatening DR are proven ways of reducing DR-related blindness. An ideal DR screening model should include personalized awareness, targeted screening, integrated follow-up reminders, and capacity building. The DR screening technology is slowly shifting from direct examination by an ophthalmologist to remote screening using retinal photographs, including telescreening and automated grading of retinal images using artificial intelligence. The ophthalmologist-to-patient ratio is poor in India, and there is an urban-rural divide. The possibility of screening all people with diabetes by ophthalmologists alone is a remote possibility. It is prudent to use the available nonophthalmologist workforce for DR screening in tandem with the technological advances. Capacity-building efforts are based on the principle of task sharing, which allows for the training of a variety of nonophthalmologists in DR screening techniques and technology. The nonophthalmologist human resources for health include physicians, optometrists, allied ophthalmic personnel, nurses, and pharmacists, among others. A concurrent augmentation of health infrastructure, conducive health policy, improved advocacy, and increased people's participation are necessary requirements for successful DR screening. This perspective looks at the characteristics of various nonophthalmologist DR screening models and their applicability in addressing DR-related blindness in India.

Pachychoroid neovasculopathy: A comparative review on pathology, clinical features, and therapy.

There have been major changes in our understanding of choroidal diseases in the last decade owing to multiple retinal and choroidal imaging related advances. A major conceptual pivot is establishment of pachychoroid and its spectrum of clinical disorders: pachychoroid pigment epitheliopathy, central serous chorioretinopathy, pachychoroid neovasculopathy, polypoidal choroidal vasculopathy/aneurysmal type 1 neovascularization, peripapillary pachychoroid syndrome, and focal choroidal excavation. However, considerable overlaps in manifestations and therapeutics of these disorders make differentiation amongst them difficult. This review is focused on pathogenesis and clinical aspects of pachychoroid neovasculopathy (PNV). Since PNV was defined as a separate entity around 5 years ago, there have been numerous contrasting observations surrounding it. We review and summarize these studies, and also compare PNV with other disorders of the pachychoroid spectrum in detail. There are important differences between etiologies of neovascular age related macular degeneration and PNV. Yet the current treatment strategies for PNV have been extrapolated from the trials for the former. Future research needs to validate this assumption with long-term results.

Recently updated global diabetic retinopathy screening guidelines: commonalities, differences, and future possibilities.

Diabetic retinopathy (DR) is a global health burden. Screening for sight-threatening DR (STDR) is the first cost-effective step to decrease this burden. We analyzed the similarities and variations between the recent country-specific and the International Council of Ophthalmology (ICO) DR guideline to identify gaps and suggest possible solutions for future universal screening. We selected six representative national DR guidelines, one from each World Health Organization region, including Canada (North America), England (Europe), India (South- East Asia), Kenya (Africa), New Zealand (Western Pacific), and American Academy of Ophthalmology Preferred Practice Pattern (used in Latin America and East Mediterranean). We weighed the newer camera and artificial intelligence (AI) technology against the traditional screening methodologies. All guidelines agree that screening for DR and STDR in people with diabetes is currently led by an ophthalmologist; few engage non-ophthalmologists. Significant variations exist in the screening location and referral timelines. Screening with digital fundus photography has largely replaced traditional slit-lamp examination and ophthalmoscopy. The use of mydriatic digital 2-or 4-field fundus photography is the current norm; there is increasing interest in using non-mydriatic fundus cameras. The use of automated DR grading and tele-screening is currently sparse. Country-specific guidelines are necessary to align with national priorities and human resources. International guidelines such as the ICO DR guidelines remain useful in countries where no guidelines exist. Validation studies on AI and tele-screening call for urgent policy decisions to integrate DR screening into universal health coverage to reduce this global public health burden.

Ultra-wide field retinal imaging: A wider clinical perspective.

The peripheral retina is affected in a variety of retinal disorders. Traditional fundus cameras capture only a part of the fundus even when montaging techniques are used. Ultra-wide field imaging enables us to delve into the retinal periphery in greater detail. It not only facilitates assessing color images of the fundus, but also fluorescein angiography, indocyanine green angiography, fundus autofluorescence, and red and green free images. In this review, a literature search using the keywords "ultra-widefield imaging", "widefield imaging", and "peripheral retinal imaging" in English and non-English languages was done and the relevant articles were included. Ultra-wide field imaging has made new observations in the normal population as well as in eyes with retinal disorders including vascular diseases, degenerative diseases, uveitis, age-related macular degeneration, retinal and choroidal tumors and hereditary retinal dystrophies. This review aims to describe the utility of ultra-wide field imaging in various retinal disorders.