Peering into the eye: A comprehensive look at ultrasound biomicroscopy (UBM) and its diagnostic value in anterior segment disorders

Background: Ultrasound biomicroscopy (UBM) is a noninvasive imaging modality that enables in?vivo visualization of the structures of the anterior segment of the eye. Unlike routine ophthalmic diagnostic ultrasound which uses frequencies of 5–10 MHz, UBM utilizes ultrasound frequencies in the range of 50–100 MHz. The high?frequency probes in UBM allows for higher resolution and better visualization of subsurface ocular structures, even in the presence of anatomic or pathological obscuration. UBM has qualitative as well as quantitative applications in various disorders affecting the anterior segment of the eye. Despite its huge importance, many clinicians lack in knowledge about the technique and its clinical usefulness. The current educational video aims to address this gap in knowledge by highlighting the technique and various clinical indications of UBM. Purpose: The purpose of this video is to demonstrate the technique of UBM and showcase its quantitative and qualitative implications and importance through various clinical cases. Synopsis: UBM is an imaging technique that assesses the depth of tissue structures by measuring the time delay of the returning ultrasound signal. This modality is capable of measuring the size of various structures within the eye, such as the cornea, iris, ciliary body, sclera, and the depth of the anterior and posterior chamber. To perform a UBM, a transducer is inserted into a specially designed eye cup filled with distilled water, creating a water bath environment. Axial and longitudinal scans can be performed in a similar fashion as in routine diagnostic B?scan ultrasound. Quantitative indications for UBM depicted in this video include measurements of corneal thickness, depth of the anterior chamber, and the width of the angle. The video also showcases how UBM can aid in the diagnosis and management of various anterior segment disorders like angle?closure glaucoma, plateau iris configuration, secondary glaucoma, and anterior uveitis with complicated cataract. Qualitative indications for UBM highlighted in this video include its role in intermediate uveitis, ocular hypotony, ocular surface tumors, cystic lesions of iris, and identifying the location and type of intraocular foreign bodies in the anterior segment based on the type of artifact seen. Additionally, the video shows the applications of UBM in scleral and episcleral pathologies. Highlights: This video will educate clinicians about the technique of UBM and showcase a bouquet of UBM findings in various case scenarios, helping one to better understand the potential of this modality in clinical practice.

Clinical presentation and treatment outcomes of an algorithmic approach to uveal effusion syndrome

Purpose: To describe the clinical features and treatment outcomes in spontaneous uveal effusion syndrome (UES). Methods: A 10?year retrospective chart review of UES patients from a tertiary eye center was carried out. Optical coherence tomography (OCT), fundus fluorescein angiography, and ultrasound biomicroscopy (UBM) scans were performed. UES was managed based on presenting best?corrected visual acuity (BCVA), symptoms, and fundus findings. Patients with secondary causes of uveal effusion were excluded. Results: Twenty?five eyes of 16 patients were included. Of the 16 patients, 14 (88%) were male and 9 (56%) had bilateral disease. Fifteen of 25 affected eyes had nanophthalmos (axial length (AL) <20.5 mm) and 6 had hyperopia with AL >20.5 mm. The presenting mean distance BCVA was 0.74 ± 0.64 logMAR (mean Snellen: 20/100). Eleven eyes had exudative retinal detachment, and 4 also had exudative choroidal detachment (CD). Choroidal thickness (CT) was increased in 11 eyes on B?scan ultrasonography, and the mean CT was 1.74 ± 0.38 mm. Sub?retinal fluid (SRF) and retinal folds were the most common OCT findings. UBM findings included shallow angles, peripheral CD, and supra?ciliary effusion. A combination of local and systemic corticosteroids was used to successfully treat 12 eyes, 6 needed surgery, and 7 were observed. Partial sclerectomy with anterior chamber maintainer?assisted SRF drainage was the favored surgery. The median period of follow?up was 6.5 months (0.1–76 months), and the mean distance BCVA at the last follow?up was 0.58 ± 0.42 logMAR (mean Snellen: 20/80). Conclusion: UES can be suitably managed both medically and surgically based on clinical presentation

Feasibility study for measuring patients’ visual acuity at home by their caregivers

Purpose: To assess the feasibility of measuring patients’ visual acuity (VA) in their homes by their caregivers. Methods: Patients consulting in a tertiary eye care institute were prospectively enrolled with informed consent. All underwent standard COMPlog distance VA testing. Patients and caregivers were oriented to test distance VA using the Peek Acuity app. The app was installed on the caregiver’s or patient’s smartphone. The patient’s VA was measured by the caregiver in the clinic (baseline value) under supervision. After 1 week, the caregivers recorded the patient’s VA with the Peek Acuity app at their home and reported the value in a telephone consultation. A questionnaire to assess the ease of using the app was administered at both the baseline visit and 1 week later. Results: A total of 100 patients (age group: 13 to 76 years) and 100 caregivers (age group: 17 to 65 years) participated. VA measurements with the Peek Acuity app were comparable with COMPlog (P > 0.1) both during the baseline and after 1?week measurement, regardless of the underlying ocular condition or educational level of the caregivers/patients. Most caregivers (95%) felt the app was easy to use. Conclusion: Though the Peek Acuity app was originally developed for health care workers to be used in field visits, we found that with proper orientation, the layperson can also use it. Such orientation can enable caregivers to effectively measure VA at home. Such a tool would enhance teleophthalmology consultations and can minimize the need for short follow?up visits

Flanged intraocular lens (IOL) implantation with scleral pockets - A modification of flanged IOL technique (E-Flanged IOL) for secondary lens implantation

During pandemic, eye banks worldwide faced drastic reduction of corneal retrieval. Since precut tissues are uncommon in India, the onus is on corneal surgeons to maximize the donor corneal usage. The stumbling block making the stromal part unusable in the graft preparation of the Descemet membrane endothelial Keratoplasty is the stromal window creation to place the orientation mark on the stromal side of the folded graft. To overcome this, we simply marked directly on the folded Descemet graft, after partly stripping it from the donor cornea. Then, we unfolded, punched, and created two grafts after completely stripping it, retaining the Descemet part for the endothelial Keratoplasty and the stromal part for lamellar Keratoplasty. Initially, we used a special F marker, and later we marked an L using just a spatula. This simple technique needing no extra donor tissue or instrumentation maximizes the tissue utility with proper patient selection.

Tele-rehabilitation for persons with vision impairment during COVID-19: Experiences and lessons learned

Purpose: The COVID?19 pandemic imposed challenges to access rehabilitation intervention to individuals with visual impairment, thereby increasing their disability effects. This study explored the viability maintaining the continuum of care through telerehabilitation. Methods: This study is a retrospective analysis of individuals with vision impairment who underwent telerehabilitation at the center of excellence in eye care at Hyderabad, Telangana, India, between April and September 2020. The International Classification of Functioning, Disability and Health framework was followed to provide services such as counseling for mental well?being, information and resources, educational interventions, Assistive Technology programs, therapeutic interventions for children with multiple disabilities, access to digital audio books and rehabilitation helpline. A team of professionals involved in the service care. Phone and what’s app calls were used to facilitate the training. The duration and the number of training sessions were individual need?based with an average of 45 minutes per session and 175 training sessions. Results: Three hundred and fifty individuals and their families benefited. The service include early intervention (n = 129), and low vision care (n = 176) inclusive of computer training (n = 53), soft skills (n = 53), digital books (n = 55). Nearly two?thirds of the participants were male (n = 205). Conclusion: Evidence from this study suggests telerehabilitation as a successful model of care. A well?planned telerehabilitation approach can expand the scope of reaching the visually impaired from geographically isolated areas where scarcity of service providers and service centers.

Choroidal thickness profile in inherited retinal diseases in Indian subjects.

Purpose: To evaluate changes in choroidal thickness (CT) in inherited retinal diseases and its relationship with age, spherical equivalent, visual acuity, and macular thickness. Methods: Retrospective analysis of 51 eyes with features of retinal dystrophy of 26 subjects, who underwent enhanced depth imaging using spectral domain (SD) optical coherence tomography (OCT), were included. The CT measurements were made at the fovea and at 5 points with an interval of 500 microns in both directions, nasal and temporal from the fovea and were compared with age‑matched healthy subjects. Step‑wise regression was used to find the relationship between age, spherical equivalent, best‑corrected visual acuity (BCVA), central macular thickness (CMT), and subfoveal CT. Results: Disease distribution was as follows: Stargardt’s disease 18 eyes (9 subjects); Best disease 5 eyes (3 subjects); cone‑rod dystrophy 26 eyes (13 subjects); and Bietti’s crystalline dystrophy 2 eyes (1 subject). Mean subfoveal CT was 266.33 ± 76 microns. On regression analysis, no significant correlation was found between subfoveal CT and any other variable such as age (P = 0.9), gender (P = 0.5), CMT (P = 0.1), spherical equivalent (P = 0.3) and BCVA (P = 0.6). While comparing with age‑matched healthy subjects, no significant statistical difference was noted (P < 0.05) among all age groups. Conclusion: Our study reports quantitative changes in CT in various common inherited retinal diseases seen in Indian populations. To validate changes in choroid, a longitudinal study with larger sample size is warranted.

Impact of the day-30 screening strategy on the disease presentation and outcome of retinopathy of prematurity. The Indian twin cities retinopathy of prematurity report number 3.

Context: Outcomes of various screening strategies in retinopathy of prematurity are not well reported. Aim: To assess the impact of a city-wide, ROP screening strategy, on the disease presentation and treatment outcome. Materials and Methods: A retrospective case-control study from a prospectively collected ROP data-base was analyzed. Cases (group 1a) included ROP babies that were screened directly in neonatal intensive care units, and controls (group 1b) were babies referred directly to the institute from other neonatal centers during the same period. Historical controls (group 2) were ROP cases seen in the years preceding establishment of this ROP program and database. Primary outcome measure was the risk of eyes presenting with stage 4 or worse ROP, and main secondary outcome measure was the fi nal anatomic outcome. Results: Of the 643 cases screened, 322 eyes of 161 babies had ROP. The median age of 7.19 months at presentation for the 46 patients (92 eyes) in group 2 was higher than the median age of 1.29 months for the 115 patients (230 eyes) in group 1. Within the group 1, group 1a had lower median age at presentation than group 1b (0.91 months versus 2.30 months). The relative risk of an eye presenting in the stage 4 and 5 in group 2 was 4.7 times higher (95% confi dence interval 3.07 - 7.32) than in group 1. Eyes that could be given treatment in group 2 were signifi cantly less (P < 0.0005) than in group 1. The relative risk of poor outcome in group 2 was 3.83 times higher (95% confi dence interval 2.75 - 5.34) than in group 1. Group 1a eyes had the best outcomes. Conclusion: Early screening before one month of age in neonatal centers detects the disease early where prompt treatment can lead to favorable outcomes. The study provides early results of a model strategy for ROP screening.

Integrated model of primary and secondary eye care for underserved rural areas: The L V Prasad Eye Institute experience.

Blindness is a major global public health problem and recent estimates from World Health Organization (WHO) showed that in India there were 62 million visually impaired, of whom 8 million are blind. The Andhra Pradesh Eye Disease Study (APEDS) provided a comprehensive estimate for prevalence and causes of blindness for the state of Andhra Pradesh (AP). It also highlighted that uptake of services was also an issue, predominantly among lower socio-economic groups, women, and rural populations. On the basis of this analysis, L V Prasad Eye Institute (LVPEI) developed a pyramidal model of eye care delivery. This article describes the LVPEI eye care delivery model. The article discusses infrastructure development, human resource development, and service delivery (including prevention and promotion) in the context of primary and secondary care service delivery in rural areas. The article also alludes to opportunities for research at these levels of service delivery and the amenability of the evidence generated at these levels of the LVPEI eye health pyramid for advocacy and policy planning. In addition, management issues related to the sustainability of service delivery in rural areas are discussed. The article highlights the key factors required for the success of the LVPEI rural service delivery model and discusses challenges that need to be overcome to replicate the model. The article concludes by noting the potential to convert these challenges into opportunities by integrating certain aspects of the existing healthcare system into the model. Examples include screening of diabetes and diabetic retinopathy in order to promote higher community participation. The results of such integration can serve as evidence for advocacy and policy.

Comparison of immersion ultrasonography, ultrasound biomicroscopy and anterior segment optical coherence tomography in the evaluation of traumatic phacoceles.

Blunt ocular trauma in the elderly can result in anterior dislocation of the crystalline lens into the subconjunctival space (phacocele). Although rare, this presentation can be missed, especially if the patient presents several days after the injury and if the lid is not everted on examination. While a careful clinical examination is adequate in the diagnosis, imaging techniques can be put to use for the accurate location of the associated sclera rupture. We report three cases of post-traumatic phacocele wherein ultrasound biomicroscopy (UBM) was compared to the anterior segment optical coherence tomography (AS-OCT) and B-scan ultrasonography (B-scan), in order to establish the best imaging tool for this condition. We concluded, based on image quality, that UBM could be the imaging modality of choice to aid in the diagnosis of phacocele.

Delayed inflammation associated with retained perfluorocarbon liquid.

A 55-year-old woman, with history of cataract surgery 1 year back, presented with features of ocular inflammation for last 3 months. She had no history of any other intraocular surgery. On examination, anterior segment showed frothy material in the inferior angle with moderate anterior chamber reaction (cells+/flare+) and sulcus intraocular lens with large posterior capsule rent. Fundoscopy showed multiple, small to medium-sized transparent bubbles of perfluorocarbon liquid (PFCL) with membranes in the vitreous cavity. Ultrasonography confirmed the presence of PFCL in the vitreous cavity. Pars plana vitrectomy with anterior chamber wash was done which led to good visual recovery. To conclude, retained PFCL can cause late onset fibrinous inflammation after a quiescent period but surgical intervention may lead to good visual outcome.

Prevalence and risk factors for severity of diabetic neuropathy in type 2 diabetes mellitus.

Purpose: To estimate the prevalence of diabetic neuropathy (severity wise) and associated risk factors in a population having type 2 diabetes mellitus. Materials and Methods: A population-based sample of 1401 persons with diabetes (identified as per the WHO criteria) underwent comprehensive eye examination including stereoscopic digital photography (45° four field) for diabetic retinopathy grading. Vibration perception threshold (VPT) measurements were done to assess neuropathy (cut off ≥ 20 V). Severity of neuropathy was graded into three groups based on VPT score as mild (20-24.99 V), moderate (25-38.99 V), and severe (≥39 V). Univariate and multivariate analyses were done to find out the independent risk factors for severity of diabetic neuropathy. Results: In the overall group, the prevalence of diabetic neuropathy was 18.84% (95% CI: 16.79-20.88). The prevalence of mild diabetic neuropathy was 5.9% (95% CI: 4.68-7.15), moderate diabetic neuropathy was 7.9% (95% CI: 6.50-9.33), and severe diabetic neuropathy was 5% (95% CI: 3.86-6.14). Increasing age per year (P < 0.0001) was a statistically significant risk factor for all - mild, moderate, and severe - types of diabetic neuropathy. For severe diabetic neuropathy, other significant risk factors were duration of diabetes mellitus (P = 0.027), macroalbuminuria (P = 0.001), and presence of diabetic retinopathy (P = 0.020). Conclusions: The results suggested that every fifth individual in a population of type 2 diabetes is likely to have diabetic neuropathy. Nearly 13% had neuropathy of moderate and severe category, making this group vulnerable for complications such as foot ulceration or lower limb amputation.

Diabetic retinopathy in type II diabetics detected by targeted screening versus newly diagnosed in general practice

<p><b>INTRODUCTION</b>The aim of this study was to compare the occurrence of diabetic retinopathy in targeted screening diabetic patients (Group I) with newly diagnosed diabetic patients in general practice (Group II).</p><p><b>MATERIALS AND METHODS</b>This was an observational cross-sectional study. Data were obtained from 25,313 subjects who participated in the diabetic screening camps, and 128 newly diagnosed diabetes who presented to the diabetic retinopathy screening camps in general practice in rural and urban south India. The study variables were collected from all patients who underwent eye examination from the target screening detected diabetics [(n = 173) Group I] and those newly diagnosed in general practice [(n = 128) Group II]. The variations in prevalence of diabetic retinopathy and sight-threatening diabetic retinopathy in Group I and Group II and the factors affecting it were identified.</p><p><b>RESULTS</b>The occurrence of diabetic retinopathy was 6.35% (95% CI, 2.5-9.5) in Group I and 11.71% (95% CI, 5.6-16.4) in Group II. No significant difference was observed on occurrence of diabetic retinopathy, including sightthreatening retinopathy, in rural versus urban population and in Group I versus Group II. Patients diagnosed in general practice (Group II) with systolic blood pressure (BP) >140 were more likely to have retinopathy (P = 0.02).</p><p><b>CONCLUSIONS</b>Diabetic retinopathy including sightthreatening complications was found at the time of diagnosis of diabetes in the targeted screening group as well as in newly diagnosed diabetics in the general practice group.</p>