Ophthalmoscopic Examination Research Articles

Optometry meets ophthalmology- cycloplegic refraction and examination under general anaesthesia in a paediatric high myope

Purpose: To discuss a case of shared optometric-ophthalmic (O-O) approach in objectively refracting and examining a paediatric high myope under general anaesthesia. Methods: A paediatric high myope was cyclopleged then underwent objective retinoscopy under general anaesthesia within a surgical theatre setting. Corneal diameter, interpupillary distance, immersion biometry axial lengths, intraocular pressures, keratometry readings, A-scan and B-scan ultrasound images were all subsequently obtained. Lastly, binocular indirect ophthalmoscopic examination with 360º scleral indentation was carried out. A comprehensive O-O report was dispensed with all collated parameters. Results: A refractive error of -11.00DS bilaterally was measured. Ocular health assessment showed no significant myopic abnormalities. The patient was dispensed spectacles and adapted well with improved comfort. Low dose atropine myopia control was commenced. Conclusion: O-O shared care in refracting and examining difficult and highly myopic paediatric cases under general anaesthesia is a useful and effective tool.

A study on the prevalence of retinopathy in newly diagnosed Type 2 diabetes mellitus in a tertiary care center of Tamil Nadu

Background: Type 2 diabetes mellitus (Type 2 DM) is one of the leading risk factors for cardiovascular diseases. Although the awareness of the need for screening and treatment for Type-2 DM is widely prevalent, the awareness of complications arising out of it is not widespread. This article highlights the occurrence of diabetic retinopathy (DR) among newly detected diabetic patients. Aims and Objectives: The aim of the study was to study the prevalence of DR in patients who are diagnosed as having Type 2 diabetes mellitus for the first time. Materials and Methods: The present study involved 501 newly diagnosed Type 2 DM patients. Their history was recorded and the investigations done included haemoglobin (Hb), glycated Hb percent (HbA1c), fasting blood sugar, and post-prandial blood sugar. These patients underwent fundus examination through direct ophthalmoscope and slitlamp examination. Results: Out of the 501 patients in the study, 59.5% (298) had good knowledge about diabetes, but only 3.8% knew about retinopathy. A total of 71.5% of patients did not have periodic eye examination; the most common barrier identified was lack of awareness about the necessity for this (58.5%), 5.6% among the total population had an eye disease. Mild non-proliferative DR (NPDR) was found among 10 females and it was observed in eight males. Moderate NPDR was identified in three males and two females and while no severe cases were reported among the men, two were noted among the women. Conclusion: The study highlights the prevalence of retinopathy in newly diagnosed Type 2 DM population in tertiary care center hospital in Salem district. The study also highlights the importance of detection of Type 2 DM before the occurrence of complications which arise due to diabetes and screening for microvascular complications is necessary at the time of diagnosis of DM and periodically.

Association of Diabetic Retinopathy with Angiographic Severity of Coronary Artery Disease in Patients with Non-ST Elevation Myocardial Infarction

Background: Bed side ophthalmoscopic examination is a simple measure of diagnosis of diabetic retinopathy and has been shown to be a predictor of poor outcome in various cardiovascular conditions including coronary artery disease (CAD). Retinopathy lesions are fairly common findings in clinic settings and may predict risk of coronary heart disease (CHD). The present study was intended to find the relationship between diabetic retinopathy with the severity of coronary artery disease in patients with NSTEMI. Methods: This cross-sectional observational study was conducted in the Department of cardiology, National Institute of Cardiovascular Diseases and Hospital (NICVD), Dhaka, Bangladesh, from March 2019 to August 2020. A total of one hundred twenty DM with NSTEMI patients undergoing coronary angiogram and also fundoscopic examination with fundal photography during the index hospitalization were included in this study. Study subjects were divided into two groups on the basis of diabetic retinopathy (Group-I: NSTEMI with diabetic retinopathy ; Group- II: NSTEMI without diabetic retinopathy). Severity of coronary artery disease was determined by Gensini score and correlation between diabetic retinopathy and Gensini score was assessed. Results: Gensini score was significantly higher in patients with diabetic retinopathy than that in patients without diabetic retinopathy (62.2±27.7 vs. 43.3±25.3,p<0.001).Gensini score increased with increasing severity of diabetic retinopathy(P <0.001).The risk of having severe CAD in patient with diabetic retinopathy was 13.03 (95% CI =2.410-70.419) (P<0.003).A significant correlation between diabetic retinopathy and Gensini score was noted (p value <0.001) Conclusion: It may be concluded that Presence and severity of diabetic retinopathy is associated with angiographically severe coronary artery disease in patient with non-ST elevation myocardial infarction (NSTEMI) and it may be considered as an independent predictor of severity of CAD.As is a bed side assessment ,so before performing coronary angiography ,it appears to be additive for risk stratification. J Inv Clin Cardiol 2023; 5(1): 7-13

Direct Laser Photocoagulation of the Retinal Pigment Epithelium: A Novel Method to Seal Retinal Breaks during Pars Plana Vitrectomy for Retinal Detachment.

This study evaluates the clinical effectiveness of employing direct retinal pigment epithelium (RPE) laser photocoagulation as a technique for achieving chorioretinal adhesion to effectively seal retinal breaks. A total of 20 eyes from 20 patients were enrolled in the study; all selected eyes exhibited either rhegmatogenous or combined rhegmatogenous-tractional retinal detachment. During vitrectomy, direct RPE laser photocoagulation was executed, employing a power range of 100-150 mW and a duration of 120-200 ms, targeting the peripheries where the edges of each retinal break were anticipated to settle post-reattachment. This treated area's neuroretina thickness was compared to measurements obtained after conventional transretinal laser photocoagulation. Patients were followed for an average duration of 24 months, with a range of 11-46 months. A visible pigmentary reaction in the ophthalmoscopic examination was evident in the treated regions for all but one eye, where the retinal break was situated amidst myelinated nerve fibers. The study encountered no severe complications, and successful retinal reattachment was achieved in all 20 eyes. The mean best-corrected visual acuity (BCVA) at the final follow-up showed a statistically significant improvement compared to preoperative levels (p < 0.0001). A noteworthy difference in neuroretinal thickness was observed one-month post-surgery between areas treated with direct RPE and those treated with transretinal photocoagulation, measuring 217 μm and 104 μm, respectively. Our findings suggest that direct RPE laser photocoagulation is an effective therapeutic intervention for sealing retinal breaks.

Prevalence of Ophthalmic Manifestations in COVID-19 Positive Indoor Patients during Second Wave at Rural Tertiary Care Hospital of Gujarat: A Prospective Observational Study

Introduction: Coronavirus Disease-2019 (COVID-19) can affect multiple system of body including eye. In eye, it can cause mild conjunctivitis, posterior segment involvement, neurosensory involvement and lethal opportunistic infection like mucormycosis. Associated co-morbidities, severity of COVID19 infection and corticosteroids used in its management can affect ophthalmic involvement. Aim: To determine the frequency and various types of ophthalmic manifestation of patients with COVID-19. Materials and Methods: This prospective observational study was conducted on indoor patients of Shree Krishna Hospital, a rural, tertiary care hospital affiliated with Pramukh Swami Medical College, Karansad, Gujarat, India, from 1st May 2021 to 1st January 2022. Second wave of COVID-19 was from 13th March 2021 to 19th June 2021. Patients’ demographic data, details of COVID-19 infection severity score, oxygen requirement, use of corticosteroids, history of various co-morbidities and stages of Rhino-Orbital-Cerebral Mucormycosis (ROCM) (if present) were noted. Bedside ophthalmic examination was done with torch light, fluorescent strip, cobalt blue light of direct ophthalmoscope and fundus examination with indirect ophthalmoscopy under institutional COVID-19 guidelines. Descriptive Statistics {Mean, (SD), Frequency, (%)} were used for analysis of the collected data. Results: Out of 649 COVID-19 patients, 368 were male and 281 were female with mean age of 52.58 (±15.38) years. All over prevalence of ophthalmic manifestations was 9.86% (n=64 out of 649 patients). A total of 63 patients (9.71%) did not require any oxygen supplement, 352 patients (54.24%) required nasal prongs, 201 patients (30.97%) required non invasive ventilator support and 33 patients (5.08%) required mechanical ventilation. The 378 patients (58.24%) received cortico-steroids in oral or intravenous form. A total of 325 patients (50.1%) had diabetes,267 patients (41.1%) had hypertension, 29 patients (4.5%) had chronic kidney disease and 15 patients (2.3%) had thyroid disease. A total of 52 patients (8.01%) had conjunctivitis. Mean age of patients with conjunctivitis was 50.04 (±15.28) with male preponderance (n=30, 57.7%). Most common systemic presentation was fever (n=29,55.8%). Patients with conjunctivitis had high D-dimer (&gt;500 ng/mL) (n=42;80.8%) and C-Reactive Protein (CRP) values (&gt;3 mg/L) (n=39;75%). A total of 144 patients (22.2%) were vaccinated with COVID-19 vaccine first dose while ten patients (19.23%) out of 52 patients having conjunctivitis were vaccinated. Out of 649 patients, prevalence of ROCM was 1.85% (n=12) with mean age 58.58 years (±9.71 years) and male preponderance (n=8, 66.66%). Nine out of twelve patients had high blood sugar levels (mean level 340 mg/ dL) at the time of admission. Out of twelve, eight patients had received corticosteroids for management of COVID-19 infection. Six patients of ROCM (50%) did not require any oxygen support while two patient (16.7%) required nasal prongs for mean 7.50 days and four patient (33.3%) required non invasive ventilator support for mean 7.33 days (±2.5 days). One patient had stage 2C disease, one had stage 3B, five patients had stage 3C while five patients had stage 4C disease. Conclusion: Ocular manifestations of COVID-19 range from conjunctivitis to ROCM. Conjunctivitis has mild and self-limited course while ROCM is sight threatening and life-threatening condition, if not treated appropriately.

Окт диагностика скрытого клапанного разрыва при задней отслойке стекловидного тела

Changes in the posterior vitreous that look like hyperreflective dots are considered as a predictor of peripheral retinal breaks in acute posterior vitreous detachment (PVD), along with Shafer's sign, intraretinal and vitreous hemorrhages. Some of peripheral breaks in acute PVD remain unnoticed at the initial ophthalmoscopic examination due to poor visualization. We report a clinical case of an invisible peripheral retinal flap tear detection with overview wide-field OCT (RTVue XR Avanti, Line mode –12 mm) scanning by «sliding» method in the area of retinal hemorrhage in presence of multiple hyperreflective dots in the vitreous during acute symptomatic PVD. Key words: acute PVD; invisible flap tear; wide-field OCT; retinal hemorrhage; stardust sign; hyperreflective dots.

The yield of ophthalmoscopy as a screening tool for intracranial pathology in pediatric headache.

Headache is a common complaint in children who present at the pediatric emergency department (PED). Serious conditions such as intracranial tumors and idiopathic intracranial hypertension (IIH) should be rapidly ruled out. Ophthalmoscopy for the presence of papilledema has long been considered critical to the assessment of headaches in children; however, the yield of this procedure is poorly validated. This retrospective study implemented a computerized search of the medical records of a single tertiary center to identify all children aged 2-18years who presented at the PED complaining of headache between 2007 and 2017. The clinical, demographic, radiographic, and laboratory data were analyzed. Of the 948 children aged 2-18years who presented at the PED complaining of headache, 536 had an ophthalmoscopy examination carried out by an ophthalmologist. Forty-one had papilledema, of whom 7 had an intracranial tumor, 15 had IIH, and 9 had optic nerve head drusen. Of the 495 children without papilledema, 3 had intracranial tumor, and 11 had IIH. The sensitivity and specificity of papilledema for the diagnosis of intracranial tumor were 70% and 93.5%, respectively, with an NPV and PPV of 99.4% and 17.1%, respectively. The sensitivity and specificity of papilledema for the diagnosis of intracranial pathology in general were 61.1% and 96.2%, respectively, with an NPV and PPV of 97.2% and 53.7%, respectively. Conclusion: Assessment by ophthalmoscopy for papilledema in children presenting to the PED with headache had high sensitivity and high specificity, thus reinforcing the importance of ophthalmoscopy as a screening tool in these children. What is Known: •Headache is a common complaint in children. Serious intracranial pathologies need to be rapidly excluded. • Ophthalmoscopy for the presence of papilledema is commonly used as a screening tool for intracranial pathology, but this procedure is poorly validated. What is New: •Ophthalmoscopy for the assessment of papilledema in children who present with headache to the pediatric emergency department is shown to exhibit sensitivity and specificity for the diagnosis of intracranial pathology.

Association of Diabetic Retinopathy with Angiographic Severity of Coronary Artery Disease in Patients with Non-ST Elevation Myocardial Infarction

Background: Bed side ophthalmoscopic examination is a simple measure of diagnosis of diabetic retinopathy and has been shown to be a predictor of poor outcome in various cardiovascular conditions including coronary artery disease. The present study was intended to find the relationship between diabetic retinopathy with the severity of coronary artery disease in patients with non ST elevation myocardial infarction (NSTEMI). Methods: This cross-sectional observational study was conducted with a total of 120 NSTEMI patients with diabetes undergoing coronary angiogram and also fundoscopic examination with fundal photography during the index hospitalization. Study subjects were divided into two groups on the basis of diabetic retinopathy (Group-I: NSTEMI with diabetic retinopathy; Group- II: NSTEMI without diabetic retinopathy). Severity of coronary artery disease was determined by Gensini score and correlation between diabetic retinopathy and Gensini score was assessed. Results: Gensini score was significantly higher in patients with diabetic retinopathy than that in patients without diabetic retinopathy (62.2±27.7 vs. 43.3±25.3, p&lt;0.001).Gensini score increased with increasing severity of diabetic retinopathy (p &lt;0.001).The risk of having severe CAD in patient with diabetic retinopathy was 13.03 (95% CI =2.410-70.419) (P&lt;0.003). A significant correlation between diabetic retinopathy and Gensini score was noted (p value &lt;0.001) Conclusion: It may be concluded that presence and severity of diabetic retinopathy is associated with angiographic severe coronary artery disease in patient with NSTEMI and it may be considered as an independent predictor of severity of CAD. As is a bed side assessment, so before performing coronary angiography, it appears to be additive for risk stratification. Cardiovasc j 2022; 15(1): 49-55

The effect of different types of convergent strabismus on horizontal eye movements.

To investigate the effect of different types of convergent strabismus on horizontal eye movements and compare data with healthy control subjects. This prospective, cross-sectional study included 38 patients with convergent strabismus (16 fully accommodative, 13 partially accommodative and 9 non-accommodative esotropia) and 19 age-matched control subjects. All of the participants had a detailed ophthalmological examination including visual acuity assessment, cover-uncover prism test, slit lamp, and indirect ophthalmoscopy examination. Videonystagmography (VNG) was used for the evaluation of horizontal eye movements such as saccadic accuracy, velocity, latency, and smooth pursuit velocity gain. The saccadic accuracy in the rightward direction was lower in the fully accommodative esotropia group compared to the partially accommodative esotropia group in the right eye (p = 0.002). The saccadic latency in the rightward direction was longer in the fully accommodative esotropia group compared to the control group (p = 0.008) and smooth pursuit velocity gain in the leftward direction was lower in the partially and non-accommodative esotropia group compared to the control group in binocular recording (p = 0.004, p = 0.001, respectively). There was no difference in the saccadic velocity among the study groups (p > 0.05). Finally, asymmetry of saccadic velocity and latency was observed between right- and leftward directions in the partially accommodative esotropia group in the right eye (p = 0.003, p = 0.008, respectively). This study demonstrated that horizontal eye movements may vary in different types of convergent strabismus. VNG may be an auxiliary tool to the clinical examination in differentiating fully or non-accommodative esotropia.

Relationship of mean platelet volume in predicting severity in hypertensive retinopathy – A cross sectional study

Background: Hypertension is a major health issue in India and it has led to increasing incidences of target organ damage including hypertensive retinopathy (HR). Many factors like platelet activation show influence in levels of HR. Mean platelet volume (MPV) being an indicator of platelet activation can help in predicting the severity of HR. The present study was planned to find a correlation of levels of MPV with the severity of HR. Methodology: Data of 100 cases of hypertensive retinopathy aged 31 to 80 years diagnosed by direct and indirect ophthalmoscopic examination in the outpatient department of ophthalmology was recorded and reviewed. Complete clinical and demographic data (age, gender, weight, body mass index and socioeconomic status) was noted. Mean platelet volume was obtained from fully automated haematology analyser Horiba medical Yumizen H550. Results: The mean age (years ± standard deviation) of cases with grade 1 HR was 59.448±11.642, grade 2 HR was 56.166±10.0377 and grade 3 HR was 58±19.37. The mean value of MPV in the study population for grade 1 HR was 8.55±0.576, for grade 2 HR was 9.17±0.8224, for grade 3 was 9.6±1.5594. The comparison between grades of HR and levels of MPV was done by one way analysis of variance. Conclusion: We established a significant relationship between mean platelet volume and severity grades of hypertensive retinopathy. MPV a cheap and easily available biomarker can be used for predicting severity in hypertensive retinopathy.

A Comparison of Historical Control Data From Cynomolgus Macaques (Macaca Fascicularis) of Chinese, Cambodian, and Vietnamese Origin.

Cynomolgus macaques, the most commonly utilized nonhuman primate in nonclinical toxicology studies, are acquired from purpose-bred colonies across various geographic locations, including China, Cambodia, and Vietnam. Importation challenges and limited availability have restricted animals suitable for inclusion in nonclinical studies. The coronavirus disease 2019 (COVID-19) outbreak further stressed supply chains, reducing the ability to source animals from a singular location to complete a drug development program. These challenges raised concerns of increased variability in study endpoints due to heterogeneity of animals and that this could subsequently impact historical control data and toxicology study interpretation. To investigate the impact of Chinese, Vietnamese, or Cambodian geographic origin on standard nonclinical toxicology study endpoints, historical control data from studies conducted at a single facility from 2005 to 2020 were compiled and evaluated for the following: clinical observations, body weight, ophthalmoscopic examinations, and clinical and anatomic pathology data. Study populations consisted of 2- to 5-year-old cynomolgus macaques sourced from China (n = 750 males/741 females), Cambodia (n = 282 males/271 females), and Vietnam (n = 122 males/120 females). Interpretation of the various data demonstrated no notable differences in standard toxicology study endpoints or background findings among cynomolgus macaques originating from China, Cambodia, or Vietnam.

A Novel Mouse Model of TGFβ2-Induced Ocular Hypertension Using Lentiviral Gene Delivery.

Glaucoma is a multifactorial disease leading to irreversible blindness. Primary open-angle glaucoma (POAG) is the most common form and is associated with the elevation of intraocular pressure (IOP). Reduced aqueous humor (AH) outflow due to trabecular meshwork (TM) dysfunction is responsible for IOP elevation in POAG. Extracellular matrix (ECM) accumulation, actin cytoskeletal reorganization, and stiffening of the TM are associated with increased outflow resistance. Transforming growth factor (TGF) β2, a profibrotic cytokine, is known to play an important role in the development of ocular hypertension (OHT) in POAG. An appropriate mouse model is critical in understanding the underlying molecular mechanism of TGFβ2-induced OHT. To achieve this, TM can be targeted with recombinant viral vectors to express a gene of interest. Lentiviruses (LV) are known for their tropism towards TM with stable transgene expression and low immunogenicity. We, therefore, developed a novel mouse model of IOP elevation using LV gene transfer of active human TGFβ2 in the TM. We developed an LV vector-encoding active hTGFβ2C226,228S under the control of a cytomegalovirus (CMV) promoter. Adult C57BL/6J mice were injected intravitreally with LV expressing null or hTGFβ2C226,228S. We observed a significant increase in IOP 3 weeks post-injection compared to control eyes with an average delta change of 3.3 mmHg. IOP stayed elevated up to 7 weeks post-injection, which correlated with a significant drop in the AH outflow facility (40.36%). Increased expression of active TGFβ2 was observed in both AH and anterior segment samples of injected mice. The morphological assessment of the mouse TM region via hematoxylin and eosin (H&E) staining and direct ophthalmoscopy examination revealed no visible signs of inflammation or other ocular abnormalities in the injected eyes. Furthermore, transduction of primary human TM cells with LV_hTGFβ2C226,228S exhibited alterations in actin cytoskeleton structures, including the formation of F-actin stress fibers and crossed-linked actin networks (CLANs), which are signature arrangements of actin cytoskeleton observed in the stiffer fibrotic-like TM. Our study demonstrated a mouse model of sustained IOP elevation via lentiviral gene delivery of active hTGFβ2C226,228S that induces TM dysfunction and outflow resistance.

The Prevalence of Retinal Disease and Associated CNS Disease in Young Patients with Incontinentia Pigmenti

To evaluate the prevalence of retinal disease on fluorescein angiography (FA) in patients with incontinentia pigmenti (IP) and to compare the severity of retinal disease in those with and without known central nervous system (CNS) disease. Multi-institutional consecutive retrospective case series. New patients with a diagnosis of IP were seen at the Casey Eye Institute at the Oregon Health and Science University (OHSU), Moran Eye Center, University of Utah, or Bascom Palmer Eye Institute, University of Miami from December 2011 to September2018. Detailed ophthalmoscopic examination and FA were recommended for all new patients and performed on every patient who had parental consent. Ophthalmoscopic findings and FA images were graded for severity by 2 masked graders on a 3-point scale: 0= no disease, 1= vascular abnormalities without leakage, 2= leakage or neovascularization, and 3= retinal detachment. The presence of known CNS disease was documented. Additional cases were obtained from a pediatric retina listserv for examples of phenotypic variation. The proportion of eyes noted to have disease on ophthalmoscopy compared with FA and the severity of retinal disease in those with and without known CNS disease. Retinal pathology was detected in 18 of 35 patients (51%) by indirect ophthalmoscopy and 26 of 35 patients (74%) by FA (P= 0.048) in a predominantly pediatric population (median age, 9 months). Ten patients (29%) had known CNS disease at the time of the eye examination. A Wilcoxon rank-sum test indicated that the retinal severity scores for patients with CNS disease (median, 2) were significantly higher than the retinal severity scores for patients without CNS disease (median, 1), z= -2.12, P= 0.034. Retinal disease is present in the majority of patients with IP, and ophthalmoscopic examination is less sensitive than FA for detection of disease. There may be a correlation between the severity of retinal and CNS disease.

Myopia prevalence in school-aged children in Garki District of Abuja, Nigeria

Background: Prevalence of myopia is increasing globally, hence it poses a significant public health risk due to the association of high myopia with debilitating eye disorders.Aim: The aim of this study was to determine the prevalence of myopia in school children.Setting: The study was conducted in primary and secondary schools in Garki district, Abuja, Nigeria.Methods: A cross-sectional, multistage, random sampling involving 1028 school children (aged 5–14 years), comprising 484 boys (47.1%) and 544 girls (52.9%), was conducted. Examination performed included visual acuities, pen torch and ophthalmoscopy examination of the anterior and posterior segments, retinoscopy under cycloplegia and subjective refraction.Results: The prevalence of myopia (−0.50 dioptre [D] or more) in this study was 3.5%. Approximately 3.4% of the children had mild myopia (−0.50 to −3.00 D), 0.1% had moderate myopia (−3.25 D to −6.00 D) and none had high myopia. Myopia ranged from −0.50 D to −4.25 D. The mean spherical equivalent for myopia (right eye) was −1.11 D. The prevalence of hyperopia, astigmatism and amblyopia was 5.8%, 1.9% and 0.7%, respectively. Overall, the prevalence of refractive error was 11.2%.Conclusion: The prevalence of myopia is relatively low in a sample of school children in Garki district of Abuja, Nigeria. However, the majority of myopic children in this study without spectacles (88.9%) are a cause for concern, which could reflect the low usage of refractive error services among school children in the district.

Fluorescein Angiography Detection of Combined Branch Retinal Vein and Artery Occlusion.

A77-year-old male with a history of diabetes mellitus, hypertension, chronic kidney disease, and hyperlipidemia presented for 1-month postoperative care following cataract extraction with a subjective complaint of a dark area in his left eye superior field. His uncorrected visual acuity measured 20/25 in each eye. The posterior ophthalmoscopic examination of the left eye revealed a large calcific embolus in the inferior retinal artery exiting the optic nerve (Fig. 1). The presence of moderate retinal hemorrhages consistent with diabetic and hypertensive retinopathy was evident.Figure 1: Color photograph showing large calcific embolus of the inferior retinal artery exiting the optic nerve.The fluorescein angiography study showed delayed filling of the inferior retinal artery in the arterial phase due to obstruction from an embolic vaso-occlusive event. The patient reported branch retinal artery occlusion symptoms, yet there were no acute ophthalmoscopic signs of venous occlusion. The collateral vein occlusion resulted from the proximity ofmechanical compression at the point of the shared arterial-venous adventitial sheath by the large embolus1 and was evident from the absent fluorescein filling within the inferior venous tributary (Fig. 2). Fluorescein angiography was of great diagnostic value to detect retinal non-perfusion from the combined branch retinal artery and vein occlusions, since the latter may have otherwise gone undiagnosed.Figure 2: Fluorescein angiography showing impaired inferior arterial filling and absent intermediate phase inferior venous circulation from embolic compression.

Evaluation of Hemodynamic Changes in Retrobulbar Blood Vessels Using Color Doppler Imaging in Diabetic Patients.

Background—Diabetic retinopathy is a common complication of long-standing hyperglycemia. Microangiopathy-induced retinal changes are well-visualized on ophthalmoscopic examination. However, certain hemodynamic alterations have also been documented in the diabetic population, which have not been completely understood. Aim—To study the hemodynamic changes in retrobulbar circulation in diabetic patients with and without retinopathy, and to compare these changes with non-diabetic controls. Materials and Methods—This hospital-based prospective study included 50 diabetic and 50 non-diabetic patients. The diabetic groups consisted of 25 patients without retinopathy and 25 patients with retinopathy, and were labeled as Groups I and II, respectively. All subjects underwent orbital color Doppler ultrasonography using a linear high-frequency probe. The color Doppler parameters (peak systolic velocity (PSV), end-diastolic velocity (EDV), and resistive index (RI)) were measured and recorded using the spectral waveform of the ophthalmic artery (OA), central retinal artery (CRA), and short posterior ciliary arteries (SPCA). Comparison of obtained values was carried out using appropriate tests of significance. Results—The resistive indices of the ophthalmic, central retinal, and short posterior ciliary arteries were significantly higher in diabetic patients compared to controls (p < 0.001). The difference was also significant between Group I and Group II. Comparison of PSV and EDV of CRA and SPCAs among three groups using one-way ANOVA revealed a significant difference, with the highest blood flow velocities in the control group and the lowest in diabetics with retinopathy. The ophthalmic artery showed no significant change in blood flow velocity. Analysis using the Pearson correlation coefficient provided a positive correlation between the RI values of OA, CRA, and SPCA and the presence of diabetic retinopathy (OA = r 0.417, p < 0.001; CRA = r 0.466, p < 0.001; SPCA = r 0.438; p < 0.001). Conclusions—The resistive index of OA, CRA, and SPCA is a reliable indicator to assess diabetic-associated hemodynamic changes. The use of orbital color Doppler ultrasonography in diabetic patients can help in the identification of patients who are at risk of developing retinopathy.

Retrograde Trans-Synaptic Degeneration from an Occipital Lobe Tumor

A 29-year-old woman underwent resection of a left occipital lobe dysembryoplastic neuroepithelial tumor 12 years prior to evaluation. Visual acuity was 20/20 in each eye with normal ophthalmoscopic examination. Automated perimetry demonstrated a right homonymous hemianopsia. Magnetic resonance imaging showed a resection cavity within the left occipital lobe. Ganglion cell complex analysis demonstrated a left homonymous hemi-macular thinning. Although once thought to not be possible in adults, lesions posterior to the lateral geniculate nucleus can result in retinal changes from the loss of trophic signals incited by neuronal injury to connecting neurons, leading to retinal ganglion cell death (Magnified version of Figure 1 is available online at www.aaojournal.org).

Acute and Subchronic Toxicity Study of Flavonoid Rich Extract of Glycyrrhiza glabra (GutGard®) in Sprague Dawley Rats.

Glycyrrhiza glabra (G. glabra) is well known for its health benefits based on the traditional and current scientific evidence. The aim of the present study was to evaluate the safety of GutGard, a standardised-flavonoid rich extract of G. glabra. The study was designed to evaluate the acute and subchronic oral toxicity of GutGard in Sprague Dawley rats according to the procedures and methods of Organisation for Economic Cooperation and Development (OECD) test guidelines for acute and subchronic toxicity. A single dose of GutGard at 5000 mg/kg body weight did not produce treatment related clinical signs of toxicity or mortality in any of the animals tested during the 14-day observation period. Therefore, the median lethal dose was estimated to be more than 5000 mg/kg. A subchronic oral toxicity study for 90 days in rats at the dose levels of 250, 500, and 1000 mg/kg did not show any treatment related adverse clinical signs. The treated animals exhibited normal weight gain and comparable feed intake. Ophthalmoscope examination did not reveal any abnormalities. Further, GutGard administration in rats did not show any clinical evidence of toxicity with respect to urinalysis, haematology, and blood chemistry parameters. The relative organ weight of vital organs did not differ significantly as compared to control. Gross and histopathological findings did not show any remarkable and treatment related changes. Based on the current experimental study findings, the median lethal dose (LD50) of GutGard was found to be >5000 mg/kg b.wt and the no observed adverse effect level (NOAEL) was found to be 1000 mg/kg rat b.wt.

Diabetic Retinopathy: Role of Neurodegeneration and Therapeutic Perspectives.

Retinal neurodegeneration plays a significant role in the pathogenesis of diabetic retinopathy, the leading cause of preventable blindness. The hallmarks of diabetes-induced neurodegeneration are neural cell apoptosis and glial activation, which seem even before vascular lesions can be detected by ophthalmoscopic examination. The molecular mediators of retinal neurodegeneration include proinflamma- tory cytokines, oxidative stress, mitochondrial dysfunction, and the molecular pathways closely related to chronic hyperglycemia. In this article, an overview of the main components of neurodegeneration, its key underlying mechanisms, and the more useful experimental models for investigative purposes will be given. In addition, the results of most relevant treatments based on neuroprotection, and the research gaps that should be filled will be critically reviewed.

Choroidal imaging using optical coherence tomography:techniques and interpretations.

The choroid is vascularized membranous tissue that supplies oxygen and nutrients to the photoreceptors and outer retina. Choroidal vessels underlying the retinal pigment epithelium are difficult to visualize by ophthalmoscopy and slit-lamp examinations. Optical coherence tomography (OCT) imaging made significant advancements in the last 2 decades; it allows visualization of the choroid and its vasculature. Enhanced-depth imaging techniques and swept-source OCT provide detailed choroidal images. A recent breakthrough, OCT angiography (OCTA), visualizes blood flow in the choriocapillaris. However, despite using OCTA, it is hard to visualize the choroidal vessel blood flow. In conventional structural OCT the choroidal vessel structure appears as a low-intensity objects. Image-processing techniques help obtain structural information about these vessels. Manual or automated segmentation of the choroid and binarization techniques enable evaluation of choroidal vessels. Viewing the three-dimensional choroidal vasculature is also possible using high-scan speed volumetric OCT. Unfortunately, although choroidal image analyses are possible using the images obtained by commercially available OCT, the built-in function that analyzes the choroidal vasculature may be insufficient to perform quantitative imaging analysis. Physicians must do that themselves. This review summarizes recent choroidal imaging processing techniques and explains the interpretation of the results for the benefit of imaging experts and ophthalmologists alike.