Subretinal Hemorrhage Research Articles

Successful management of subretinal hemorrhage in patient with AMD

Successful management of subretinal hemorrhage in patient with AMD

Targeting Oxidative Stress and Inflammation in the Eye: Insights from a New Model of Experimental Autoimmune Uveitis

Autoimmune uveitis is a relapsing blind-causing ocular condition with complex pathogenesis that is not completely understood. There is a high demand for accurate animal models of experimental autoimmune uveitis (EAU) suitable for elucidating the molecular mechanisms of the disease and testing new therapeutic approaches. Here, we demonstrated that photoreceptor Ca2+/Zn2+-sensor protein recoverin is a uveoretinal antigen in albino rabbits provoking typical autoimmune chorioretinitis 2–4 weeks after immunization. The pathologic process in recoverin-induced EAU shared features with human disease and included lymphocytic infiltration of the retina, Dalen–Fuchs nodules and foci of subtotal or total retinal atrophy, manifested as a decrease in amplitude of the a-wave of the electroretinogram. In some cases, changes in the retinal vascular pattern and subretinal hemorrhages were also observed. These signs were accompanied by a gradual accumulation of serum antibodies against recoverin. Biochemical examination of the aqueous humor (AH) revealed typical characteristics of inflammation and oxidative stress, including increased levels of TNF-α and IL-6 and decreased levels of IL-10, as well as decreased total antioxidant activity, superoxide dismutase and glutathione peroxidase activities, and increased zinc concentration. Consistently, metabolomic and targeted lipidomic analysis of AH showed high lactate and low ascorbic acid levels in early EAU; increased levels of key pro-inflammatory signaling lipids such as PGE2, TXB2, 11-HETE and Lyso-PAF; and reduced levels of the anti-inflammatory fatty acid DHA in advanced stages of the disease. Uveitic AH became enriched with recoverin, confirming disruption of the blood–ocular barrier and photoreceptor damage. Notably, the application of mitochondria-targeted antioxidant therapy impeded EAU progression by maintaining local antioxidant activity and suppressing TNF-α, IL-6 and PGE2 signaling. Overall, our results demonstrate that recoverin-induced EAU in rabbits represents an accurate model of human autoimmune posterior uveitis and suggest new directions for its therapy that can be trialed using the developed model.

Intravitreal Melphalan versus Topotecan for Vitreous Seeds in Retinoblastoma: A Comparative Study of 64 Asian Indian Eyes

PurposeTo compare the outcomes of intravitreal melphalan (IVit-M) versus intravitreal topotecan (IVit-T) for vitreous seeds (VS) in retinoblastoma (RB). Study designRetrospective interventional study. ParticipantsPatients of RB with VS receiving intravitreal chemotherapy between December 2012 and December 2022, at a single quaternary ocular oncology referral center. InterventionIVit-M injection of 25mcg/0.1cc in 25 eyes and IVit-T. of 30mcg/0.15cc in 39 eyes. OutcomesResolution of VS, globe salvage, intravitreal chemotherapy-related complications ResultsThe mean age at presentation was 28 months (median, 24 months; range, 4 to 144 months) for the IVit-M group and 25 months (median, 24 months; range, 2 to 60 months) for the IVit-T group. At the time of initiation of intravitreal injection, the VS belonged to type 1 (1 (4%) vs. 1 (3%)), type 2 (9 (36%) vs. 14 (36%)), type 3 (8 (32%) vs.18 (46%)), or a combination of these (7 (28%) vs. 6 (15%)) in IVit-M and IVit-T groups, respectively. Complete resolution of VS following intravitreal chemotherapy was seen in 22 (92%) and 28 (72%) eyes (p=0.069) in IVit-M and IVit-T groups, respectively. At a mean follow-up period of 44 months after the first IVit-C injection in the IVit-M group and 19 months in the IVit-T group, globe salvage was higher in the IVit-T group (77%) than in the IVit-M group (60%, p=0.148), respectively. Posterior segment complications were significantly higher in the IVit-M group than in the IVit-T group (p<0.001). These included retinal pigment epithelial atrophy (p<0.001), optic atrophy (p<0.001), vascular attenuation (p<0.001), and retinal/ subretinal hemorrhages (p=0.004). ConclusionIVit-T is as efficacious as IVit-M for controlling VS in RB, with a better safety profile in pigmented Asian Indian eyes.

Submacular hemorrhage: My personal journey to the goal.

Acute submacular hemorrhage (SMH) can be caused by various diseases including age-related macular degeneration (AMD), polypoidal choroidal vasculopathy (PCV), and retinal arterial microaneurysm (RAM). The natural course of submacular hemorrhage is generally poor. Animal studies have suggested that the removal of subretinal hemorrhage may effectively reduce retinal damage caused by hemorrhage in humans and removal of submacular hemorrhage have been performed with limited visual outcomes. Pneumatic displacement involving intravitreal expansile gas with or without adjunctive intravitreal injection of tissue plasminogen activator (tPA) has demonstrated effective displacement of SMH and improvement in visual acuity in the majority of cases. Although tPA may not be indispensable, its use may facilitate displacement. Combining pneumatic displacement with vitrectomy and subretinal injection of tPA may achieve superior displacement of SMH compared to pneumatic displacement of SMH, implying that pneumatic displacement of SMH with vitrectomy and subretinal injection may offer enhanced effectiveness in SMH displacement,while noobvious different was found in visual outcomes between the two treatments.Complications associated with these procedures encompass breakthrough hemorrhage, retinal detachment and macular hole formation. Breakthrough hemorrhage is more commonly observed following pneumatic displacement whereas retinal detachment appears to be more prevalent following vitrectomy. Macular hole formation subsequent to vitrectomy represents a significant complication, particularly in eyes with SMH attributed to ruptured retinal arterial microaneurysm. Both pneumatic displacement and vitrectomy present advantages and disadvantages, and the superiority between the two remains undetermined. Sequential strategy for the treatment of submacular hemorrhage is another option. As the initial step, pneumatic displacement of SMH should be attempted, and if displacement is insufficient, pneumatic displacement following vitrectomy with subretinal injection of tPA may be pursued. Further investigations are warranted to ascertain optimal management strategies for SMH leading to improved outcomes. KEY MESSAGES: What is known • Pneumatic displacement with/without intravitreal tPA injection, and vitrectomy with subretinal tPA injection and gas are the two major treatments for submacular hemorrhage. What is new • No obvious different was found in visual outcomes between vitrectomy, subretinal tPA injection and gas, and intravitreal tPA injection and gas while vitrectomy with subretinal tPA injection and gas may achieve better displacement of submacular hemorrhage. • Macular hole formation is a specific complication for submacular hemorrhage due to ruptured retinal arterial macroaneurysm.

Role of fundus autofluorescence imaging in the management of submacular hemorrhage

PurposeTo evaluate the baseline characteristics of fundus autofluorescence (FAF) in patients with submacular hemorrhage (SMH).MethodsThis retrospective study included patients diagnosed with treatment-naive, foveal-involving subretinal hemorrhage (size > 2-disc diameters) of any etiology, presenting between June 2017 and June 2023. Only cases with good-quality color fundus photographs, optical coherence tomography (OCT) scans, and blue-light FAF images at baseline were included. SMH imaging characteristics were documented and correlated with treatment outcomes. A successful treatment outcome was defined as the reduction, displacement or clearance of the SMH from beneath the fovea.ResultsNineteen cases of SMH (13 males, 6 females), ranging from 14 to 85 years, were analyzed. Neovascular age-related macular degeneration (nAMD) was the most common etiology (n = 11, 58%). Baseline visual acuity ranged from 6/9 to counting fingers at ½ meter, with a median presentation time of 7 days from symptom onset (range: 1–57 days). Treatment success was observed in 13 eyes (68%). Hypoautofluoroscence on FAF was significantly associated with SMH resolution (p = 0.021). However, no association was found between treatment success and clinical hemorrhage characteristics (p = 0.222), OCT findings (p = 0.222), or specific treatments (p > 0.05). Hypoautofluoroscence on FAF was the sole predictor of treatment success, as demonstrated by Spearman’s correlation (r = 0.637; p = 0.003) and linear regression analysis (p = 0.003).ConclusionFAF, in conjunction with color fundus photography and OCT, may provide valuable insights for clinicians in formulating treatment strategies for patients with SMH. Hypoautofluoroscence on FAF was a significant predictor of successful SMH resolution in this study.

Comprehensive review of angioid streaks.

Angioid streaks are irregular breaks in the brittle Bruch's membrane and commonly present as pigmented linear lines radiating from the optic disc. They may be associated with systemic disease in up to 50% of the patients. Systemic diseases such as pseudoxanthoma elasticum, Paget's disease, and hemoglobinopathies are commonly associated with angioid streaks. However, they may be idiopathic in a small number of cases. Patients may be asymptomatic until complications such as choroidal neovascular membrane and subretinal hemorrhage involving the fovea develop. Due to the brittle nature of Bruch's membrane, even minor trauma could lead to subretinal hemorrhage in these eyes. Diagnosis is commonly made through clinical examination and investigations such as fundus autofluorescence and optical coherence tomography. Treatment consists of management of the choroidal neovascular membrane commonly through intravitreal antivascular endothelial growth factor injections. In this review, we provide an overview of angioid streaks right from their epidemiology to their management.

INTRAVITREAL ANTI-VASCULAR ENDOTHELIAL GROWTH FACTOR TREATMENT IN PATIENTS WITH NEOVASCULAR AGE-RELATED MACULAR DEGENERATION AND POOR VISUAL ACUITY.

To investigate the significance of intravitreal anti-vascular endothelial growth factor treatment in patients with neovascular age-related macular degeneration and poor visual acuity. Retrospective study of patients with neovascular age-related macular degeneration with baseline best-corrected visual acuity of ≤20/200. Patients were divided into regular treatment and scarce treatment groups according to whether they underwent consecutive intravitreal anti-vascular endothelial growth factor treatments at intervals of ≤4 months or not. A total of 131 eyes were included: 87 and 44 eyes in the regular treatment and scarce treatment groups, respectively. The regular treatment group showed significantly improved preservation of lesion size at both Years 1 and 2, with significantly fewer incidences of new subretinal hemorrhage. Improvements in visual acuity, reduction in central subfield macular thickness, and maximal height of choroidal neovascularization were significantly favorable in the regular treatment group at Year 1, and central subfield macular thickness was significantly decreased at Year 2. Survival analysis revealed that the regular treatment group had significantly greater preservation of visual acuity and lesion size than that in the scarce treatment group. Maintaining intravitreal anti-vascular endothelial growth factor treatment for patients with neovascular age-related macular degeneration and poor vision showed significant advantages in visual acuity and lesion size stability and reduced the incidence of new subretinal hemorrhage, which suggests preservation of paracentral vision.

Development and validation of optical coherence tomography (OCT) and OCT angiography prediction model for short-term vitreous haemorrhage secondary to polypoidal choroidal vasculopathy

AimsTo construct and validate an optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) image model for predicting the occurrence of short-term vitreous haemorrhage (VH) in polypoidal choroidal vasculopathy...

Prevalence, Features, and Outcomes of Type 1 Neovascularization in Eyes with Angioid Streaks

This study aimed to delineate the characteristics, prevalence, and outcomes of neovascularization (NV), particularly aneurysmal Type 1 NV, in patients with angioid streaks (AS) secondary to pseudoxanthoma elasticum (PXE), and to introduce a clinical classification based on multimodal imaging (MMI). Retrospective longitudinal cohort study. 85 patients (168 eyes) with AS secondary to PXE at two tertiary referral centers. Data collection included demographic, medical, and ocular histories. Diagnostic methods comprised fundus photography, autofluorescence, indocyanine green angiography, optical coherence tomography (OCT), and OCT angiography. Prevalence of Type 1 NV, visual acuity (VA), risk of exudation. Type 1 NV was identified in 127 eyes (76%), with 85 of these (67%) showing exclusively Type 1 NV. These lesions often originated around the disc, at sites of Bruch's membrane dehiscences, and followed the path of AS, extending to the posterior pole in 101 eyes (80%). Despite 65% of Type 1 NV remaining non-exudative, 36% evolved into exudative over five years, and 11 eyes experienced mid-peripheral subretinal hemorrhages. Aneurysmal dilations, observed in 57% of cases, substantially increased exudation risk (hazard ratio = 3.86, p=0.02). Despite treatment, VA significantly deteriorated in exudative Type 1 NV (p=0.02). Type 2 NV, detected in 56 eyes (33%), often coexisted with Type 1 NV and was associated with poorer visual outcomes and higher rates of macular atrophy. A classification of AS was developed, ranging from empty AS (stage 0, no NV) to advanced NV (stage 3, both Type 1 and Type 2 NV). Type 1 NV predominates in AS. Although predominantly non-exudative, its progression correlates with substantial visual impairment, similar to the deficits observed with Type 2 NV. Aneurysmal Type 1 NV poses a significant exudation risk, underscoring the need for vigilant monitoring.

Prothrombin deficiency with recurrent subretinal hemorrhage.

Ocular hemorrhage has been recorded in congenital factor deficiencies like hemophilia A, but it has never been documented in prothrombin deficiency. Here, we describe an unusual case of sudden vision loss in the right eye caused by subretinal hemorrhage following a coughing episode in a 67-year-old woman. Notably, the patient underwent left eye enucleation 12 years previously under similar circumstances due to subretinal hemorrhage. During the interview, it was discovered that the patient had a history of prothrombin deficiency, which was subsequently confirmed through laboratory testing. Aside from recurrent ocular bleeding and 1 instance of bleeding following dental extraction in childhood, there is no other history of bleeding. Subsequent molecular studies revealed a homozygous missense mutation at G1499A (Arg500Gln), a variant previously identified as R457Q. Although the likelihood of prothrombin deficiency initiating subretinal hemorrhage is low, it is likely to worsen retinal hemorrhage and contribute to difficulty in controlling bleeding. A comprehensive coagulation workup is essential in patients with ocular hemorrhage. Determining factor II activity should be included in individuals exhibiting variably prolonged prothrombin time and activated partial thromboplastin time with correction in mixing studies. Additional investigations, such as genetic sequencing and family studies, are advised for those with isolated low prothrombin levels.

BULBOSITIES AND INTERVORTEX VENOUS ANASTOMOSIS IN VENOUS OVERLOAD CHOROIDOPATHY MASQUERADING AS POLYPOIDAL CHOROIDAL VASCULOPATHY.

To describe a patient with venous overload choroidopathy in whom venous bulbosities masqueraded as polyps and intervortex venous anastomosis mimicked a branching vascular network, giving the appearance of polypoidal choroidal vasculopathy. The patient had complete ophthalmic examination including indocyanine green angiography and optical coherence tomography. Venous bulbosities were defined on indocyanine green angiography as focal dilations in which the diameter of the dilation is two times that of the host vessel. A 75-year-old woman presented with combined subretinal and subretinal pigment epithelium hemorrhages in the right eye. During indocyanine green angiography, focal nodular hyperfluorescent lesions connected to a network of vessels were observed, which looked like polyps and branching vascular network in polypoidal choroidal vasculopathy. In both eyes, the midphase angiogram had multifocal choroidal vascular hyperpermeability. There was late-phase placoid staining nasal to the nerve in the right eye. During enhanced depth imaging-optical coherence tomography evaluation, there were no retinal pigment epithelium elevations that would be expected with polyps or branching vascular network in the right eye. A double-layer sign was seen corresponding to the placoid area of staining. Diagnosis of venous overload choroidopathy and choroidal neovascularization membrane was made. She was treated with intravitreal antivascular endothelial growth factor injections for the choroidal neovascularization membrane. Indocyanine green angiography findings in venous overload choroidopathy may mimic polypoidal choroidal vasculopathy, but differentiation is essential because it has implications for treatment. Similar findings may have been misinterpreted in the past and may have previously contributed to conflicting clinical and histopathologic descriptions of polypoidal choroidal vasculopathy.

Разработка программы для персонализированного подхода в лечении субретинальных кровоизлияний

Abctract Software development for a personalized approach in the treatment of subretinal hemorrhages R.R. Fayzrakhmanov, E.D. Вosov, V.A. Bogdanova, I.I. Tumanov, G.O. Karpov N.I. Pirogov National Medical Surgical Center, Moscow, Russian Federation Institute of Advanced Training of Physicians N.I. Pirogov National Medical Surgical Center, Moscow, Russian Federation Design Bureau «Rus’», Moscow, Russian Federation Purpose. Development and clinical application of software for individual calculation of the volume of fibrinolytic infusion solution for surgical treatment of submacular hemorrhages. Material and methods. Based on the processing of optical coherence tomography data using threedimensional visualization, the program 3D volume calculator was developed. As a vitreoretinal intervention, a two-port 27G surgery was performed with controlled subretinal administration of a calculated recombinant prourokinase solution through a 38G cannula and hexafluoroethane tamponade at 20% of the volume of the vitreal cavity. Results. Developed software makes it possible to measure the volume of submacular hemorrhage, and also calculates an individualized amount of subretinal infusion solution for reliable displacement of the blood clot to the periphery. 2 weeks after surgery for submacular hemorrhage, complete dislocation was observed in 40 cases (93%). Conclusion. Сurrently, minimally invasive surgery and a personalized approach are the fundamental directions in modern ophthalmology. Application of the proposed software in clinical practice has proven its effectiveness in relation to morphological and functional perspectives in the treatment of submacular hemorrhages. Key words: submacular hemorrhage, software, calculation of fibrinolytic volume, minimally invasive surgery

Subretinal hemorrhages with subfoveal involvement after blunt ocular trauma, in a patient with pseudoxanthoma elasticum and angioid streaks

Subretinal hemorrhages with subfoveal involvement after blunt ocular trauma, in a patient with pseudoxanthoma elasticum and angioid streaks

A Second-Generation (44-Channel) Suprachoroidal Retinal Prosthesis: A Single-Arm Clinical Trial of Feasibility

To assess the feasibility of a second-generation (44-channel) suprachoroidal retinal prosthesis for provision of functional vision in recipients with end-stage retinitis pigmentosa (RP) over 2.7 years. Prospective, single-arm, unmasked interventional clinical trial. Four participants, with advanced RP and bare-light perception vision. The 44-channel suprachoroidal retinal prosthesis was implanted in the worse-seeing eye. Device stability, functionality, and adverse events were investigated at approximately 12-week intervals up to 140 weeks (2.7 years) postdevice activation. Serious adverse event (SAE) reporting, visual response outcomes, functional vision outcomes, and quality-of-life outcomes. All 4 participants (aged 39-66 years, 3 males) were successfully implanted in 2018, and there were no device-related SAEs over the duration of the study. A mild postoperative subretinal hemorrhage was detected in 2 recipients, which cleared spontaneously within 2weeks. OCT confirmed device stability and position under the macula. Improvements in localization abilities were demonstrated for all 4 participants in screen-based, tabletop, and orientation and mobility tasks. In addition, 3 of 4 participants recorded improvements in motion discrimination and 2 of 4 participants recorded substantial improvements in spatial discrimination and identification of tabletop objects. Participants reported their unsupervised use of the device included exploring new environments, detecting people, and safely navigating around obstacles. A positive effect of the implant on participants' daily lives in their local environments was confirmed by an orientation and mobility assessor and participant self-report. Emotional well-being was not impacted by device implantation or usage. The completed clinical study demonstrates that the suprachoroidal prosthesis raises no safety concerns and provides improvements in functional vision, activities of daily living, and observer-rated quality of life. Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Clinical study of ocular manifestations in patients with newly diagnosed and relapsed hematolymphoid malignancies at a tertiary care hospital

Objectives: To estimate the proportion of ocular manifestations in new and relapsed cases of various hematolymphoid malignancies and to determine an association between these ocular manifestations and the hematological parameters of the patients. Materials and Methods: The study was conducted in the department of ophthalmology in association with medical oncology. All patients with newly diagnosed or presenting with a relapse of hematolymphoid malignancies underwent a complete ocular evaluation. Results: A total of 63 patients were included in this study. The mean age of the patients was 34.71 ± 19.80 years. Acute myeloid leukemia and B-ALL accounted for 73% of the cases. At the time of examination, 47.61% of patients (n = 30) were newly diagnosed and 52.38% (n = 33) had relapsed. Acute leukemias had more probability of having ocular manifestations than chronic leukemias (P = 0.01). Subconjunctival hemorrhage was found to be the most common anterior segment finding (n = 10, 15.87%; P = 0.05). The most common posterior segment finding seen in both the right and left eyes was dot blot hemorrhages (n = 20). Those patients who had hemoglobin counts &lt;6.5 mg/dl had the most ophthalmic manifestations (n = 20); of which Roth spots were seen the most (n = 6; P = 0.04). And those who had platelet counts &lt;50,000 cells/cumm presented with Roth spots (n = 6, P = 0.05) followed by subretinal hemorrhages (n = 5, P = 0.05) and preretinal hemorrhages (n = 5, P = 0.05). Conclusion: Screening to detect ocular manifestations is of importance in hematolymphoid malignancy, especially in newly detected and relapsed cases. A complete ocular examination is recommended in these patients, as most patients are asymptomatic and ocular manifestation could be an early sign of worsening of the disease. Among the various blood parameters, low hemoglobin and platelet counts are definite indicators of the presence of intraretinal bleeding manifestations.

Outcomes after giant peripheral retinotomy and anterior flap retinectomy for rhegmatogenous retinal detachments with advanced proliferative vitreoretinopathy using small gauge vitrectomy.

To analyze the visual and anatomical outcomes for eyes with rhegmatogenous retinal detachment (RRD) and advanced proliferative vitreoretinopathy (PVR) undergoing giant peripheral retinotomy (GPR) using 25-gauge pars plana vitrectomy (PPV). In this retrospective multi-center study, patients with RRD with either anteroposterior or circumferential retinal shortening and advanced PVR requiring more than 90-degree GPR with/without relaxing retinotomy were included. Subjects of either gender, any age group, and with complete surgical notes were included. Outcome measures of the study included anatomical success (i.e. complete retinal re-attachment) at 6 months using survival analysis, visual outcomes, and post-operative complications. Forty-one eyes of 41 patients (33 males) with a mean age of 44.9 ± 21.4 years were included. At 6 months follow-up, anatomical success was seen in 29 eyes (70.7%) with a cumulative re-attachment rate of 66% (95% confidence interval = 48 = 79%). All re-detachments occurred at ≤6 months with a peak at 4-6 months (n = 9). Twenty-three eyes (56%) achieved ambulatory vision (5/200) or better. Direct perfluorocarbon liquid-silicone oil exchange was performed in 20 eyes. Intra-operative complications included persistent retinal folds (2 eyes), subretinal air (1 eye), and subretinal bleed (1 eye). Eleven eyes (26.8%) developed secondary glaucoma (2 eyes required a drainage device), and hypotony of ≤6 mmHg was noted in 3 eyes (7.3%). Corneal decompensation was noted in 8 eyes (19.5%), and 3 eyes (7.3%) underwent re-surgery for re-RRD. After GPR using small gauge PPV, two-thirds achieve anatomical success, and over half have ambulatory vision, but overall post-operative complications can occur in more than half of the eyes.

Both hemoglobin and hemin cause damage to retinal pigment epithelium through the iron ion accumulation

Subretinal hemorrhages result in poor vision and visual field defects. During hemorrhage, several potentially toxic substances are released from iron-based hemoglobin and hemin, inducing cellular damage, the detailed mechanisms of which remain unknown. We examined the effects of excess intracellular iron on retinal pigment epithelial (RPE) cells. A Fe2+ probe, SiRhoNox-1 was used to investigate Fe2+ accumulation after treatment with hemoglobin or hemin in the human RPE cell line ARPE-19. We also evaluated the production of reactive oxygen species (ROS) and lipid peroxidation. Furthermore, the protective effect of-an iron chelator, 2,2′-bipyridyl (BP), and ferrostatin-1 (Fer-1) on the cell damage, was evaluated. Fe2+ accumulation increased in the hemoglobin- or hemin-treated groups, as well as intracellular ROS production and lipid peroxidation. In contrast, BP treatment suppressed RPE cell death, ROS production, and lipid peroxidation. Pretreatment with Fer-1 ameliorated cell death in a concentration-dependent manner and suppressed ROS production and lipid peroxidation. Taken together, these findings indicate that hemoglobin and hemin, as well as subretinal hemorrhage, may induce RPE cell damage and visual dysfunction via intracellular iron accumulation.

Subretinal hemorrhage in macular neovascularization secondary to age-related macular degeneration managed with intravitreal faricimab monotherapy

Subretinal hemorrhage in macular neovascularization secondary to age-related macular degeneration managed with intravitreal faricimab monotherapy

Snakebite hemotoxin-induced unilateral retinopathy: Case report and review of the literature

Ocular manifestations of snakebite depend on the nature of envenomation. Neurotoxic venoms usually cause neurological manifestations such as ptosis and external ophthalmoplegia, whereas hemotoxic poisons cause hemorrhagic manifestations such as hemorrhagic retinopathy and arterial occlusions. However, most of the ocular manifestations present bilaterally. We report a unique case of a female in her 5th decade presenting with unilateral snakebite hemotoxin-induced retinopathy in the form of subretinal and preretinal hemorrhages presenting 5 days after the snakebite. She was managed conservatively. Preretinal and subfoveal bleed gradually resolved with fair visual recovery. Anatomical differences in the vasculature between the two eyes along with some degree of venous occlusion in the left eye might have contributed to such an asymmetrical presentation.

Predicting central choroidal thickness from colour fundus photographs using deep learning.

The estimation of central choroidal thickness from colour fundus images can improve disease detection. We developed a deep learning method to estimate central choroidal thickness from colour fundus images at a single institution, using independent datasets from other institutions for validation. A total of 2,548 images from patients who underwent same-day optical coherence tomography examination and colour fundus imaging at the outpatient clinic of Jichi Medical University Hospital were retrospectively analysed. For validation, 393 images from three institutions were used. Patients with signs of subretinal haemorrhage, central serous detachment, retinal pigment epithelial detachment, and/or macular oedema were excluded. All other fundus photographs with a visible pigment epithelium were included. The main outcome measure was the standard deviation of 10-fold cross-validation. Validation was performed using the original algorithm and the algorithm after learning based on images from all institutions. The standard deviation of 10-fold cross-validation was 73 μm. The standard deviation for other institutions was reduced by re-learning. We describe the first application and validation of a deep learning approach for the estimation of central choroidal thickness from fundus images. This algorithm is expected to help graders judge choroidal thickening and thinning.