PURPOSE: People with central vision loss (CVL) watch television, videos and movies, but often report difficulty and have reduced video comprehension. An approach to assist viewing videos is electronic magnification of the video itself, such as Bubble Magnification. METHODS: We created a Bubble Magnification technique that displayed a magnified segment around the centre of interest (COI) as determined by the gaze of participants with normal vision. The 15 participants with CVL viewed video clips shown with 2× and 3× Bubble Magnification, and unedited. We measured video comprehension and gaze coherence. RESULTS: Video comprehension was significantly worse with both 2× (p = 0.01) and 3× Bubble Magnification (p < 0.001) than the unedited video. There was no difference in gaze coherence across conditions (p ≥ 0.58). This was unexpected because we expected a benefit in both video comprehension and gaze coherence. This initial attempt to implement the Bubble Magnification method had flaws that probably reduced its effectiveness. CONCLUSIONS: In the future, we propose alternative implementations of Bubble Magnification, such as variable magnification and bubble size. This study is a first step in the development of an intelligent-magnification approach to providing a vision rehabilitation aid to assist people with CVL.
PURPOSE: To evaluate corneal subbasal nerve alterations in evaporative and aqueous-deficient dry eye disease (DED) as compared to controls. METHODS: In this retrospective, cross-sectional, controlled study, eyes with a tear break-up time of less than 10 s were classified as DED. Those with an anesthetized Schirmer's strip of less than 5 mm were classified as aqueous-deficient DED. Three representative in vivo confocal microscopy images were graded for each subject for total, main, and branch nerve density and numbers. RESULTS: Compared to 42 healthy subjects (42 eyes), the 70 patients with DED (139 eyes) showed lower total (18,579.0 ± 687.7 μm/mm2 vs. 21,014.7 ± 706.5, p = 0.026) and main (7,718.9 ± 273.9 vs. 9,561.4 ± 369.8, p < 0.001) nerve density, as well as lower total (15.5 ± 0.7/frame vs. 20.5 ± 1.3, p = 0.001), main (3.0 ± 0.1 vs. 3.8 ± 0.2, p = 0.001) and branch (12.5 ± 0.7 vs. 16.5 ± 1.2, p = 0.004) nerve numbers. Compared to the evaporative DED group, the aqueous-deficient DED group showed reduced total nerve density (19,969.9 ± 830.7 vs. 15,942.2 ± 1,135.7, p = 0.006), branch nerve density (11,964.9 ± 749.8 vs. 8,765.9 ± 798.5, p = 0.006), total nerves number (16.9 ± 0.8/frame vs. 13.0 ± 1.2, p = 0.002), and branch nerve number (13.8 ± 0.8 vs. 10.2 ± 1.1, p = 0.002). CONCLUSIONS: Patients with DED demonstrate compromised corneal subbasal nerves, which is more pronounced in aqueous-deficient DED. This suggests a role for neurosensory abnormalities in the pathophysiology of DED.
Glaucoma is a group of optic neuropathies characterised by the degeneration of retinal ganglion cells, resulting in damage to the optic nerve head (ONH) and loss of vision in one or both eyes. Increased intraocular pressure (IOP) is one of the major aetiological risk factors in glaucoma, and is currently the only modifiable risk factor. However, 30-40% of glaucoma patients do not present with elevated IOP and still proceed to lose vision. The pathophysiology of glaucoma is therefore not completely understood, and there is a need for the development of IOP-independent neuroprotective therapies to preserve vision. Neuroinflammation has been shown to play a key role in glaucoma and, specifically, the NLRP3 inflammasome, a key driver of inflammation, has recently been implicated. The NLRP3 inflammasome is expressed in the eye and its activation is reported in pre-clinical studies of glaucoma. Activation of the NLRP3 inflammasome results in IL-1β processing. This pro inflammatory cytokine is elevated in the blood of glaucoma patients and is believed to drive neurotoxic inflammation, resulting in axon degeneration and the death of retinal ganglion cells (RGCs). This review discusses glaucoma as an inflammatory disease and evaluates targeting the NLRP3 inflammasome as a therapeutic strategy. A hypothetical mechanism for the action of the NLRP3 inflammasome in glaucoma is presented.
PURPOSE: To evaluate the clinical effect of topical cyclosporine A (CsA) (0.05%) on dry eye patients with Sjogren's syndrome (SS) and non-Sjogren's syndrome (NSS). METHOD: This retrospective comparative study includes the dry eye (DE) patients who were treated with topical CsA. DE patients were divided into two groups as follows: DE with Sjogren's syndrome (DE-SS) and DE with Non-Sjogren's syndrome (DE-NSS). Dry eye parameters were recorded at baseline and each visit. RESULTS: Schirmer's test 1 scores were 2.7 ± 0.5 mm at baseline and 3.5 ± 0.7 mm at 12th month in DE-SS, 2.9 ± 0.7 mm at baseline and 9.5 ± 0.7 mm in DE-NSS groups at 12th month. Mean ST score was higher in DE-NSS group than DE-SS group at sixth and 12th months of the treatment (both p = 0.001). Tear break-up time score showed a significant improvement in DE-NSS group, and it was lower in DE-NSS group than DE-SS group group at sixth and 12th months of the treatment (p = 0.044 and 0.027, respectively). Mean OSDI score was lower in DE-NSS group than DE-SS group at sixth and 12th months of the treatment (p = 0.030 and 0.032, respectively). CONCLUSION: Topical CsA seems to be more effective in the treatment of the DE-NSS.
AIMS: To compare widefield swept-source optical coherence tomography angiography (WF SS-OCTA) with ultra-widefield colour fundus photography (UWF CFP) and fluorescein angiography (UWF FA) for detecting diabetic retinopathy (DR) lesions. METHODS: This prospective, observational study was conducted at Massachusetts Eye and Ear from December 2018 to October 2019. Proliferative DR, non-proliferative DR and diabetic patients with no DR were included. All patients were imaged with a WF SS-OCTA using a Montage 15×15 mm scan. UWF CFP and UWF FA were taken by a 200°, single capture retinal imaging system. Images were independently evaluated for the presence or absence of DR lesions including microaneurysms (MAs), intraretinal microvascular abnormalities (IRMAs), neovascularisation elsewhere (NVE), neovascularisation of the optic disc (NVD) and non-perfusion areas (NPAs). All statistical analyses were performed using SPSS V.25.0. RESULTS: One hundred and fifty-two eyes of 101 participants were included in the study. When compared with UWF CFP, WF SS-OCTA was found to be superior in detecting IRMAs (p<0.001) and NVE/NVD (p=0.007). The detection rates of MAs, IRMAs, NVE/NVD and NPAs in WF SS-OCTA were comparable with UWF FA images (p>0.05). Furthermore, when we compared WF SS-OCTA plus UWF CFP with UWF FA, the detection rates of MAs, IRMAs, NVE/NVD and NPAs were identical (p>0.005). Agreement (κ=0.916) between OCTA and FA in classifying DR was excellent. CONCLUSION: WF SS-OCTA is useful for identification of DR lesions. WF SS-OCTA plus UWF CFP may offer a less invasive alternative to FA for DR diagnosis.
PURPOSE: To compare neonatal eye screening using the red reflex test (RRT) versus the wide-field digital imaging (WFDI) system. METHODS: Prospective cohort study. Newborns (n = 380, 760 eyes) in the Maternity Ward of Irmandade Santa Casa de Misericórdia de São Paulo hospital from May to July 2014 underwent RRT by a paediatrician and WFDI performed by the authors. Wide-field digital imaging (WFDI) images were analysed by the authors. Validity of the paediatrician's RRT was assessed by unweighted kappa [κ] statistic, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). RESULTS: While WFDI showed abnormalities in 130 eyes (17.1%), RRT was only abnormal in 13 eyes (1.7%). Wide-field digital imaging (WFDI) detected treatable retina pathology that RRT missed including hyphema, CMV retinitis, FEVR and a vitreous haemorrhage. The sensitivity of the paediatrician's RRT to detect abnormalities was poor at 0.77% (95% confidence interval, CI, 0.02%-4.21%) with a PPV of only 7.69% (95% CI, 1.08%-38.85%). Overall, there was no agreement between screening modalities (κ = -0.02, 95% CI, -0.05 to 0.01). The number needed to screen to detect ocular abnormalities using WFDI was 5.9 newborns and to detect treatable abnormalities was 76 newborns. CONCLUSION: While RRT detects gross abnormalities that preclude visualization of the retina (i.e. media opacities and very large tumours), only WFDI consistently detects subtle treatable retina and optic nerve pathology. With a higher sensitivity than the current gold standard, universal WFDI allows for early detection and management of potentially blinding ophthalmic disease missed by RRT.
Optical Coherence Tomography (OCT) enables non-invasive imaging of the retina and is used to diagnose and manage ophthalmic diseases including glaucoma. We present the first large-scale genome-wide association study of inner retinal morphology using phenotypes derived from OCT images of 31,434 UK Biobank participants. We identify 46 loci associated with thickness of the retinal nerve fibre layer or ganglion cell inner plexiform layer. Only one of these loci has been associated with glaucoma, and despite its clear role as a biomarker for the disease, Mendelian randomisation does not support inner retinal thickness being on the same genetic causal pathway as glaucoma. We extracted overall retinal thickness at the fovea, representative of foveal hypoplasia, with which three of the 46 SNPs were associated. We additionally associate these three loci with visual acuity. In contrast to the Mendelian causes of severe foveal hypoplasia, our results suggest a spectrum of foveal hypoplasia, in part genetically determined, with consequences on visual function.
Ophthalmology has been at the forefront of medical specialties adopting artificial intelligence. This is primarily due to the "image-centric" nature of the field. Thanks to the abundance of patients' OCT scans, analysis of OCT imaging has greatly benefited from artificial intelligence to expand patient screening and facilitate clinical decision-making.In this review, we define the concepts of artificial intelligence, machine learning, and deep learning and how different artificial intelligence algorithms have been applied in OCT image analysis for disease screening, diagnosis, management, and prognosis.Finally, we address some of the challenges and limitations that might affect the incorporation of artificial intelligence in ophthalmology. These limitations mainly revolve around the quality and accuracy of datasets used in the algorithms and their generalizability, false negatives, and the cultural challenges around the adoption of the technology.
PURPOSE: To describe 3 cases of corneal clearance after the use of topical rho-kinase inhibitor, netarsudil, in the setting of endothelial cell dysfunction in comparison to one case without corneal clearance after the use of netarsudil. METHODS: Four patients presenting to a busy academic clinical corneal practice with visual complaints from corneal edema secondary to endothelial cell dysfunction were treated with topical netarsudil one drop daily in the affected eye. RESULTS: Corneal clearance was observed in 1) a case of peripheral corneal edema in the setting of iridocorneal endothelial syndrome after 4 weeks on netarsudil, 2) a case of corneal edema in the setting of early penetrating keratoplasty graft failure after 2-week use of netarsudil, and 3) a case of corneal edema in the setting of chronic penetrating keratoplasty graft failure after 4-week use of netarsudil. Corneal clearance was not observed in a case of corneal edema in the setting of pseudophakic bullous keratopathy from previous complicated intraocular lens exchange surgery with placement of an anterior chamber intraocular lens after the use of netarsudil for 12 weeks. CONCLUSIONS: Addition of topical rho-kinase inhibitor in the form of netarsudil can result in corneal clearance in a variety of certain cases of endothelial cell dysfunction, not previously documented in the literature.
BACKGROUND: Patients presenting to emergency departments for ophthalmic emergencies benefit from prompt evaluation. However, Few emergency departments (EDs) have ophthalmologists on call, and eye care provided in EDs without ophthalmic services can be inaccurate. METHODS: We review the current state of ophthalmic telemedical care in EDs and highlight important considerations when implementing telemedicine in this setting. RESULTS: Telemedicine allows ophthalmologists to work with on-site emergency care providers to interview and examine patients remotely in EDs, enabling proper assessment of patient history, visual acuity, pupils, intraocular pressure, as well as the anterior and posterior segment. To date, patients' perceptions of this new model of care have been largely positive. DISCUSSION: The use of telemedical consultations for remote evaluation of patients with ophthalmic complaints stands to improve the quality of care provided to patients and extend the reach of remote ophthalmologists. The onset of the COVID-19 pandemic and the risk of in-person care further highlights the potential for telemedicine to augment existing models of emergency care.
Purpose: In this review we discuss the broad clinical application of qAF and provide a descriptive summary of the phenotypic findings of different chorioretinal pathologies.Background: Quantitative Fundus autofluorescence (qAF) is a novel developing technology that can aid in diagnosis and longitudinal disease monitoring by measuring and comparing autofluorescence intensities. Fundus autofluorescence (FAF) is a noninvasive imaging method that creates a density map of the fluorophores of the ocular fundus and provides both functional and topographic anatomic information about retinal cells. Fluorophores are molecules that have the ability to temporarily absorb irradiated light, and emit a small amount of light of a different wavelength. Different endogenous fluorophores can be found in the ocular fundus. Changes in accumulation of retinal fluorophores usually indicate retinal pathology and create characteristic patterns of hyper-autofluorescence and hypo-autofluorescence that help establish a diagnosis.Conclusion: qAF allows a safe non-invasive visualization of the retina, enables a standard for AF intensities comparison and aids to the understanding of the genotype-phenotype correlations.
The cornea actively maintains its own avascular status to preserve its ultimate optical function. This corneal avascular state is also defined as "corneal angiogenic privilege", which results from a critical and sensitive balance between anti-angiogenic and pro-angiogenic mechanisms. In our review, we aim to explore the complex equilibrium among multiple mediators which prevents neovascularization in the resting cornea, as well as to unveil the evolutive process which leads to corneal angiogenesis in response to different injuries.
BACKGROUND: Photophobia is a potentially debilitating symptom often found in dry eye disease (DE), migraine and traumatic brain injury (TBI). METHODS: We conducted a review of the literature via a PubMed search of English language articles with a focus on how photophobia may relate to a shared pathophysiology across DE, migraine and TBI. RESULTS: DE, migraine and TBI are common conditions in the general population, are often comorbid, and share photophobia as a symptom. Across the three conditions, neural dysregulation of peripheral and central nervous system components is implicated in photophobia in various animal models and in humans. Enhanced activity of the neuropeptide calcitonin gene-related peptide (CGRP) is closely linked to photophobia. Current therapies for photophobia include glasses which shield the eyes from specific wavelengths, botulinum toxin, and inhibition of CGRP and its receptor. Many individuals have persistent photophobia despite the use of these therapies, and thus, development of new therapies is needed. CONCLUSIONS: The presence of photophobia in DE, migraine and TBI suggests shared trigeminothalamic pathophysiologic mechanisms, as explained by central neuroplasticity and hypersensitivity mediated by neuropeptide CGRP. Treatment strategies which target neural pathways (ie, oral neuromodulators, transcutaneous nerve stimulation) should be considered in patients with persistent photophobia, specifically in individuals with DE whose symptoms are not controlled with traditional therapies.
PURPOSE: Rule-based approaches to determining glaucoma progression from visual fields (VFs) alone are discordant and have tradeoffs. To detect better when glaucoma progression is occurring, we used a longitudinal data set of merged VF and clinical data to assess the performance of a convolutional long short-term memory (LSTM) neural network. DESIGN: Retrospective analysis of longitudinal clinical and VF data. PARTICIPANTS: From 2 initial datasets of 672 123 VF results from 213 254 eyes and 350 437 samples of clinical data, persons at the intersection of both datasets with 4 or more VF results and corresponding baseline clinical data (cup-to-disc ratio, central corneal thickness, and intraocular pressure) were included. After exclusion criteria-specifically the removal of VFs with high false-positive and false-negative rates and entries with missing data-were applied to ensure reliable data, 11 242 eyes remained. METHODS: Three commonly used glaucoma progression algorithms (VF index slope, mean deviation slope, and pointwise linear regression) were used to define eyes as stable or progressing. Two machine learning models, one exclusively trained on VF data and another trained on both VF and clinical data, were tested. MAIN OUTCOME MEASURES: Area under the receiver operating characteristic curve (AUC) and area under the precision-recall curve (AUPRC) calculated on a held-out test set and mean accuracies from threefold cross-validation were used to compare the performance of the machine learning models. RESULTS: The convolutional LSTM network demonstrated 91% to 93% accuracy with respect to the different conventional glaucoma progression algorithms given 4 consecutive VF results for each participant. The model that was trained on both VF and clinical data (AUC, 0.89-0.93) showed better diagnostic ability than a model exclusively trained on VF results (AUC, 0.79-0.82; P < 0.001). CONCLUSIONS: A convolutional LSTM architecture can capture local and global trends in VFs over time. It is well suited to assessing glaucoma progression because of its ability to extract spatiotemporal features that other algorithms cannot. Supplementing VF results with clinical data improves the model's ability to assess glaucoma progression and better reflects the way clinicians manage data when managing glaucoma.
Neurotrophic Keratitis (NK) is a degenerative disorder of the cornea characterized by decreased or absent sensory corneal innervation, corneal epitheliopathy and impaired healing.The clinical presentation of NK can range from persistent epithelial defects to corneal perforation and management is often both challenging and protracted. Historically, the management of NK has consisted of non-specific strategies to facilitate corneal epithelial healing such as lubrication, bandage contact lenses and tarsorrhaphy. Recent advances in the development of therapeutics for NK have provided new and efficacious targeted strategies for its management.In this article, we review recombinant human nerve growth factor (Cenegermin), currently approved for clinical use in the United States and Europe, as well as other promising therapeutic options that are in pre-clinical development such as thymosine β4, connexin43 inhibitors, and artificial extracellular matrix components.