Silver, aside from its physical properties making it popular for electric applications and in jewellery, has a history of being used to treat various medical conditions. 1 It has been used to treat mental illness, epilepsy, gastrointestinal disorders, and infectious diseases and in surgical prostheses. 1 A review performed by Drake and Hazelwood in 2005 suggested that metallic silver posed minimal risk to health—the most common side effects being argyria (greyish discoloration of the skin) and argyrosis (greyish discoloration of the sclera). 1 Exposure to soluble silver may result in toxic effects such as kidney, liver, respiratory, gastrointestinal, hematopoietic ...

Objective To develop a methodology to correlate optical coherence tomography (OCT) images and histopathological sections from the same eye. Part 1: To determine the best fixative for optimal OCT and histopathological analysis in post-mortem eyes. Part 2: A protocol is proposed to correlate histopathological features and OCT scans from the same post-mortem eyes. Design Experimental study. Participants Part 1: Twenty-three rabbit eyes and 14 post-mortem human eyes. Part 2: Nineteen post-mortem human eyes. Methods Part 1: Six different fixatives were tested, and specimens were evaluated on 4 criteria: globe shape, structure opacification, retinal detachment, and nuclear details. Part 2: Based ...

Deep learning is an emerging technology with numerous potential applications in Ophthalmology. Deep learning tools have been applied to different diagnostic modalities including digital photographs, optical coherence tomography, and visual fields. These tools have demonstrated utility in assessment of various disease processes including cataracts, glaucoma, age-related macular degeneration, and diabetic retinopathy. Deep learning techniques are evolving rapidly, and will become more integrated into ophthalmic care. This article reviews the current evidence for deep learning in ophthalmology, and discusses future applications, as well as potential drawbacks.

Wolfram syndrome (WS), also known by the acronym DIDMOAD (diabetes insipidus, diabetes mellitus, optic atrophy, and deafness), is an autosomal recessive, progressive neurodegenerative disease. Patients with WS characteristically present with early onset diabetes mellitus and optic atrophy in the first decade of life, 1 diabetes insipidus and deafness in the second decade, and urinary tract with neurological complications in the third decade. WS has been shown to be associated with mutations in the WFS1 or CISD2 (WFS2) gene, probably leading to impaired calcium homeostasis and consequent widespread cellular apoptosis. 2 , 3 Optic atrophy is a constant and profound feature in ...

Melanocytoma of the optic nerve head (ONH) is a benign pigmented hamartoma with rare malignant potential. Malignant transformation is seen in 1%–2% cases. 1 They may extend into the adjacent retina and the choroid. 2 Histopathologically, melanocytoma is composed of intensely pigmented round to oval nevus cells with benign features. Most cases are asymptomatic with no loss of visual acuity. 3 , 4 Diagnosis is based on ophthalmoscopic features. Ancillary tests such as ultrasonography and optical coherence tomography help in follow-up. Optical coherence tomography angiography (OCT-A) is a noninvasive imaging modality that can construct a map of blood flow in ...

In contrast to dystrophic calcification seen in several rare genetic disorders, such as pseudoxanthoma elasticum, generalized arterial calcification of infancy, and Keutel syndrome, hyperphosphatemic familial tumoural calcinosis (HFTC) is a rare disorder of phosphate metabolism characterized by hyperphosphatemia and primary ectopic or metastatic calcifications in various locations. 1 A recently published review reported eye involvement in 16% of cases having this disorder. 2 Ocular involvement includes calcifications on the eyelids, conjunctiva, and peripheral cornea; optic nerve head drusen (ONHD); and angioid streaks (AS). 3 , 4 , 5 The presence of ONHD and AS in HFTC was first described by Ghanchi et ...

Objective To assess the ability of novice clinicians to use a commercially available high-resolution anterior segment optical coherence tomography (HR-OCT) device to diagnose various lesions of the ocular surface and cornea. Methods Cross-sectional study. Twenty-six black-and-white HR-OCT images were projected, and clinicians were asked to determine whether the lesions represented ocular surface squamous neoplasia (OSSN) or another ocular surface pathology. A 20-minute instructional lecture was given on HR-OCT interpretation, and the same 26 images were shown. The clinicians were asked to repeat their assessment of the lesions. Thirty-four novice clinicians at the Bascom Palmer Eye Institute, Miami, FL, participated. A ...

Dear Editor: Purtscher retinopathy is an occlusive microvasculopathy associated with trauma and was first described by Purtscher. 1 It usually results from head trauma or chest compression. A similar condition as a result of nontraumatic cause is referred to as “Purtscher-like retinopathy.” The diagnosis is primarily clinical and includes unilateral or bilateral sudden vision loss with fundus features, including cotton wool spots, intraretinal hemorrhage, and pathognomonic Purtscher flecken (retinal whitening with periarteriolar sparing). These features result from the occlusion of precapillary arteriole possibly from fat embolus or leukoaggregates. 2 Fluorescein angiogram may show blocked choroidal fluorescence because of retinal whitening ...

Optic disc drusen (ODD) is hyaline material within the disc that frequently shows flecks of calcium. 1 Electron microscopic examination revealed that ODD is composed of aggregates of extracellular mitochondria containing calcium crystals. 2 Most diagnostic methods, such as B-scan ultrasonography and computed tomography, focus on the calcification signal. 3 However, calcification is not always detectable, as seen in the buried ODD. 4 Spectral-domain optical coherence tomography (SD-OCT) enables the acquisition of cross-sectional images of the optic nerve head with ODD. 5 , 6 , 7 Notably, SD-OCT can capture the margin of ODD without definite calcification. 5 , 6 ODD in childhood ...

Objective To describe optical coherence tomography angiography (OCTA) reflectance artifacts secondary to retinal pigment epithelial detachment (RPED). Design Retrospective review. Methods Four eyes from 4 subjects were included. Three presented with RPED and 1 eye was a normal control. Two eyes diagnosed with RPED and the normal eye were evaluated using en face OCTA centred at the fovea acquired using the RTVue XR Avanti (Optovue Inc). In the third eye with RPED, OCTA imaging was performed using a CIRRUS 5000 prototype modified to do OCTA imaging on a spectral domain OCT platform provided by Carl Zeiss Meditec, Inc. The segmented ...

Optical coherence tomography angiography (OCTA) is a novel imaging modality that incorporates blood motion contrast to create angiograms of the retinal vasculature in a noninvasive manner, without the use of dye. It is a safe procedure and can be repeated as frequently as desired. The use of OCTA for delineation of choroidal neovascular membranes, for the study of microvascular abnormalities in diabetic patients, to assess nonperfused areas in retinal occlusions and vascular changes in macular telangiectasia are some of the potential OCTA applications. However, it is not free of drawbacks. Major limitations include the small field of view and its ...

Paracentral acute middle maculopathy (PAMM) has been described as a hyperreflective band or plaque-like region on spectral-domain optical coherence tomography (SD-OCT) at the level of the inner nuclear layer (INL), which is straddled by the intermediate and deep retinal capillary plexuses. 1,2 PAMM has been reported to cause eccentric wedge-shaped lesions that extend to the edge of the foveal avascular zone. 3 Although these lesions resolve over time, patients are left with irreversible INL atrophy, resulting in a permanent paracentral visual field defect.

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Retinal astrocytic hamartomas are rare, benign glial tumours that most commonly accompany tuberous sclerosis complex but may occur with neurofibromatosis type 1 or as isolated cases. We present a case of an isolated retinal astrocytic hamartoma, evaluated with multimodal imaging including spectral domain optical coherence tomography (SD-OCT), en face OCT, and OCT angiography. OCT angiography is a novel, noninvasive method for analyzing the retinal capillary system. This modality revealed a central feeder vessel with an associated abnormal vascular plexus, which correlated with the topographic location of the tumour on en face OCT.

The point mutation in mitochondrial DNA (mtDNA) 3243A→G is associated with many clinical disorders such as MELAS (mitochondrial encephalomyopathy with lactic acidosis and stroke like episodes) and MIDD (maternally inherited diabetes and deafness). 1 MELAS is characterized by strokelike episodes with headache, episodic nausea and vomiting, and lactic acidosis. Other findings include renal failure, neurosensory hearing loss, diabetes mellitus, and short stature. 1 Ocular findings include pigmentary retinopathy, retinal pigment epithelial (RPE) atrophy, posterior subcapsular cataract, external ophthalmoplegia, and ptosis.

Retinal arteriovenous malformations (AVMs) are a rare congenital, nonhereditary vascular abnormality. They are typically unilateral and asymptomatic, ranging from a single arteriovenous communication to a complex anastomotic system. 1,2 The lesions most commonly involve the superotemporal arcade (41%), papillomacular bundle (34%), and optic disc (6%) 2,3 and are classified into 3 groups by Archer on the basis of capillary characteristics and systemic findings. 1 Characteristically, the lesions demonstrate rapid filling without capillary leakage on fluorescein angiography.

Objective This pilot study aimed to describe the swept-source optical coherence tomography (SS-OCT) features of a series of choroidal tumours. Design This was an observational case series. Participants Patients in our ocular oncology unit were recruited: 32 eyes belonging to 31 patients. Methods All of the patients underwent fundus photography, ultrasonography (US), fundus autofluorescence (FAF), and SS-OCT. The main assessed characteristics were maximal tumour diameter and thickness, inner structure, and disturbances in the choroidal layers, sclera, retinal pigment epithelium, and retina. Results The tumours examined consisted of 16 nevi, 6 lesions with risk factors for growth, 4 melanomas, 4 hemangiomas ...

Objective Our study aimed to characterize the natural course of vitreomacular traction (VMT) syndrome, on which discrepancies have been reported in previous publications, by spectral-domain optical coherence tomography (SD-OCT). Design Retrospective chart review. Participants A total of 23 eyes of 23 patients with idiopathic symptomatic VMT syndrome diagnosed and followed up in Peking Union Medical College Hospital from 2008 to 2013. Methods Clinical records of all patients who underwent SD-OCT examination and were diagnosed and followed up as idiopathic VMT syndrome were reviewed. Those who had at least 2 visits were included. The median observation period of the patients was ...

Objective To evaluate the efficacy of high-speed Fourier-domain optical coherence tomography (FD-OCT) and fundus microperimetry (MP-1) in identifying the anatomic and functional features of ischemic diabetic maculopathy. Design Prospective noninterventional study. Participants Forty-two consecutive eyes (23 patients) with ischemic diabetic maculopathy and 40 normal eyes (25 control subjects) were included in this study. Methods Best corrected visual acuity, ganglion cell complex (GCC) thickness measured with FD-OCT, and central light sensitivity recorded with MP-1 were evaluated. Results GCC thickness and light sensitivity were significantly reduced in all affected eyes versus control eyes. logMAR BVCA was significantly correlated with mean macular sensitivity ...

Pigmented paravenous retinochoroidal atrophy (PPRCA) is a rare ocular disease with unknown etiology characterized by bilateral retinal pigment epithelium (RPE) and choroidal atrophy along retinal veins usually found incidentally during an eye examination. 1 In the past, fluorescein angiography (FA), electrophysiologic tests, and visual field testing have helped in the diagnosis. 1–3 Noninvasive imaging techniques including fundus autofluorescence (FAF) and spectral-domain optical coherence tomography (SD-OCT) are now available to assist retina specialists in the diagnosis of retinal degenerations, dystrophies, 4,5 and also drug toxicity.

Objective To evaluate the effects of posterior capsular opacification (PCO) and Nd:YAG laser capsulotomy on the evaluation of peripapillary retinal nerve fibre layer (RNFL) as measured by Stratus (Carl Zeiss Meditec, Dublin, CA) optical coherence tomography (OCT). Design Prospective interventional case series. Participants We studied 98 eyes of 89 patients experiencing PCO. Methods We performed a complete ophthalmologic examination and evaluation of RNFL as measured by Stratus OCT before and after Nd:YAG capsulotomy. The patients were classified on the basis of PCO score or signal strength (SS) obtained by prelaser OCT scans. Results The preoperative and postoperative peripapillary ...