Niloofar Piri

Choroidal Hyperreflective Foci in Stargardt Disease Shown by Spectral-Domain Optical Coherence Tomography Imaging: Correlation With Disease Severity

IMPORTANCE The presence of choroidal hyperreflective foci in Stargardt disease is, to our knowledge, a potentially new finding. Evaluation of these foci may aid in better understanding of the disease process. OBJECTIVES To report the presence of choroidal hyperreflective foci in spectral-domain optical coherence tomography (SD-OCT) images from eyes with Stargardt disease and investigate the relationship between the number of hyperreflective foci and disease severity. DESIGN, SETTING, AND PARTICIPANTS Twenty-six eyes of 13 patients with a clinical diagnosis of Stargardt disease were evaluated in a retrospective case series. Patient data were collected between January 1, 2009, and August 31, 2014. MAIN OUTCOMES AND MEASURES The number of choroidal hyperreflective foci in Stargardt disease as well as correlation with visual acuity, central macular thickness (CMT), and disease duration were the main outcomes. A total of 707 macular SD-OCT scans of 13 patients with Stargardt disease were reviewed and evaluated for the presence and number of retinal/choroidal hyperreflective foci, central macular thickness, visual acuity, and disease duration. Enhanced depth imaging with OCT (EDI-OCT) scans available for 2 patients were compared with SD-OCT scans. A PubMed/Google search was performed to identify SD-OCT images in Stargardt disease; these findings were reviewed for the presence of choroidal hyperreflective foci. RESULTS The mean (SD) numbers of hyperreflective foci in each retinal/choroidal layer in decreasing frequency were as follows: Bruch membrane/retinal pigment epithelial (RPE) complex, 78.22 (24.39); choriocapillaris, 25.77 (17.57); Sattler layer, 18.59 (12.89); outer retina, 16.64 (6.96); inner retina, 0.95 (1.58); and Haller layer, 0.73 (0.87). The number of hyperreflective foci in the Bruch membrane/RPE complex increased exponentially with decreasing CMT (R2 = 0.99; P = .008). The number of hyperreflective foci in the Bruch membrane/RPE complex, choriocapillaris, and Sattler layer increased proportionally with decreasing visual acuity (R2 = 0.97, R2 = 0.95, and R2 = 0.99, respectively; and P = .007, P = .006, and P = .008, respectively). Direct correlation existed between the number of hyperreflective foci in the choriocapillaris and the Sattler layer and disease duration (R2 = 0.98 and R2 = 0.99, respectively; and P = .006 and P =.009, respectively). In the 10 studies on Stargardt disease, choroidal hyperreflective foci were present in 51 of 54 SD-OCT images (94%). CONCLUSIONS AND RELEVANCE Based on the findings of the present study, choroidal hyperreflective foci in Stargardt disease, prominent at the Bruch membrane/RPE complex, choriocapillaris, and Sattler layer, correlate with disease severity in terms of retinal atrophy, decline in vision, and disease duration. Further studies are necessary to assess whether these findings are unique to Stargardt disease.

A comparison of 3D video display and 2D video display in the ability to enhance medical students’ understanding of different steps of vitreoretinal surgical procedures

Purpose We investigated the effect of graded range of horizontal duction on the shape of the peripapillary Bruchs membrane (ppBM) and optic nerve head (ONH). Methods In 50 eyes of 25 normal subjects, the ONH and peripapillary retina were imaged by optical coherence tomography (OCT) in central gaze and incremental angles of add- and abduction. Displacements of the Bruchs membrane opening (BMO), optic cup (OC), and change in ONH angle in eccentric gazes were compared to those of central gaze, in add- and abduction. Results With increasing duction, the nasal edge of the BMO (nBMO) shifted progressively anteriorly in adduction and posteriorly in abduction, while the temporal edge of the BMO (tBMO) shifted posteriorly in adduction and anteriorly in abduction. The summed absolute nBMO and tBMO displacements in 30° and 35° adduction significantly exceeded those in comparable abduction angles (P < 0.005 for both). The ONH progressively tilted temporally in adduction and nasally in abduction; absolute ONH tilt in adduction was significantly greater than that in abduction for 30° and 35° ductions (P < 0.005 for both). BMO displacement and ONH tilt in adduction exhibited bilinear behavior, with greater effects for both at angles exceeding 26°. The OC shifted significantly farther anteriorly in abduction than adduction at every angle from 10° to 35°. Conclusions Horizontal duction deforms the ONH and ppBM, but more in adduction than in abduction, and increasingly so for angles greater than 26°. This behavior is consistent with optic nerve sheath tethering for adduction exceeding 26°.

Homozygosity Mapping and Whole Exome Sequencing Reveal a Novel Homozygous COL18A1 Mutation Causing Knobloch Syndrome

The aim of this study was to identify the genetic basis of a chorioretinal dystrophy with high myopia of unknown origin in a child of a consanguineous marriage. The proband and ten family members of Iranian ancestry participated in this study. Linkage analysis was carried out with DNA samples of the proband and her parents by using the Human SNP Array 6.0. Whole exome sequencing (WES) was performed with the patients’ DNA. Specific sequence alterations within the homozygous regions identified by whole exome sequencing were verified by Sanger sequencing. Upon genetic analysis, a novel homozygous frameshift mutation was found in exon 42 of the COL18A1 gene in the patient. Both parents were heterozygous for this sequence variation. Mutations in COL18A1 are known to cause Knobloch syndrome (KS). Retrospective analysis of clinical records of the patient revealed surgical removal of a meningocele present at birth. The clinical features shown by our patient were typical of KS with the exception of chorioretinal degeneration which is a rare manifestation. This is the first case of KS reported in a family of Iranian ancestry. We identified a novel disease-causing (deletion) mutation in the COL18A1 gene leading to a frameshift and premature stop codon in the last exon. The mutation was not present in SNP databases and was also not found in 192 control individuals. Its localization within the endostatin domain implicates a functional relevance of endostatin in KS. A combined approach of linkage analysis and WES led to a rapid identification of the disease-causing mutation even though the clinical description was not completely clear at the beginning.

High-definition Optical Coherence Tomography Findings in Acute Idiopathic Blind Spot Enlargement (AIBSE) Syndrome

Acute idiopathic blind spot enlargement (AIBSE) syndrome is characterized by an enlarged blind spot that can occur either as an isolated finding or as a part of several other chorioretinopathies, such as acute zonal occult outer retinopathy (AZOOR), acute macular neuroretinopathy (AMN), multiple evanescent white dot syndrome (MEWDS), and multifocal choroiditis and panuveitis (MCP). Current belief is that these entities are a spectrum of outer retinal inflammatory disorders that regardless of etiology may result in overlapping clinical features. 1–3

Fuch's heterochromic iridocyclitis in Iran: Is the disease going to fade away?

353 Dear Editor, There is a diverse group of well‐known uveitic entities which are of unknown etiology. Many experts believe that the majority of them are the consequences of unknown infectious pathogens, most probably viral.[1] Fuch’s heterochromic iridocyclitis (FHI) is a well‐known entity, which usually presents as a unilateral low‐grade inflammation in a white eye with diffuse, stellate keratic precipitates and, mild anterior chamber inflammation, iris atrophy and no posterior synechiae.[2,3] In addition there is an associated 70% risk of cataracts and 15% risk of glaucoma.[2,3] FHI is unique in that polymerase chain reaction (PCR) studies on aqueous samples in several clinical studies has identified the rubella virus as the cause of the entity.[4‐6] Nowadays, FHI is rarely seen in uveitis cases in the United States which is in contrast to developing countries. We assume the reason is the difference in national immunization programs between Western countries and developing countries. The mumps, measles, and rubella (MMR) vaccine was licensed in the United States in 1971, although it was first used in 1969. In an epidemiologic study at the University of Chicago, it was shown that after vaccination with MMR vaccine, the incidence of the diseases were decreased by almost 30% each decade afterwards.[7] Today, after over 40 years since starting immunization, a patient with FHI younger than 40 years of age is hardly ever seen which supports the efficacy of vaccination in preventing the disease. MMR vaccination was started routinely as a national health care protocol in Iran since 2005, before which rubella and mumps were not included in the national immunization program. Fuch’s Heterochromic Iridocyclitis in Iran: Is the Disease Going to Fade Away?