Optical Coherence Tomographic Findings in Highly Myopic Eyes

Optical coherence tomography (OCT) has enhanced our understanding of changes in different ocular layers when axial myopia progresses and the globe is stretched. These findings consist of dehiscence of retinal layers known as retinoschisis, paravascular inner retinal cleavage, cysts and lamellar holes, peripapillary intrachoroidal cavitation, tractional internal limiting membrane detachment, macular holes (lamellar and full thickness), posterior retinal detachment, and choroidal neovascular membranes. In this review, recent observations regarding retinal changes in highly myopic eyes explored by OCT are described to highlight structural findings that cannot be diagnosed by simple ophthalmoscopy

Prevalence and Risk Factors of Retinopathy of Prematurity in Iran

Purpose: The present study aimed to evaluate the frequency and risk factors of retinopathy of prematurity (ROP) among Iranian infants. Methods: A retrospective cohort study was conducted on infants who had undergone screening for ROP at Farabi Eye Hospital, between March 2016 and March 2017. Data were analyzed based on the presence of extreme prematurity (gestational age ≤ 28 weeks), extremely low-birth-weight (≤ 1000 g), and multiplegestation (MG) infants. Results: The prevalence of ROP was 27.28% (n = 543) among all screened infants, 74.4% for extremely preterm (EP) infants, 77.5% for extremely low birth weight (ELBW) babies, and 27.25% for infants from MG pregnancies. On multivariate analysis, gestational age, birth weight, and history of transfusion (P < 0.0001, P < 0.0001, and P = 0.04, respectively) were found to be significantly associated with ROP. More advanced stages of ROP (P < 0.0001) were observed in EP and ELBW infants. Birth weight (P = 0.088), history of transfusion (P = 0.066), and intubation (P = 0.053) were not associated with increased risk of ROP in EP infants, while gestational age (P = 0.037) and history of transfusion (P = 0.040) were significant risk factors for ROP in ELBW infants. Gestational age (P < 0.001) and birth weight (P = 0.001) were significantly associated with ROP in infants from MG pregnancies in multivariate analysis. Conclusion: ROP remains a commonly encountered disease, especially in ELBW and EP infants. The history of transfusion may have a role in stratifying the risk for ROP and guiding future screening guidelines

Macular surgery using intraoperative spectral domain optical coherence tomography

Purpose: To report the use of intraoperative spectral domain optical coherence tomography (SD-OCT) for detecting anatomical changes during macular surgery. Methods: In a consecutive case series, 32 eyes of 32 patients undergoing concurrent pars plana vitrectomy and intraoperative SD-OCT for macular hole (MH), epiretinal membrane (ERM) and vitreomacular traction (VMT) were enrolled. Intraoperative changes in retinal thickness and dimensions of the macular hole were measured in patients with ERM and VMT following surgical manipulation using a hand-held SD-OCT device (iVue, Optovue Inc., Fremont, CA, USA). Results: SD-OCT images of sixteen eyes with macular hole were subjected to quantitative and qualitative analysis. All MH dimensions remained stable during consecutive stages of surgery except for MH apex diameter, which showed a significant decrease after internal limiting membrane (ILM) peeling (P=0.025). Quantitative analysis of ten patients with ERM showed a significant decrease in retinal thickness after membrane removal (P=0.018) which did not remain significant until the end of the procedure (P=0.8). In three cases, subretinal fluid was formed after ILM peeling. Quantitative analysis of five patients with VMT showed a decrease in retinal thickness during consecutive steps of the surgery, although these changes were not significant. In two cases, subretinal fluid was formed after ILM peeling. Conclusion: Intraoperative SD-OCT is a useful imaging technique which provides vitreoretinal surgeons with rapid awareness of changes in macular anatomy during surgery and may therefore result in better anatomical and visual outcomes

Autofluorescence Imaging for Diagnosis and Follow-up of Cystoid Macular Edema

Lipofuscin results from digestion of photoreceptor outer segments by the retinal pigment epithelium (RPE) and is the principal compound that causes RPE fluorescence during autofluorescence imaging. Absorption of the 488-nanometer blue light by macular pigments, especially by the carotenoids lutein and zeaxanthin, causes normal macular hypo-autofluorescence. Fundus autofluorescence imaging is being increasingly employed in ophthalmic practice to diagnose and monitor patients with a variety of retinal disorders. In macular edema for example, areas of hyper-autofluorescence are usually present which are postulated to be due to dispersion of macular pigments by pockets of intraretinal fluid. For this reason, the masking effect of macular pigments is reduced and the natural autofluorescence of lipofuscin can be observed without interference. In cystic types of macular edema, e.g. cystoid macular edema due to retinal vein occlusion, diabetic macular edema and post cataract surgery, hyperautofluorescent regions corresponding to cystic spaces of fluid accumulation can be identified. In addition, the amount of hyper-autofluorescence seems to correspond to the severity of edema. Hence, autofluorescence imaging, as a noninvasive technique, can provide valuable information on cystoid macular edema in terms of diagnosis, followup and efficacy of treatment

Bilateral multiple serous retinal detachments following bone marrow transplantation

Purpose: To describe a case of bilateral multiple serous retinal detachments (SRD) following bone marrow transplantation (BMT), which showed bilateral response to a single unilateral intravitreal bevacizumab injection. Case Report: A 37-year-old man with acute myelogenous leukemia who had received bone marrow transplantation four months prior was referred to our clinic with the chief complaint of gradually decreasing vision in both eyes for three months. During the funduscopic examination, multiple serous retinal detachments (SRD) were observed bilaterally, and he was diagnosed with multiple foci of central serous chorioretinopathy (CSCR). He was advised to discontinue the steroid dosage, which did not make significant improvement, and he was treated with intravitreal bevacizumab injection in the more severely affected eye. One month later, significant improvement was noticed in both eyes. Conclusion: Serous retinal detachment is a rare complication following BMT. Significant bilateral improvement after single unilateral intravitreal bevacizumab injection shows not only the possible role of increased level of vascular endothelial growth factor (VEGF) in this case, but also the systemic diffusion of the drug and effect on the contralateral eye following unilateral injection

Choroidal Mapping; a Novel Approach for Evaluating Choroidal Thickness and Volume

There are a limited number of non-invasive imaging techniques available for assessing the choroid, a structure that may be affected by a variety of retinal disorders or become primarily involved in conditions such as polypoidal choroidal vasculopathy and choroidal tumors. The introduction of enhanced depth imaging optical coherence tomography (EDI-OCT) has provided the advantage of in vivo cross-sectional imaging of the choroid, similar to the retina, with standard commercially available spectraldomain OCT machines. In this article, we review this imaging technique and introduce choroidal mapping as a novel approach for obtaining accurate topographic and volumetric information on the choroid in normal and diseased states

Endophthalmitis in the Tertiary Referral Center in Iran; Etiology and Causative Organisms

Background: Endophthalmitis is a severe and sight-threatening complication of ocular surgery or ocular trauma. The identification of common types and causative organisms is essential for prevention and management. Objective: The current study describes the prevalence of various types of endophthalmitis and the causative microbiological spectrum of each type treated in the Tertiary Referral Center in Iran. Methods: All cases of endophthalmitis admitted to the Emergency Department of Farabi Eye hospital (Tehran, Iran) between July 2013 and December 2014 were included in this study. The patients’ demographic data, type of endophthalmitis, aqueous or vitreous culture results, and treatment methods were recorded. Results: From 108 presumed endophthalmitis cases, post-operative endophthalmitis (68.5%) was the most frequent type followed by post-traumatic (25%), bleb-associated (4.6%), and endogenous (1.9%) types. Streptococcus viridians (37.5%) was the most common isolated organism in post-operative cases. In post-traumatic endophthalmitis patients, the most frequent causative organism was Staphylococcus epidermidis (70%). Conclusion: Many studies from other countries have reported that S. epidermidis is the leading cause of endophthalmitis after either intraocular surgeries or open-globe injuries, but the current study has shown that S. viridians is the most common isolated organism in post-operative endophthalmitis

The Role of Mitochondria in AMD: Current Knowledge and Future Applications.

Mitochondria are organelles which comprise the main respiratory machinery in the eukaryotic cells. In addition to their crucial role in energy production, they have profound effects on apoptosis and retrograde signaling to nucleus. Mitochondria have their own DNA, which codes for different proteins mostly involved in oxidative phosphorylation. Significant changes in the mitochondria of retinal pigment epithelium have been reported in age-related macular degeneration (AMD), which is correlated with the severity of the disease. Cybrid cell lines that have identical nuclei but mitochondria from different individuals can provide a unique means for studying the relationship between mitochondria and AMD. Different approaches for protection of mitochondria have been introduced which can be considered as potential future treatments for AMD and other age- related disorders

The Role of Mitochondria in AMD: Current Knowledge and Future Applications.

Mitochondria are organelles which comprise the main respiratory machinery in the eukaryotic cells. In addition to their crucial role in energy production, they have profound effects on apoptosis and retrograde signaling to nucleus. Mitochondria have their own DNA, which codes for different proteins mostly involved in oxidative phosphorylation. Significant changes in the mitochondria of retinal pigment epithelium have been reported in age-related macular degeneration (AMD), which is correlated with the severity of the disease. Cybrid cell lines that have identical nuclei but mitochondria from different individuals can provide a unique means for studying the relationship between mitochondria and AMD. Different approaches for protection of mitochondria have been introduced which can be considered as potential future treatments for AMD and other age- related disorders