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Background: Retinopathy of prematurity (ROP) is a leading cause of irreversible blindness in infants. The Postnatal Growth and ROP (G-ROP) study proposed new screening criteria for ROP. This study aimed to validate the G-ROP screening criteria in a group of Iranian premature infants who were treated in the neonatal intensive care unit (NICU) for at least 40 days. Methods: In this retrospective study, we extracted the data pertaining to infants admitted to the NICU from January 2020 to December 2021. We screened all the included infants for ROP based on the Iranian national screening criteria. We applied the G-ROP criteria to our study population, and if no criterion was met, the infant was exempted from ROP screening. We determined the sensitivity and specificity of the G-ROP guidelines for ROP detection, along with its capacity for predicting the requirement for ROP treatment. Moreover, we compared the G-ROP guidelines with the Iranian and North American guidelines for ROP screening. Results: A total of 166 premature infants with complete datasets were included: 130 had ROP, of whom 61 were treated. There were 109 female infants (65.7%). The mean (standard deviation [SD]) birth weight and gestational age were 1080 (256) g and 28.28 (1.97) weeks, respectively. Applying the G-ROP criteria, 127 of 130 infants with ROP were identified (sensitivity, 97.69%; 95% confidence interval [CI], 95.11% – 100%), and of 36 infants without ROP, three were correctly excluded (specificity, 8.33%; 95% CI, 0% – 17.36%). The G-ROP criteria did not fail to identify infants who required treatment for ROP (sensitivity, 100%; 95% CI, 98.29 – 100) and had a specificity of 8.69% (95% CI, 2.04% – 15.34%). Although the Iranian and North American criteria had 100% sensitivity for infants with any stage of ROP, they could not detect infants without ROP (0% specificity). Conclusions: The G-ROP screening criteria had a sensitivity of 100% in identifying infants requiring treatment for ROP in our high-risk group; however, specificity was not sufficiently high. Further studies with larger numbers of referred infants could confirm a decrease in the burden of retinal examinations using these criteria.

The study aims to classify the eyes with proliferative diabetic retinopathy (PDR) and non-proliferative diabetic retinopathy (NPDR) based on the optical coherence tomography angiography (OCTA) vascular density maps using a supervised machine learning algorithm.OCTA vascular density maps (at superficial capillary plexus (SCP), deep capillary plexus (DCP), and total retina (R) levels) of 148 eyes from 78 patients with diabetic retinopathy (45 PDR and 103 NPDR) was used to classify the images to NPDR and PDR groups based on a supervised machine learning algorithm known as the support vector machine (SVM) classifier optimized by a genetic evolutionary algorithm.The implemented algorithm in three different models reached up to 85% accuracy in classifying PDR and NPDR in all three levels of vascular density maps. The deep retinal layer vascular density map demonstrated the best performance with a 90% accuracy in discriminating between PDR and NPDR.The current study on a limited number of patients with diabetic retinopathy demonstrated that a supervised machine learning-based method known as SVM can be used to differentiate PDR and NPDR patients using OCTA vascular density maps.

Millions of cataract surgeries with intraocular lens (IOL) implantation are performed worldwide. Although cataract surgery brings many benefits to the patients, the risk of various complications is still a concern. One of the infrequent adverse events but potentially affecting on patients’ visual acuity and contrast sensitivity is losing the transparency of IOL. IOL opacification may lead to IOL removal or exchange, which is unpleasant to both the patient and the surgeon. Several reports of acute IOL clouding are available in the literature describing various etiologies of this phenomenon, however, the exact mechanism remained unclear in some cases. Herein, we aimed to review the causes and outcomes of intraoperative and early postoperative IOL opacification.

The purpose of current study was to evaluate different optical coherence tomography angiography (OCTA) metrics in eyes with diabetic retinopathy with and without diabetic macular edema (DME). In this retrospective study, macular OCTA images of eyes with non-proliferative or proliferative diabetic retinopathy were evaluated. Vascular density, vascular complexity and non-perfusion densities were compared between eyes with and without DME. One-hundred-thirty-eight eyes of 92 diabetic patients including 49 eyes with DME were included. In multivariate analysis, the presence of DME was positively associated with geometric perfusion deficit (GPD) in superficial capillary plexus (SCP), capillary non-perfusion (CNP) of SCP, and GPD in deep capillary plexus (DCP) (all P

To investigate the alteration of choroid in patients with very severe non-proliferative diabetic retinopathy (NPDR) or early proliferative diabetic retinopathy (PDR) following panretinal photocoagulation (PRP). Thirty-nine eyes of 21 patients with very severe non-proliferative diabetic retinopathy (NPDR) (19 eyes) and early proliferative diabetic retinopathy (PDR) (20 eyes) were recruited. Enhanced-depth imaging optical coherence tomography at baseline, 1, and 6 months after PRP was employed to measure choroidal parameters including total choroidal area (TCA) and choroidal vascular index (CVI). In eyes with very severe NPDR, subfoveal TCA decreased non-significantly at month 1, which increased significantly at month 6 (539 ± 131µm2, 502 ± 134µm2, and 598 ± 168µm2 at baseline and months 1 and 6, respectively; P = 0.003). Subfoveal CVI increased at month 1 and then decreased at month 6 (68.25 ± 3.05, 69.74 ± 3.62, and 67.84 ± 1.77 at baseline and months 1 and 6, respectively; P

Purpose: To describe the optical coherence tomography (OCT) findings of toxoplasmic retinochoroiditis at different stages of activity.Methods: Observational case series.Results: A total of 32 eyes of 31 patients were included; 43 sets of OCT were reviewed. A total of 14 lesions were classified as active, 13 as partially active, and 16 as inactive. All active lesions demonstrated increased retinal thickness and reflectivity with blurring of details of retinal layers. Choroidal granuloma was detected in eight (61.5%) and serous retinal detachment in nine (64%). In partially active lesions, sustained thickening and/or attachment of posterior hyaloid face with fine epiretinal membrane was the hallmark. Scarified lesions showed decreased retinal and choroidal thickness starting from the periphery. Characteristic signs for decreased activity of a lesion seen in majority of both partially active and inactive lesions were RPE changes and retina-RPE approximation. We called this unique feature 'hourglass configuration'.Conclusion: Features in OCT are helpful to specify and monitor the activity of toxoplasmic retinochoroiditis.

Purpose: Determine the risk of immunomodulatory therapy (IMT) for COVID-19 infection morbidity.Method: A telemedicine survey on patients of a referral uveitis clinic was performed. Signs of infection, habits, and hospitalizations during the 7 months of the COVID-19 pandemic prior to the study date were recorded. Suggestive findings in chest CT scan and/or positive RT-PCR were considered as confirmed COVID-19 infection while those with only suggestive symptoms were considered as suspected cases. Risk factors including sanitary measures and IMT were compared between patients with confirmed cases and patients without infection.Result: 694 patients were included. Eight patients were identified as confirmed cases and 22 patients as suspected cases of COVID-19 infection. Close contact with infected persons was the only significant risk factor for contracting COVID-19.Conclusion: Using IMT did not affect hospitalization and/or ICU admission and can thus be continued during the pandemic, provided that instructions for preventive measures are followed.

Objectives To evaluate the outcomes and complications of Descemet-stripping automated endothelial keratoplasty (DSAEK) in children with congenital hereditary endothelial dystrophy (CHED). Methods Eighteen eyes from 10 children with CHED who underwent standard phakic DSAEK were enrolled in this retrospective interventional case series. Medical records including slit-lamp biomicroscopy, cycloplegic refraction, visual acuity, and measurements of central corneal thickness, corneal topography, and endothelial cell density were evaluated. All complications were recorded. Results The mean age of cases was 8.1±4.2 (range: 3-16) years at the time of surgery. Descemet-stripping automated endothelial keratoplasty was performed successfully in all eyes, which survived in 16/18 (88.9%) of cases during a median follow-up period of 38 (range 19-64) months. In patients with clear graft, best-corrected visual acuity was improved to a range of 20/100 to 20/40 and improved to fix and follow in one younger child. Endothelial cell density decreased by an average of 42.1%, comparing baseline and 6-month follow-up and was relatively stable thereafter. A marked flattening of the anterior corneal curvature (mean change of anterior K reading: +2.56±3.14 diopters) was observed after DSAEK. The only major complication in patients with clear graft was intraocular pressure elevation in 61.1% of the eyes, which was easily controlled with one antiglaucoma medication. None of the eyes developed cataract. Conclusion Descemet-stripping automated endothelial keratoplasty is a safe and successful procedure in children with an acceptable graft survival in a mid-term follow-up period. A marked hyperopic shift could occur after DSAEK in children with CHED.

Background To assess the impact of brachytherapy on macular microvasculature utilizing optical coherence tomography angiography (OCTA) in treated choroidal melanoma. Methods In this retrospective observational case series, we reviewed the recorded data of the patients with unilateral extramacular choroidal melanoma treated with ruthenium − 106 (106Ru) plaque radiotherapy with a follow-up period of more than 6 months. Automatically measured OCTA retinal parameters were analysed after image processing. Results Thirty-one eyes of 31 patients with the mean age of 51.1 years were recruited. Six eyes had no radiation maculopathy (RM). From 25 eyes with RM, nine eyes (36%) revealed a burnout macular microvasculature with imperceptible vascular details. Twenty-one non-irradiated fellow eyes from the enrolled patients were considered as the control group. Foveal and optic disc radiation dose had the highest value to predict the burnout pattern (ROC, AUC: 0.763, 0.727). Superficial and deep foveal avascular zone (FAZ) were larger in irradiated eyes in comparison to non-irradiated fellow eyes (1629 μm2 vs. 428 μm2, P = 0.005; 1837 μm2 vs 268 μm2, P = 0.021; respectively). Foveal and parafoveal vascular area density (VAD) and vascular skeleton density (VSD) in both superficial and deep capillary plexus (SCP and DCP) were decreased in all irradiated eyes in comparison with non-irradiated fellow eyes (P P Conclusion The OCTA is a valuable tool for evaluating RM. Initial subclinical microvascular insult after 106Ru brachytherapy is more likely to occur in DCP. The deep FAZ area was identified as a more critical biomarker of BCVA than superficial FAZ in these patients.

Purpose: This study aimed To evaluate the rate and risk factors for primary failure and recurrence after intravitreal anti-VEGF injection in retinopathy of prematurity (ROP).Methods: This retrospective study was performed on 865 eyes from 441 patients with retinopathy of prematurity receiving intravitreal Bevacizumab from 2012 to 2019. Medical records of patients were evaluated.Results: Mean gestational age (GA) and birth weight of patients were 28±2 weeks and 1121±312 g, respectively. Thirty-five eyes (4.04%) had a primary failure, including 18 eyes from 187 eyes in zone 1 (9.6%) and 17 eyes from 678 eyes in zone 2 (2.5%). The mean time of retreatment was 16.64±13.68 days in eyes without regression ROP. The remaining 830 eyes (95.95%) were included in recurrence analysis. The recurrence occurred in 33 eyes (3.97 %) of them in 20 patients, with the meantime of 77.52 days after the first treatment (IVB). Presence of plus disease, history of oxygen therapy or phototherapy, and GA less than 32 were associated with significantly increased prevalence of treatment failure. The risk factor predicting recurrence are lower birth weight, zone 1 pretreatment, history of intubation, anemia, and sepsis.Conclusion: Intravitreal anti-VEGF is a successful treatment for ROP with a low rate of primary failure and recurrence. Attention to risk factors accompanied by special care to patterns of treatment failure and recurrence helps to achieve early detection of treatment failure and vigilant follow up for recurrence.

Purpose To investigate the differences in the choroidal biomarkers between two forms of flat irregular pigment epithelial detachment (FIPED): avascular (aFIPED) and vascularized (vFIPED) in eyes with chronic central serous chorioretinopathy (CSC). Materials and methods Enhanced depth imaging optical coherence tomography (EDI-OCT) was done in eyes with FIPED correlated to chronic CSC, fellow eyes, and also in healthy eyes from gender- and age-matched subjects. Eyes with FIPED were classified into two subgroups based on optical coherence tomography angiography (OCTA) findings: vFIPED and aFIPED. Different choroidal biomarkers such as subfoveal choroidal thickness (SFCT), total choroidal area (TCA), and choroidal vascular index (CVI) were compared between the groups. Results Forty-four eyes from 42 patients with chronic CSC and FIPED along with 40 eyes from 20 healthy subjects were included. OCTA identified vascularization in 14 eyes in the FIPED group (31.8%). Mean SFCT was higher in the FIPED group compared to two other groups (p = 0.005). In comparison to patients with aFIPED, patients with vFIPED had lower SFCT (p = 0.003) and higher CVI (p = 0.020) based on multivariate analysis. Conclusions It seems that measurement of CVI along with SFCT may help to differentiate aFIPED from vFIPED in patients with CSC. Further longitudinal studies would be required to confirm the clinical significance of these findings.

Purpose To assess the effect of night shift work on image quality and artifacts when performing optical coherence tomography angiography (OCT-A). Methods In a prospective case series study, twenty nurses underwent OCT-A in two separate sessions: early in the morning before duty shift and at the end of a night shift. Quantitative measurements of horizontal and vertical saccadic, blink, and stretch artifacts and also signal strength of the images were recorded. Moreover, using visual analogue scale of pain (VAS), the perceived pain and discomfort by blue focus light and red scanning laser were recorded. Results Vertical and horizontal saccades, blink, and stretch artifacts were significantly higher after the night shift (P = 0.004, P = 0.015, P

Background: To determine the discrepancy between quantitative measurement of retinal and choriocapillaris (CC) vascular density (VD) in diabetic retinopathy (DR) stages using spectral domain optical coherence tomography angiography (SD OCTA) and compare it with normal subjects.Methods: 188 eyes of 97 participants were recruited in this cross-sectional study. Macular OCTA (3x3mm) scan was performed and VD at the level of superficial capillary plexus (SCP), deep capillary plexus (DCP) and CC were measured with the device software.Results: In normal subjects, VD in SCP, DCP, and CC were higher in all subsegments. In retinal VD, all calculated parameters were reduced in the more extreme stages of DR, except for foveal VD of SCP. There was a constant pattern of decrease in VD of CC from normal cases to cases of NDR and NPDR and then a slight increase happened in the PDR stage but never touching the normal quantities. Age, fasting blood sugar, and years of diabetes mellitus were correlated with reduced VD in different segments. Multivariate linear regression analysis showed that best-corrected visual acuity (BCVA) was positively correlated with parafoveal VD at SCP and VD of foveal area at CC. VD of all subfields of macular area except foveal DCP VD showed reduced levels in diabetic macular edema (DME) patients compared to those without DME.Conclusions: The findings of the study endorse retina VD changes as a potential biomarker for DR development before retinopathy becomes clinically evident. It seems that parafoveal VD of SCP and foveal VD of CC are good biomarkers to predict VA in the diabetic patients.

Background Quantitative assessment of vascular density (VD) of retinal and choriocapillaris (CC) in various stages of diabetic retinopathy (DR) using spectral domain optical coherence tomography angiography (SD OCTA). Methods 188 eyes of 97 participants were recruited in this cross-sectional study. The macular OCTA (3x3mm) scan was performed and the computer algorithm assessed VD at the level of superficial capillary plexus (SCP), deep capillary plexus (DCP) and CC. Results All measured parameters were decreased in retinal VD at the more extreme stages of DR, with the exception of SCP foveal VD. There was a constant pattern of decrease in VD of CC from normal cases to cases of NDR and NPDR and then a slight increase occurred in the PDR stage but never touching the normal quantities. Age, fasting blood sugar, and years of diabetes mellitus were correlated with reduced VD in different segments. Multivariate linear regression analysis showed that best-corrected visual acuity (BCVA) was positively correlated with parafoveal VD at SCP and VD of foveal area at CC. VD of all subfields of macular area except foveal DCP VD showed reduced levels in diabetic macular edema (DME) patients compared to those without DME. Conclusions The findings of the study endorse retina VD changes as a potential biomarker for DR development before retinopathy becomes clinically evident. It seems that parafoveal VD of SCP and foveal VD of CC are good biomarkers to predict VA in the diabetic patients.

Background To describe the features of multimodal imaging and the diagnostic role of en face OCT in the paracentral acute middle maculopathy (PAMM) spectrum. Methods In this observational case series, 5 eyes of 5 patients with acute PAMM were identified. Demographic characteristics as well as data regarding the underlying disease, presenting visual acuity (VA) and ophthalmic examination results were recorded. All patients underwent multimodal imaging within 3 days after symptom onset. Results The mean age of patients was 52.2 (range, 33–67) years. Systemic comorbidities including diabetes mellitus and hypertension were identified in two patients. Except for one patient diagnosed with isolated PAMM, other patients had signs of retinal vascular disease such as a cilioretinal artery or branch retinal artery obstruction, non-ischemic central retinal vein occlusion, or a combination of these vascular disorders. The central vision was preserved in two cases; however, the remaining cases presented with profound VA reduction. Different patterns of PAMM including arterial, globular, and fern-like were observed in en face OCT at deep capillary plexus (DCP) level. En face OCT images could precisely delineate the margin of the PAMM area. Optical coherence tomography angiography (OCTA) showed decreased vascular density in DCP. Unresolved projection artifact by conventional OCTA software was observed in DCP and choriocapillaris slabs in all cases. Conclusion En face structural OCT in PAMM can delineate the area of ischemia and the degree of foveal involvement. Unresolved projection artifact by conventional OCTA software in the PAMM area can be seen in DCP and choriocapillaris layers.

Inflammation can involve several ocular structures, including the sclera, retina, and uvea, and cause vascular changes in these tissues. Although retinal vasculitis is the most common finding associated with uveitis involving the posterior segment, other vascular abnormalities may be seen in the retina. These include capillary nonperfusion and ischemia, vascular occlusions, preretinal neovascularization, microaneurysms and macroaneurysms, and telangiectasia. Moreover, vasoproliferative tumors and subsequent coat-like response can develop secondary to uveitis. Fluorescein angiography is ideal for the investigation of retinal vascular leakage and neovascularization, while optical coherence tomography angiography can provide depth resolved images from the superficial and deep capillary plexus and can demonstrate vascular remodeling. Choroidal vascular abnormalities primarily develop in the choriocapillaris or in the choroidal stroma and can appear as flow void in optical coherence tomography angiography and filling defect and vascular leakage in indocyanine green angiography. Extensive choriocapillaris nonperfusion in the presence of choroidal inflammation can increase the risk of choroidal neovascular membrane development. Iris vascular changes may manifest as dilation of vessels in stroma due to inflammation or rubeosis that is usually from ischemia in retinal periphery secondary to chronic inflammation. More severe forms of scleral inflammation, such as necrotizing scleritis, are associated with vascular occlusion in the deep episcleral plexus, which can lead to necrosis of sclera layer and uveal exposure.

Purpose Lichen planopilaris (LPP) is a chronic lymphocytic- mediated disorder that selectively involves hair follicles, leading to cicatricial alopecia. The eyelash follicle and meibomian gland (MG) might also be involved in the disease process leading to ocular surface problems. Methods In this Cross-sectional case -control study, twenty-three patients with histologically confirmed LPP and 23 healthy controls were recruited in this controlled study. To quantify the signs and symptoms of LPP, we used the Lichen Planopilaris Activity Index. The ophthalmologic examination was performed by the same ophthalmologist at Farabi Eye Hospital. Results Patients with LPP had a statistically significant lower tear breakup time (worse test outcome) compared with the control (7.1 6 4.1 vs. 9.6 6 4.4; respectively, P = 0.011). Both MG quality score and expressibility were higher in patients with LPP than in control subjects (14.1 6 4.3 vs. 9.3 6 4.4; P = 0.001; 1.5 6 1.0 vs. 0.4 6 0.8; P = 0.001; respectively). The Schirmer test score was not different between groups. A significant but weak correlation was found between the Lichen Planopilaris Activity Index and tear breakup time. Other ophthalmologic examinations including conjunctiva, lid margin shape, intraocular pressure, and funduscopy were normal in patients with LPP. Conclusions Patients with LPP, scored worse in ocular surface tests. This finding warrants special scrutiny for dry eye and MG dysfunction in these patients.

Fariba Ghassemi,1,2 Reza Mirshahi,1,2 Kaveh Fadakar,1,2 Siamak Sabour3 1Retina & Vitreous Service, 2Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, 3Safety Promotion and Injury Prevention Research Centre, Department of Clinical Epidemiology, Shahid Beheshti University of Medical Sciences, Tehran, Iran Synopsis: In optical coherence tomography angiography, the choroidal vascular flow rate in choroidal melanoma is significantly lower than that in choroidal nevus.Objective: The objective of this study was to describe the choriocapillaris and retinal features imaged by optical coherence tomography angiography (OCTA) in eyes with choroidal nevus from small malignant choroidal melanoma.Methods: In this retrospective, noninvasive, observational study, 11 patients diagnosed with small choroidal mass (five with choroidal nevus and six with malignant melanoma) who underwent dilated fundus examination, ocular ultrasonography and OCTA images were compared.Results: In choroidal nevus of all patients, OCTA demonstrated a hyporeflective mass with no significant deformity of choroidal vasculature and an intact retinal pigment epithelium (RPE)–Bruch’s membrane complex. The flow void mass was surrounded by an intense vascular rim named as surface microvasculature (SMV) that had an approximately similar flow rate median of 63.68 mm2 (60.42–67.62 mm2), comparable with the median of the contralateral normal eye of 61.77 mm2 (60.42–64.53 mm2; P>0.09) for nevi. OCTA showed an obscured Bruch’s membrane–RPE–Bruch’s membrane complex and outer retinal layer in choroidal melanomas. Choriocapillaris flow rate over the melanomas was 55.73% (41.93%–60.82%), and the corresponding normal areas had a flow area of 62.75% (61.99%–63.10%; P=0.01). A flow rate difference between choroidal melanoma and nevus was significant (P=0.006). Axial and peripheral feeding vessels were more dilated and tortuous compared with benign nevi.Conclusion: Decreased flow rate of SMV of choroidal melanoma cases compared with nevi was a significant finding. Detection of characteristic vascular features of choroidal melanoma by OCTA could make OCTA an assuring diagnostic modality to differentiate malignant lesions. Keywords: melanoma, choroidal nevus, OCT, OCTA, uveal melanoma

Purpose To describe a case of bilateral choroidal neovascularization in a patient with beta-thalassemia major and an interventional therapeutic attempt. Method Retrospective case report. Result A known case of beta-thalassemia major presented with gradual vision loss. Fundoscopy revealed bilateral macular edema accompanied by intraretinal hemorrhages. Optical coherence tomography and fluorescein angiography were compatible with the diagnosis of choroidal neovascularization. No signs of angioid streaks or other related abnormalities were noticed in examination and imaging. The patient was treated with intravitreal bevacizumab, and visual acuity improved within 6 months of follow-up. Conclusion Bilateral choroidal neovascularization can be a presenting pathology in patients with beta-thalassemia major. Anti-vascular endothelial growth factor is a promising treatment option.

Purpose: To provide normative data of foveal avascular zone (FAZ) and thickness. Methods: In this cross-sectional study both eyes of each normal subject were scanned with optical coherence tomography angiography (OCTA) for foveal superficial and deep avascular zone (FAZ) and central foveal thickness (CFT) and parafoveal thickness (PFT). Results: Out of a total of 224 eyes of 112 volunteers with a mean age of 37.03 (12â67) years, the mean superficial FAZ area was 0.27Â mm2, and deep FAZ area was 0.35Â mm2 (PÂ

Purpose To evaluate the best piggyback intraocular lens (IOL) implantation method and the outcomes in nanophthalmos eyes and to define the postoperative structural changes. Setting Farabi Eye Hospital, Tehran, Iran. Design Prospective case series. Methods Candidates for refractive surgery who were nanophthalmic were recruited. Patients had refractive lens exchange followed by implantation of both IOLs in the bag or 1 IOL in the bag and 1 IOL in the sulcus. The baseline and follow-up visual acuity, refractive status, and structural Scheimpflug imaging were evaluated. Ultrasound biomicroscopy (UBM) was performed 6 months postoperatively. Results The study comprised 9 nanophthalmic patients (18 eyes) with a mean preoperative uncorrected distance visual acuity (UDVA) of 1.53 logarithm of the minimum angle of resolution (logMAR) ± 0.3 (SD), mean corrected distance visual acuity (CDVA) of 0.34 ± 0.2 logMAR, and mean spherical equivalent (SE) of +13.55 ± 4.0 diopters (D). The mean postoperative UDVA improved from baseline. There was no significant difference in the mean UDVA and CDVA between the 2 IOL groups. Postoperatively, both groups had a significant improvement in SE, a significant rise in anterior chamber depth and angle, and similar UBM measurements. Conclusions Piggyback IOL implantation was an effective refractive procedure in nanophthalmic eyes. Both implantation methods resulted in similar outcomes; however, the small number of patients in each group made it less likely that possible differences would be found. The increase in angle values might help prevent the development of closed-angle glaucoma.

The purpose of this study was to evaluate the vascular density (VD) and the flow area on optic nerve head (ONH) and peripapillary area, and the impact of age and sex using optical coherence tomography angiography (OCTA) in healthy human subjects.Both eyes of each volunteer were scanned by an RTVue XR Avanti; Optovue with OCTA using the split-spectrum amplitude-decorrelation angiography algorithm technique. Masked graders evaluated enface angiodisc OCTA data. The flow area of ONH and the VD were automatically calculated.A total of 79 eyes of patients with a mean age of 37.03±11.27 were examined. The total ONH (papillary and peripapillary) area VD was 56.03%±4.55%. The flow area of the ONH was 1.74±0.10 mm/1.34 mm. The temporal and inferotemporal peripapillary VD was different between male and female patients. Increasing age causes some changes in the flow area of the ONH and the papillary VD from the third to the fourth decade (analysis of variance test; P0.05).A normal quantitative database of the flow area and VD of the papillary and peripapillary area, obtained by RTVue XR with OCT angiography technique, is presented here.

Purpose: To evaluate the normative values of anterior chamber parameters measured by Pentacam and corneal hysteresis (CH) and corneal resistance factor (CRF) measured by Ocular Response Analyzer (ORA) and their relationship. Methods: In an observational cross-sectional study, patients aged 18–35 years were included. Exclusion criteria were history of any intraocular or corneal disease, anomaly or surgery; hyperopic spherical refraction more than +3, and myopic spherical refraction less than −5.00 diopters (D) or cylindrical refraction more than 2.00 D. ORA was used to measure CH and CRF. Corneal volume (CV), anterior and posterior Q value (QA and QP), anterior and posterior elevation (AE and PE), central corneal thickness (CCT), corneal thinnest thickness (CTT), anterior chamber depth (ACD), anterior chamber volume (ACV) and anterior chamber angle (ACA) were measured with Pentacam. Results: This study evaluated 506 eyes of 253 cases (182 females) with a mean age of 28.43 ± 6.36 years. The average CH and CRF were 10.07 ± 1.61 and 10.33 ± 1.68 mmHg. CH and CRF were not correlated with PQ, AQ, AE and PE. CH and CRF were significantly correlated with CCT (r = 0.499, p

Purpose: To evaluate the optical coherence tomography angiography (OCTA) parameters in patients with diabetic retinopathy following panretinal photocoagulation (PRP). Methods: Eleven eyes of 6 patients with very severe nonproliferative diabetic retinopathy (NPDR) or early proliferative diabetic retinopathy (PDR) were recruited in this prospective interventional pilot study. All patients underwent OCTA imaging at baseline, and choroidal flow, foveal avascular zone (FAZ), retinal thickness, and vascular density were measured at baseline. Three months after treatment, OCTA was repeated, and the alteration in variables was analyzed. Results: The FAZ area remained unchanged following treatment, (P = 0.75). Retinal thickness increased along (P = 0.02) with an increase in vascular density in the superficial and deep foveal area and the macular temporal sector (P = 0.007, 0.03 and 0.049, respectively). Choroidal flow surface area was unchanged (P = 0.10). Conclusion: In this study, foveal vascular density increased and FAZ remained unchanged after PRP for diabetic retinopathy. Keywords: Diabetic retinopathy, Foveal avascular zone, FAZ, Optical coherence tomography angiography, OCTA, Panretinal photocoagulation

BACKGROUND AND OBJECTIVE: The quantification of the density of macular vascular networks and blood flow areas in the foveal and parafoveal area in healthy subjects using optical coherence tomography angiography (OCTA). PATIENTS AND METHODS: Cross-sectional, prospective study in an institutional setting at the Retina Services of Farabi Eye Hospital. One hundred twelve normal volunteers with no known ocular or systemic disease were included, including patient numbers (one or both eyes), selection procedures, inclusion/exclusion criteria, randomization procedure, and masking. En face angiogram OCTA was performed on a 3 mm × 3 mm region centered on the macula. Automated thresholding and measuring algorithm method for foveal and parafoveal blood flow and vascular density (VD) were used. The density of macular vascular networks and blood flow area in the foveal and parafoveal area were measured. RESULTS: A total of 224 healthy eyes from 112 subjects with a mean age of 36.4 years ± 11.3 years were included. In the foveal region, the VD of the superficial capillary network (sCN) was significantly higher than that of the deep capillary network (dCN) (31.1% ± 5.5% vs. 28.3% ± 7.2%; P < .001), whereas in the parafoveal area, VD was higher in the dCN (62.24% ± 2.8% vs. 56.5% ± 2.5%; P < .001). Flow area in the 1-mm radius circle in the sCN was less than in the dCN. Superficial foveal avascular zone (sFAZ) size was negatively correlated with the VD of the foveal sCN, but in the deep FAZ (dFAZ) was not correlated with VD or blood flow area of the fovea. There was no difference between measured VD and blood flow surface area in both eyes of the subjects. CONCLUSIONS: OCTA could be used as a noninvasive, repeatable, layer-free method in quantitative evaluation of VD and blood flow of macular area. The normal quantities of the vascular plexus density and flow will help in better understanding the pathophysiological basis of the vascular disease of retina. [ Ophthalmic Surg Lasers Imaging Retina . 2017;48:478–486.]