Renal Function following Fluorescein Angiography in Diabetic Patients with Chronic Kidney Disease

Purpose: To evaluate the effect of fluorescein dye usage on renal function in patients with diabetic retinopathy (DR) and chronic kidney disease (CKD). Methods: Diabetic patients with retinopathy who were candidate for fundus fluorescein angiography (FA) were evaluated for serum creatinine and urea levels within five days prior to performing the FA. Serum creatinine levels of 1.5 mg/dl or more in males and 1.4 mg/dl or more in females were both identified as CKD and were included in the study. An increase of 0.5 mg/dl or 25% in creatinine after FA was considered as contrast-induced acute kidney injury (AKI). Estimated glomerular filtration rate (eGFR) was also calculated for all patients using a CKD-Epi formula. CKD grading was determined based on eGFR values. Results: Forty-two patients agreed to participate, of which 23 (54.8%) were male. Seventeen patients were identified with grade 3a or lower CKD, 12 with grade 3b, 11 with grade 4, and two with grade 5 CKD. Considering all grades of CKD, the mean blood urea before and after angiography was 58.48 ± 26.7 and 57 ± 27.81 mg/dl, respectively (P = 0.475). The mean serum creatinine before and after the test was 1.89 ± 1.04 and 1.87±0.99 mg/dl, respectively (P = 0.993). The mean eGFR before and after the test was 44.024 ± 23.5447 and 43.850 ± 21.8581 mL/min/1.73 m2 (P = 0.875). Conclusion: According to the findings of this study, FA does not seem to further deteriorate kidney function in patients with diabetic associated CKD

Ankylosing Spondylitis

The seronegative spondyloarthropathies are a group of autoimmune inflammatory diseases lacking rheumatoid factor or antinuclear antibody in their serum. They include ankylosing spondylitis (AS), reactive arthritis, psoriatic arthritis, spondylitis associated with Crohn’s disease and ulcerative colitis, and undifferentiated spondyloarthropathies. Inflammation mostly affects the axial joints, entheses, and extra-articular structures such as uveal tract, gastrointestinal tract, mucocutaneous tissue, and heart. Uveitis is the most common extra-articular manifestation. Spondyloarthropathies, especially AS, have a strong association with the presence of Human Leukocyte Antigen (HLA)-B27 gene. AS happens earlier in HLA-B27 patients and men are more prone to the disease. Uveitis, typically unilateral nongranulomatous acute anterior uveitis, occurs in up to 50% of the patients with AS. HLA-B27 positivity correlates with more frequent flare-ups. Conjunctivitis and scleritis are rare ocular manifestations of AS. To establish the diagnosis of AS, at least one clinical and one radiologic parameter are required for definitive diagnosis. Magnetic resonance imaging (MRI) or bone scan can help early detection of the axial skeleton inflammation. The course of eye and joint involvement are not correlated. Short-term treatment with topical corticosteroids and cycloplegic agents control the uveitis attack. In resistant cases, local or systemic therapy with corticosteroids are recommended. NSAIDs, disease-modifying anti-rheumatic drugs (DMARDs), methotrexate, azathioprine, anti-IL-17A monoclonal antibodies, and TNF- α antagonists are effective treatments for ocular and systemic manifestations of AS. If not treated adequately, uveitis may become recalcitrant and extend posteriorly. Functional impairment due to joint destruction can also occur as a result of undertreatment

Acute zonal occult outer retinopathy misdiagnosed as giant cell arteritis: a challenging case

Background: Acute zonal occult outer retinopathy (AZOOR) is a rare autoimmune retinopathy that is challenging to diagnose and treat. It usually presents with subtle fundus changes and severe visual symptoms. Herein, we report a challenging case of AZOOR, emphasizing that multimodal imaging could be valuable in diagnosis and monitoring of treatment response. Case Presentation: A 53-year-old woman presented to the emergency department with a one-week history of subacute, severe, painless vision loss without photopsia in her right eye. Her best-corrected distance visual acuity was 20/800 in the right eye and 20/20 in the left eye. Slit-lamp examination findings were unremarkable, and intraocular pressure was normal in both eyes. Initially, fundus examination findings appeared normal; however, serum levels of inflammatory markers were elevated. Brain and orbital magnetic resonance imaging results were unremarkable. A relative afferent pupillary defect was present in subsequent follow-up examinations at the hospital. The patient initially received a diagnosis of posterior ischemic optic neuropathy secondary to occult giant cell arteritis, underwent steroid treatment, and was evaluated by rheumatology and neurology consultants. Both consultants concurred with the presumed diagnosis. Subsequent multimodal imaging in the ophthalmology clinic revealed a trizonal pattern of fundus autofluorescence. Corresponding to these areas, we noted a loss of the ellipsoid zone on optical coherence tomography, depression on multifocal electroretinogram, and scotoma on visual field testing. Accordingly, the diagnosis of AZOOR was made. The patient was referred back to the rheumatologist for initiation of steroid-sparing treatment, and methotrexate was administered. Five months after the initial presentation, the patient showed significant visual field improvement in both eyes. Conclusions: Eye care practitioners should consider AZOOR in the differential diagnosis of patients with subacute painless severe unilateral vision loss and unremarkable findings on fundus examination. Multimodal imaging could be valuable in diagnosis and monitoring of treatment response, as observed in the current case. Further studies with larger sample sizes are needed to confirm the value of multimodal imaging and the available management options for AZOOR

Topographic correspondence of peripheral retinal lesions between the fellow eyes of patients with rhegmatogenous retinal detachment and retinal break

Background: In rhegmatogenous retinal detachment (RRD), the risk of fellow eye involvement varies from 5% to 34% according to the follow-up duration and criteria used for patient selection. The aim of the present study was to investigate the frequency, characteristics, and predisposing factors for symmetric lesions in the fellow eyes of patients with RRD or retinal breaks. Results: Of the 68 participants, with a mean (standard deviation) age of 48 (12.1) years, 54 (79.4%) were men, and 14 (20.6%) were women. Of the 68 primary eyes, 60 (88.2%) had RRDs, and eight (11.8%) had retinal breaks. Horseshoe tears were the main lesion in 41 (68.3 %) primary eyes with RRD. Symmetric lesions were observed in 37 (54.4%) fellow eyes, including retinal breaks in 16 (43.2%) and lattice degeneration without breaks in 21 (56.8%) eyes. Lattice degeneration and multiple breaks were observed in 15 of 28 (53.6%) primary eyes with a lattice, whereas only seven of 40 (17.5%) lattice-free primary eyes had multiple breaks (P = 0.002). A multiple logistic regression model revealed that the presence of lattice degeneration in the primary eye (odds ratio, 26.91; 95% confidence interval, 4.18 – 173.20; P < 0.001) was the only factor predicting symmetricity in the fellow eye. Conclusions: More than half of the patients with RRD or retinal breaks in the primary eye harbored symmetrical retinal lesions in their fellow eyes. This emphasizes the importance of regular examination of the fellow eyes with a greater focus on symmetric positions in the fellow eye. The presence of a lattice in the primary eye was the only predictor of symmetry in the contralateral eye. Further longitudinal studies with larger populations are required to determine the significance of these symmetric lesions in the fellow eyes of patients with RRD and the value of prophylactic treatment

Intraocular Injection of Stivant® (A Biosimilar to Bevacizumab): A Case Series

Purpose: To report the results of intravitreal injection of a bevacizumab biosimilar called Stivant®. Methods: This prospective interventional case series was conducted on eyes with neovascular age-related macular degeneration (nAMD), retinal vein occlusion (RVO), and diabetic macular edema (DME). Stivant® was injected in three consecutive months and changes in best-corrected visual acuity (BCVA) and central macular thickness (CMT) were measured at baseline and monthly up to one month after the third injection. Results: Three hundred and eighty-five eyes with DME (234 eyes, 61%), nAMD (87 eyes, 22%), and macular edema secondary to RVO (64 eyes, 17%) were enrolled. The mean ± standard deviation age of the patients was 61.7 ± 7.20 years. The mean BCVA and CMT changed from 0.63 ± 0.3 to 0.51 ± 0.3 LogMAR (P = 0.12 ) and from 420.4 ± 47.3μm at baseline to 316.7 ± 50.6 μm (P < 0.001) in the DME group; from 0.79 ± 0.3 to 0.68 ± 0.3 LogMAR (P = 0.19) and from 376.1 ± 31.7 μm to 303 ± 31.3 μm (P = 0.019) in the nAMD group; and from 0.81 ± 0.4 to 0.63 ± 0.4 LogMAR (P = 0.05) and from 424.21 ± 18 μm to 303.4 ± 18.8 μm (P < 0.001) in the RVO group, respectively. Conclusion: Our limited experience showed that the intravitreal injection of Stivant® was well tolerated. Although the results of this case series showed relative improvement in CMT one month after the last injection of Stivant®, BCVA improvement was statistically significant only in the RVO group. This would be essential to design a randomized clinical trial to evaluate the non-inferiority of Stivant® in comparison to bevacizumab

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

Validation of the Postnatal Growth and Retinopathy of Prematurity (G-ROP) screening criteria

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

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

Power pattern sensitivity analysis of reflectarray antennas to substrate uncertainties through the minkowski interval analysis

International audienceIn this work, the effect of the fabrication uncertainties on the substrate thickness on the radiation performance of the reflectarray antenna is addressed. An interval analysis (7A)-based method is used to compute the upper and lower bounds of the power pattern as a function of the deviations in the substrate thickness. The Minkowski Sum (MS) is exploited to combine interval phasors in order to mitigate the over-estimation of the power pattern bounds affecting standard Cartesian IA (IA-CS) techniques. A representative numerical example shows that the proposed IAMS method provides narrower and more reliable bounds than the IA-CS

Tolerance analysis of the reflectarray antenna through Minkowski-based interval analysis

International audienceHaving a robust architecture against tolerances is one of the most important aspects in high frequency antenna design. In this paper, the effect of the fabrication errors on the power pattern of reflectarray antenna is investigated. The uncertainty on the actual size of the patch width is modeled as an interval value. The rules of Interval Analysis (IA) and Interval Arithmetic are then exploited to compute the bounds of the deviation of the resonance frequency, the reflection phase of each element, and the resulting radiated power pattern. The Minkowski Sum (MS) is used to combine the interval phasors in the complex domain in order to avoid the bounds over-estimation affecting the standard/Cartesian Interval Analysis (IA-CS). We show that the IA-MS can produce narrower, but still inclusive bounds, as compared to the IA-CS. To guarantee the validity of the model and reliability of the obtained bounds, a Monte Carlo test has been carried out