The Effect of Circle of Willis Morphology on Retinal Blood Flow in Patients with Carotid Stenosis Measured by Optical Coherence Tomography Angiography.

The Circle of Willis (CoW) is the main collateral system, and its morphological variants are more common in patients who have severe carotid artery stenosis. Earlier data suggest that optical coherence tomography angiography (OCTA) may help to assess the changes in cerebral vascular perfusion by imaging the retinal blood flow. In this single-center prospective clinical study, patients scheduled for carotid endarterectomy (CEA) underwent preoperative computed tomography angiography (CTA) of the extra- and intracranial cerebral circulation. OCTA imaging was performed one week before surgery and postoperatively one month later. The patients were divided into two subgroups based on CTA evaluation of CoW: compromised CoW or non-compromised CoW (containing hypoplastic and normal segments). The effect of the patient's age, OCTA scan quality (SQ), CoW morphology, laterality, and surgery on superficial capillary vessel density (VD) in the macula were assessed in multivariable regression models using linear mixed models. We found that VD significantly decreased with aging (-0.12%; 95%CI: -0.07--0.15; p < 0.001) and was significantly higher in patients with non-compromised CoW morphology (by 0.87% 95%CI (0.26-1.50); p = 0.005). After CEA, retinal blood flow significantly improved by 0.71% (95%CI: 0.18-1.25; p = 0.01). These results suggest that in the case of carotid artery occlusion, patients with non-compromised CoW have more preserved ocular blood flow than subjects with compromised CoW due to remodeling of the intra-orbital blood flow. Measuring the retinal blood flow might be used as a relevant and sensitive indicator of collateral cerebrovascular circulation.

Assessment of Visual Quality Improvement as a Result of Spectacle Personalization.

Personalized spectacles customized according to an individual's facial anatomy were developed to provide enhanced visual performance and overall comfort when compared to standard spectacles. In this comparative crossover trial, each subject was randomly assigned to wear either personalized spectacles or standard spectacles for two weeks and then tried the second pair for another two weeks. Visual acuity and reading speed were measured, and visual quality and comfort were assessed using specific questionnaires. The correlation of the wearing parameters with the subjects' satisfaction was calculated. According to our results, the subjects wearing personalized glasses reported significantly less experience of swaying and significantly higher overall satisfaction compared to those wearing the control spectacles. At the end of the study, 62% of subjects preferred the personalized spectacles, and visual quality was the primary reason for their spectacle preference followed by wearing comfort. The difference from the ideal cornea-vertex distance was significantly lower when wearing the personalized spectacles compared to the control frames. In addition, the absolute value of the difference from the ideal cornea-vertex distance was significantly correlated with patient satisfaction. These results suggest that personalized spectacles, customized according to an individual's facial anatomy for the ideal wearing parameters, result in both visual and comfort advantages for wearers.

Intraocular neutralizing antibodies against aflibercept in patients with age related macular degeneration.

PURPOSE: To detect immunoglobulins in aqueous humour of AMD patients after repeated administration of intravitreal aflibercept. PATIENTS AND METHODS: Twenty-one patients (age: 77.85 ± 9.21 years) previously treated with intravitreal aflibercept due to wet type age-related macular degeneration (AMD group) and 18 age-matched control subjects (age: 69.75 ± 12.67 years) were included in this study. Patients in the AMD group received a mean of 5 intravitreal injections (min: 1 max: 17) prior to the cataract surgery. Samples of aqueous humour (50 µl) were obtained by anterior chamber paracentesis as the first step of routine cataract surgery. The IgG content of the samples was analysed by an in-house developed ELISA system. RESULTS: A significant increase in nonspecific IgG levels in the AMD group was detected compared to the control group (13.37 ± 6.65 vs. 9.44 ± 6.55 µg/ml; p = 0.03). In 11 patients, intraocular anti-aflibercept immunoglobulins could be detected (0.05 ± 0.01 µg/ml) which was significantly higher than the limit of detection for anti-aflibercept (0.04 µg/ml; p = 0.001). No correlation was found between the number of injections or the type of CNV and the aqueous level of anti-aflibercept (r = 0.02; p = 0.95). CONCLUSION: According to our results, penetration of non-specific systemic antibodies through the impaired blood-retinal barrier is higher in patients with neovascular AMD than in subjects with an intact structural barrier. Evaluation of neutralizing antibodies to anti-VEGF agents in the aqueous humour can lead us to understanding tachyphylaxis and changes in intraocular immune mechanisms due to AMD.

The effect of systemic factors on retinal blood flow in patients with carotid stenosis: an optical coherence tomography angiography study.

Carotid artery stenosis (CAS) is among the leading causes of mortality and permanent disabilities in the Western world. CAS is a consequence of systemic atherosclerotic disease affecting the majority of the aging population. Optical coherence tomography angiography (OCTA) is a novel imaging technique for visualizing retinal blood flow. It is a noninvasive, fast method for qualitative and quantitative assessment of the microcirculation. Cerebral and retinal circulation share similar anatomy, physiology, and embryology; thus, retinal microvasculature provides a unique opportunity to study the pathogenesis of cerebral small vessel disease in vivo. In this study, we aimed to analyze the effect of systemic risk factors on retinal blood flow in the eyes of patients with significant carotid artery stenosis using OCT angiography. A total of 112 eyes of 56 patients with significant carotid stenosis were included in the study. We found that several systemic factors, such as decreased estimated glomerular filtration rate (eGFR), hypertension, and carotid occlusion have a significant negative effect on retinal blood flow, while statin use and carotid surgery substantially improve ocular microcirculation. Neither diabetes, clopidogrel or acetylsalicylic acid use, BMI, serum lipid level, nor thrombocyte count showed a significant effect on ocular blood flow. Our results demonstrate that a systematic connection does exist between certain systemic risk factors and retinal blood flow in this patient population. OCTA could help in the assessment of cerebral circulation of patients with CAS due to its ability to detect subtle changes in retinal microcirculation that is considered to represent changes in intracranial blood flow.

The Impact of Deterministic Signal Loss on OCT Angiography Measurements.

Purpose: In this study, we aimed at investigating the impact of deterministic signal loss on image quality and, thus, on optical coherence tomography angiography (OCTA) measurements performed by the RTVue-XR Avanti System. Methods: Absorptive filters with different optical densities (ODs) were used to simulate signal loss in a controlled way in 30 eyes from 15 healthy subjects. Scan Quality (SQ), provided by the AngioVue software, was applied as a measure of image quality. Results: Assessing the effect of decreased light transmittance on SQ values as well as that of attenuated image quality on OCTA parameters revealed a strong systematic dependence between these quantities. Attenuated image quality was associated with significantly decreased macular and peripapillary vessel density (VD) values, and we calculated a correction factor of 2.27% to 3.97% for a one-unit change in SQ for the different VD parameters. Conclusions: Our findings suggest that the influence of systematic changes in image quality on OCTA parameters needs to be considered during patient follow-up in order to make valid assessment of progression. Translational Relevance: For accurate evaluation of longitudinal changes in OCTA parameters, equal scan quality or using a correction factor is suggested.

The effect of image quality on the reliability of OCT angiography measurements in patients with diabetes.

BACKGROUND: This study aimed to determine the relationship between image quality and measurement repeatability of optical coherence tomography angiography (OCTA) parameters in patients with non-proliferative diabetic retinopathy. METHODS: A total of 100 eyes of 50 patients were included in the study. Three OCTA images were obtained consecutively during one session of imaging in all patients using the RTVue AngioVue OCTA device. We applied the signal strength index (SSI) provided by the RTVue system to define scan quality. Superficial vessel density (VD) in the central 3 × 3 mm macular and in the perifoveal region, as well as foveal avascular zone (FAZ) area were evaluated by the AngioAnalytics software for each scan from three consecutive measurements, whereby measurement repeatability of the OCTA parameters were calculated. The effect of SSI value on OCTA parameters, as well as on measurement errors was assessed. RESULTS: Values of SSI ranged from 30 to 85 with an overall mean of 61.79 ± 10.38. Mean SSI values showed significant positive correlation with the mean retinal capillary vessel density values, but not with non-flow area. Repeatability of OCTA parameters was generally improved with higher SSI values. We calculated a mean correction factor of 0.22% (95% CI 0.20-0.24 µm; p < 0.001) for VD at the 3 × 3 mm macular scan, 0.23% (95% CI 0.21-0.26%; p < 0.001) for perifoveal VD and - 0.001 mm2 (95% CI - 0.001 to 0.002; p = 0.001) for the non-flow area for each unit increase in SSI for the comparison of images with different SSI values. CONCLUSIONS: The influence of image quality on OCTA metrics should be considered for image comparisons during follow-up to avoid misinterpretation of small changes in OCTA parameters in patients with diabetes.

[Systemic biological treatment in ophthalmology]. / Biológiai terápia szisztémás alkalmazása a szemészetben.

We present herewith cases of non-infectious uveitis with biological treatment where the ocular complaints were the initial symptoms indicating a multi-organ autoimmune disease. The first case was a patient with panuveitis and Vogt-Koyanagi-Harada disease, the second case was also a panuveitic patient with sarcoidosis and the third case was a patient with intermediate uveitis and inflammatory bowel disease. In all cases, emerging new, biological therapy (adalimumab) was necessary to achieve permanent inactive period of uveitis and the autoimmune disease. Introducing systemic biological treatment (adalimumab) in ophthalmology is crucial in the therapy of immune-mediated, non-infectious uveitis in order to preserve visual acuity. Orv Hetil. 2019; 160(44): 1744-1750.

[Results after graded recession of inferior oblique muscle in strabismus sursoadductorius]. / Az alsó ferde szemizom dozírozott transzpozíciójának hatásossága strabismus sursoadductorius esetén.

Introduction: Idiopathic strabismus sursoadductorius is characterized by an overaction of the inferior oblique (IO) muscle, with elevation of the eye in adduction. This can result in chronic headache, eye pain, diplopia and abnormal head posture. Aim: Presentation of clinical results after graded recession of inferior oblique overaction (IOOA) in strabismus sursoadductorius. Method: During a period of 6 years (2012-2017) we performed a dosed transposition of IO muscle in 53 patients in the Department of Ophthalmology of the Semmelweis University and analyzed the clinical results retrospectively. The mean age was 12.8, min-max: 2-51 years. The transposition of the muscle (8 mm, 10 mm or maximal) was performed because of IOOA and was planned depending on the vertical deviation (VD) in maximal adduction. In case of maximal transposition, the insertion of IO was placed under the lateral part of the lower rectus muscle. We evaluated the squint angle in five positions of gaze preoperatively and postoperative 1 week, 1 month and 3-6 months. We examined best corrected visual acuity, binocular vision and complications after surgery. Results: Postoperatively 25 patients had acceptable stereopsis (Titmus 5). Visual acuity remained stable after surgery in all cases. The VD measured in maximal adduction changed with a decrease of 7.5° when 8 mm transposition was performed, and changed with a decrease to 12°, when maximal recession was performed. The mean reduction of VD was 17.8 prism dioptres (PD) after 1 week (p<0.01), 20.5 PD after 1 month and remained stable during a follow-up of 3-6 months. Conclusion: Graded recession of inferior oblique muscle is a suitable proposed procedure in patients with marked strabismus sursoadductorius. The rates of functional under- or overcorrection or other complications are low. Orv Hetil. 2019; 160(27): 1064-1069.