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In this study, we investigated the vasodilation properties on pre-contracted retinal arteries of a restricted series of carbonic anhydrase inhibitors (CAIs) of the sulfonamide type with enhanced lipophilicity, to assess if it affects the potency of CAIs as vasodilators.Carbonic anhydrase (CA) inhibition andAll compounds induced vasodilation but at different concentrations. Among the tested compounds the most potent vasodilators were found to be the seleno-compoundAll the data reported in this study (i.e. results from myography

Purpose: To determine the presence of unruptured retinal arterial macroaneurysms (RAMs) and to examine the characteristics of the detected lesions. Methods: This retrospective observational study included the affected and contralateral eyes of 50 patients (100 eyes) with symptomatic, unilateral, ruptured RAMs who visited the Department of Ophthalmology at the Kyoto University Hospital (April 2014–April 2020) and were followed up for at least 6 months after the onset. The presence and characteristics of unruptured RAMs were examined by reviewing the findings of color fundus photography and infrared scanning laser ophthalmoscopy performed before the onset or during the follow-up period. Results: Unruptured RAMs were detected in six of the 50 patients. Some patients had bilateral or multiple unruptured RAMs, and a total of 12 unruptured RAMs were detected in eight eyes of the six patients. Among the detected lesions, eight exhibited a longitudinal increase in their diameter during the follow-up period, whereas six exhibited ruptures. Conclusion: Unruptured RAM is not an uncommon retinal vascular abnormality and can enlarge and progress to ruptured RAM.

Purpose To report a case of symptomatic multiple retinal emboli during a carotid doppler ultrasonography (CDU) procedure. Material and methods Case report documented with clinical records, fundus photography (FP), optical coherence tomography angiography (OCT-A) of the retina and computed tomography angiography (CT-A) of the supra-aortic vessels. Results A 60-year-old male patient, presented to the emergency department with sudden vision loss in the left eye (LE) and pain in the left upper eyelid noticed during a CDU procedure. On the LE, the best corrected visual acuity (BCVA) was 20/200 and fundus observation revealed retinal arteriolar attenuation, retinal whitening with cherry point and multiple intra-arterial emboli in all arcades of the central retinal artery. CT-A of the supra-aortic vessels revealed an absence of filling throughout the cervical, petrous and cavernous segment of the left internal carotid artery, resuming only in the ophthalmic segment and an important stenosis of the left external carotid artery. He had no indication to be submitted to left carotid endarterectomy and began ocular massage and oral anticoagulant. 4 months later, ptosis was no longer present, BCVA improved to 20/20 with a residual scotoma and emboli disappeared on FP. Conclusion Embolic occlusion of retinal arteries may be an extremely rare but serious complication associated with CDU and patients and clinicians should be aware of it.

This study aimed to evaluate ocular blood flow and, retinal, choroidal and retinal nerve fiber layer thickness in children with familial Mediterranean fever (FMF) with patients who had at least five attacks.Fifty-six patients with FMF and 56 healthy subjects were enrolled in the study. Each participant's choroidal thickness (CT) and retinal thickness (RT) measurements were performed in the foveola and at horizontal nasal and temporal quadrants within 500-μm intervals up to 1.500 μm from the foveola using spectral-domain optical coherence tomography as well as the retinal nerve fiber layer thickness (RNFLT). Disc boundaries were determined manually by identifying seven points on the inner edge of the scleral ring. Following complete ophthalmological evaluation, peak systolic velocity (PSV), end-diastolic velocity (EDV), and resistivity index (RI) values in the central retinal artery (CRA), ophthalmic artery (OA), and nasal posterior ciliary artery (NPCA) were measured using color Doppler ultrasonography (CDU) in the left eyes of the patients diagnosed with FMF and the controls. The results were subsequently compared.No statistically significant differences were observed between the groups in terms of all RNFLT quadrant and RT measurements. All CT measurements were thinner in patients with FMF than in the controls (For Central and Temporal_1500 p = 0.01; For Temporal_500, Nasal 500 and Nasal_1000 p 0.001; Temporal_1000 p = 0.002) except than the Nasal_1500 point. For nasal_1500 p = 0.121). The PSV and EDV values in the OA, CRA, and NPCA were significantly lower in patients with FMF compared to healthy controls (p 0.001 for all). In contrast, the RI values of all arteries were significantly higher than in the control group (Regarding OA, CRA and NPCA RI, p = 0.003, p = 0.039, and p = 0.039, respectively).The results of this study support the idea that chronic inflammation and frequent attacks in FMF may have an effect on decreased ocular blood flow and choroidal thinning.

OBJECTIVE The optic nerve sheath diameter (ONSD) excluding the dura mater (ONSDE; i.e., the subarachnoid diameter) and the ONSD including the dura mater (ONSDI) have been used differently in studies, but the predictive ability of these two different measurements of the ONSD as measured by invasive intracranial pressure (ICP) monitoring has never been compared. Additionally, studies on the prediction of ICP using central retinal artery (CRA) Doppler ultrasonography are scarce. The authors aimed to determine how the two different ONSD measurements, the ONSD/eyeball transverse diameter (ETD) ratio, and transorbital Doppler ultrasonography parameters are associated with ICP via external ventricular drainage (EVD). METHODS This prospective observational study included 50 patients with brain injury who underwent EVD between August 2019 and September 2020. The mean of three repeated measurements of the ONSDI and ONSDE was calculated to reduce artifact and off-axis measurements. ETD, an immutable value, was measured from the initial brain CT with a clear outline of the eyeball. Simultaneously, flow velocities in the CRA and posterior ciliary artery (PCA) were compared with the ICP. RESULTS The ONSDE, ONSDI, and ONSD/ETD ratio were significantly associated with ICP (p = 0.005, p < 0.001, and p < 0.001, respectively). The ONSD/ETD ratio showed the highest predictive power of increased ICP (area under the curve [AUC] 0.897). The ONSDI was correlated more with the ICP than was the ONSDE (AUC 0.855 vs 0.783). None of the Doppler ultrasonography parameters in the CRA and PCA were associated with ICP. CONCLUSIONS The ONSD/ETD ratio is a better predictor of increased ICP compared with the ONSDI or ONSDE in brain-injured patients with nonsevere ICP. The ONSDI may be more available for predicting the ICP than the ONSDE.

Background There are multiple tools available to visualize the retinal and choroidal vasculature of the posterior globe. However, there are currently no reliable in vivo imaging techniques that can visualize the entire retrobulbar course of the retinal and ciliary vessels. Purpose To identify and characterize the central retinal artery (CRA) using cone-beam CT (CBCT) images obtained as part of diagnostic cerebral angiography. Materials and Methods In this retrospective study, patients with catheter DSA performed between October 2019 and October 2020 were included if CBCT angiography included the orbit in the field of view. The CBCT angiography data sets were postprocessed with a small field-of-view volume centered in the posterior globe to a maximum resolution of 0.2 mm. The following were evaluated: CRA origin, CRA course, CRA point of penetration into the optic nerve sheath, bifurcation of the CRA at the papilla, visualization of anatomic variants, and visualization of the central retinal vein. Descriptive statistical analysis was performed. Results Twenty-one patients with 24 visualized orbits were included in the analysis (mean age, 55 years ± 15; 14 women). Indications for angiography were as follows: diagnostic angiography (n = 8), aneurysm treatment (n = 6), or other (n = 7). The CRA was identified in all orbits; the origin, course, point of penetration of the CRA into the optic nerve sheath, and termination in the papilla were visualized in all orbits. The average length of the intraneural segment was 10.6 mm (range, 7-18 mm). The central retinal vein was identified in six of 24 orbits. Conclusion Cone-beam CT, performed during diagnostic angiography, consistently demonstrated the in vivo central retinal artery, demonstrating excellent potential for multiple diagnostic and therapeutic applications. © RSNA, 2021 Online supplemental material is available for this article.

BACKGROUND AND OBJECTIVE: To examine whether new cases of retinal artery occlusion (RAO) or retinal vein occlusion (RVO) increased during the coronavirus 209 (COVID-19) pandemic. PATIENTS AND METHODS: This was a retrospective cohort study of patients visiting retina clinics with a new diagnosis in two time periods: between January 1, 2019, and February 29, 2020 (the pre–COVID-19 period), and between March 1, 2020, and December 31, 2020 (the COVID-19 period). The key outcome was the percentage of newly diagnosed central RAO (CRAO), branch RAO (BRAO), central RVO (CRVO), and branch RVO (BRVO) seen in each period. RESULTS: The study population included 285,759 new patients in the pre–COVID-19 period and 156,427 new patients in the COVID-19 period. The overall number of new patients dropped dramatically during the first few months of the COVID-19 pandemic (24%, 66%, and 51% less new patients in March, April, and May 2020 than in the same months in 2019; P < .0001 for all 3 months). However, the decrease in the number of newly diagnosed patients with CRAO, CRVO, and BRAO during these months was less dramatic. As most states reopened in June and the number of patients in retina clinics started to increase, the newly diagnosed patients with these conditions as a percentage of all new diagnoses returned to similar trends as seen in the pre–COVID-19 period. CONCLUSIONS: The percentage of new cases of RAO and RVO with respect to all new diagnoses in retina clinics remained stable for the majority of the COVID-19 period. There was an increase in these percentages during the first few months of the COVID-19 pandemic, particularly for CRAO, CRVO, and BRAO, which may have led to the presumption that more patients presented with these conditions during the COVID-19 period evaluated in this study. [ Ophthalmic Surg Lasers Imaging Retina . 2022;53:22–30.

The aim of this experimental study was to investigate the pathogenesis of Terson syndrome (TS), which currently is controversial.The central retinal artery (in 39 orbits), posterior ciliary arteries (in 8 orbits), and central retinal vein (CRV in 21 orbits) were occluded in rhesus monkeys by exposing them to lateral orbitotomy. Fundus examination and fluorescein fundus angiography were performed before and immediately after cutting the vessels and serially thereafter during the follow-up period. The rationale of the experimental study design is discussed.In eyes with central retinal artery occlusion, retinal hemorrhages were seen soon after the procedure in 7 eyes, and on follow-up in a total of 15 eyes. In posterior ciliary artery occlusion, retinal hemorrhages were seen soon after the procedure in one eye, and on follow-up in a total of three eyes. In eyes with CRV, all eyes had extensive scattered retinal hemorrhages.The findings of this experimental study, and my basic, experimental, and comprehensive clinical studies on CRVO, suggest the following concept of the pathogenesis of TS: Compression of the CRV plays a crucial role in the development of TS. The CRV is compressed, as it lies in the subarachnoid space of the optic nerve sheath, by raised cerebrospinal fluid pressure and/or accumulated blood.venous stasis and raised venous pressure in the retinal veins, leading to venous engorgement, rupture of the retinal capillaries.retinal hemorrhages. The clinical importance of compression of the CRV and not occlusion of CRV in TS is that optic nerve sheath decompression by opening it and releasing the blood and raised cerebrospinal fluid (CSF) pressure, would result in immediate decompressing of the CRV in the subarachnoid space and restoration of normal circulation and prevent visual loss.

Ocular hypertension (OHT) is a clinical entity characterized by elevated intraocular pressure (IOP) without optic nerve damage. In the presence of other risk factors, OHT may progress to glaucoma. This study aimed to evaluate ocular blood flow (OBF) and choroidal thickness (CT), which may be markers and/or risk factors that could assess the progression of OHT to glaucoma. Age and gender matched 60 eyes of 32 patients with OHT and 61 eyes of 31 control patients were included for this study. All participants underwent a detailed ophthalmological examination including best-corrected visual acuity, IOP measurement with Goldmann applanation tonometry, gonioscopy, optic nerve evaluation with 78 D lens, and visual field test with Humphrey visual field analyzer. Retinal nerve fiber layer, ganglion cell complex, and central corneal thickness measurements were performed by optical coherence tomography (OCT). CT was measured with OCT in the fovea, 1.5 mm, 2 mm, 2.5 mm nasal and temporal to the fovea and from nasal and temporal to the optic disk. OBF data including peak systolic velocity (PSV), end-diastolic velocity (EDV), resistivity index (RI) and pulsatility index (PI) were measured with color Doppler imaging (CDI) from the ophthalmic artery (OA), central retinal artery (CRA), medial and lateral branches of short posterior ciliary arteries (MPCA, LPCA). Systolic (SBP) and diastolic arterial blood pressure were also noted. CT measurement at each point in the OHT group compared to the control group were found to be significantly thinner (p = 0.001). There was a decrement in CT from the fovea to the nasal and temporal retina in both groups. In the OHT group, there was a significant decrease in PSV and EDV of OA, CRA, MPCA, and LPCA, and a significant increase in PI and RI of measured arteries. (EDV p = 0.036, PI p = 0.006, RI p = 0.006 for OA and p = 0.001 for other arteries and all OBF measurements). There was a negative correlation between CT and age, IOP and axial length (AL) in OHT group (r = − 0.529, p = 0.001; r = − 0.258, p = 0.047; r = − 0.345, p = 0.007, respectively, for fovea). But there was no statistically significant correlation between CT and other measurements in the control group, except age (r = − 0.860 p = 0.001 for fovea). We found that OBF decrement and choroidal thinning in OHT group compared with controls. Interpretation both of CT measurements with OCT and OBF parameters with CDI and new imaging technologies may help to prevent and reduce the possible optic nerve damage.

PURPOSE To find out clinical characteristics, therapeutic options, and visual outcome in symptomatic retinal artery macroaneurysm (RAMA) patients. METHOD Newly diagnosed cases of symptomatic RAMA from January 2015 to December 2019 were included. Fifteen eyes of 15 patients with mean age 62.46 years ± 14.89 (SD) fulfilled the inclusion criteria. RESULT Hypertension was present in 66.6% of the patients, and the commonest site was superotemporal (12 eyes, 80%). The most commonly employed treatment was Nd: Yag laser hyaloidotomy in 4 eyes (26.6%). Other treatments were intravitreal bevacizumab in 3 eyes (20%), focal laser with intravitreal bevacizumab in 3 eyes (20%), PPV with focal laser (13.3%) in 2, focal laser only in one (6.6%), PPV with focal and intravitreal bevacizumab in one (6.6%). The mean best-corrected visual acuity (BCVA) at baseline was 1.35 ± 0.84 LogMAR, which improved to 0.39 ± 0.53 LogMAR at the last follow-up. Presenting VA 0.77 (±0.40) improved to 0.20 (±0.17) p value (0.180) in intravitreal bevacizumab only group, 1.29 (±0.35) to 0.75 (±0.15) p value 0.66 in Nd: Yag laser group, 2.67 (±0.58) to 0.46 (±0.28) p value 0.019 in PPV group and did not improve in combined anti-VEGF and focal laser group due to dense hard exudates at the fovea in one and persistent cystoid macular edema in another case. CONCLUSION With regard to its presentation, which can vary tremendously, there are no approved guidelines for its treatment. The present study reinforces the need for a treatment guideline development. Customization of treatment should be considered depending on the clinical presentation of each case.

We aimed to investigate the increase in resistivity of the retinal artery in the branch retinal vein occlusion (BRVO)-affected area, and to visualize it. Thirty-two eyes of 32 patients with BRVO were measured by laser speckle flowgraphy (LSFG). The retinal artery and vein running to the BRVO-affected area and vertically symmetrical vessels in the unaffected area were examined. We applied the LSFG parameter beat strength over mean blur rate (BOM), calculated using a similar method to the pulsatility index used in Doppler flowmetry to evaluate resistivity of the vessels. Our results showed that the BOM map could clearly visualize the increase of resistivity in the retinal artery as a two-dimensional map. The BOM of the arteries in the affected area was significantly higher than that of the unaffected area (P = 0.001). Multiple regression analysis showed that the ratio of BOM in retinal arteries of the affected area to the unaffected was significantly associated with the extent of retinal hemorrhage (β = 0.447, P = 0.009). In conclusion, the index of resistivity of the retinal artery in the BRVO-affected area was higher and could be visualized in a two-dimensional map. These findings and techniques would contribute to elucidate the pathophysiology of BRVO.

Diabetic retinopathy is one of the most common causes of blindness in work-aging adults and develops in one third of diabetic patients. Calcium dobesilate (CaD) treatment have protective effects on blood retinal barrier (BRB) and anti-oxidant as well as anti-inflammatory properties. To assess effects of CaD administration on retrobulbar blood flow and choroidal thickness in patients with diabetic retinopathy. In this quasi-experimental study, diabetic patients with diabetic retinopathy (DR) were recruited from Shahid Motahari and Poostchi ophthalmology clinic affiliated to Shiraz University of Medical Sciences. Patients were treated with CaD, 1 gr per day for seven days. Before and after CaD administration, retrobulbar blood flow and subfoveal choroidal thickness were assessed. Retrobulbar blood flow were evaluated by measuring peak systolic velocity (PSV), end diastolic velocity (EDV) and resistive index (RI) of ophthalmic artery (OA), central retinal artery (CRA) and short ciliary artery (SCA). In this study, 26 DR patients with a mean age of 56.15 ± 8.93 years and mean diabetes mellitus duration of 15.04 ± 7.64 years were enrolled. Subfoveal choroidal thickness was significantly increased from 316.08 ± 61.69 to 327.81 ± 58.03 after CaD treatment (P value

Los problemas vasculares oculares constituyen una patología emergente dentro de la actividad del internista. La ecografía ocular es una técnica ampliamente utilizada para evaluar una variedad de afecciones oculares; en particular, el estudio por ecografía Doppler de los vasos oftálmicos se ha convertido en una herramienta muy útil en el diagnóstico de diversas enfermedades oculares. La ecografía Doppler permite examinar el flujo sanguíneo ocular, incluso en presencia de opacidades oculares que impidan una visión del segmento posterior del ojo. En esta revisión describimos los principios y técnicas para el examen ecográfico Doppler vascular ocular y proporcionamos una aproximación general a las características ecográficas de los trastornos vasculares oculares más importantes para la práctica clínica de los internistas, entre los que se incluyen la oclusión de la arteria y de la vena central de la retina, el síndrome isquémico crónico retiniano, la neuropatía óptica isquémica anterior y la retinopatía diabética. Ocular vascular problems represent an emerging pathology within the activity of the internist. Ocular ultrasound is a widely used technique to evaluate a variety of eye conditions. Specifically, Doppler ultrasound of the ophthalmic vessels has become a very useful tool in diagnosing various eye diseases. Doppler ultrasound allows for examining blood flow in the eye even in the presence of eye opacities that impede viewing the posterior segment of the eye. In this review, we describe the principles and techniques of an ocular vascular Doppler ultrasound examination in clinical practice and provide a general approach to the ultrasound characteristics of the most important vascular eye disorders for internists. These include central retinal artery and vein occlusions, chronic retinal ischemic syndrome, anterior optic ischemic neuropathy, and diabetic retinopathy. Sin financiación 3.064 JCR (2021) Q2, 82/172 Medicine, General & Internal 0.300 SJR (2021) Q3, 1734/2489 Medicine (miscellaneous) No data IDR 2021 UEM

Wyburn-Mason syndrome (WMS) is a rare congenital disease that presents with unilateral arteriovenous malformation (AVM) in the visual pathway, midbrain, and/or skin. We report a case of a 5-year-old girl with a history of cerebral and orbital AVM who presented with left exotropia and was found to have group 3 retinal AVM consistent with WMS. Here, we use ultrawide field imaging to show the progression of retinal AVM and peripheral nonperfusion areas for a period of 1 year in a pediatric patient with WMS. [ Ophthalmic Surg Lasers Imaging Retina . 2022;53:46–48.]

Background The associations of time‐averaged cumulative blood pressure (BP) from midlife to late life with microvasculature expressed as retinal vessel diameters is not well studied. The aim of this study was to evaluate the association of cumulative systolic BP and diastolic BP (DBP) with retinal vessel calibers, focusing on race differences. Methods and Results The analysis included 1818 adults from the ARIC (Atherosclerosis Risk in Communities) study attending the fifth visit (2011–2013; age 77±5 years, 17.1% Black participants). Time‐averaged cumulative BPs were calculated as the sum of averaged BPs from adjacent consecutive visits (visits 1–5) indexed to total observation time (24±1 years). Summarized estimates for central retinal arteriolar equivalent and central retinal venular equivalent at the fifth visit represent average retinal vessel diameters. The arteriole:venule ratio was calculated. We tested for effect modification by race. Results from multiple linear regression models suggested that higher time‐averaged cumulative DBP (β [95% CI] per 1‐SD increase: −1.78 [−2.53, −1.02], P P =0.004, respectively) but not systolic BP (−0.52 [−1.30, 0.26], P =0.189 and 0.001 [−0.002, 0.005], P =0.485, respectively) was associated with smaller central retinal arteriolar equivalent and arteriole:venule ratio. The association between time‐averaged cumulative DBP and arteriole:venule ratio was strongest in White participants (interaction P =0.007). The association of cumulative systolic BP and DBP with central retinal venular equivalent was strongest in Black participants (interaction P =0.015 and 0.011, respectively). Conclusions Exposure to higher BP levels, particularly DBP, from midlife to late life is associated with narrower retinal vessel diameters in late life. Furthermore, race moderated the association of cumulative BP exposure with retinal microvasculature.

To evaluate the severity of hemodynamic changes in the ocular vessels of patients recovered from COVID-19.The study included 44 patients (88 eyes) aged 28-60 years, among them 24 (54.5%) women and 20 (45.4%) men, with SARS-CoV-2 infection confirmed by PCR no more than 2 months prior to enrollment and with no ophthalmological complaints within 2 months before the disease, as well as 20 healthy volunteers (40 eyes). At the time of the study all patients had a negative PCR result for SARS-CoV-2. The patients were divided into 2 groups. The first group comprised 24 patients who did not take any anticoagulants during the treatment. The second group consisted of 20 patients who received anticoagulants (Rivaroxaban (Xarelto)) at a dosage of 10 mg per day for 1-1.5 months. The maximum systolic (Vs), end-diastolic (Vd) blood flow velocity, as well as resistance index (RI) in the ophthalmic artery (OA), central retinal artery (CRA) and short posterior ciliary arteries (SPCA) were measured in all study patients with the ultrasound imaging system VOLUSON E8 Expert («Kretz», USA). Additionally, the flowmetry method was used to assess the volumetric ocular blood flow (VOBF) on Ocular Blood Flow Analyzer system («Paradigm Medical Industries, Inc.», USA).In the first group, a decrease in Vs and Vd was noted amid a significant increase of RI in CRA and SPCA, as well as an increase of RI in OA compared with the age-normal values (Blood flow velocity parameters in the ocular vessels are reduced in patients recovered from COVID-19 compared to the age-normal values. There was a significant decrease in volumetric ocular blood flow parameters in COVID-19 patients who did not take any anticoagulants compared to the age-normal values. Anticoagulants intake has a positive impact on hemodynamic characteristics in the ocular vessels and volumetric ocular blood flow in patients with COVID-19.Оценка выраженности гемодинамических изменений в сосудах глаза у пациентов, перенесших COVID-19.В исследовании приняли участие 44 пациента (88 глаз) в возрасте 28—60 лет, из них 24 (54,5%) женщины и 20 (45,5%) мужчин, с инфекцией SARS-CoV-2, подтвержденной методом полимеразной цепной реакции (ПЦР), не более 2 мес назад и отсутствием офтальмологических жалоб в течение 2 мес до начала заболевания, а также 20 здоровых добровольцев (40 глаз). На момент исследования пациенты имели отрицательный результат ПЦР к SARS-CoV-2 (COVID-19).Все пациенты были разделены на две группы: 1-ю группу составили 24 пациента, не получавших в процессе лечения антикоагулянты, 2-ю группу — 20 пациентов, принимавших антикоагулянт: ривароксабан (Ксарелто) в дозе 10 мг/сут в течение 1—1,5 мес. Всем пациентам проводили оценку максимальной систолической (Vs), конечной диастолической (Vd) скорости кровотока, а также индекса резистентности (RI) в глазной артерии (ГА), центральной артерии сетчатки (ЦАС) и задних коротких цилиарных артериях (ЗКЦА) методом цветового допплеровского картирования на ультразвуковом диагностическом приборе VOLUSON Е8 Expert («Kretz», США) и оценку объемного глазного кровотока (ОГК) методом флоуметрии на анализаторе глазного кровотока Paradigm Blood Flow Analyzed («Medical Indastries Inc.», США).В 1-й группе отмечено снижение Vs и Vd на фоне существенного увеличения RI в ЦАС и ЗКЦА, а также увеличение RI в ГА по сравнению с возрастной нормой (У пациентов, перенесших COVID-19, отмечается снижение показателей скорости кровотока в сосудах глаза по сравнению с возрастной нормой. У пациентов с COVID-19, не принимавших антикоагулянты, отмечено существенное снижение показателей ОГК по сравнению со значениями возрастной нормы. Прием антикоагулянтов положительно влияет на показатели гемодинамики в сосудах глаза и ОГК у пациентов с COVID-19.

ObjectiveThe purpose of this study is to investigate the potential of using the tortuosity of branch retinal artery as a more promising indicator for early detection and accurate assessment of diabetic retinopathy (DR).Design and methodThe diagnoses, consisting of whether DR or not as well as DR severity, were given by ophthalmologists upon the assessment of those fundus images from 495 diabetic patients. Meanwhile, benefiting from those good contrast and high optical resolution fundus images taken by confocal scanning laser ophthalmoscope, the branch arteries, branch veins, main arteries and main veins in retina can be segmented independently, and the tortuosity values of them were further extracted to investigate their potential correlations with DR genesis and progress based on one-way ANOVA test.ResultsFor both two comparisons, i.e., between non-DR group and DR group as well as among groups with different DR severity levels, larger tortuosity increments were always observed in retinal arteries and the increments in branch retinal vessels were even larger. Furthermore, it was newly found that branch arterial tortuosity was significantly associated with both DR genesis (p=0.030) and DR progress (pConclusionBased on this cohort study of 495 diabetic patients without DR and with different DR severity, the branch arterial tortuosity has been found to be more closely associated with DR genesis as well as DR progress. Therefore, the branch arterial tortuosity is expected to be a more direct and specific indicator for early detection of DR as well as accurate assessment of DR severity, which can further guide timely and rational management of DR to prevent from visual impairment or even blindness resulting from DR.

The optic nerve is the second cranial nerve. It is supplied by the central retinal artery. It is said that this artery starts getting incorporated within the optic nerve at around the sixth week of gestation, and by the ninth week it is entirely inside the optic nerve. However, the point of incorporation lies in the intraorbital course of the optic nerve. The present study aimed at identifying the location of the central retinal artery inside the optic nerve, i.e. the peripheral or central position. Human fetuses of second and third trimester were dissected to expose the optic nerve. Morphometric measurements were taken and sectioned in 3 regions. These transverse sections were subjected to histological procedures. The results showed that the central retinal artery, at its entry into the optic nerve, was peripheral and inferior in 3 of 25 optic nerves and peripheral and lateral in the remaining optic nerves. However, the arteries were all centrally placed, close to the posterior pole of the eyeball. These findings are important for the ophthalmologist in identifying certain congenital anomalies of the eyeball in neonates.

Purpose To evaluate the retinal vasculature pathophysiological changes of indirect traumatic optic neuropathy (ITON) patients after effective surgery. Methods Monocular ITON patients who underwent endoscopic trans-ethmosphenoid optic canal decompression (ETOCD) or conservative treatments in Zhongshan Ophthalmic Center from January 2017 to June 2020 were recruited. Visual acuity (VA), visual evoked potential (VEP), oxygen saturation of retinal blood vessels (SO2), and optical coherence tomography angiography (OCT-A) were measured. All patients were followed up at least 3 months after treatments. Results A total of 95 ITON patients were recruited, including 77 patients who underwent ETOCD and 18 patients who underwent conservative treatments. After treatments, more patients received ETOCD (59/77 = 76.6%) presented with improved VA compared with the patients with conservative treatments (6/18 = 33.3%). Compared with the pre-therapeutic measurements, VEP were significantly improved after surgery in ETOCD-treated patients (P P 2 and the differences between arteries and veins were improved in ETOCD-treated patients (P (P Conclusions Vision recovery after effective treatment of ITON patients was associated with the increased oxygen saturation of retinal vessels, better availability of oxygen in the retina, greater vessel density, and thicker retinas, which might further underlie the vasculature mechanism of vision recovery in ITON patients.

PURPOSE To report a case of vitreous seeding in a medium-sized choroidal melanoma and review the literature. METHODS Observational case report and review of literature for pathogenesis, role of vitreous biopsy, and treatment outcomes. RESULTS A case of 57-year-old man diagnosed with vitreous seeding in the left eye 1 year after episcleral brachytherapy for medium-sized choroidal melanoma. The patient was initially diagnosed to have subretinal and vitreous hemorrhage due to rupture of a retinal artery macroaneurysm for which focal laser and intravitreal antivascular endothelial growth factor injections were administered. Over the next 9 months, the vitreous hemorrhage cleared and choroidal melanoma with retinal invasion became evident. One year after brachytherapy, the primary tumor regressed with resolution of surrounding subretinal fluid and hemorrhage. However, gradual decline in the visual acuity from 20/50 to 20/500 with increase of pigmented debris over the retinal surface and in the vitreous cavity was noted. A vitreous biopsy confirmed the presence of viable melanoma cells (epithelioid type), and the eye was enucleated. Histopathology showed microscopic persistence of primary tumor with diffuse vitreous seeding. CONCLUSION Vitreous seeding of choroidal melanoma poses a diagnostic and management challenge.

Describing optic disc appearance in familial retinal arteriolar tortuosity (fRAT) using multimodal imaging and raising awareness of peripapillary arterial changes due to this disorder.A cross-sectional study was performed in four consecutive patients of two non-related families. Detailed ophthalmological examination was performed and supported by medical and family history and multimodal imaging.In all subjects, increased tortuosity of second- and third-order retinal arteries in superior and deeper vascular plexus was documented. Furthermore, tortuosity in the peripapillary circle of Zinn-Haller was found. In addition, retinal vessel oximetry confirmed tortuosity only of the arterial vessels.The present data suggests that a blurry bordered, hyperemic optic disc in the presence of abnormally tortuous arteriolar vessels and asymptomatically or oligosymptomatically spontaneously resolved hemorrhages could be associated with a fRAT. This finding could be linked to peripapillary arterial vessel tortuosity.Dokumentation und Beschreibung der Konfiguration des N. opticus mittels multimodaler Bildgebung bei vorliegender familiärer retinaler arterieller Tortuositas (fRAT) sowie Schaffung von mehr Bewusstsein für peripapilläre arterielle Veränderungen im Rahmen dieser Erkrankung.Es erfolgte die Datenerhebung mittels Querschnittsuntersuchung von 4 Patienten zweier unterschiedlicher Familien. Wir führten eine multimodale Bildgebung, eine ausführliche ophthalmologische Untersuchung sowie eine Familienanamnese durch.Bei allen Patienten konnten wir eine vermehrte Tortuositas der Arterien 2. und 3. Grades im Bereich des oberflächlichen und tiefen Gefäßplexus im Bereich der Makula dokumentieren. Des Weiteren zeigten sich Veränderungen im Bereich der Arterien des Zinn-Haller-Gefäßkranzes. Die ausschließliche Beteiligung des arteriellen Gefäßsystems konnten wir durch die Messung des Sauerstoffgehaltes, mittels retinaler Oxymetrie, belegen.Die hier dargestellte Fallserie unterstützt die These, dass ein unscharf begrenzter, hyperämischer Sehnerv bei Vorliegen einer bilateralen Tortuositas der arteriellen Gefäße sowie asymptomatischen/oligosymptomatischen retinalen Blutungen bei fRAT vorkommen kann und durch tortuöse arterielle peripapilläre Gefäße bedingt ist.

OBJECTIVE: To describe the role of local anaesthetic blocks as a potential cause of paracentral acute middle maculopathy (PAMM) after uneventful ocular surgery. METHODS: Retrospective, observational, international, multicentre case series. Nine cases of PAMM with associated visual loss following uneventful ocular surgery with local anaesthetic blocks were observed in a 9-year period (2011–2020). Demographic, ocular and systemic data, anaesthetic data and surgical details were collected. Visual acuity (VA), fundus photography, fluorescein angiography, optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) images were reviewed. RESULTS: All nine cases were associated with decreased VA at 24 h postoperative check (ranging from hand movement to 20/200). A hyperreflective band within the middle retinal layers was observed in the structural OCT in the acute phase, evolving to thinning and atrophy of the inner retinal layers in sequential follow-up scans performed. Fluorescein angiography showed delayed perfusion in early arterial phase with normal perfusion in late venous phases. OCTA showed decreased perfusion in the deep capillary plexus. Visual recovery was variable between cases during follow-up (ranging from count fingers to 20/20). CONCLUSIONS: A combination of a vasoconstrictive effect of the anaesthetic agent, an intraocular pressure spike and a mechanical effect of the volume of anaesthetic injected may result in decreased retinal artery perfusion and be evidenced as PAMM in OCT scans. PAMM may present as a potential complication of local anaesthetic blocks in cases of unexpected visual loss after uneventful ocular surgery.

The aim of the study was to obtain the values of oxygen saturation in retinal vessels and ophthalmic blood flow parameters in a healthy Caucasian population and assess whether the oximetry parameters are affected by the flow rate or the vascular resistance.The spectrophotometric retinal oximetry and colour Doppler imaging (CDI) of retinal vessels were successfully performed with 52 healthy subjects (average age 29.7 ± 5.6 years). The retinal oximeter simultaneously measures the wavelength difference of haemoglobin oxygen saturation in retinal arterioles and venules. The arteriolar and venular saturation in both eyes was measured. The peak systolic (PSV) end diastolic (EDV) velocities, resistive (RI) and pulsatility (PI) indices were obtained for both eyes using CDI in the ophthalmic artery. A paired t-test and two sample t-tests were used for statistical analyses. The correlation was assessed using the Pearson coefficient correlation.The mean oxygen saturation level was 96.9 ± 3.0% for the retinal arterioles and 65.0 ± 5.1% for the retinal venules. The A-V difference was 31.8 ± 4.6%. The mean of the measured haemodynamic parameters was PSV 46.6 ± 9.4 cm/s, EDV 12.0 ± 3.5 cm/s, PI 1.68 ± 0.38 and RI 0.74 ± 0.05. No significant difference in oxygen saturation and haemodynamic parameters was found between the left and the right eyes or the dominant and non-dominant eye. The oximetry and ultrasound values were sex independent. The Pearson correlation coefficient demonstrated a significant yet weak negative correlation between A-V difference and RI (r = -0.321, p = 0.020).A negative correlation between A-V difference and resistance index was observed, suggesting that reduced oxygen consumption may reflect the increased vascular tone of the ophthalmic vessels, which is likely determined by autoregulatory mechanisms.

BackgroundPolycythemia vera (PV) is a myeloproliferative neoplasm with increased hemoglobin, hematocrit, platelet count and leukocytosis, resulting in increased blood viscosity. PV which is initially presenting with ocular symptoms is rare, but irreversible retinal vessel occlusions leading to the diagnosis of PV have been described in literature.Case presentationWe describe a patient with PV, initially presenting with attacks of monocular temporary loss of vision due to intermittent retinal artery occlusions of different retinal arteries. The patient was immediately treated with phlebotomy and the impaired arterial retinal perfusion could be restored without permanent retinal ischemia. We were able to document these transient arterial occlusions with fundus photography as well as fluorescein angiography. To the best of our knowledge, a case like this has never been documented before.ConclusionThis report is pertinent, in order to raise awareness among clinicians for polycythemia vera, as it can in fact be used as a differential diagnosis for patients with retinal artery occlusion. We would like to stress that early therapy might reverse the vessel complications.

To evaluate the effects of COVID-19 infection on the ocular vascular structure including choroidal thickness and retrobulbar blood flow values in comparison with healthy subjects.Ninety eyes of 90 patients were included in this study. Participants were divided into Group 1 (n = 30) with mild COVID-19 infection, Group 2 (n = 31) with moderate disease, and Group 3 with age- and sex-matched healthy subjects (n = 29). Choroidal thickness was measured at the subfoveal area and at 500-µm intervals nasal and temporal to the fovea up to a distance of 1500 µm, using the enhanced depth imaging (EDI) technique of spectral coherence tomography (SD-OCT). The peak systolic velocity (PSV), end diastolic velocity (EDV), resistive index (RI), and pulsatility index (PI) values of the central retinal artery (CRA) and ophthalmic artery (OA) were evaluated with color Doppler ultrasonography (CDU).The choroidal thickness was significantly thinner in Group 1 and Group 2 than in Group 3 at all measurement points (p0.001). This difference was not present between Group 1 and Group 2 who had COVID-19 disease of different severity (p0.05).Among the retrobulbar blood flow parameters, OA PSV value was significantly lower in Group 1 and Group 2 compared to Group 3 (p = 0.025, p = 0.016, respectively). However, the CRA PSV and EDV and OA EDV values, and the CRA and OA PI and RI values were not statistically different between the groups (p0.05).COVID-19 infection may predispose patients to ocular vascular pathologies by affecting both choroidal and retrobulbar blood flow.

Automatic classification of retinal arteries and veins plays an important role in assisting clinicians to diagnosis cardiovascular and eye-related diseases. However, due to the high degree of anatomical variation across the population, and the presence of inconsistent labels by the subjective judgment of annotators in available training data, most of existing methods generally suffer from blood vessel discontinuity and arteriovenous confusion, the artery/vein (A/V) classification task still faces great challenges. In this work, we propose a multi-scale interactive network with A/V discriminator for retinal artery and vein recognition, which can reduce the arteriovenous confusion and alleviate the disturbance of noisy label. A multi-scale interaction (MI) module is designed in encoder for realizing the cross-space multi-scale features interaction of fundus images, effectively integrate high-level and low-level context information. In particular, we also design an ingenious A/V discriminator (AVD) that utilizes the independent and shared information between arteries and veins, and combine with topology loss, to further strengthen the learning ability of model to resolve the arteriovenous confusion. In addition, we adopt a sample re-weighting (SW) strategy to effectively alleviate the disturbance from data labeling errors. The proposed model is verified on three publicly available fundus image datasets (AV-DRIVE, HRF, LES-AV) and a private dataset. We achieve the accuracy of 97.47%, 96.91%, 97.79%, and 98.18% respectively on these four datasets. Extensive experimental results demonstrate that our method achieves competitive performance compared with state-of-the-art methods for A/V classification. To address the problem of training data scarcity, we publicly release 100 fundus images with A/V annotations to promote relevant research in the community.

The retinal vasculature provides important clues in the diagnosis and monitoring of systemic diseases including hypertension and diabetes. The microvascular system is of primary involvement in such conditions, and the retina is the only anatomical site where the microvasculature can be directly observed. The objective assessment of retinal vessels has long been considered a surrogate biomarker for systemic vascular diseases, and with recent advancements in retinal imaging and computer vision technologies, this topic has become the subject of renewed attention. In this paper, we present a novel dataset, dubbed RAVIR, for the semantic segmentation of Retinal Arteries and Veins in Infrared Reflectance (IR) imaging. It enables the creation of deep learning-based models that distinguish extracted vessel type without extensive post-processing. We propose a novel deep learning-based methodology, denoted as SegRAVIR, for the semantic segmentation of retinal arteries and veins and the quantitative measurement of the widths of segmented vessels. Our extensive experiments validate the effectiveness of SegRAVIR and demonstrate its superior performance in comparison to state-of-the-art models. Additionally, we propose a knowledge distillation framework for the domain adaptation of RAVIR pretrained networks on color images. We demonstrate that our pretraining procedure yields new state-of-the-art benchmarks on the DRIVE, STARE, and CHASE_DB1 datasets. Dataset link: https://ravirdataset.github.io/data/, Comment: Paper accepted to IEEE Journal of Biomedical Health Informatics (JBHI)

Permanent perioperative vision loss is caused by ischemic optic neuropathy (ION) or central retinal artery occlusion (CRAO). Whereas diffusion restriction of the optic nerve (ON) on brain magnetic resonance imaging has been previously reported in perioperative posterior ION (PION), there are no reports of ON diffusion restriction in patients diagnosed with acute perioperative CRAO. We present a case of perioperative CRAO to highlight this neuroimaging finding for neuroradiologists and neurologists.A 71-year-old male without vascular risk factors underwent maxillary bilateral antrostomy and septoplasty for chronic sinusitis. Twenty to thirty minutes upon awakening, he complained of painless left eye vision loss. Ophthalmoscopic examination showed retinal whitening, segmented arterioles, and hyperemic disc. Brain MR-diffusion weighted imaging/apparent diffusion coefficient revealed ON diffusion restriction in the proximal segment. Despite attempted reperfusion, left eye remained with no light perception at 6 months. Patients undergoing nonocular surgeries who develop perioperative vision loss related to PION may exhibit ON diffusion restriction but usually have normal ophthalmoscopic findings. CRAO shows retinal whitening, edema, segmentation of arterioles, and cherry red spot on ophthalmoscopy. A recent study reported that ON diffusion restriction in nonperioperative CRAO cases has a sensitivity and specificity of 55% and 70% to 100%. Here, PION was initially considered based on imaging. However, given the neuro-ophthalmic findings, a proximal embolus in the central retinal artery, obstructing its entrance into the proximal ON was deemed more likely.We highlight that proximal ON diffusion restriction on brain magnetic resonance imaging can be diagnostic of proximal thromboembolic CRAO. Future studies should evaluate the diagnostic utility and accuracy of MR-diffusion weighted imaging/apparent diffusion coefficient in perioperative visual loss.

Purpose: Few studies have explored the central retinal artery (CRA) using neuroimaging. Our study aimed to explore this using magnetic resonance imaging (MRI).Methods: A total of 81 patients with intact orbital structures and visual function underwent thin-slice contrast MRI.Results: The identified CRAs showed highly variable morphologies on both axial and sagittal images. On the axial images, the CRAs were detected in the right orbit in 11.1% and in the left orbit in 19.8%. The distance between the site of CRA branching from the ophthalmic artery to the posterior limit of the bulb was 18.8±3.9 mm (range: 12.8–24.6 mm) on the right and 18.9±3.3 mm (range: 14.6–26.7 mm) on the left. On the sagittal images, CRAs were detected on the right in 76.5% and on the left in 85.2%. The distance between the CRA branching site and the posterior limit of the bulb was 20.4±3.8 mm (range: 14.2–28.2 mm) on the right and 19.2±3.7 mm (range: 11.3–27.1 mm) on the left.Conclusions: Thin-slice contrast MRI can be used to explore the proximal part of the CRA. In particular, serial sagittal imaging may be useful for detecting the CRAs and their relationship with relevant structures.

Background In this case report, we present for the first time central retinal artery occlusion (CRAO) and central retinal vein occlusion (CRVO) as a complication of persistent hyaloid artery (PHA). Case presentation In August 2019, a six-year-old male patient manifested right eye (RE) excessive tearing, conjunctival injection and pain. On examination, RE demonstrated light perception and intraocular pressure of 36 mmHg. The diagnoses of neovascular glaucoma, CRVO and CRAO were established as affirmed with fluorescein angiography (FA). PHA was not reported. Extensive work-up and family history were unremarkable. The child was born on term after uncomplicated twin pregnancy. In December 2019, he was referred to our Centre. Transillumination revealed fully dilated, non-reactive RE pupil, clear lens and tubular remnant of HA containing blood cells in its lumen freely rotating in the anterior vitreous. Conclusions PHA results from failure of apoptosis during gestation. It can easily be observed during the red reflex screening at neonatal wards. We hypothesized that PHA twisting led to torsion of the residual primordial common bulb, branching off to HA and CRA with CRAO occurring first. The consequential CRVO presumably advanced by venous stasis due to decrease in arterial inflow. Liquid vitreous appears as early as 4 years of age enabling PHA to whirl more freely. Thus, in case of PHA, we advocate FA to be performed and if connection with retinal artery is proven, parents should be informed on the possible devastating complications and prompt surgical treatment should be considered.

Purpose Retinal vein occlusions (RVOs) are a common disease, but there are no animal models for spontaneous RVO formation. The critical sites of predilection, especially for branch RVO (BRVO), are the arteriovenous crossing sites in the inner retina. To gain more insight into possible animal models, the anatomic structure of retinal arteriovenous crossings was investigated in mice, rats, and pigs and compared to the human situation. Methods Retinal flat mounts and paraffin sections of eyes from mice, rats, pigs, and humans were stained with GS lectin, Masson’s trichrome, or immunohistochemistry for ACTA2 and GFAP. Serial sections of arteriovenous crossing sites were investigated. Results Mice usually do not show retinal arteriovenous crossings. Rats have a mean of 2.8±1.4 crossings per eye at a mean distance from the optic nerve head of 2.79±0.53 mm, though the diameters of the crossing vessels are small. The situation in pigs is similar to that in humans, with many arteriovenous crossings of vessels and with similar diameters as found in humans. A mean of 28.4±3.5 crossings per retina was found, and 23% of these were arterial overcrossings. Serial paraffin sections showed that the tunica media of the artery touched that of the vein, but they did not fuse. Conclusions While the retinal arteriovenous crossings of mice and rats are absent or comprised of rather thin vessels, those in the porcine retina are similar to adult humans. Therefore, the porcine retinal vascular bed may serve as a model to assess early steps in the formation of RVOs.

When retinal activity is increased by exposure to dynamic visual stimuli, blood vessels dilate and the flow of blood within vessels increases to meet the oxygen and glucose demands of the neurons. This relationship is termed ‘neurovascular coupling’ and it is critical for regulating control of the human retinal vasculature. In this study, we used a recently developed technique based on a dual-beam adaptive optics scanning laser ophthalmoscope to measure changes in red blood cell velocities, vessel diameter, and flow in interconnected small parafoveal retinal vessels (t-test showed significant increases in velocity and flow in arterioles and venules. These measurements indicate that the mechanism of neurovascular coupling systematically affects the vascular response in small retinal vessels in order to maintain hemodynamic regulation in the retina when exposed to visual stimulation, in our case flicker. Our findings may provide insight into future investigations on the impairments of neurovascular coupling from vascular diseases such as diabetic mellitus.

There are controversies regarding ophthalmic artery (OA) flow after peribulbar block in the presence of epinephrine. Therefore, we aimed to evaluate OA flow via echo-Doppler before and after peribulbar block with lidocaine in the presence or absence of epinephrine. Fifty-six patients who had an American Society of Anesthesiologists (ASA) classification of I, II or III and were eligible for cataract phacoemulsification surgery were selected. Patients with other eye diseases were excluded. Patients were divided into two groups: group 1—peribulbar block with lidocaine and 1/200,000 epinephrine; group 2—peribulbar block with lidocaine in the absence of epinephrine. The resistance index (RI), peak systolic velocity (PSV), end diastolic velocity (EDV) of the OA were evaluated using echo-Doppler before and 10 min after the peribulbar block. No differences between groups were observed in the RI before the peribulbar block as well regarding the presence of hypertension and the age or gender of the patient. After the peribulbar block, we observed a decrease in the RI in group 1 (p = 0.038, Cohen’s d = 0.336) and no difference in the RI in group 2 (p = 0.109, Cohen’s d = 0.172). When comparing group 1 and group 2, we observed a decrease in the RI in group 1 (p = 0.028, Cohen’s d = 0,583). There was no difference between groups regarding the PSV and EDV after the peribulbar block. A decrease in RI was observed in the OA after peribulbar block with a vasoconstrictor, an effect that could be a benefit in some ocular surgeries.

OBJECTIVES The aim of this study was to identify changes in Doppler flow parameters in the central retinal artery (CRA) and ophthalmic artery (OA) that could be indicative of de novo development of thyroid-associated orbitopathy in the early period after radioiodine treatment. METHODS Eighty-two patients with hyperthyroidism were enrolled: 44 with Graves disease and 38 with toxic nodular goiter. In both groups, blood flow parameters in the CRA and OA were analyzed before and 2 and 4 weeks after radioiodine administration. The peak systolic velocity and end-diastolic velocity (EDV) were evaluated, and the resistive index (RI) was calculated. RESULTS There were no statistically significant differences in the peak systolic velocity, EDV or RI between groups at baseline and 4 weeks after radioiodine administration. Two weeks after radioiodine administration, the RI in the CRA (P = .034) and EDV in the OA (P = .026) were significantly lower, and the EDV in the CRA (P = .004) was higher in patients with Graves disease than in patients with toxic nodular goiter. There was an inverse correlation between baseline thyrotropin receptor autoantibody (TRAb) levels and the difference between the RI at weeks 4 and 2 (RI3-RI2) in the CRA (r = -0.458; P

Objectives To evaluate ophthalmic Doppler velocimetry patterns in pregnant women with pregestational diabetes mellitus with and without retinopathy in comparison to pregnant women without gestational intercurrences. Methods This cross-sectional observational study analyzed Doppler indices of the ophthalmic arteries, including the resistive index (RI), pulsatility index, peak systolic velocity, second peak systolic velocity, peak ratio, and end-diastolic velocity (EDV), in 3 groups of pregnant women: diabetic with retinopathy (n = 12); diabetic without retinopathy (n = 85); and nondiabetic controls (n = 122). The Kruskal-Wallis test was used for the statistical analysis with a probability of 95%. Results The mean gestational ages ± SDs of pregnant women with and without retinopathy and nondiabetic controls were 29.1 ± 2.2, 29.7 ± 2.7, and 31 ± 1.0 weeks, respectively, with no significant differences between the groups (P > .099). The mean RI in the group with retinopathy was significantly higher (P = .030) than in the control group, but it did not significantly differ compared to the group without retinopathy (P = .204). The RI in the control group did not differ from that in the group without retinopathy (P = .079). The EDV was significantly lower in the group with retinopathy (P = .015) in relation to the control group, but there were no differences compared to the group without retinopathy (P = .217). Conclusions Pregnant women with pregestational diabetes mellitus and retinopathy had increased vascular impedance in the ophthalmic artery together with a reduction in the EDV, which was probably related to ischemia, thrombosis, and neovascularization of retinal vessels.

To evaluate retrobulbar hemodynamics in patients with optic disc drusen (ODD) by color Doppler imaging. A prospective study included 52 patients with bilateral ODD and 50 age-matched controls. Blood flow in the central retinal artery (CRA) in both eyes was evaluated. Peak-systolic velocity (PSV), end-diastolic velocity (EDV), and the resistivity index (RI) were measured. Mean values of the blood flow Doppler parameters were compared between the patients with ODD and the controls. Both PSV and EDV in the CRA were significantly lower in patients with ODD than in the controls (p p p = 0.05 and p = 0.03, respectively). Arterial hypertension, cigarette smoking and location of ODD in the left or right eye did not exert a significant effect on the blood flow in the CRA. Blood flow in the CRA is considerably disturbed in patients with ODD. This disturbance might result from mechanical stenosis of the vascular wall caused by the drusen. Color Doppler ultrasound is a useful method in the assessment of retrobulbar hemodynamics in ODD.