Radial Peripapillary Capillary Research Articles

Ocular perfusion characteristics of children with newly diagnosed epilepsy

BackgroundTo investigate the vascular changes of the optic nerve head (ONH) and macula by using optical coherence tomography angiography (OCT-A), and also the choroidal vascular structure by using an image binarization tool in children with newly diagnosed epilepsy and to then compare these parameters with healthy subjects. MethodsForty-one epilepsy children and 36 healthy controls were included in this prospective and cross-sectional study.The radial peripapillary capillary (RPC) vessel density (VD) and macular foveal,parafoveal,perifoveal of superficial capillary plexus (SCP),deep capillary plexus (DCP) and choriocapillaris (CC) VD, and CC flow area were analyzed.Enhanced depth imaging (EDI) OCT scans of the macula were obtained and the images were binarized using the ImageJ software (National Institutes of Health, Bethesda, MD, USA).The subfoveal choroidal thickness (SFCT),the area of choroidal, luminal, and interstitial and the percentage of luminal area in the choroid (Choroidal vascular index (CVI)) were analyzed.We also evaluated the thickness of the peripapillary retinal nerve fiber layer (RNFL),the macular ganglion cell layer (GCL), and the inner plexiform layer (IPL). ResultsThere was a significant decrease in the VD of the CC and the CC flow area in children with epilepsy compared to healthy subjects (p<0.05).However, the VD of the RPC, and of the SCP and DCP of the macula were similar between the two groups(p>0.05).The SFCT,choroidal area,luminal area, and CVI were statistically significant lower in children with newly diagnosed epilepsy compared to healthy subjects. ConclusionThis study has demonstrated that the choroidal perfusion from the microcirculation is lower in children with newly diagnosed epilepsy.The pathophysiology of epilepsy and neurodegenerative processes may also include this vascular dysfunction as one of the factors.

Evaluation of ocular microvascular characteristics in smokers and patients with chronic obstructive pulmonary disease using an optical coherence tomography angiography

PurposeTo investigate retinal microvascular changes in patients with chronic obstructive pulmonary disease (COPD) using optical coherence tomography angiography (OCTA) and to compare these values with those of smokers and healthy non-smokers. MethodsThis study was performed on 38 eyes of 38 patients with COPD, 30 eyes of 30 smokers, and 31 eyes of 31 healthy non-smokers. Foveal avascular zone (FAZ) area, superficial (SCP) and deep (DCP) capillary plexus (whole image, fovea, parafovea, and perifovea) and radial peripapillary capillary (RPC) vessel densities (whole image, peripapillary, and inside disc) were evaluated via OCTA device (Optovue, Fremont, CA, USA). The forced expiratory volume in the first second (FEV1)/forced vital capacity (FVC) ratio and FEV1 values of patients with COPD were recorded. ResultsThere were statistically similar values in smoking pack-years between the smoker and COPD groups (p = 0.059). Entire SCP and DCP vessel densities were significantly different among the all groups (p < 0.05); for these parameters, the control group had the highest and the COPD group had the lowest vessel density values. Significantly decreased RPC vessel densities in all regions were detected in the COPD group compared with the other groups. Multiple regression analysis showed significant positive correlations between the FEV1 and the SCP, DCP, and RPC vessel densities (for all, p < 0.05). ConclusionsThis study detected lower vessel densities in patients with COPD than in smokers and healthy controls and reported decreased vessel density measurements with increasing COPD severity. COPD patients with or without a history of smoking may benefit from higher prioritization in terms of ophthalmic screening to prevent ocular complications.

Quantitative Measurements of Macular and Optic Nerve Head Blood Flow Parameters Following Cataract Surgery in Eye Department, Red Cross Tertiary General Hospital, Athens, Greece

Objective: To evaluate the effect of uncomplicated cataract surgery on macular and optic nerve head blood flow with Optical Coherence Tomography Angiography (OCT-A). Retinal vascular changes and macular vessel remodeling following cataract surgery is an area of interest, as the effect, cause and duration of such changes remain debatable.&#x0D; Setting: Eye Department, Red Cross Tertiary General Hospital, Athens, Greece.&#x0D; Methods: In this study, we recruited cataract surgery candidates who had regular post operative visits and underwent longitudinal OCT-A examinations before and after surgery.&#x0D; Results: Macular vessel density increased in the post operative visits both in the superficial (SCP) and deep capillary network (DCP) (P&lt;0.001) and showed a persistent effect over 3 months follow-up. Macular thickness increased over the first postoperative month, but returned to preoperative values at 3 months. Foveal avascular zone (FAZ) measurements and vessel density at radial peripapillary capillaries (RPC) were unaffected.&#x0D; Conclusions: OCT-A enables a quantitative analysis of blood flow by regular patient monitoring. In this study, we found that after cataract surgery, macular blood flow increased significantly. The reason for this could be attributed to post operative inflammatory process or vascular remodeling due to change in retinal metabolic demands.

Optical coherence tomography angiography features of retinal artery occlusion before and after intra‐arterial thrombolysis

AbstractBackgroundTo evaluate the ability of optical coherence tomography angiography (OCTA) to quantitatively assess the effectiveness of intra‐arterial thrombolysis (IAT) surgery for the treatment of retinal artery occlusion (RAO).MethodsThis was a prospective observational study. Patients diagnosed with RAO who received IAT were enrolled. All participants underwent comprehensive ophthalmologic examinations and OCTA scans. The best‐corrected visual acuity (BCVA), vascular densities (VDs) of the superficial capillary plexus (SCP), deep capillary plexus (DCP), radial peripapillary capillaries, and central retinal thickness (CRT) were recorded. The above parameters were compared between RAO eyes and the fellow healthy eyes before and after IAT. Correlations between the BCVA and OCTA parameters in RAO eyes were calculated.ResultsThirty‐four eyes from 34 consecutive RAO patients with a mean age of 51.0 ± 12.9 years were enrolled. There was a considerable decrease of VDs in the SCP, DCP, and radial peripapillary capillaries in all RAO eyes (all p &lt; 0.001). Compared with contralateral normal eyes, CRT was significantly increased in RAO eyes (p &lt; 0.001). The SCP and DCP VDs were significantly improved after IAT surgery (p = 0.010 and 0.014, respectively). BCVA in logMAR unit was negatively correlated with the DCP VD (r = −0.664, p = 0.010) and positively correlated with CRT (r = 0.597, p = 0.024) after surgery, but not significantly correlated with VDs or CRT before surgery.ConclusionMacular and peripapillary VDs of the retina detected by OCTA were greatly decreased in RAO eyes and improved after IAT treatment. OCTA is capable of quantifying VDs in separate retinal layers non‐invasively, conveniently, efficiently, and precisely.

EVALUATION OF OPTIC DISK AND MACULAR VASCULARITY CHANGES IN CRVO USING OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY.

To quantify changes in optic disk and macular vasculature in patients with central retinal vein occlusion using optical coherence tomography angiography and detect its correlation with visual acuity. The study included 20 eyes of 20 patients with treatment-naive central retinal vein occlusion and 20 age-matched controls. Optical coherence tomography and optical coherence tomography angiographywere performed on the macula and optic disk. Central 1-mm subfield foveal thickness was measured. Vessel densities (VD) of superficial and deep macular capillary plexuses with whole disk VD, inside disk VD, and radial peripapillary capillary plexus were analyzed. Macular ischemia was evaluated by fundus fluorescein angiography. Visual acuity was correlated with measured parameters. All measured macular and disk VDs differed significantly between cases and controls except inside disk VD. Visual acuity showed a highly significant negative correlation with whole disk VD ( P = 0.005) and radial peripapillary capillary ( P = 0.002), borderline correlation with central subfield foveal thickness ( P = 0.06), and insignificant correlation with macular VDs. Radial peripapillary capillary VD showed a significant correlation with deep parafoveal ( P = 0.04), and superficial and deep perifoveal VDs ( P = 0.01). Optic disk VD could provide more accurate indication of retinal blood supply than macular VD in cases of central retinal vein occlusion with severe macular edema.

Detecting changes in the blood flow of the optic disk in patients with nonarteritic anterior ischemic optic neuropathy via optical coherence tomography-angiography.

This study aimed to evaluate the changes in the blood flow of the optic disk in patients with nonarteritic anterior ischemic optic neuropathy (NAION) using optical coherence tomography-angiography (OCTA) and to investigate the relationship among the changes in the blood flow of the optic disk, visual field defect, peripapillary retinal nerve fiber layer (RNFL), and macular ganglion cell complex (mGCC). This was a prospective observational case series study. A total of 89 patients (89 eyes) with NAION were included in this study. All patients underwent best corrected visual acuity (BCVA), slit-lamp and direct ophthalmoscopic examinations, color fundus photography, visual field test, and blood flow indicators of the radial peripapillary capillaries (RPC) including whole en face image vessel density (VD), peripapillary VD by OCTA, the peripapillary RNFL, and mGCC by spectral-domain optic coherence tomography (OCT). The changes of blood flow in the optic disk at ≤3, 4-8, 9-12, 13-24, and >24 weeks of the natural course of NAION were measured, and the relationship among the changes in the blood flow of the optic disk, visual field defect, peripapillary RNFL, and mGCC was also analyzed. The mean age of 89 patients with NAION was 56.42 ± 6.81 years (ranging from 39 to 79). The initial RPC whole en face image VD was significantly reduced after acute NAION (≤3 weeks) (F = 45.598, P < 0.001) and stabilized from the eighth week onward. Over the course of NAION, the superonasal RPC, superior mGCC, and superotemporal RNFL decreased mostly with time (F = 95.658, 109.787, 263.872, respectively; P < 0.001). Maximal correlations were found between superior mGCC and temporosuperior RPC in the NAION phase (R = 0.683, P < 0.01) and between superonasal RPC and superonasal RNFL (R = 0.740, P < 0.01). The mean defect was correlated with temporosuperior RPC (R = -0.281, P < 0.01) and superior mGCC (R = -0.160, P = 0.012). Over the course of NAION, OCTA shows a tendency toward change in the retinal capillary plexus of the optic disk. OCTA is proved to be a practical and useful tool for observing papillary perfusion in NAION.

Vascular density and macular sensitivity in eyes after scleral buckling surgery for macula-on rhegmatogenous retinal detachment.

To investigate the structure and function of the retina after scleral buckling (SB) surgery due to macula-on rhegmatogenous retinal detachment (RRD). Twenty eyes with repaired macula-on RRD and 20 fellow eyes were included. All patients within 6-12 months of the procedure, were examined to evaluate retinal structure using spectral domain optical coherence tomography (SD-OCT) and vessel density (VD) by OCT angiography (OCTA). Best corrected visual acuity (BCVA) and microperimetry (MP) tests were used to assess retinal function. Analysis of the microvascular network using OCTA between the operated and healthy fellow eyes showed a significant reduction on VD in superficial vascular plexus (SVP), deep vascular plexus (DVP) and radial peripapillary capillaries (RPC) (p< 0.001, p = 0.019 and p = 0.008, respectively). Comparison of retinal structure in SD-OCT showed no significant differences on thickness in ganglion cell complex (GCC) and peripaillary retinal nerve fiber layer (pRNFL) (p> 0.05) between examined eyes. Retinal function analysis by MP examination showed a decrease of retinal sensitivity (p = 0.0013) whereas postoperative BCVA showed no differences (p = 0.62) in the operated eyes. Significant Pearson's correlations were observed between retinal sensitivity and VD in SVP, RPC (p< 0.05). In the eyes after SB surgery due to macula-on RRD, changes in retinal sensitivity were accompanied by impairment of the microvascular network assessed by the OCTA.

The effect of various types of COVID-19 vaccines on the retinal microvasculature.

To detect the effect of various types of COVID-19 vaccine on macular and optic disc microvasculature. One hundred subjects receiving various types of COVID-19 vaccine (AstraZeneca, Sinopharm, Sinovac, Pfizer, and Moderna) were included in this study. A complete ophthalmic examination was done which included best-corrected visual acuity measurement, slit-lamp biomicroscopy, intraocular pressure measurement with Goldmann applanation tonometry, and fundus examination. Optical coherence tomography angiography (OCT-A) was done before and 1 week after receiving the vaccine. Superficial and deep macular capillary densities were measured in the form of the whole image, fovea, parafoveal, and perifoveal capillary density. Optic disc vessel density in the form of the whole disc, inside disc, and peripapillary were also measured. The superficial macular vessel densities, (whole image, fovea, parafoveal, and perifoveal) showed statistically non-significant changes with P-values (0.269, 0.167, 0.346, and 0.476) respectively. Also, the deep macular vessel densities showed statistically non-significant changes with P-values (0.491, 0.096, 0.724, and 0.386) for the whole image, fovea, parafoveal, and perifoveal respectively. Moreover, RPC (radial peripapillary capillary) density showed no significant changes either (the whole disc, inside disc, or peripapillary) with P-values (0.807, 0.141, 0.883) respectively. Various types of COVID-19 vaccines had no statistically significant effects on macular or optic disc microvasculature.

Comparison of optic disc head vascular density status between crowded and normal discs: An optical coherence tomography angiography study.

To compare the optic disc capillary vascular status between crowded and normal optic discs using optical coherence tomography angiography (OCT-A). A total of 101 eyes were included in this cross-sectional, comparative study. Fifty-one eyes with crowded optic discs (Group 1) were compared with 50 eyes with normal discs (Group 2). Peripapillary and optic disc head capillary vascular density measurements were obtained quantitatively with OCT-A. Mean ages were 46.2±6.2 years in Group1 and 45.9±6.0 years in Group2 (p=0.796).Vertical disc diameters were 1.52±0.2mm in Group 1 and 1.61±0.16mm in Group 2 (p=0.022) whereas horizontal disc diameters were 1.53±0.17mm in Group 1 and 1.61±0.13mm in Group 2(p˂0.014). OCT-A findings were as follows: radial peripapillary capillary, vascular density whole image measurements (%); 49.6±2.3 in Group 1 and 49.1±2.3 in Group 2 (p=0.292), peripapillary capillary density; 53.3±2.8 in Group 1 and 52.6±2.6 in Group 2 (p=0.176), inside disc measurements 52.4 (48.7-54.7) in Group 1 and 46.5 (42.6-49.6) in Group 2 (p˂0.001). RNFL was 118.2±12.2µm in Group 1 and 110.8±11.4µm in Group 2(p=0.002). The vascular density of the disc circumference in individuals with healthy crowded optic discs is not different from those with normal discs. However, inside disc measurements differ between crowded and normal size discs. This finding suggests that when the disc size is reduced, the amount of vessels in it does not decrease in a way that correlates with the size. Therefore, the vascular structures are suitable for compression in the narrow optic nerve head.

Optic disc and retinal vessel densities assessment by optical coherence tomography angiography in patients with keratoconus.

This study aimed to evaluate retinal and optic disc vascular changes in patients with keratoconus (KC) using optical coherence tomography angiography (OCTA). Thirty-two eyes of 22 patients with KC and 24 eyes of 24 age- and sex-matched healthy controls were included in this study. Corneal topography and OCTA were performed. Quantitative vessel density of the macular superficial capillary plexus (SCP), macular deep capillary plexus (DCP), and radial peripapillary capillaries (RPC); choriocapillaris flow area; and choroidal thickness were compared between the KC and control groups. SCP and DCP vessel densities showed a significant reduction in the KC group compared to that in the control group (p < 0.001 and p < 0.001 in the whole image and parafovea, respectively). Choriocapillaris flow area was significantly higher in patients with KC than in the control group (p=0.003). The foveal avascular zone area did not significantly differ between the two groups (p=0.949). RPC inside disc vessel density was significantly decreased in the KC group compared to that in the control group (p < 0.001). This study revealed important macular, choroidal, and optic disc vessel densities changes in patients with KC. Macular whole vessel density and parafoveal vessel density of the SCP and DCP decreased, while choriocapillaris flow area increased in patients with KC.

Retinal and peripapillary vascular deformations in prematurely born children aged 4–12 years with a history of retinopathy of prematurity

In this study, foveal, parafoveal, peripapillary anatomical, and microvascular anomalies in prematurely born children aged 4–12 years with a history of retinopathy of prematurity (ROP) were evaluated. Seventy-eight eyes of 78 prematurely born children ([tROP]: ROP with laser treatment, [srROP]: spontaneously regressed ROP) and 43 eyes of 43 healthy children were included. Foveal and peripapillary morphological parameters (including ganglion cell and inner plexiform layer (GCIPL) thickness, peripapillary retinal nerve fiber layer (pRNFL) thickness) and vasculature parameters (including foveal avascular zone area, vessel density from superficial retinal capillary plexus (SRCP), deep retinal capillary plexus (DRCP), and radial peripapillary capillary (RPC) segments) were analyzed. Foveal vessel densities in SRCP and DRCP were increased and parafoveal vessel densities in SRCP and RPC segments vessel density were decreased in both ROP groups compared with those of control eyes. The best-corrected visual acuity was negatively correlated with pRNFL thickness in the tROP group. Refractive error was negatively correlated with vessel density of RPC segments in the srROP group. In children born preterm with a history of ROP, it was found that foveal, parafoveal, and peripapillary structural and vascular anomalies and redistribution were accompanied. These retinal vascular and anatomical structure anomalies showed close relationships with visual functions.

Retinal microvasculature is a potential biomarker for acute mountain sickness.

Increased cerebral blood flow resulting from altered capillary level autoregulation at high altitudes leads to capillary overperfusion and then vasogenic cerebral edema, which is the leading hypothesis of acute mountain sickness (AMS). However, studies on cerebral blood flow in AMS have been mostly restricted to gross cerebrovascular endpoints as opposed to the microvasculature. This study aimed to investigate ocular microcirculation alterations, the only visualized capillaries in the central neural system (CNS), during early-stage AMS using a hypobaric chamber. This study found that after high altitude simulation, the optic nerve showed retinal nerve fiber layer thickening (P=0.004-0.018) in some locations, and the area of the optic nerve subarachnoid space (P=0.004) enlarged. Optical coherence tomography angiography (OCTA) showed increased retinal radial peripapillary capillary (RPC) flow density (P=0.003-0.046), particularly on the nasal side of the nerve. The AMS-positive group had the largest increases in RPC flow density in the nasal sector (AMS-positive, Δ3.21±2.37; AMS-negative, Δ0.01±2.16, P=0.004). Among multiple ocular changes, OCTA increase in RPC flow density was associated with simulated early-stage AMS symptoms (beta=0.222, 95%CI, 0.009-0.435, P=0.042). The area under the receiver operating characteristics curve (AUC) for the changes in RPC flow density to predict early-stage AMS outcomes was 0.882 (95%CI, 0.746-0.998). The results further confirmed that overperfusion of microvascular beds is the key pathophysiologic change in early-stage AMS. RPC OCTA endpoints may serve as a rapid, noninvasive potential biomarker for CNS microvascular changes and AMS development during risk assessment of individuals at high altitudes.

Evaluation of the Optic Nerve Head Using Optical Coherence Tomography Angiography in Systemic Sclerosis Patients.

To quantify microvascular vessel density in the optic disc using optical coherence tomography angiography (OCTA) in patients with systemic sclerosis (SS); to determine whether there is a difference in values between patients and controls; and to correlate the OCTA measurements with disease activity, damage risk, and drug usage. Patients aged 20 - 76 years who were followed up after a diagnosis of SS and age- and gender-matched controls. The patients underwent RTVue-XR AngioVue OCTA imaging in this cross-sectional observational study. A total of 61 eyes of 61 consecutive SS patients and 60 eyes of 60 controls were investigated. There was no statistically significant difference between the patients and control groups regarding the average RNFL (retinal fiber layer) and radial peripapillary capillary (RPC) vessel density (VD) measurements (p = 0.35, p = 0.25, respectively). As the antinuclear antibody (ANA) titer increased, RNFLsuperior (p = 0.01, r = - 0.327), RPCwhole (p = 0.029, r = 0.279), RPCperipapillary (p = 0.037, r = - 0.267), RPCsuperior (p = 0.003, r = - 0.371), and RPCinferior (p = 0.02, r = 0.297) values decreased with statistical significance. The RPCinside values were lower in anti-Scl-70-positive patients compared to patients negative for anti-Scl-70 (topoisomerase I) (p = 0.021). The RNFLnasal (p = 0.03, r = - 0.278) value decreased as the years of disease increased. The RPCinside value was higher in patients using hydroxychloroquine and calcium channel blockers than those who did not use them (p = 0.021 and p = 0.027, respectively). The RPCwhole, RPCperipapillary, and RPCnasal values were higher, with statistical significance in corticosteroid users than in those patients who did not use corticosteroids (p = 0.043, 0.030, and 0.033, respectively). There was no significant difference between the patients and control groups regarding the average RPC VD measurements. However, since this is the first study to analyze optic disc vessel density in SS patients, optic nerve blood flow changes in scleroderma with OCTA could be studied.

Variability of Vascular Reactivity in the Retina and Choriocapillaris to Oxygen and Carbon Dioxide Using Optical Coherence Tomography Angiography.

To investigate the regional and layer-specific vascular reactivity of the healthy human retina and choriocapillaris to changes in systemic carbon dioxide or oxygen. High-resolution 3 × 3-mm2 optical coherence tomography angiography (OCTA) images were acquired from the central macula, temporal macula, and peripapillary retina while participants were exposed to three gas breathing conditions-room air, 5%CO2, and 100% O2. OCTA from all three regions were extracted and the apparent skeletonized vessel density (VSD) was assessed. The mean flow deficit sizes (MFDSs) of the choriocapillaris were also assessed. Repeated-measures analysis of variance was used to compare the ratio of intrasubject VSD change induced by the gas conditions from baseline in the superficial retinal layer (SRL) and deep retinal layer (DRL) for each retinal region independently, as well as the MFDS of the choriocapillaris. We also compared the vessel reactivity between the retinal capillaries and the choriocapillaris. The cumulative intrasubject response to the gas conditions differed significantly among regions of the SRL (F(2, 7) = 28.22, P < 0.001), with the temporal macula showing the largest response (15%) compared to the macula (8%) and radial peripapillary capillaries (7%). A similar trend was found in the DRL. The choriocapillaris reactivity was similar between the macula (5.8%) and temporal macula (5.6%). There was also a significant heterogeneity in the layer-specific gas responses, with the DRL showing the largest response (28.2%) and the choriocapillaris showing the smallest response (2.8%). Capillary reactivity to changes in inhaled O2 and CO2 is spatially heterogeneous across the retina but not choriocapillaris.

Optic nerve head perfusion changes in eyes with proliferative diabetic retinopathy treated with intravitreal ranibizumab or photocoagulation: a randomized controlled trial.

Proliferative diabetic retinopathy (PDR) is a serious sight-threatening disease, and half of the patients with high-risk PDR can develop legal blindness within 5 years, if left untreated. This study was aimed at comparing panretinal photocoagulation (PRP) and intravitreal ranibizumab injections in terms of radial peripapillary capillary (RPC) density on optical coherence tomography angiography (OCTA) in patients with treatment-naive PDR. This open-label, prospective, randomized clinical trial included 50 patients with treatment-naive PDR with optic disc neovascularization and randomized them into two groups: group 1, with patients undergoing two sessions of PRP 2 weeks apart, and group 2, with patients received three intravitreal ranibizumab injections (0.5 mg) 1 month apart for 3 consecutive months. Patients underwent a full ophthalmological examination, including best-corrected distance visual acuity (BCDVA) measurement in the logarithm of minimal angle of resolution (logMAR) notation and OCTA before intervention and monthly after the last laser session or the first intravitreal ranibizumab injection for 3 months of follow-up. Visual field (VF) was tested at the beginning and end of 3 months. Forty-two (84%) eyes completed the 3-month follow-up, including 22 eyes in the PRP group (88%) and 20 (80%) eyes in the ranibizumab group. The two groups were comparable in terms of demographic characteristics, diabetes duration, baseline BCDVA, glycated hemoglobin level, OCTA parameters, VF indices, and intraocular pressure (all P > 0.05). The RPC density change from baseline to the 3-month follow-up was significantly lower in the PRP group than in the ranibizumab group (mean difference in RPC density change: - 3.61%; 95% confidence interval: - 5.57% to - 1.60%; P = 0.001). The median (interquartile range) logMAR change from baseline to the 3-month follow-up (0.0 [0.2]) was significantly higher in the PRP group than in the ranibizumab group (- 0.15 [0.3]; P < 0.05). The median changes in central foveal thickness from baseline to the 3-month follow-up differed significantly between the two groups (P = 0.001). In eyes with PDR and neovascularization of the disc RPC density on OCTA increased in the ranibizumab group and decreased in the PRP group. Visual acuity gain was higher in the ranibizumab group than in the PRP group. Future multicenter trials addressing our limitations are required to verify the findings of this study.

The effect of acetazolamide on the retinal and choroidal vasculature of the macula and the optic disc using OCT angiography

Introduction and objectivesTo investigate the effect of acetazolamide (AZ) on the retinal and choroidal ocular microvasculature in the macula and radial peripapillary capillaries (RPC) of the optic disc with OCT Angiography (OCTA). Materials and methodsNine-month observational cross-sectional study. Forty-five eyes from 45 healthy participants who underwent cataract surgery were recruited. Macular retina and choriocapillaris vessel density (VD) and RPC VD in the optic disc area were compared before and 60min after 250mg acetazolamide per os. Intraocular pressure (IOP) and systemic blood pressure (BP) were also measured before each scan. ResultsMean age was 73.1±6.9 years. VDs in the superficial (SCP) and deep (DCP) capillary plexus of the retina and the choriocapillaris (CC) in the macular area showed no significant change (P>.5, for all parameters). VD in the RPC showed no significant change with AZ (P>.5, for all parameters). Foveal and parafoveal thickness increased from 248.98 (±23.89) to 250.33 (±23.74) and from 311.62 (±16.53) to 311.98 (±16.38) (P<.001 and P=.046), respectively. IOP decreased from 13.2 (±3.0) mmHg to 11.8 (±3.2) mmHg (P<.001), while systolic and diastolic BP decreased from 144.8 (±21.8) to 137.7 (±19.0) and from 80.0 (±12.7) to 76.2 (±11.7) (P=.021 and P=.030), respectively. ConclusionsOCTA imaging did not reveal any significant changes in the VD of the optic disc or the retinal and choroidal VD in the macula with oral AZ one hour after its administration in otherwise healthy participants who underwent cataract surgery.

Efecto de la acetazolamida en la vasculatura retiniana y coroidea de la mácula y el disco óptico mediante angiografía OCT

Introduction and objectivesTo investigate the effect of acetazolamide (AZ) on the retinal and choroidal ocular microvasculature in the macula and radial peripapillary capillaries (RPC) of the optic disc with OCT Angiography (OCTA). Materials and methodsNine-month observational cross-sectional study. Forty-five eyes from 45 healthy participants who underwent cataract surgery were recruited. Macular retina and choriocapillaris vessel density (VD) and RPC VD in the optic disc area were compared before and 60minutes after 250mg acetazolamide per os. Intraocular pressure (IOP) and systemic blood pressure (BP) were also measured before each scan. ResultsMean age was 73.1±6.9 years. VDs in the superficial (SCP) and deep (DCP) capillary plexus of the retina and the choriocapillaris (CC) in the macular area showed no significant change (p>0.5, for all parameters). VD in the RPC showed no significant change with AZ (p>0.5, for all parameters). Foveal and parafoveal thickness increased from 248.98 (±23.89) to 250.33 (±23.74) and from 311.62 (±16.53) to 311.98 (±16.38) (p<0.001 and p=0.046), respectively. IOP decreased from 13.2 (±3.0) mmHg to 11.8 (±3.2) mmHg (p<0.001), while systolic and diastolic BP decreased from 144.8 (±21.8) to 137.7 (±19.0) and from 80.0 (±12.7) to 76.2 (±11.7) (p=0.021 and p=0.030), respectively. ConclusionsOCTA imaging did not reveal any significant changes in the VD of the optic disc or the retinal and choroidal VD in the macula with oral AZ one hour after its administration in otherwise healthy participants who underwent cataract surgery.

Significant retinal microvascular impairments in multiple sclerosis assessed through optical coherence tomography angiography.

Multiple sclerosis (MS) is associated with different ocular disorders. This study aimed to investigate the retinal microvascular changes detected by optical coherence tomography angiography (OCTA) in eyes with MS with or without a history of optic neuritis (ON). A comprehensive literature search was conducted in the Web of Science, Embase, PubMed, and Cochrane Library databases on September 26, 2021 for articles focused on OCTA manifestations in the eyes of MS patients compared with healthy controls. RevMan Manager (v.5.4) and Stata (v.14.1) were used to analyze the main differences and publication risks. Weighted mean differences and 95% confidence intervals were calculated for continuous estimates. This study also included subgroup analysis between three groups: eyes with multiple sclerosis and with optic neuritis (MSON); eyes with multiple sclerosis and without optic neuritis (MSNON); and healthy controls. Thirteen studies with a total of 1803 eyes were identified, including 957 eyes with MS and 846 eyes of healthy controls. The vessel density of the MS eyes decreased significantly in most areas of the radial peripapillary capillary. A marked reduction in the macular superficial capillary plexus of MS eyes regardless of ON history was also confirmed. The results suggest that MS patients demonstrated significant retinal microvasculature impairment regardless of ON history, compared to healthy controls. Retinal vessel density attenuation detected by OCTA may serve as a reliable early marker of MS.

Optical coherence tomography angiography findings in transfusion-dependent beta-thalassemia patients with and without splenectomy

BackgroundOcular involvement is common in transfusion-dependent beta-thalassemia (TDβ-T) patients. We aimed to investigate the effect of splenectomy on optical coherence tomography angiography (OCTA) findings in TDβ-T patients. MethodsThe study is a prospective cross-sectional study. A total of 45 eyes of 23 patients with splenectomy (34.04±8.83 years), 18 eyes of 9 patients without splenectomy (27.44±5.43 years), and 54 eyes of 27 controls (33.22±6.44 years) were included. Vessel density in superficial capillary plexus, deep capillary plexus and radial peripapillary capillary, foveal avascular zone, choriocapillaris flow area, choroidal and retinal thickness detected by OCTA were evaluated. p < 0.05 was considered significant. ResultsVessel density of superficial capillary plexus and deep capillary plexus were similar in patients with and without splenectomy, and controls. Choriocapillaris flow area was significantly decreased in patients with splenectomy than that in those without splenectomy and controls (2.02±0.12 vs. 2.17±0.1 and 2.14±0.12; p < 0.001). Choroidal thickness was significantly lower in patients without splenectomy than in patients with splenectomy and controls (260.05±61.02 vs. 305.11±42.13 and 298.89±29.14, p = 0.008). Parafoveal and perifoveal thickness of the full retina and outer retina were significantly lower in patients without splenectomy than in patients with splenectomy and controls (301.06±10.0, 279.78±10.28 vs. 311.04±14.89, 290.87±13.67 and 316.63±13.57, 289.56±9.31, p < 0.001 and p = 0.002; 174.72±7.81, 167.17±6.21 vs. 182.87±8.81, 173.60±7.09 and 185.11±9.26, 173.96±6.79, p = 0.001 and p < 0.001, respectively). ConclusionsOCTA findings can provide information about the microvascular effects of splenectomy on the retina of patients with TDβ-T.

Impact of peripapillary staphylomas on the vascular and structural characteristics in myopic eyes: a propensity score matching analysis

PurposeTo apply propensity score matching to evaluate the impact of peripapillary staphylomas (PPS) on vascular and structural characteristics in the myopic eyes.MethodsThis was a prospective, cross-sectional study. Forty-one control eyes and 41 eyes with PPS were analyzed. The eyes were selected using propensity score matching analysis based on the age and axial length. All subjects underwent ophthalmologic examinations for assessing vessel and structure parameters using swept-source optical coherence tomography (SS-OCT), OCT angiography, color fundus photography, and ocular biometry.ResultsAs compared with control eyes, the eyes with PPS had shallower anterior chamber depth (3.61 ± 0.24 mm vs 3.77 ± 0.24 mm, P = 0.004), higher intraocular pressure (IOP) (16.59 ± 2.88 mmHg vs 14.53 ± 2.45 mmHg, P = 0.002), and higher myopic spherical equivalent (− 11.52 ± 3.22D vs − 9.88 ± 2.20D, P = 0.009). while corneal curvature and lens thickness between the two groups were not statistically different. Compared with control eyes, increased macular deep vessel density, reduced macular choriocapillaris and radial peripapillary capillary, and thinning retinal layer, ganglion cell complex, choroidal layer as well as the superior and inferior peripapillary retinal nerve fiber layer were observed in eyes with PPS, apart from larger disc area, parapapillary atrophy area, and degree of disc rotation. Logistic regression analysis revealed that the IOP (P = 0.046), disc rotation (P = 0.003), and average peripapillary choroidal thickness (P = 0.009) were associated with the presence of PPS.ConclusionClose association of PPS with exacerbation of myopia and anatomical alterations was observed which not only affected the eye posterior segment but also the anterior segments. We further identified significant reductions in the radial peripapillary capillary and macular choroidal perfusion with the increase in macular deep retinal flow blood of myopic eyes with PPS. Higher IOP, thinner peripapillary choroidal thickness, and rotated optic disc were risk factors for the presence of PPS.