Reduced choroidal peripapillary capillaries in thyroid-associated ophthalmopathy with early stage of dysthyroid optic neuropathy.

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.

Objective: To analyze the characteristics of vessel density in the optic disc and macular area of patients with different phases of thyroid-associated ophthalmopathy (TAO) and their correlation with visual function. Methods: This case-control study was conducted at the Department of Ophthalmology of Peking Union Medical College Hospital between June 2019 and September 2019. TAO patients and healthy volunteers were included in the study. Patients with a clinical activity score greater than or equal to 3 points were categorized as active TAO. Dysthyroid optic neuropathy (DON) patients with a course less than 6 months were categorized as acute phase of DON, and those more than 6 months were in the chronic group. Healthy volunteers were in the control group. Each group included 12 subjects, with right eyes for analysis. There were 6 males and 6 females in each group. All participants underwent comprehensive ophthalmic examination including best corrected visual acuity and visual field examination for the mean defect (MD). Best corrected visual acuity was subsequently converted to logarithm of minimum angle of resolution (logMAR). Optical coherence tomography was used to measure the thickness of the retinal nerve fiber layer (RNFL) and retinal ganglion cell complex (GCC). Optical coherence tomography angiography was used to the peripapillary and macular vessel density. The differences in the vessel densities in the optic disc and macular area between groups and their correlation with different factors were analyzed. Analysis of variance, non-parametric Mann-Whitney U test and Spearman coefficient were conducted for statistical analysis. Results: There was no significant difference in age among the four groups (P>0.05). The logMAR of the acute DON group was 0.1 (0.0, 0.2), worse than the control group, which was 0.0 (0.0, 0.0) (U=114.000, P<0.05). The overall vessel densities of the optic disc in acute DON and chronic DON were significantly lower than the control group (54.70%±2.31% and 54.31%±3.65% vs. 57.54%±2.17%; t=3.104, 2.636; both P<0.05). The overall superficial vessel densities of the macular area in active TAO, acute DON and chronic DON were significantly lower than the control group (46.07%±3.06% and 42.26%±5.05% and 45.63%±3.87% vs. 49.34%±3.08%), and the differences were statistically significant (t=2.614, 4.147, 2.603; all P<0.05). There was no statistically significant difference in the size of the foveal avascular zone or the density of deep blood vessels in the macular area among the four groups (all P>0.05). In the active TAO period, there was no correlation between the MD value, RNFL thickness, GCC thickness and the vessel densities of the optic disc and macular area (all P>0.05). The vascular density of the whole layer of the optic disc in acute DON was negatively correlated with the MD value (r=-0.591, P<0.05) and positively correlated with the RNFL thickness and GCC thickness (r=0.595, 0.693; both P<0.05). In chronic DON, the overall capillary density of the optic disc was negatively correlated with the MD value (r=-0.673, P<0.05); the superficial overall blood vessel density of the macular area was positively correlated with the thickness of RNFL and GCC (r=0.732, 0.712;both P<0.01). Conclusions: In active TAO, only the blood supply to the superficial layer of the macular area is decreased. In the acute and chronic phases of DON, the blood supply to the superficial layer of the macular area and the optic disc is both reduced; the smaller the blood vessel density, the more severe the visual field defect, and the thinner the RNFL and GCC. (Chin J Ophthalmol, 2020, 56:824-831).

Although previous research has explored the involvement of the choroid in the pathogenesis of non- arteritic anterior ischaemic optic neuropathy (NAION), the relationship between optical coherence tomography angiography (OCTA) findings and choroidal features remains unclear. An understanding of this relationship may help clarify the vascular mechanisms underlying this disease. The aim of this study was to investigate the relationships between OCTA and choroidal parameters in patients with NAION during the post-acute phase, after the resolution of optic disc oedema. This retrospective analysis included the affected eyes of patients with unilateral NAION, their unaffected fellow eyes, and the eyes of age- and sex-matched healthy controls. The three groups were compared with regard to OCTA and choroidal parameters. Retinal imaging was conducted approximately 2 months after NAION occurrence to allow for the spontaneous resolution of characteristic optic disc oedema. A total of 75 eyes were included in the final analysis: 25 NAION-affected eyes, 25 fellow eyes, and 25 control eyes (13 women and 12 men). Age and sex distributions were similar across groups. The peripapillary vessel density (pVD), flow area (FA), retinal nerve fibre layer (RNFL) thickness, and choroidal vascularity index (CVI) in all quadrants were significantly lower in NAION eyes than in unaffected and control eyes. Unaffected eyes also demonstrated significantly lower radial peripapillary capillary (RPC) mean, RPC temporal, and RPC FA values than did the healthy controls. A moderate correlation was observed between RPC pVD and the mean RNFL thickness in NAION eyes and between RPC FA and the mean RNFL thickness in both NAION and unaffected eyes. The strong relationship between RPC perfusion and RNFL thinning could not be statistically confirmed after false discovery rate correction; thus, a direct cause-and-effect relationship could not be validated. There were no significant correlations between OCTA and choroidal parameters across all groups. These findings suggest that the retina and choroid are affected through distinct mechanisms in NAION. However, reductions in OCTA parameters, including CVI, were evident in NAION eyes. Overall, the study findings underscore the potential of OCTA as a non-invasive tool for identifying risk factors and monitoring disease progression in NAION.

Vision Loss in Optic Disc Drusen Correlates With Increased Macular Vessel Diameter and Flux and Reduced Peripapillary Vascular Density

To evaluate the structural, microvascular, and functional progression of normal tension glaucoma (NTG) with or without high myopia by examining longitudinal changes in optical coherence tomography angiography (OCTA) and visual field (VF) parameters. We evaluated 61 NTG eyes and classified 25 of the eyes with axial lengths (ALs) of ≥26 mm as highly myopic. We assessed the rate of change in OCTA parameters, namely radial peripapillary capillary (RPC) vessel density (VD), parafovea VD, deep parafovea VD, retinal nerve fibre layer (RNFL) thickness, and ganglion cell complex thickness. We evaluated the correlation of the rate of change in OCTA parameters with VF loss and AL. Among the 61 NTG eyes, rates of loss of RPC VD, parafovea VD, deep parafovea VD, and RNFL thickness were significantly different from zero despite the nonsignificant rate of change in VF mean deviation (MD). Changes in these OCTA parameters did not differ significantly in highly myopic NTG eyes. The rate of change in VF MD was significantly correlated with the rate of change in parafovea VD in highly myopic and non-highly myopic NTG eyes. In highly myopic NTG eyes, AL was negatively correlated with the rates of loss of RNFL thickness, VF MD, and VF PSD. NTG eyes with a relatively stable VF exhibited loss of VD and RNFL thickness. VF progression in NTG was correlated with decreasing parafovea VD, indicating a structure-function correlation. Greater AL may indicate faster VF loss and RNFL thinning in highly myopic NTG eyes.

For patients with nonfunctioning pituitary adenoma (NFPA) without manifesting visual acuity impairment or visual field defect (VFD), more sensitive and objective assessment methods will allow earlier detection before irreversible damage to the visual system. This study aimed to evaluate retinal vessel densities (VDs) alterations in these patients using optical coherence tomography angiography and to determine its diagnostic abilities. Between patients with NFPA without VFDs and age-matched, sex-matched healthy control individuals, comparisons of visual field metrics, retinal structural thickness, and microcirculation were conducted after adjusting for axial length (AL) and signal index of scans. Receiver operating characteristic (ROC) curves were further depicted to assess the diagnostic performance of significant parameters. To explore the impact of symptom duration, tumor size, and axial length on the significant parameters, multivariate regression analysis was conducted. This cross-sectional study reviewed 107 patients with NFPA. Twenty-seven eyes of patients with NFPA without VFDs and 27 eyes of healthy controls were enrolled. Compared with healthy controls, patients with NFPA without VFDs had similar foveal avascular zone areas and perimeters, macular ganglion cell complex (mGCC) and peripapillary retinal nerve fiber layer thicknesses, and macular VDs. Only the VD in the radial peripapillary capillary (RPC) segment of the inferior temporal (IT) sector was much lower in the patient group. The 2 largest area under the ROC curves were the focal loss volume (FLV) of the mGCC and the VD in the RPC of the IT sector, both of which were significantly related to symptom duration and tumor size. At the early stage of NFPA before VFD and retinal thickness thinning, fundus microcirculation impairments may occur initially in the microvascular density of the RPC segment of the IT sector. The FLV and the VD of RPC at the IT sector may provide a basis for the early diagnosis of NFPA without VFD in clinical practice.

PurposeThe purpose of this study was to investigate the changes in structural spectral-domain optical coherence tomography (SD-OCT), OCT Angiography (OCTA) parameters, and visual acuity, 1 year after endoscopic endonasal approach for the removal of an intra-suprasellar pituitary adenoma compressing optic chiasm and compare outcomes with 48 hours postoperative data.MethodsSixteen eyes of eight patients (4 males, 4 females, mean age 52 ± 11 years) were enrolled in this prospective study. The primary outcome was to evaluate the changes over time before and after surgery, analyzing the Best Corrected Visual Acuity (BCVA), Ganglion Cell Complex (GCC), Retinal Nerve Fiber Layer (RNFL) thicknesses, the retinal vessel density (VD) of Superficial Capillary Plexus (SCP), Deep Capillary Plexus (DCP), Radial Peripapillary Capillary (RPC) and the Foveal Avascular Zone (FAZ). The secondary outcome was to identify potential biomarkers that could predict visual acuity changes after 1-year follow-up.ResultsWhen comparing SD-OCT and OCTA measurements obtained after 1 year with those observed 48 hours after surgery, GCC and RNFL were significantly improved. After a significant reduction at 48 hours, GCC thickness showed a significant increase at 1 year after surgery (p = 0.007), while a significant restoration of RNFL thickness was found at 1 year (p = 0.005), as well as the VD of SCP, DCP, and RPC values. FAZ area did not change over time. BCVA significantly improved at each time after surgery (p = 0.037, p = 0.013). A statistically significant correlation was found between the preoperative BCVA, VD of SCP, DCP, RPC, and the postoperative BCVA at 1 year (p = 0.017, p = 0.029, p = 0.031, p = 0.023).ConclusionSD-OCT and OCTA provide helpful information to identify the retinal structural and vascular improvements 1 year after surgery. OCTA parameters could serve as potential predictive markers for visual acuity recovery at long-term follow-up.

Objective: To evaluate the changes of peripapillary and macular retinal vasculature parameter in nonarteritic anterior ischemic optic neuropathy (NAION) patients. Methods: In this case-control study, eighteen consecutive patients (18 eyes) who were clinically diagnosed with atrophic NAION (at least 3 months after onset of symptoms) between October 2017 and June 2018 were included. Twenty healthy outpatient patients (20 eyes) with normal eye examination were selected as the control group. The optic nerve head and macular was scanned by optic coherence tomography angiography (OCTA) for all subjects.The following parameters, including peripapillary retinal nerve fibre layer (pRNFL), macular ganglion cell complex (GCC), whole en face image vessel density (wiVD) of the radial peripapillary capillaries (RPC), peripapillary RPC vessel density (ppVD), superficial capillary plexus (SCP), deep capillary plexus (DCP), and parafoveal vessel density (pfVD) were measured. Multi-factor regression analyses were used to analyze the effects of blood flow parameters on the incidence of NAION, LogMAR BCVA, pRNFL and GCC. Pearson correlation between ppVD and pRNFL was analyzed. Results: Compared with the control group, pRNFL thickness, RPC wiVD and ppVD of the NAION group were significantly reduced (t=-6.567, -6.958, -6.668, P<0.001) and the SCP wiVD, DCP wiVD and GCC thickness were significantly reduced (t=-6.226, -2.760, -6.340, P<0.001). NAION development was related to ppVD (b=0.502, OR=1.653, P=0.045). The LogMAR BCVA of the NAION group was related to SCP wiVD (b=-0.726, P=0.003), the pRNFL thickness was related to ppVD (b=0.883, P=0.001), and significant correlations were also found between ppVD and pRNFL thickness in the superior and inferior sectors (r=0.946, P<0.001; r=0.680, P=0.031). Conclusions: OCTA provided detailed visualization of the peripapillary and macular retinal capillary rarefaction predominating near larger vessels, correlated with visual acuity loss and pRNFL thickness thin in affected eyes of NAION whose disease course was more than 3 months. The sparser the ppVD of the affected eye is, the more likely NAION is to develop, and the poorer visual acuity is correlated with thinner pRNFL and sparser of SCP wiVD. Key words: optic neuropathy, ischemic; regional blood flow; retinal ganglion cells; optical coherence tomography

To study the influence of weight reduction after bariatric surgery on the intraocular pressure (IOP), retinal nerve fiber layer (RNFL) thickness, and blood flow of optic nerve head by optical coherence tomography angiography (OCTA). This prospective observational cohort study included 60 obese patients. Body mass index (BMI), IOP, RNFL, and ganglion cell complex (GCC) thickness, rim area, and radial peripapillary capillary (RPC) vessel density were assessed before and 3 months after bariatric surgery. The BMI and the IOP showed significant postoperative reduction to 40.45 ± 4.3 kg/m2 and 14.83 ± 2.5 mmHg while the preoperative results were 51.13 ± 4.83 kg/m2 and 16.95 ± 4.2 mm (p < 0.0001), respectively. No statistically significant change was detected in the RNFL, GCC thickness, rim area, or the RPC vessel density (p > 0.05). No statistically significant correlation was detected between the BMI changes and changes in the IOP, RNFL thickness, rim area, GCC thickness, or RPC vessel density. No significant effect of bariatric surgery on the RNFL thickness and the optic nerve head blood flow measured by OCTA despite a significant IOP reduction 3 months post-surgical. OCTA can be a useful tool to assess the short-term influence of significant weight reduction on the retinal microcirculation. Despite a significant BMI and IOP reduction following bariatric surgery in obese patients, the vascular flow of the ONH, measured by OCTA, and the RNFL thickness were not significantly affected. The former might be attributed to the complex autoregulatory mechanisms related to the ONH and its microcirculation.

The retinal microvascular density changes have been identified in thyroid-associated ophthalmopathy (TAO) patients. Whereas a lack of research has been done on the diagnostic ability of optical coherence tomography (OCT) combined with optical coherence tomography angiography (OCTA) parameters. This study aims to evaluate the retina perfusion variations in eyes with active and stable TAO and its diagnostic abilities using OCT and OCTA. This is cohort longitudinal retrospective study. A total of 51 patients with TAO and 39 healthy controls (HCs) were recruited. The TAO eyes were divided into active and stable stage groups. The foveal avascular zone (FAZ), macular perfusion density (mPD), and peripapillary PD were measured by OCTA. The peripapillary retinal nerve fiber layer (RNFL), central retinal thickness (CRT), and whole macular volume (wMV) were measured by OCT. Visual evoked potential (VEP) and visual field (VF) were also assessed. The mPD of the superficial retinal capillary plexus (SRCP) was significantly different in all subfields among active, stable, and HC groups (p < 0.05) except for the temporal inner (p = 0.137), and the active group achieved the lowest PD. The FAZ size increased significantly in the active and stable groups compared with the HC group (p < 0.001). Significant difference was observed in mPD of deep retinal capillary plexus (DRCP) in all quadrants among three groups (p < 0.05). Moreover, PD parameters of optic nerve head (ONH) and radial peripapillary capillary plexus (RPCP) showed a different trend among three groups (p < 0.05). The r-value of visual field-mean deviation (VF-MD) of TAO with DRCP-whole PD (wPD) and RPCP-wPD was 0.421 and 0.299, respectively (p < 0.05). The DRCP-wPD in OCTA and RNFL in OCT were significantly higher in area under the receiver operating characteristic curve (AUC) than that of HC eyes. OCT and OCTA can noninvasively detect the peripapillary and macular changes in various stages of TAO patients, and it might be a high diagnostic value tool to monitor the TAO progression.

To evaluate the macular and peripapillary morpho-vascular changes in ADOA, using optical coherence tomography (OCT) and OCT angiography (OCTA). Prospectively defined, cross-sectional case-control study. Consecutive patients with a genetic or clinical diagnosis of ADOA along with age- and sex-matched controls were included. The radial peripapillary capillary (RPC) density and vessel density (VD) in the parafoveal superficial and deep capillary plexuses (SCP and DCP, respectively) were evaluated with OCTA. The ganglion cell complex (GCC) and retinal nerve fiber layer (RNFL) thickness were determined using structural OCT. We applied a previously validated customized macro (Fiji, SciJava Consortium) to compute RPC density. The remaining parameters were calculated by the built-in software. Non-parametric methods were used for data analysis. The target α level was 0.05, which was adjusted through Bonferroni's correction when multiple outcomes were tested. Fifty-eight eyes (n = 29 control; n = 29 ADOA) from 30 subjects (mean age 42.43 ± 15.30years; 37.93% male) were included. Parafoveal SCP VD, GCC thickness, RPC VD in the temporal quadrant, as well as RNFL thickness in the nasal and temporal quadrants were decreased in ADOA eyes (all p < 0.001). When only patients with genetically confirmed diagnosis were included, capillary dropout in the circumpapillary superior and inferior quadrants also became evident (both p < 0.001). The GCC/parafoveal SCP ratio was increased in ADOA, relatively to matched controls. In contrast, none of the circumpapillary morpho-vascular ratios was significantly different in ADOA eyes. The microvascular and structural changes found in ADOA suggest that both the macular and peripapillary regions are involved, although the threshold for damage of the structural and vascular components may be different for each region. Larger series with longitudinal follow-up may validate OCTA biomarkers helpful for disease monitoring.

To investigate the applicability of ISNT (inferior ≥ superior ≥ nasal ≥ temporal), IST (inferior ≥ superior ≥ temporal), and T min (temporal quadrant with the minimum value) rules to the peripapillary nerve fiber layer (NFL) thickness and radial peripapillary capillary (RPC) vessel density (VD) using Optical Coherence Tomography (OCT) and OCT angiography (OCT-A). This cross-sectional study included 134 eyes of 74 healthy individuals. NFL thickness and RPC VD were measured in all four quadrants using OCT and OCT-A in order to determine the number of eyes that obey the ISNT, IST, and T min rules. Mean age was 48.8 ± 15.5 (range 25-82) years. The ISNT rule was valid in 52 eyes (38.81%) on OCT and only 12 eyes (8.95%) on OCT-A scans. The IST rule was followed by 83 (61.94%) and 37 (27.61%) eyes on OCT and OCT-A scans respectively. The T min rule was valid in 86 eyes (64.18%) in OCT scans and in 26 eyes (19.4%) in OCT-A scans. The topography of the RPC network does not obey the ISNT rule in healthy eyes. The ISNT rule and its variants were found to be more relevant in OCT NFL thickness measurements compared to OCT-A RPC VD measurements.

Objective: To evaluate the retinal vessel density in eyes with primary open-angle glaucoma (POAG) with single-hemifield visual field (VF) defects and its relationship to retinal nerve fiber layer (RNFL) thickness and visual field indices. Methods: Cross-sectional study. Twenty-eight POAG patients with single-hemifield VF defects and 31 normal controls were recruited from October 2015 to October 2018 in the Eye, Ear, Nose and Throat Hospital of Fudan University. All subjects underwent complete ophthalmological examinations, including RNFL, retinal ganglion cell complex (GCC) thickness and visual field tests, and the general information was collected. The peripapillary radial peripapillary capillaries (RPC) and macular superifical retinal capillary plexus (SCP) were derived from optical coherence tomography angiography. The retinal vessel density, structural values, and VF values were compared among the corresponding hemifields of POAG and healthy eyes using the Rank Sum test. Results: There were 16 males and 12 females in POAG patients, with the age of (47±12) years; there were no significant differences in gender distribution, age, intraocular pressure, central corneal thickness, axial length and intraocular perfusion pressure between POAG patients and the normal controls (all P>0.05). Among POAG patients, there were 19 cases with upper and 9 cases with lower visual field defect. In the POAG eyes, the vascular density of peripapillary RPC and macular SCP were 45.86% (34.92%-52.78%) and 39.31% (32.55%-46.79%), respectively. In the normal eyes, the vascular density of peripapillary RPC and macular SCP were 56.90% (51.69%-60.84%) and 47.48% (37.95%-52.25%), respectively. The difference was statistically significant (Z=-6.56, -5.86; both P<0.01). The RNFL and GCC thicknesses in the POAG group were 84.4 (62.1-97.1), 76.4 (60.3-92.5) μ m, respectively, which were smaller than those in normal controls [110.6 (95.7-131.6), 98.1 (84.0-109.2) μm; Z=-6.57, -6.36; both P<0.01]. In the POAG eyes, the peripapillary RPC [44.12% (34.73%-53.20%) vs. 51.85% (38.64%-61.02%); Z=-4.62; P<0.01] and macular SCP [36.81% (29.73%-47.82%) vs. 41.78% (33.93%-49.22%); Z=-4.12; P<0.01] vessel densities were reduced in the abnormal hemisphere compared with the opposite hemisphere. Compared with the normal eyes, the normal hemisphere of the POAG eyes had lower peripapillary RPC and macular SCP vessel densities (Z=-5.08, -4.95; both P<0.01), a thinner RNFL and a thinner retinal GCC [93.0 (61.9-116.5) μm vs. 110.6 (95.7-131.6) μm, Z=-5.15; 86.3 (67.2-98.2) μm vs. 98.1 (84.0-109.2) μm, Z=-5.35; both P<0.01]. But the mean deviation and pattern standard deviation values of the VF were not significantly different between them (both P>0.05). Conclusions: The retinal vessel density reduce in eyes with POAG with single-hemifield VF defects. The normal hemisphere of POAG eyes have a reduced retinal microcirculation along with the thinning of the RNFL and GCC, suggesting that vascular dysfunction and structural changes preceded VF loss in POAG. (Chin J Ophthalmol, 2021, 57: 201-206).

To investigate microvascular changes in the macular and peripapillary area in prolactinoma patients by using optical coherence tomography angiography (OCTA). A retrospective study. This study included 40 patients with treatment-naive prolactinoma and 42 healthy controls. Participants underwent comprehensive ophthalmic examinations, visual field testing, and optical coherence tomography (OCT) assessments, including retinal nerve fiber layer (RNFL) thickness, macular, and peripapillary region OCTA by using the Topcon DRI OCT Triton Swept Source-OCT system. The OCTA results were evaluated between groups and then correlated with PRL levels. The differences in best-corrected visual acuities were statistically significant among the groups. The RNFL thickness in the superior and nasal quadrants was significantly lower in the prolactinoma group. The prolactinoma group showed significant reductions in macular vessel density (VD) across all layers than the control group, except in the deep retinal capillary plexus temporal quadrants. The radial peripapillary capillary (RPC) temporal VD in the prolactinoma group was significantly lower. In patients with optic neuropathy, correlations were observed between the RPC temporal and RNFL temporal sectors (r = 0.650, P = 0.03), and between the RPC inferior and RNFL inferior sectors (r = -0.612, P = 0.045). Between PRL levels and OCTA parameters, negative correlations were observed (RPC inferior: r = -0.452, P = 0.003; DCP superior: r = -0.379, P = 0.016). Our study revealed reduced VD in the macula and RPC temporal regions in patients with treatment-naive prolactinoma. OCTA holds significant importance in detecting potential retinopathies and vasculopathies. Future research should focus on examining pre- and post-treatment changes in treatment-naive patients without ON to better understand the impact of prolactinoma.

PurposeTo investigate the vessel density (VD) of the radial peripapillary capillary (RPC) plexus in patients affected by preperimetric glaucoma (PPG), amnestic mild cognitive impairment (aMCI) and in a healthy control group using optical coherence tomography angiography (OCTA) in order to clarify the pathogenetic mechanisms of these neurodegenerative diseases.MethodsIn this prospective study, we studied 54 eyes of 54 patients with PPG, 54 eyes of 54 patients with aMCI and 54 healthy controls. All subjects underwent structural spectral domain optical coherence tomography (SD)-OCT to assess the ganglion cell complex (GCC) and the retinal nerve fibre layer (RNFL). OCTA was used to evaluate the VD of the RPC in different regions (whole image, inside disc and peripapillary).ResultsThe PPG and aMCI groups showed a statistically significant reduction in SD-OCT and parameters with respect to controls (p < 0.001). No statistically significant difference was found in GCC and RNFL parameters between the two study groups (p > 0.05). At OCTA examination, PPG and aMCI patients exhibited a statistically significant reduction in the VD of the RPC in whole image, inside and peripapillary regions compared to healthy controls (p < 0.001). When comparing the two study groups, the OCTA parameters were significantly impaired in PPG with respect to aMCI patients. Significant correlations were found between structural OCT and OCTA parameters in PPG and aMCI groups (p < 0.05).ConclusionsRPC vessel density could represent a helpful and sensible biomarker to identify early retinal microvascular changes in PPG and MCI in order to better understand the vascular pathophysiological mechanisms involved in these neurodegenerative diseases.