The effect of calcium channel blocker (CCB) treatment on retinal and choroidal vessels in a group of hypertensive patients.

PURPOSE: The present study was designed to observe the vasoreactivity in retina and choroid after calcium channel blocker (CCB) treatment in a group of hypertensive patients. METHOD: The study was based on 56 hypertensive patients (56 eyes) and 56 control subjects (56 eyes). Choroidal scans and the measurement of peripapillary retinal vessel diameters was performed at baseline and optical coherence tomography (OCT) scans were also performed at first month . Subfoveal choroidal thickness (SFCT) and the diameters of superior temporal artery (STA), inferior temporal artery (ITA), superior temporal vein (STV), inferior temporal vein (ITV) were compared between the groups. RESULTS: The baseline diameters of the STA, ITA were significantly decreased in the patient group compared with the control group (all p < .05). There was a significant increase at first month after the CCB treatment in comparison to baseline measurements (all p < .05). When compared with the controls, the diameter of venules showed a decrease at baseline but was not significant. After the treatment, the diameters of venules were insignificantly increased compared with baseline measurements (p = .178 and p = .275) and there were also no significant differences between the control group and the patient group in first month (all p > .05). The average choroidal thickness measurements of the hypertensive group was lower than the control group (p = .404) and there was a tendency to increase after the treatment (p = .055). CONCLUSION: This study demonstrates that, treatment with CCB seems to improve retinal arteries and has almost no affect on the choroidal thickness in newly diagnosed hypertensive patients.

Short-term effect of angiotensin-converting enzyme inhibitor on retinal vessel diameter in patients with systemic hypertension.

PURPOSE: To determine the retinal vessel diameter changes after angiotensin-converting enzyme (ACE) inhibitor treatment in a group of hypertensive patients. METHODS: This study included 60 treatment-naive hypertensive patients who were treated with ACE inhibitor. Sixty healthy volunteers served as control group. An optical coherence tomography scan protocol including the measurement of peripapillary retinal vessel diameters was performed at baseline and at 1st month. The diameters of superior temporal artery (STA), inferior temporal artery (ITA), superior temporal vein (STV), inferior temporal vein (ITV), superior nasal artery (SNA), inferior nasal artery (INA), superior nasal vein (SNV) and inferior nasal vein (INV) were statistically compared. RESULTS: The baseline diameters of the STA, ITA, SNA, and INA were significantly decreased in the patient group compared with the control group (all p < 0.05). There was a significant increase at 1st month after the treatment in comparison to baseline measurements (all p < 0.05). When compared with the controls, only the diameter of SNV showed a significant decrease at baseline (p = 0.031). After the treatment, the diameters of SNV and INV were significantly increased compared with baseline measurements (p = 0.049 and p = 0.035, respectively). There were no significant differences between the control group and the patient group at 1st month (all p > 0.05). CONCLUSION: Short-term treatment with ACE inhibitor led to a significant improvement in the retinal vessel diameters of patients with hypertension.

The impact of macular edema on microvascular and metabolic alterations in retinitis pigmentosa.

PURPOSE: The primary aim of our study was to evaluate retinal microvascular anomalies recorded with optical coherence tomography angiography (OCTA) and the retinal metabolic function measured with retinal oximetry (RO) in patients with retinitis pigmentosa (RP). The secondary aim of the study was to link the presence of macular edema to microvascular and metabolic parameters in RP. METHODS: OCTA and RO were performed on 94 eyes: 64 eyes diagnosed with RP with (ME-RP) and without (no-ME-RP) macular edema were compared with 30 control eyes. Study end points were as follows: mean superficial (FAZ-S) and deep foveal avascular zone (FAZ-D) determined by OCTA. In addition, we evaluated the mean arterial (A-SO2; %), venular (V-SO2; %) oxygen saturation, their difference (A-V SO2; %), as well as the corresponding mean diameter of the retinal arterioles (D-A; µm) and venules (D-V; µm). RESULTS: RP patients differed from controls by enlarged FAZ-S and FAZ-D (p ≤ 0.001), attenuated retinal vessels (p ≤ 0.001), and increased retinal vessel oxygen saturation (p ≤ 0.010). Subgroup analyses within RP patients revealed more pronounced alterations of microvascular parameters and metabolic function in the presence of macular edema. In the no-ME-RP subgroup, significant interactions were present between FAZ-S, A-SO2, and V-SO2, whereas in the ME-RP subgroup, we found significant correlations between FAZ-D and D-A. CONCLUSION: A combined microvascular structure-metabolic function approach enhances our understanding of inherited retinal diseases. The presence of macular edema in RP seems to be a result of more altered microvascular-metabolic function. Macular edema should thus be taken into consideration when evaluating microvascular and/or metabolic changes in RP.

Retinal and choroidal vascularity changes in healthcare professionals wearing FFP3 respirators.

PURPOSE: To evaluate short-term retinal and choroidal vascularity changes in the healthcare professionals after four hours of use filtering facepiece respirators (FFR). MATERIALS AND METHODS: This prospective study included 20 healthcare professionals. Oxygen saturation, pulse rate, systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), mean ocular perfusion pressure (MOPP), and spectral domain optical coherence tomography (OCT) imaging were evaluated at baseline and after four hours wearing of FFP3 FFRs without an exhalation valve. Superior temporal artery (STA), inferior temporal artery (ITA), superior temporal vein (STV), and inferior temporal vein (ITV) diameter were measured from OCT images. The total subfoveal choroidal area (TCA), luminal area (LA), stromal area (SA) choroidal vascularity index [(CVI), the ratio of LA to TCA] were determined after binarization of enhanced depth imaging OCT (EDI-OCT) images of the choroid. RESULTS: The mean age of the participants was 27.35 ± 2.80 years (range, 25-34). Eight of them were female and 12 were male. After wearing the FFR for four hours, a significant decrease was observed in the mean DBP (p = 0.018), MAP (p = 0.016), and MOPP (p = 0.007) when compared to base-line values. STV diameter (p = 0.019) and ITV diameter (p = 0.046) measurements were found significantly higher than baseline measurements. A significant increase in the choroidal vascularity was observed in the LA (p = 0.004) and TCA values (p = 0.043) after wearing the FFR for four hours. CONCLUSION: The current study shows that after four hours usage of FFR, in addition to systemic changes, retinal and choroidal vascularity might be affected significantly. With further studies, long-term effects and clinical significance of these short-term changes should be investigated on healthcare professionals.

Metabolic monitoring of transcorneal electrical stimulation in retinitis pigmentosa.

PURPOSE: Transcorneal electrical stimulation (TES) is a novel treatment approach for patients with retinitis pigmentosa (RP). With progression of RP, loss of photoreceptors leads to less oxygen consumption and lower demand in the retina. Retinal oximetry (RO), as a non-invasive method to analyse oxygen saturation in retinal vessels, promises to be a useful therapy monitoring tool. The aim of our study was to observe changes in RO that would be attributed to therapeutic intervention. METHODS: A total of 43 eyes of 22 subjects (11♀ 11♂) suffering from RP were examined at baseline, after the first stimulation, 1 week and 6 months after TES (OkuStim®). Stimulation was performed for 30 min weekly at 200% of the individual phosphene threshold, simultaneously on both eyes. The oxygen saturation was examined at baseline and following TES stimulation with the oxygen saturation tool of the Retinal Vessel Analyser (RVA; IMEDOS Systems UG, Jena, Germany). The global oxygen saturation parameters (in %), within 1.0-1.5 optic disc diameters from the disc margin, in retinal arterioles (A-SO2) and venules (V-SO2) were estimated and their difference (A-V SO2) was calculated. In addition, we evaluated the diameters (in µm) in the corresponding arterioles (D-A) and venules (D-V). ANOVA-based linear mixed-effects models were calculated with SPSS®. RESULTS: Six months after TES treatment, the mean A-SO2 increased (from 96.48 ± 12.27 to 100.15 ± 5.56%, p = 0.09), while the V-SO2 decreased (from 61.61 ± 12.78 to 59.79 ± 11.15%, p = 0.48). The A-V SO2, which represents the oxygen consumption of the retina, showed a statistically significant increase from 34.87 ± 9.38% at baseline to 41.36 ± 9.18% after 6 months (p = 0.02). TES had no influence on the D-A and D-V (p > 0.6). CONCLUSION: These data indicate that TES therapy in RP leads to an increased oxygen consumption of the retina. RO may thus serve as a sensitive monitoring method for TES therapy in RP.

Effect of intravitreal aflibercept treatment on retinal vessel parameters in diabetic macular oedema: Arteriolar vasoconstriction.

Purpose: To evaluate the effects of intravitreal aflibercept (IVA) treatment on retinal vein parameters and choroidal thickness used in the treatment of diabetic macular oedema (DME). Methods: This retrospective study administered Afyonkarahisar Health Sciences University Department of Ophthalmology. Twenty-nine patients who were diagnosed with naive DME in a single eye were included in the study. A three consecutive, monthly intravitreal injection of 2 mg aflibercept were administered to patients. Each patient's contralateral (untreated) eyes, which did not diagnose DME and did not receive any treatment, were the control group. The central retinal artery equivalent (CRAE), central retinal vein equivalent (CRVE), and artery-vein ratio (AVR) values were measured using a semi-automatically computer-based software before the first IVA injection and 30 d after the first, second, and third injections. The main outcome measurements were the central macular thickness (CMT), best-corrected visual acuity (BCVA), subfoveal choroidal thickness (sf-CT), CRAE, CRVE, and AVR. Results: The mean age of patients was 59.25 ± 9.48 years. Patients were 15 males and 14 females. A significant vasoconstriction of the retinal arterioles, a thinning of sf-CT and CMT, and an increase of BCVA have observed in IVA-treated eyes compared to baseline (respectively, p < 0.001, p < 0.001, p < 0.001, p < 0.001). But, no significant differences were found for CRVE and AVR in IVA-treated eyes compared to baseline. No significant difference was found for all parameters in untreated eyes compared to baseline. Conclusions: This study demonstrates that IVA treatment can change retinal blood flow by reducing retinal artery diameter and thinning in the choroid.

Retinal vessel diameter obtained by optical coherence tomography is spared in Parkinson's disease.

PURPOSE: To define the alterations in retinal vessel diameter in Parkinson's disease (PD) by optical coherence tomography (OCT). METHODS: This is a case-control study including 41 eyes of 41 patients with diagnosis of PD and 35 eyes of 35 age- and sex-matched control subjects. All subjects underwent complete neurological and ophthalmological examinations before measurements. Retinal vessel diameters and peripapillary retinal nerve fiber layer (pRNFL) thicknesses were evaluated with spectral domain OCT (SD-OCT) with a circular scan centered at the optic disc. The diameters of the superior nasal and temporal arteries and veins, and inferior nasal and temporal arteries and veins were measured and then compared between the groups. Correlations with the duration of the disease, usage of levodopa, and pRNFL thicknesses between retinal vessel diameters were examined with Pearson and Spearman correlation analysis. RESULTS: Average pRNFL thickness is significantly decreased in PD compared to age- and sex-matched controls (p < 0.05). At all measurement points, retinal artery diameter measurements were decreased in the PD group compared to controls, but the differences did not reach statistical significance. Diameters of the retinal veins also did not show any significant difference in the PD and control groups. Superior temporal artery diameter was significantly decreased in patients using levodopa compared to nonusers (p = 0.022). There were no statistically significant correlations between pRNFL thicknesses or disease duration with retinal vessel diameters in PD group. CONCLUSIONS: Parkinson's disease does not seem to have an impact on the retinal vessel diameters obtained by SD-OCT.

Review of the association between retinal microvascular characteristics and eye disease.

Computerized retinal imaging technologies enable the static and dynamic measurement of a range of retinal microvascular parameters. Large population-based studies have reported associations between these microvascular indices and various ophthalmic diseases including diabetes, age-related macular degeneration, retinal artery embolism, retinal vein occlusion, glaucoma and non-glaucomatous optic neuropathies. Increasingly, sophisticated imaging and analysis techniques have the potential to provide relevant clinical information regarding disease risk and progression; however, further studies are required to verify associations and strengthen the predictive power of these techniques. We summarize the current state of knowledge regarding retinal microvascular characteristics and eye disease.

Retrospective analysis of the effect of aflibercept loading dose on the retinal vessel diameters in patients with treatment-naive neovascular AMD.

BACKGROUND: To evaluate the effects of intravitreal aflibercept (IVA) on retinal vessel diameters in patients with neovascular age-related macular degeneration (AMD). DESIGN, SETTING, AND PARTICIPANTS: A retrospective study conducted at the Kutahya Dumlupinar University Faculty of Medicine included 15 eyes of 15 patients with treatment naive neovascular AMD. METHODS: All eyes received IVA injections once per month for 3 months; untreated contralateral eyes were used as controls. The central retinal artery equivalent (CRAE), central retinal vein equivalent (CRVE), and artery-vein ratio (AVR) values were measured using a computer-based program before the first IVA injection and 30 days after the first, second, and third injections. The main outcome measurements were the central macular thickness (CMT), best-corrected visual acuity (BCVA), choroidal thickness, CRAE, CRVE, and AVR. RESULTS: Significant vasoconstriction of the retinal arterioles was observed in all eyes treated with IVA when compared to baseline (p = 0.009). However, no significant differences were found for CRVE or AVR throughout the study period in treated eyes. In the control group, all parameters measured during each visit were similar to baseline measurements (p > 0.05). The mean BCVA significantly improved at the end of the loading dose of IVA, when compared to baseline (p = 0.006). After the IVA injections, the mean CMT and choroidal thickness were significantly reduced at all visits, compared to baseline (p < 0.001). CONCLUSIONS: The current study showed that IVA led to significant retinal arteriolar vasoconstriction and choroidal thinning, which may cause reduced retinal blood flow.

Evaluation of the effect of fluorescein angiography on retinal vessel diameter: an optical coherence tomography study.

PURPOSE: To evaluate the effect of fluorescein angiography on retinal vessel diameter with Optical Coherence Tomography (OCT). METHODS: In this cross-sectional study, a total of 81 eyes of 81 patients who were performed fluorescein angiography (FA) procedure were included. Retinal vessels were examined with the Spectral-domain OCT at baseline and immediately after FA procedure. A cube scan consisting of seven horizontal scans were placed at the inferior border of the disk to include the inferior temporal retinal vessels. Vessels diameters were measured at five measurement points (480-1440 µm inferiorly from the optic disk border). RESULTS: The mean age of the study subjects was 58.02 ± 14.1 years. At baseline, the mean diameter of the retinal artery was 120.16 ± 24.56 µm and of the vein 157.94 ± 32.34 µm at the measurement point of 480 µm, with a gradual decrease to 114.91 ± 25.59 and 152.17 ± 28.17 µm, respectively, at 1440 µm. After FA procedure, the mean diameter of the retinal artery was 122.85 ± 26.35 and of the vein 158.30 ± 32.21 µm at the measurement point of 480 µm, with a gradual decrease to 115.22 ± 22.91 and 151.94 ± 28.93 µm, respectively, at 1440 µm. There were no statistical differences for either of these comparisons at any of the points of both artery and vein measurements. CONCLUSION: There was not any clinically significant change in retinal artery diameter such as a dilatatory response after FA procedure in patients with hypertension, diabetes, and age-related macular degeneration (AMD).

Retinal vessel diameters and reactivity in diabetes mellitus and/or cardiovascular disease.

BACKGROUND: Retinal vessel calibre and vascular dilation/constriction in response to flicker light provocation may provide a measure distinguishing patients suffering from diabetes mellitus and/or cardiovascular disease. METHODS: One hundred and sixteen age and sex matched patients with diabetes mellitus (DM), cardiovascular disease (CVD) and both DM and CVD (DM + CVD) underwent systemic and intraocular pressure measurements. Retinal vessel calibres were assessed using a validated computer-based program to compute central retinal artery and vein equivalents (CRVE) from monochromatic retinal images. Vessel dilation and constriction responses to flicker light provocation were assessed by continuous retinal vessel diameter recordings. Plasma endothelial markers von Willebrand factor (vWf) and soluble E selectin (sEsel) were measured by ELISA. RESULTS: Retinal vessel calibres were comparable across groups but CRVE correlated significantly with disease duration in DM patients (r = 0.57, p < 0.001). Patients suffering DM only exhibited reduced arterial vasomotion at rest and reduced arterial constriction following flicker light induced vessel dilation compared to patients with CVD and those suffering both CVD + DM (p = 0.030). Patients suffering from CVD + DM exhibited significant differences between each flicker cycle in regards to arterial maximum constriction (p = 0.006) and time needed to reach arterial maximum dilation (p = 0.004), whereas the other two groups did not show such inconsistencies between individual flicker cycles. vWf was raised in CVD + DM compared to the other two groups (p ≤ 0.02), whilst sEsel was raised in CVD + DM compared to DM alone (p = 0.044). CONCLUSIONS: Dynamic retinal vascular calibres as obtained by continuous diameter measurements using flicker light provocation can reveal subtle differences between groups suffering from CVD with and without DM. This difference in reaction pattern and lack of arterial constriction in DM may provide a suitable marker to monitor progression.

Comparative Retinal Vessel Size Study of Intravitreal Ranibizumab and Bevacizumab in Eyes with Neovascular Age-Related Macular Degeneration.

PURPOSE: The aim of this paper was to assess and compare the effects of intravitreal ranibizumab and bevacizumab on retinal vessel diameter in eyes with neovascular age-related macular degeneration (AMD). METHODS: Patients with neovascular AMD who underwent intravitreal injection of either ranibizumab or bevacizumab were included. Noninjected fellow eyes served as a control. The main outcome measures were central retinal artery equivalent (CRAE), central retinal vein equivalent (CRVE), and the artery-vein ratio (AVR). RESULTS: In the ranibizumab group, the mean CRAE value decreased significantly at 1 week and 1 month (p = 0.002). The AVR value decreased significantly at 1 month (p = 0.028). CRVE values did not change at 1 week and 1 month (p = 0.083). In the bevacizumab group, the preinjection CRAE, CRVE, and AVR values did not change through the study period (p = 0.128, p = 0.600, and p = 0.734, respectively). CONCLUSION: These results suggest that intravitreal ranibizumab led to significant retinal arteriolar vasoconstriction in eyes with neovascular AMD.

Review of paediatric retinal microvascular changes as a predictor of cardiovascular disease.

Recent studies have supported the hypothesis that exposure to established cardiovascular risk factors in early life predisposes to the development of adult cardiovascular disease. Retinal imaging is an emerging technique which facilitates non-invasive, accurate and reproducible assessment of the retinal microvasculature. The assessment may be in the form of static vascular calibre measurements and assessment of the vascular geometry or dynamic structural and functional assessments. Paediatric retinal microvascular changes are reported in response to elevated blood pressure, type 1 diabetes, increasing adiposity, diet, physical activity, systemic inflammation, metabolic peptides, family history and prenatal factors. The resultant microvascular changes have been linked to sub-clinical and overt cardiovascular, cerebrovascular and metabolic disease states in the adult population. Still missing however is longitudinal evidence showing the persistence of retinal microvascular alterations into adulthood. Future studies will enable retinal microvascular assessment to further evaluate the pathogenesis of disease states and response to intervention. The data obtained will also aid in expanding the clinical utility of retinal imaging as a cardiovascular risk prediction and monitoring tool and supplement existing recommendations to reduce cardiovascular morbidity and mortality.

Surgically induced changes in retinal vessel diameter, retinal nerve fibre layer thickness, and the optic disc after 23-gauge pars plana vitrectomy.

The aim of the study is to investigate the retinal vascular calibre, retinal nerve fibre layer's thickness, and optic disc changes in patients after pars plana vitrectomy. We examined 40 eyes in 40 patients who had undergone unilateral pars plana vitrectomy at three time points: prior to surgery, and at 3 and 6 months after the operation. The diameters of central retinal arteries and veins were measured using retinal photographs. The central retinal arteriolar equivalent (CRAE) and central retinal venular equivalent (CRVE) were calculated using the revised Parr-Hubbard formula. Retinal nerve fibre layer thickness was obtained using Stratus optical coherence tomography. The cup-to-disc vertical ratio of the optic disc was evaluated using stereo optic disc photography. There were no significant differences between the eyes of individual patients before the operation. Cup-to-disc vertical ratios of the optic disc were significantly increased 3 and 6 months postoperatively (p < 0.01, p < 0.01), and there was a significant difference between the operative eye and fellow eye at the same time points (p < 0.01, p < 0.01). Changes in CRAE and CRVE in the operative eyes were significantly larger than the fellow eyes 6 months postoperatively (p < 0.01, p < 0.01). The retinal nerve fibre layer thickness showed no significant changes. While there were no changes in retinal nerve fibre layer thickness, vitrectomy induced changes in the cup-to-disc vertical ratio of the optic disc and retinal vessel diameter for at least 6 months after surgery.

Recurrence of macular edema in eyes with branch retinal vein occlusion changes the diameter of unaffected retinal vessels.

PURPOSE: To measure unaffected retinal vessel diameter in eyes with macular edema (ME) secondary to branch retinal vein occlusion (BRVO) after intravitreal injection with bevacizumab (IVB). METHODS: Patients with BRVO-induced ME who responded to IVB were assessed at baseline and 1, 3, and 6 months. In both eyes, the diameters of the largest arteriole and venule in all quadrants (except occlusion quadrant) were measured by using a computer-assisted method. The same vessels chosen at baseline were measured at each follow-up examination. RESULTS: Forty-two eyes were participated. At baseline, venular diameters of unaffected quadrants in eyes with BRVO were larger than the venules in the corresponding quadrant of the fellow eyes (p < 0.05, respectively). The venular diameters in all quadrants of the affected eyes decreased significantly relative to baseline after IVB (p < 0.05 respectively). Twenty-two eyes (52.4 %) developed recurrent ME. On recurrence at 3 (n = 15, 35.7 %) or 6 months (n = 7, 16.7 %), the unaffected venular diameters increased significantly (p < 0.05 respectively). These diameters again decreased significantly after a second IVB (p < 0.05 respectively). CONCLUSION: Unaffected retinal venular diameters associate with the course of BRVO with ME. This may help elucidate the pathological mechanism underlying BRVO.

Retinal vessel diameter in bilateral glaucoma suspects: comparison between the eye converted to glaucoma and the contralateral non-converted eye.

PURPOSE: To investigate retinal vessel diameter in patients classified as bilateral glaucoma suspects who showed unilateral glaucomatous conversion. METHODS: This retrospective study included 21 patients who had initially been diagnosed as bilateral glaucoma suspects but showed unilateral glaucomatous conversion during a follow-up period of more than 2 years. Conversion to glaucoma was determined either by documentation of a new retinal nerve fiber layer defect on red-free photography or a reproducible glaucomatous visual field defect. The central retinal arteriolar equivalent (CRAE) and central retinal venular equivalent (CRVE) were measured from fundus photographs taken at baseline and at the point of glaucoma conversion. RESULTS: The mean CRAE of the converted eyes was significantly lower than that of the non-converted eyes at baseline (164.9 ± 13.2 µm vs 175.2 ± 15.6 µm; p = 0.001), but no significant difference was observed in the mean CRVE (p = 0.108). The mean CRAE of the converted eyes was also lower than in the non-converted eyes at the point of glaucoma conversion (158.6 ± 13.5 µm vs 168.0 ± 17.2 µm; p = 0.011). CONCLUSION: In bilateral glaucoma suspects, there was a significant inter-eye difference in CRAE at baseline between eyes that converted to glaucoma and those that did not. These findings suggest that measurement of retinal arteriolar diameter may help clinicians when evaluating the risk of conversion in glaucoma suspects.

Changes in retinal vessels related to varicocele: a pilot investigation.

The aim of this study was to investigate whether retinal vasculature changes had occurred (retinal artery diameter, retinal vein diameter and artery/vein ratio) in patients with varicocele. This pilot study included 50 healthy subjects with any eye disease apart from slight refractive errors and 55 patients with varicocele. Retinal arteriolar and venular diameters were measured and summarised as central retinal arteriolar equivalent (CRAE) and central retinal venular equivalent (CRVE). Retinal microvascular diameters and the arteriolar-to-venular ratio (AVR) were assessed with a digital retinal camera. All measurements and calculations were performed using a computer-based program. The mean CRAE value was 151.8 ± 3.6 µm in the study group and 150.4 ± 4.5 µm in the control group. Mean CRVE value was 209.4 ± 5.9 µm in the study group and 200.1 ± 8.7 µm in the control group. AVR was found 0.72 ± 0.02 in the study group and 0.75 ± 0.03 in the control group. There were significant differences between groups in terms of CRVE and AVR. There were no significant differences between groups in terms of CRAE. The results of this study showed that the patients with varicocele showed significant changes on retinal vascular diameter.

Dynamic Changes in Retinal Vessel Diameters and Arteriovenous Ratio within 10 Days of Birth.

PURPOSE: This study monitored the dynamic changes in retinal vascular width and the AVR in full-term neonates within 1-10 days of birth. METHODS: It was conducted at hospitals in the Anhui province from October 2020 to March 2022. A total of 700 full-term, healthy infants were chosen randomly within 10 days of birth, and the Star Pupil Medical Cloud Data System (XBDS) was used to collect fundus images. Infants within 6 days of birth were grouped into groups one to six, while those within the 7th to 10th days were grouped into group seven. The fundus photographs were imported into Image-Pro-Plus (IPP) software. The optic disc diameter was measured. The retinal artery and vein's diameter was measured at a distance between 0.5- and 1.0-disc diameter from the optic disc's margin. The AVR was also calculated. Finally, each group's retinal vessel diameters and AVR were compared separately to show their dynamic changes. RESULTS: There were differences in the retinal artery diameter between groups one and two, three and four, four and five, and five and six. For retinal vein diameter, there were differences between groups one and two and groups six and seven. There were also differences in the AVR between all groups. In addition, there was a significant positive correlation between the small retinal artery and vein diameters. CONCLUSION: The retinal artery and vein diameters and AVR in neonates change dynamically during the first 10 days of life. The AVR undergoes the most dramatic change daily and is considerably smaller than the AVR in adults. Hence, this study found that the external environment undergoes significant changes following birth that affect the microcirculation. Then, the retinal central vascular system undergoes similar emergency and adaptive alterations.

Exploring Retinal Blood Vessel Diameters as Biomarkers in Multiple Sclerosis.

We aimed to determine whether retinal vessel diameters and retinal oxygen saturation in newly diagnosed patients with multiple sclerosis (pwMS) are different from those of a healthy population. Retinal blood vessel diameters were measured using imaging with a spectrophotometric non-invasive retinal oximeter. Twenty-three newly diagnosed untreated relapsing-remitting MS (RRMS) patients (mean age: 32.2 ± 7.5 years, age range = 18-50 years, 56.5% female) were measured and compared to 23 age- and sex-matched healthy controls (HCs) (mean age: 34.8 ± 8.1 years). Patients with Optic Neuritis were excluded. Retinal venular diameter (143.8 µm versus 157.8 µm: mean; p = 0.0013) and retinal arteriolar diameter (112.6 µm versus 120.6 µm: mean; p = 0.0089) were smaller in pwMS when compared with HCs, respectively. There was no significant difference in the oxygen saturation in retinal venules and arterioles in pwMS (mean: 60.0% and 93.7%; p = 0.5980) compared to HCs (mean: 59.3% and 91.5%; p = 0.8934), respectively. There was a significant difference in the median low contrast visual acuity (2.5% contrast) between the pwMS and the HC groups (p = 0.0143) Retinal arteriolar and venular diameter may have potential as objective biomarkers for MS.

The Presence of Hyperreflective Foci Reflects Vascular, Morphologic and Metabolic Alterations in Retinitis Pigmentosa.

BACKGROUND: The presence of hyperreflective foci (HRF) in retinitis pigmentosa (RP) is a potentially new finding. We investigated the presence of HRF in SD-OCT images in eyes with RP and its relation to vascular, morphologic and metabolic findings in RP. METHODS: The study was performed on 42 RP patients and 24 controls. Using SD-OCT, we calculated the amount of HRF within the entire retina (HRF-ER) and the outer nuclear layer (HRF-ONL). Retinal vessel diameters (µm) and oxygen saturation (%) values were measured using Oxymap T1. We evaluated the mean diameter in retinal arterioles (D-A) and venules (D-V), the corresponding oxygen saturation values (A-SO2, V-SO2) and the oxygen saturation difference (A-V SO2). RESULTS: RP differed from controls by HRF-ER, HRF-ON and EZ-length (p < 0.001). D-A and D-V were narrower and A-SO2 and V-SO2 were higher in RP (p ≤ 0.001). Within RP, significant interactions were found between the HRF-ER* group and: BCVA, EZ length, D-A, A-SO2 and A-V SO2 (p ≤ 0.018). The HRF-ONL* group interactions were significant for: BCVA, EZ length, D-A, A-SO2 and A-V SO2 (p ≤ 0.014). CONCLUSION: The present study highlights the presence of HRF to reflect the vascular, morphologic and metabolic alterations in RP. These biomarkers seem to be associated with remodeling and apoptosis that occur with the progression of degeneration.