Does the ISNT rule apply to the radial peripapillary capillary vessel density in OCT angiography?

PURPOSE: 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). MATERIALS AND METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Iridocorneal angle assessment in children with spontaneously regressed retinopathy of prematurity.

PURPOSE: To assess anterior segment anatomic parameters in school-aged children with spontaneously regressed retinopathy of prematurity (sr-ROP) and in children born preterm without ROP history (preT). METHODS: sr-ROP and preT children were compared with healthy, born at term children (control group). Biometric characteristics were measured with the IOLMaster. Iridocorneal angle structure was evaluated using Visante AS-OCT, and angle opening distance, trabecular iris space area and scleral spur angle were calculated. Best-corrected visual acuity (BCVA) was measured with the ETDRS chart. RESULTS: We examined 22 eyes of 11 children with sr-ROP, 26 eyes of 13 preT children and 24 eyes of 12 healthy controls, with a median age of 8 years. sr-ROP children exhibited worse mean BCVA and reduced AL compared to controls (p = 0.001 and p = 0.007, respectively). A narrower iridocorneal angle was found in sr-ROP compared to the preT and the control groups. Preterm children were found to have similar anterior chamber angle metrics compared to the full-term control group. CONCLUSION: In this study, school-aged children with a history of sr-ROP had narrower angles compared to preterm- and term-born children. AS-OCT demonstrated structural differences of the iridocorneal angle in sr-ROP, possibly reflecting a mild developmental arrest of the anterior segment.

Macular sequelae in vasoproliferative tumors: results of surgical approach.

PURPOSE: The purpose of this study is to report the clinical manifestations and treatment outcomes in three patients diagnosed with vasoproliferative tumors (VPTs). METHODS: A retrospective, single-center case series was conducted, and retinal findings from three cases were documented by clinical examination and multimodal imaging. RESULTS: Three patients presented with an elevated, yellow-white retinal lesion located at the peripheral retina and extensive retinal exudation. All three patients were closely monitored, and tumor-associated features included lipid exudates, cystoid macular edema (CMO), pre-retinal fibrosis and epi-retinal membrane (ERM). Clinical management relied on observation, cryotherapy, laser photocoagulation, intravitreal steroids and anti-vascular endothelial growth factor (anti-VEGF) treatment. Despite different clinical courses, two patients underwent vitreo-retinal surgery to address VPT-related complications of macular hole and vitreo-macular traction, whereas a patient underwent phacoemulsification to treat steroid-induced cataract. CONCLUSION: VPTs are uncommon benign vascular tumors and usually located at the infero-temporal peripheral retina. Close observation and early diagnosis of VPTs are of great importance in preventing vision-threatening complications and ensuring the best final visual outcome. The optimal treatment has yet to be defined due to lack of multi-center clinical studies. Despite the availability of less invasive therapeutic interventions, however, our case series show that pars plana vitrectomy is sometimes the most appropriate choice to restore visual acuity.

Potential applications of optical coherence tomography angiography in glaucoma.

PURPOSE OF REVIEW: Optical coherence tomography angiography (OCTA) is a novel, noninvasive imaging modality that allows assessment of the retinal and choroidal vasculature. The scope of this review is to summarize recent studies using OCTA in glaucoma and highlight potential applications of this new technology in the field of glaucoma. RECENT FINDINGS: OCTA studies have shown that retinal vascular changes may not develop solely as a result of advanced glaucoma damage. OCTA-derived measurements have provided evidence for lower retinal vascular densities at the optic nerve head, peripapillary and macula in preperimetric-glaucoma and early-glaucoma, as well as, in more advanced glaucoma, in comparison to with normal eyes. SUMMARY: OCTA is a novel imaging modality that has already started to expand our knowledge base regarding the role of ocular blood flow in glaucoma. Future studies will better elucidate the role of OCTA-derived measurements in clinical practice, research, and clinical trials in glaucoma.

Choroidal Imaging with Swept-Source Optical Coherence Tomography in Patients with Birdshot Chorioretinopathy: Choroidal Reflectivity and Thickness.

PURPOSE: To characterize choroidal thickness and choroidal reflectivity in the eyes of patients with birdshot chorioretinopathy (BSCR). DESIGN: Cross-sectional observational study. PARTICIPANTS: Two hundred twenty BSCR patients and 59 healthy controls. METHODS: Patients with BSCR and healthy controls underwent imaging of the macula in both eyes with a swept-source optical coherence tomography device (DRI-OCT1 Atlantis; Topcon). Images were exported from the device, and analysis was performed by 2 graders in the Doheny Image Reading Center using Image J software. The choroidal thickness at the foveal center was measured. In addition, the inner and outer boundaries of the choroid and retinal pigment epithelium (RPE) as well as the inner retinal surface all were segmented to allow the brightness and reflectivity of the pixels in the choroid, RPE band, and overlying vitreous to be quantified. An adjusted or normalized choroidal reflectivity, with the RPE as the bright reference standard and the vitreous as the dark reference standard, was computed using the formula: normalized choroidal reflectivity = (choroidal reflectivity-vitreous reflectivity)/RPE reflectivity. MAIN OUTCOME MEASURES: Choroidal reflectivity and choroidal thickness. RESULTS: Three hundred eighty-six eyes in the BSCR group and 59 eyes in the control group were included in this analysis. Higher choroidal reflectivity and lower choroidal thickness were documented in inactive BSCR patients compared with active BSCR and controls (P < 0.01). Active BSCR patients showed lower choroidal thickness compared with controls (P < 0.01). There was a negative correlation between choroidal reflectivity and choroidal thickness (r = -0.793; P < 0.001). On multiple regression analysis, choroidal thickness, age, and disease duration (all P < 0.01) all were significant predictors of choroidal reflectivity. CONCLUSIONS: Choroidal reflectivity and choroidal thickness changes are evident in active and inactive BSCR patients. Novel choroidal parameters such as choroidal reflectivity may warrant further study in the setting of BSCR.

Effects of diurnal, lighting, and angle-of-incidence variation on anterior segment optical coherence tomography (AS-OCT) angle metrics.

BACKGROUND: First reported study to assess the effect of diurnal variation on anterior chamber angle measurements, as well as, to re-test the effects of lighting and angle-of-incidence variation on anterior chamber angle (ACA) measurements acquired by time-domain anterior segment optical coherence tomography (AS-OCT). METHODS: A total of 30 eyes from 15 healthy, normal subjects underwent anterior chamber imaging using a Visante time-domain AS-OCT according to an IRB-approved protocol. For each eye, the inferior angle was imaged twice in the morning (8 am - 10 am) and then again in the afternoon (3 pm - 5 pm), under light meter-controlled conditions with ambient room lighting 'ON' and lights 'OFF', and at 5° angle of incidence increments. The ACA metrics measured for each eye were: angle opening distance (AOD, measured 500 and 750 µm anterior from scleral spur), the trabecular-iris-space area (TISA, measured 500 and 750 µm anterior from scleral spur), and scleral spur angle. Measurements were performed by masked, certified Reading Center graders using the Visante's Internal Measurement Tool. Differences in measurements between morning and afternoon, lighting variations, and angle of incidence were compared. RESULTS: Mean age of the participants was 31.2 years (range 23-58). Anterior chamber angle metrics did not differ significantly from morning to afternoon imaging, or when the angle of incidence was offset by 5° in either direction away from the inferior angle 6 o'clock position. (p-value 0.13-0.93). Angle metrics at the inferior corneal limbus, 6 o'clock position (IC270), with room lighting 'OFF', showed a significant decrease (p < 0.05) compared to room lighting 'ON'. CONCLUSIONS: There does not appear to be significant diurnal variation in AS-OCT parameters in normal individuals, but lighting conditions need to be strictly controlled since variation in lighting led to significant variability in AS-OCT parameters. No changes in ACA parameters were noted by varying the angle-of-incidence, which gives confidence in being able to perform longitudinal studies in approximately the same area (plus/minus 5° of original scan location).

Identification of anterior chamber angle parameters with a portable SD-OCT device compared to a non-portable SD-OCT.

The aim of this study is to compare a portable spectral domain optical coherence tomography (SD-OCT) device with a non-portable SD-OCT for the identification of anterior chamber angle parameters based on location of Schwalbe's line (SL) and to measure their reproducibility. 99 eyes from 46 normal, healthy participants underwent imaging of the inferior iridocorneal angle with the iVue and Cirrus SD-OCT under well-controlled low-light conditions. SL-angle opening distance (SL-AOD) and SL-trabecular iris space area (SL-TISA) were measured by masked, certified graders at the Doheny Image Reading Center using customized Image J grading software. Inter- and intrainstrument, as well as inter- and intraobserver reproducibility of SL-AOD and SL-TISA measurements were evaluated with intraclass correlation coefficients (ICCs) and Bland-Altman plots with limits of agreement. The mean SL-AOD was 0.814 ± 0.315 mm with the iVue and 0.797 ± 0.294 mm with the Cirrus. The mean SL-TISA was 0.247 ± 0.112 mm2 with iVue and 0.259 ± 0.113 mm2 with Cirrus. Interinstrument correlation coefficients (r) were 0.93 (P < 0.0001), 0.92 (P < 0.0001), and 0.92 (P < 0.0001) for SL_AOD and SL_TISA, respectively. Intraclass correlation coefficient showing the degree of agreement among SL-AOD and SL-TISA was 0.923 (95 % confidence interval 0.885-0.948) and 0.921 (95 % confidence interval 0.883-0.947) for both devices. The agreement for intrainstrument (ICCs > 0.95), intragrader (ICCs > 0.93), and intergrader (ICCs > 0.96) was excellent. Excellent agreement between the two devices was also documented with Bland-Altman analysis. Both instruments provide consistent and reproducible measurements of anterior chamber angle metrics.

Optical coherence tomography-guided classification of epiretinal membranes.

To study and classify epiretinal membranes (ERMs) based on spectral domain optical coherence tomography (SD-OCT) findings. One hundred and twelve patients with ERMs were examined clinically and underwent OCT examination. The anatomical structure of the macula and vitreoretinal interface was studied. ERMs were classified in two categories: A, with posterior vitreous detachment (PVD) (91 cases), and B, with the absence of PVD (21 cases). Category A was divided into two subcategories: A1, without contraction of the ERM (37 cases), and A2, with the presence of membrane contraction (54 cases). A2 was further subdivided into A2.1, with retinal folding (15 cases), A2.2, with edema (23 cases), A2.3, with cystoid macular edema (9 cases), and A2.4, with lamellar macular hole (7 cases). Category B was divided in two subcategories: B1, without vitreomacular traction (VMT) (4 cases), and B2, with the presence of VMT (17 cases). Category B2 was subdivided into B2.1, with edema (9 cases), B2.2, presenting retinal detachment (5 cases), and B2.3, with schisis (3 cases). OCT classification of ERMs provides useful information on the anatomical structure of the retina, and the accurate estimation of vitreoretinal interface.

Laser flare photometry in eyes receiving brolucizumab intravitreal injections for age related macular degeneration.

PURPOSE: To measure aqueous flare levels in treatment naïve eyes suffering from wet age- related macular degeneration (wAMD) treated with intravitreal brolucizumab. METHODS: Patients with treatment naïve wAMD in one eye were prospectively enrolled. Flare levels were measured with laser flare photometry at baseline, 1 day and 1 month after each of the 3 monthly injections during the loading phase. RESULTS: Twenty-two eyes from 22 patients aged 76.7 ± 6.0 years were enrolled. Flare values were 10.6 ± 3.7 photons/msec at baseline and 12.6 ± 5.8 photons/msec at the last follow up visit, 1 month after the third injection (p = 0.289, repeated measures ANOVA). The mean change in flare after the first injection was 4.2 ± 3.6. photons/msec, 6.6 ± 8.9 photons/msec after the 2nd and 8.6 ± 20.8 photons/msec after the 3rd injection (p = 0.640, repeated measures ANOVA). No patient had clinical signs of intraocular inflammation. CONCLUSIONS: Eyes receiving brolucizumab injections for wAMD showed similar flare at baseline, during and 1 month after completion of three-monthly intravitreal injections. There was no evidence of subclinical inflammation during the loading phase of brolucizumab based on laser flare photometry measurements.

Macular Ischemia Changes in Patients with Diabetic Macular Edema Treated with Aflibercept and Ranibizumab.

Τhis study aims to assess changes in the fovea avascular zone (FAZ) in treatment naïve patients receiving aflibercept or ranibizumab injections for diabetic macular edema (DME). Best corrected visual acuity (BCVA) testing, OCT, and OCT-angiography imaging were performed at baseline and 1 month after each injection. Injections of either aflibercept or ranibizumab were administered monthly for 6 consecutive months. FAZ in the superficial (SCP) and the deep capillary plexus (DCP) using OCT angiography was recorded for each visit. Fifty eyes from fifty patients with a mean age of 67.0 ± 10.7 years were included in the study. Twenty-five patients received aflibercept and twenty-five received ranibizumab. BCVA was 40.8 ± 10.0 and increased to 52.1 ± 7.9 ETDRS letters at the last visit (p < 0.001). CRT was 295.6 ± 34.0 at baseline and 247.9 ± 29.7 at the last study visit (p < 0.001). SCP FAZ was 350.6 ± 79.5 µm2 at baseline and 339.0 ± 71.3 µm2 after sox monthly injections (p = 0.132). DCP FAZ was 558.6 ± 199.0 µm2 at baseline and 459.5 ± 156.1 µm2 after six monthly injections (p < 0.001). There was no effect of the choice of ranibizumab or aflibercept on DCP FAZ change (p = 0.277). In conclusion, treatment with 6 monthly injections of ranibizumab and aflibercept led to an increase in BCVA and a decrease in CRT and DCP FAZ area. Both drugs led to an improvement in DCP ischemia.

The Effect of Phacoemulsification on the Intraocular Pressure of Patients with Open-angle Glaucoma: A Systematic Review and Meta-Analysis.

PRECIS: There is evidence that cataract surgery can reduce intraocular pressure in patients with primary open angle-, normal tension-, or exfoliative glaucoma. The complete effect of phacoemulsification is masked by topical intraocular pressure-lowering medications. PURPOSE: To assess the impact of phacoemulsification and intraocular lens implantation on intraocular pressure (IOP) level in individuals with primary open-angle glaucoma (POAG), exfoliative glaucoma (XFG), exfoliation syndrome (XFS), normal tension glaucoma (NTG), ocular hypertension (OH) or healthy controls 12 months after the surgery. METHODS: In July 2023, a comprehensive literature review was conducted across six databases. The analysis focused on the phacoemulsification arms of randomized controlled trials (RCTs). The primary outcome of interest was the mean IOP change observed 12 months after phacoemulsification. RESULTS: This meta-analysis included nine arms from nine RCTs, comprising a total of 502 participants. Overall, the average IOP was reduced by 3.77 mmHg (95%CI: -5.55 to -1.99, I2=67.9%) 12 months after surgery. The subgroup analysis, focused on whether a washout period was employed before measuring IOP, revealed that studies with a washout period exhibited a more pronounced IOP reduction of 5.25 mmHg (95%CI: -7.35 to -3.15, I2=0%), while studies without a washout period exhibited a reduction of 3.13 mmHg (95%CI: -5.46 to -0.81, I2=75.8%). The sensitivity analysis for the latter group, excluding an outlier study, showed a reduction of 1.81 mmHg (95%CI: -2.95 to -0.67, I2=0%). CONCLUSIONS: The findings of this systematic review and meta-analysis indicate that cataract surgery meaningfully lowers IOP in POAG, XFG/XFS, or OH 12 months after surgery. However, the use of topical medications masks the precise impact of phacoemulsification upon postoperative IOP. Further research using appropriate washout periods is warranted.

Transscleral diode laser cyclophotocoagulation for refractory glaucoma secondary to juvenile idiopathic arthritis: a short term follow-up.

To evaluate the success rates of transscleral diode cyclophotocoagulation (TD-CPC) for refractory secondary glaucoma in a paediatric patient with juvenile idiopathic arthritis. Report of a case of a 6-year-old boy suffering from severe uveitis, and secondary open angle glaucoma. The patient had undergone bilateral cataract surgery, two prior trabeculectomies in the left and one in the right eye. He was under systemic immunomodulation with methotrexate and cyclosporine. He presented with medically uncontrolled glaucoma, with an intraocular pressure (IOP) of 36 and 34 mmHg in the right and left eye, respectively, under maximal medical antiglaucoma therapy. TD-CPC was performed under general anesthesia, including a total of 20 spots in the right and 34 in the left eye (2,000 mW, 2 s/spot) applied in one session. Visual acuity remained stable in the right eye and deteriorated in the left eye from 0.1 to no light perception. Postoperative hypotony was present 1 month post op and IOP was 14 mmHg in the left and 17 mmHg in the right eye, respectively, in the 6-month follow-up with a topical beta-blocker. The anterior chamber was quiet in both eyes. TD-CPC was effective in the short term as IOP lowering therapy in a pediatric patient with refractory uveitic glaucoma.

The Role of Color Doppler Imaging in the Diagnosis of Glaucoma: A Review of the Literature.

Glaucoma is a progressive optic neuropathy and one of the leading causes of irreversible blindness worldwide. Elevated intraocular pressure (IOP) is the major risk factor for the onset and progression of glaucoma. In addition to elevated IOP, impaired intraocular blood flow is also considered to be involved in the pathogenesis of glaucoma. Various techniques have been used to assess ocular blood flow (OBF), including Color Doppler Imaging (CDI), a technique used in ophthalmology in recent decades. This article reviews the role of CDI in both the diagnosis and effective monitoring of glaucoma progression, presenting the protocol for imaging and its advantages, as well as the limitations of its use. Moreover, it analyzes the pathophysiology of glaucoma, focusing on vascular theory and its role in the onset and progression of the disease.

Radiotherapy in Uveal Melanoma: A Review of Ocular Complications.

Uveal melanoma represents the most prevalent form of primary malignant intraocular tumor in adults. Historically, enucleation was considered the gold-standard approach in the treatment of uveal melanoma. Currently, radiotherapy is the most commonly used therapy, aiming at a better quality of life. However, radiotherapy can result in several ocular complications, some of which may be vision-threatening. Radiation-induced dry eye, scleral necrosis, cataract, rubeosis iridis, neovascular glaucoma, radiation retinopathy, maculopathy, and optic neuropathy are the most common complications. This article aims to summarize the current literature regarding the ocular complications after radiotherapy, as well as their clinical features, risk factors, and management strategies. A thorough understanding of these issues is crucial for ophthalmologists and oncologists to provide optimal patient care, improve visual outcomes, and minimize long-term complications.

Predictive Value of Dynamic Corneal Response Parameters Evaluated with Scheimpflug High-Speed Video (Corvis ST) on the Visual Field Progression in Prostaglandin Treated Ocular Hypertension and Open-Angle Glaucoma Patients.

INTRODUCTION: The aim of this work is to compare the Corvis ST stress-strain index (SSI) and highest concavity (HC) parameters at baseline and 1 month after initiating monotherapy with prostaglandin analogues (PGs) in eyes showing visual field (VF) progression or stability. METHODS: In this prospective, single-center, observational study, newly diagnosed and treatment-naïve OAG patients were examined at baseline and 1 month after beginning monotherapy with topical PGs monotherapy. Goldmann applanation tonometry pressure readings, Corneal Hysteresis (ORA-CH), and the Corvis ST measurements were obtained at both visits. VF progression (Humphrey) was evaluated based on data from 6 years of follow-up after the baseline visit. Stress-strain index (SSI) and HC parameters in progressing (P) and non-progressing (NP) eyes were the main outcome measures. RESULTS: Sixty-three eyes were analyzed; mean age was 64.63 ± 11.26 years; 47 eyes were NP and 16 eyes were P according to the event analysis performed by the Humphrey device. There were no significant differences in IOP, CCT, or Corvis parameters between NP and P groups at baseline. Nevertheless, at 1 month, the SSI index was 1.60 ± 0.34 vs. 1.80 ± 0.34 (p = 0.003) in NP vs. P eyes, respectively. HC parameters were different between the groups at 1 month (p < 0.05) suggesting an increased scleral rigidity in the P group. There was no significant difference in IOP between groups at 1 month. CONCLUSIONS: The Corvis ST provides a corneal rigidity index (SSI) that seems to be related to VF progression when measured 1 month after initiating PGs monotherapy. Differences in HC parameters, indicative of increased scleral stiffness, are also evident at 1 month on latanoprost in the P eyes.

Perimetric and retinal nerve fiber layer findings in patients with Parkinson's disease.

BACKGROUND: Visual dysfunction is common in Parkinson's disease (PD). It remains, however, unknown whether it is related to structural alterations of the retina. The aim of this study is to compare visual field (VF) findings and circumpapillary retinal nerve fiber layer (RNFL) thickness in a series of PD patients and normal controls, in order to assess possible retinal anatomical changes and/or functional damage associated with PD. METHODS: PD patients and controls were recruited and underwent VF testing with static automated perimetry and RNFL examination with optical coherence tomography (OCT). Cognitive performance using Mini Mental State Examination (MMSE), PD staging using modified Hoehn and Yahr (H-Y) scale and duration of the disease was recorded in PD patients. RESULTS: One randomly selected eye from each of 24 patients and 24 age-matched controls was included. OCT RNFL thickness analysis revealed no difference in the inferior, superior, nasal or temporal sectors between the groups. The average peripapillary RNFL was also similar in the two groups. However, perimetric indices of generalized sensitivity loss (mean deviation) and localized scotomas (pattern standard deviation) were worse in patients with PD compared to controls (p < 0.01). 73% of eyes of PD patients had glaucomatous-like asymmetrical hemifield defects with abnormal Glaucoma Hemifield Test and various combinations of arcuate defects (n = 12), nasal steps (n = 11) and paracentral scotomas (n = 16). Bilateral defects were found in 14 patients (58%). No correlation was found between VF indices and MMSE or H-Y scores. CONCLUSION: PD patients may demonstrate glaucomatous-like perimetric defects even in the absence of decreased RNFL thickness.

Part-time Versus Full-time Spectacles for Myopia Control (ParMA Study): A Randomized Clinical Trial.

Introduction To compare myopia progression in school-aged children of Caucasian origin wearing part-time vs. full-time full correction with single-vision spectacles. Methods This prospective, randomized controlled trial included 30 children with bilateral myopia, who received either full-time or part-time treatment with single-vision spectacle lenses. Myopia progression was assessed as the mean change in cycloplegic spherical equivalent refraction (SE), mean change in axial length (AL), and mean change in sub-foveal choroidal thickness (SChT), over a 12-month follow-up period. Results A total of 32 eyes were treated with part-time single-vision spectacles (intervention group) and 28 eyes with full-time single-vision spectacles (control group), respectively. The part-time treated group reported no spectacle use during near-work activities for a mean of 6.2 hours/day. At the 12-month assessment, there was no significant difference between part-time and full-time correction groups in mean SE change (MD: -0.05 D, 95% CI: -0.50 - 0.39 D; P 0.81), in mean AL change (MD: -0.07 mm; 95% CI: -0.20 - 0.06 mm; P 0.30), and in mean SChT change (MD: -11.45 µm; 95% CI -22.60 - 14.16 µm; P 0.67). Conclusion Myopia progression in Caucasian children treated with part-time, single-vision spectacle use was not different compared to full-time, single-vision spectacle use, over a 12-month follow-up period.

Age and signal strength-related changes in vessel density in the choroid and the retina: an OCT angiography study of the macula and optic disc.

PURPOSE: To investigate the effects of ageing and signal strength index (SSI) on vessel density (VD) measurements of the radial peripapillary capillaries (RPC) in the optic disc, the retinal superficial (SCP) and deep (DCP) capillary plexi and the choriocapillaris (CC) of the macular area using optical coherence tomography angiography (OCT-A) imaging. METHODS: This cross-sectional study included 138 eyes from 77 healthy participants. High-definition (HD) disc Angio scan (4.5X4.5 mm) and HD Angio retina scan (6X6 mm) were acquired. Whole image (WI) VDs, inside disc (ID) VD and global and hemifield peripapillary RPC VDs were evaluated from the Angio Disc scans. Global and hemifield VD for the SCP, DCP and CC slab in the macula area were also recorded across different age groups. RESULTS: Mean age was 48.2 ± 15.0 years (range 25-82 years). Signal strength index (SSI) was 71.6 ± 7.6 in the macula and 74.6 ± 9.2 in the disc OCT-A image. VD for both SCP and DCP decreased by 0.084% and 0.188%/year (both p < 0.001). WI VD and ID VD also decreased by 0.037%/year (p = 0.005) and 0.092%/year (p < 0.001). Peripapillary RPC VD did not change with age or SSI. The effect of SSI was significant in SCP, DCP, WI RPC, ID RPC and CC VD. In the generalized estimating equation model testing for both SSI and age, SSI remained significant against SCP, DCP and ID RPC. CONCLUSION: With ageing, a decrease in VD in the SCP, DCP, WI and ID RPC, as well as in SSI, is seen. SSI and age are associated with VD changes, but only SSI is the significant variable that explains the variation in the retina microvasculature in the macula and the optic disc in multivariate analysis. In the CC, a larger SSI was associated with a lower VD. These findings underscore the importance of controlling for SSI in future studies using OCT-A.