REPEATABILITY OF MACULAR MICROVASCULATURE MEASUREMENTS USING OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY ACCORDING TO TEAR BREAKUP TIME IN DRY EYE DISEASE.

PURPOSE: It is hypothesized that an unstable tear film would affect the quality and repeatability of optical coherence tomography angiography (OCTA). Therefore, OCTA repeatability according to tear break-up time (TBUT) was compared. METHODS: The 3 × 3 OCTA was performed twice and, the eyes were divided into 3 groups according to the TBUT (Group 1: TBUT ≤ 5 seconds, 43 eyes; Group 2: 5 seconds < TBUT ≤ 10 seconds, 35 eyes; Group 3: TBUT > 10 seconds, 34 eyes). The intraclass correlation coefficient, coefficient of variation, and test-retest SD were calculated and compared. RESULTS: The signal strengths of OCTA were 9.1 ± 1.2, 9.5 ± 0.8, and 9.5 ± 0.8 in each group from Groups 1, 2, and 3, respectively, which showed significant difference (P = 0.049). The intraclass correlation coefficient of vessel density were 0.733, 0.840, and 0.974 in Groups 1 to 3, respectively, and the values increased in the order of Groups 1, 2, and 3. The coefficient of variation were 6.41 ± 6.09, 3.29 ± 2.22, and 1.30 ± 1.17, and the test-retest SD were 0.83 ± 0.70, 0.47 ± 0.31, and 0.19 ± 0.17 in Groups 1, 2, and 3, respectively. The coefficient of variation and test-retest SD values decreased in the order of Groups 1, 2, and 3, and showed a significant difference (all, P < 0.05). CONCLUSION: The repeatability of OCTA tended to decrease with a shorter TBUT. When the TBUT is <5 seconds, care must be taken to interpret the OCTA results correctly.

THICKNESSES OF CENTRAL MACULAR, RETINAL NERVE FIBER, AND GANGLION CELL INNER PLEXIFORM LAYERS IN PATIENTS WITH HYPERTENSION.

PURPOSE: To compare retinal thickness between patients with chronic hypertension without retinopathy, hypertensive retinopathy, Keith-Wagener-Barker Grade IV status, and normal controls using spectral domain optical coherence tomography. METHODS: In this retrospective study, we analyzed patients who visited our retinal clinic from January 2013 to February 2016. Of those included, 58 eyes of 58 patients were in the healthy control group (Group A), 37 eyes of 37 patients were in the chronic hypertension without retinopathy group (disease duration of at least 10 years; Group B), and 31 eyes of 31 patients with relieved hypertensive retinopathy (Grade IV hypertensive retinopathy a year or more ago but no longer had hypertensive retinopathy at the time of the study; Group C). The thicknesses of the central macula, retinal nerve fiber layer (RNFL), and ganglion cell inner plexiform layer (GCIPL) were measured by spectral domain optical coherence tomography in each group. RESULTS: The average thicknesses of the central macula, RNFL, and GCIPL layers were lower in Group B than in Group A (P < 0.001, 0.001, and <0.001, respectively). The thicknesses of the three layers were lower in Group C than in Group B (P < 0.001, <0.001, and <0.001, respectively). Of the three groups, the average thicknesses of the central macula, RNFL, and GCIPL were lowest in the Group C (P < 0.001, <0.001, and <0.001, respectively). CONCLUSION: The central macula, RNFL, and GCIPL in Group B were significantly thinner than those of healthy eyes, and these retinal changes were more prominent in Group C. Thus, the effects of retinal changes associated with hypertension should be considered when analyzing the thicknesses of the central macular, RNFL, and GCIPL layers in patients with ocular disorders, including retinal, glaucoma, and neuro-ophthalmological diseases.

Effect of combined goniotomy and phacoemulsification on intraocular pressure in open-angle glaucoma patients.

IMPORTANCE: Although goniotomy is known to be successful in treating congenital glaucoma, its effect in adult glaucoma patients remains unclear. BACKGROUND: To evaluate the efficacy and safety of goniotomy performed simultaneously with cataract surgery in treatment of open-angle glaucoma (OAG). DESIGN: Retrospective comparative study. PARTICIPANTS: A total of 76 patients with moderately controlled OAG (intraocular pressure [IOP] ≤ 21 mmHg using medications) undergoing cataract surgery. METHODS: Comparison of patients who underwent the conventional goniotomy during cataract surgery (combined goniotomy group) with those who underwent cataract surgery alone (phaco group). MAIN OUTCOME MEASURES: Changes in IOP and medications, and complications through 12 months. RESULTS: Baseline IOP was 18.2 ± 2.4 mmHg in the combined goniotomy group and 17.4 ± 1.9 mmHg in the phaco group; number of medications was 2.6 ± 1.1 and 2.4 ± 0.9, respectively (P > 0.05). The reduction in IOP and medication use from baseline in the combined goniotomy group was significantly greater at 12 months compared to the phaco group (-3.1 ± 2.9 mmHg vs -1.3 ± 2.4 mmHg and -1.2 ± 0.9 vs -0.7 ± 0.9, respectively, both P < 0.05). The success rate was 76.7% in the combined goniotomy group and 50.0% in the phaco group at 12 months (P = 0.021). No significant complication was observed in either group. CONCLUSIONS AND RELEVANCE: Combined goniotomy and cataract surgery showed a significantly greater reduction in IOP and number of medications compared to cataract surgery alone at 1 year after surgery, with similarly favourable safety profiles.

THICKNESS OF THE MACULA, RETINAL NERVE FIBER LAYER, AND GANGLION CELL-INNER PLEXIFORM LAYER IN THE AGE-RELATED MACULAR DEGENERATION: The Repeatability Study of Spectral Domain Optical Coherence Tomography.

PURPOSE: To determine the repeatability of measuring the thickness of the central macula, retinal nerve fiber layer, and ganglion cell-inner plexiform layer (GC-IPL) using spectral domain optical coherence tomography (Cirrus HD-OCT) in eyes with age-related macular degeneration. METHODS: One hundred and thirty-four eyes were included. The measurement repeatability was assessed by an experienced examiner who performed two consecutive measurements using a 512 × 128 macular cube scan and a 200 × 200 optic disk cube scan. To assess changes in macular morphology in patients with age-related macular degeneration, the patients were divided into the following three groups according to the central macular thickness (CMT): A group, CMT < 200 µm; B group, 200 µm ≤ CMT < 300 µm; and C group, CMT > 300 µm. RESULTS: Measurement repeatability was assessed using test-retest variability, a coefficient of variation, and an intraclass correlation coefficient. The mean measurement repeatability for the central macular, retinal nerve fiber layer, and GC-IPL thickness was high in the B group. The mean measurement repeatability for both the central macula and retinal nerve fiber layer thickness was high in the A and C groups, but was lower for the GC-IPL thickness. The measurement repeatability for GC-IPL thickness was high in the B group, but low in the A group and in the C group. CONCLUSION: The automated measurement repeatability for GC-IPL thickness was significantly lower in patients with age-related macular degeneration with out of normal CMT range. The effect of changes in macular morphology should be considered when analyzing GC-IPL thicknesses in a variety of ocular diseases.

Interocular Asymmetry of the Ganglion Cell-inner Plexiform Layer in Diabetic Retinopathy.

SIGNIFICANCE: The interocular difference in the ganglion cell-inner plexiform layer thickness showed a significant correlation with the diabetic retinopathy (DR) severity. PURPOSE: The purpose of this study was to analyze the interocular differences in the foveal, retinal nerve fiber layer (RNFL), and ganglion cell-inner plexiform layer (GC-IPL) thickness of DR patients using spectral-domain optical coherence tomography. METHODS: A total of 508 eyes from 254 patients with different severities of DR and 184 eyes from 92 control subjects were included. The GC-IPL, foveal, and RNFL thicknesses were measured, and the interocular differences in these thicknesses were correlated in control subjects and DR patients. RESULTS: The interocular difference in the average GC-IPL thickness significantly increased with the severity of DR. The interocular differences in the average GC-IPL thicknesses of the severe nonproliferative DR (NPDR) and the proliferative DR patients were significantly higher than those of the control group. However, there was no significant difference in thickness between the control group and the group with mild to moderate NPDR. In the group with proliferative DR, the interocular difference in the average GC-IPL was greater than those in the central foveal and RNFL thicknesses. Multivariate regression analyses showed that the DR severity and the interocular difference in central foveal thickness were significantly correlated with the interocular difference in the average GC-IPL thickness. CONCLUSIONS: The interocular differences in the central foveal, RNFL, and GC-IPL thicknesses significantly increased with increased DR severity. However, there was no significant difference between the control group and the group with mild to moderate NPDR. The GC-IPL differences showed a significant correlation with DR severity. These findings may be an indicator of DR progression.

Changes in Central Macular Thickness and Retinal Nerve Fiber Layer Thickness in Eyes with Vogt-Koyanagi-Harada Disease: A 2-Year Follow-Up Study.

PURPOSE: To investigate the central macular thickness (CMT) and retinal nerve fiber layer (RNFL) thickness in eyes with Vogt-Koyanagi-Harada (VKH) disease associated with optic disc swelling and serous retinal detachment through a 24-month follow-up period. METHODS: We prospectively investigated 28 eyes of 14 treatment-naïve patients with acute VKH disease associated with optic disc swelling and serous retinal detachment and 30 eyes of 15 normal individuals to compare changes in the CMT and average RNFL thickness. RESULTS: The CMT was significantly lower in the eyes of the VKH group at 12 and 24 months. The RNFL thickness was significantly higher in the eyes of the VKH group at the initial visit and at the 6- and 12-month follow-up visits, but no significant difference was found between the VKH group and control group at the 24-month follow-up visit. CONCLUSION: Significant changes in the CMT and RNFL thickness in the eyes with VKH disease were observed during the 24-month follow-up period. When diagnosing or monitoring diseases including glaucoma and neuro-ophthalmic diseases that affect the retinal thickness in patients with VKH disease, we recommend considering longitudinal changes in the retinal thickness.

Analyses of the ratio of ganglion cell-inner plexiform layer thickness to vessel density according to age in healthy eyes.

PURPOSE: To identify how the inner retinal layer and microvasculature change with age by analyzing the relationships of ganglion cell-inner plexiform layer (GC-IPL) thickness, vessel density (VD), and the ratio of these measurements with age in healthy eyes. METHODS: Participants were divided into five groups according to age. The GC-IPL thickness, VD, and GC-IPL/VD ratio were compared among the groups. Linear regression analyses were performed to identify relationships of GC-IPL/VD ratio with age. RESULTS: The average GC-IPL thicknesses were 84.84 ± 5.28, 84.22 ± 5.30, 85.20 ± 6.29, 83.29 ± 7.06, and 82.26 ± 5.62 µm in the 20s, 30s, 40s, 50s, and 60s age groups, respectively. The VDs were 20.94 ± 1.50, 21.06 ± 1.50, 20.99 ± 1.03, 20.71 ± 0.93, and 19.74 ± 1.73 mm-1 in the 20s, 30s, 40s, 50s, and 60s age groups, respectively. The GC-IPL/VD ratio was 4.05, 4.00, 4.06, 4.02, and 4.17 in each group, respectively, and the ratio of the 60s age group was significantly higher than that of other groups. In linear regression analyses, the GC-IPL/VD ratio was significantly associated with age in the participants aged ≥ 50 years (B = 0.014, P = 0.013), whereas it was not in the participants aged < 50 years (B = 0.003, P = 0.434). CONCLUSIONS: GC-IPL thickness and macular VD showed a tendency to decrease beginning in the 50s age group and the GC-IPL/VD ratio was significantly increased in the 60s age group. Additionally, the GC-IPL/VD ratio was positively associated with age in subjects aged ≥ 50 years, which implies a more pronounced decline over time in VD rather than GC-IPL thickness.

Synthesis and Corrosion Inhibition Potential of Cerium/Tetraethylenepentamine Dithiocarbamate Complex on AA2024-T3 in 3.5% NaCl.

In this work, a cerium/tetraethylenepentamine dithiocarbamate complex was synthesized and evaluated for the corrosion inhibition capability on an AA2024-T3 Al alloy in a 3.5% NaCl medium. The synthesized compounds were characterized via spectroscopic techniques. The corrosion inhibition behaviour of the complex was elucidated by electrochemical measurements and surface analysis techniques. Based on electrochemical test results, the corrosion inhibition efficiency of the complex increases with the immersion time of aluminium alloy in the test solution. The corrosion inhibition reaches 96.80% when the aluminium is immersed in a 3.5% NaCl solution containing a corrosion inhibitor for 120 h. The potentiodynamic polarization test results show that the complex acts as a mixed-type corrosion inhibitor and the passive range is widened. The surface analysis methods reveal that the corrosion inhibition ability of the complex originated from the formation of a protective layer on the Al surface. This film is created from the physisorption and chemisorption of cerium ions and organic parts simultaneously released from the complex molecules.

Effect of Weiss ring on peripapillary retinal nerve fiber layer thickness measurements using SD-OCT.

Spectral-domain optical coherence tomography (SD-OCT) must accurately identify and measure the peripapillary retinal nerve fiber layer (pRNFL) thickness to improve the repeatability and reproducibility, and reduce measurement errors. Because Weiss ring can be located in front of the optic disc, we hypothesized that it may affect pRNFL thickness measurements obtained using SD-OCT. We retrospectively reviewed the medical records of patients with (group W) and without (group N) Weiss ring, observed on OCT fundus image and an RNFL map devised using SD-OCT. Optic disc cube scans (200 × 200) were obtained to measure pRNFL thicknesses (superior, temporal, inferior, nasal, and average) at two consecutive visits. Pearson's correlation coefficient (r), intraclass correlation coefficient (ICC), and coefficient of variation (CV) were calculated. The r and ICC values for the pRNFL thickness measurements at the two visits were lower for group W compared to group N, but statistical significance was reached only for inferior pRNFL thickness. In addition, CV values were greater for group W compared to group N, but the differences were significant only for inferior and average pRNFL thickness measurements (p < 0.001 and p = 0.004, respectively). Weiss ring located near the optic disc can affect pRNFL thickness measurements and repeatability thereof, especially the inferior quadrant and average values. Therefore, it is important to identify the presence of Weiss ring when analyzing pRNFL thickness values.

Retinal nerve fibre layer/ganglion cell-inner plexiform layer thickness ratio in patients with systemic hypertension.

PURPOSE: Acute and chronic hypertension may have different pathophysiological mechanisms in the retina. Here, we compared the retinal nerve fibre layer (RNFL)/ganglion cell-inner plexiform layer (GC-IPL) thickness ratios of patients with 'relieved' severe hypertensive retinopathy (relieved HTNR) and chronic hypertension without retinopathy (chronic HTN) to those of normal controls. METHODS: We performed cross-sectional study. The eyes were divided into the following groups: normal controls (Group A, age ≥50 years; Group D, age <50 years); chronic HTN (Group B, <10 years of HTN; TNHT; Group C, ≥10 years of HTN); and relieved HTNR (previously diagnosed with grade IV HTNR and relieved retinopathy for >1 year; Group E), and the RNFL/GC-IPL thickness ratio was compared among Groups A-C and between Groups D and E. RESULTS: A total of 379 eyes were included in this study. Groups A-E consisted of 145, 59, 63, 60 and 52 eyes, respectively. The RNFL/GC-IPL thickness ratios were 1.161 ± 0.093, 1.158 ± 0.082 and 1.162 ± 0.089 in groups A-C, respectively, and did not showed a statistically difference (p = 0.966). The RNFL/GC-IPL thickness ratio of groups D and E were 1.169 ± 0.080 and 1.221 ± 0.080, respectively, and showed a statistically difference (p = 0.001). CONCLUSIONS: The RNFL/GC-IPL thickness ratios of the chronic HTN group did not show a difference compared with the normal controls. However, relieved HTNR patients showed a higher ratio than the normal controls. Physicians should be aware that acute hypertensive injury could affect the RNFL/GC-IPL thickness ratio.

Bilateral retinal pigment epithelial tears in acute central serous chorioretinopathy without bullous retinal detachment: A case report.

RATIONALE: Several reports have described retinal pigment epithelial (RPE) tears in central serous chorioretinopathy (CSC). However, there have been no reports of spontaneously large RPE tears in acute CSC without bullous retinal detachment (RD). Herein, we report and provide sequential images of a case of bilateral spontaneous large RPE tears in patient with acute CSC without bullous RD. PATIENT CONCERNS: An 88-year-old female patient was admitted with impaired vision in both eyes, which began 10 days prior. The visual acuity was 0.4 and 0.5 in the right and left eye, respectively. She had started taking oral steroids 2 weeks prior for polymyalgia. DIAGNOSIS: Ophthalmologic examinations, including fundus photography, optical coherence tomography, and fluorescence angiography, were performed, and she was diagnosed with steroid-induced acute CSC in both eyes with large pigment epithelial detachment (PED) of approximately 4-disc diameter. Discontinuation of steroids and follow-up ophthalmic examinations were performed. However, a spontaneous large RPE tear occurred in the right eye. INTERVENTIONS: We performed follow-ups more frequently and CSC treatment such as laser photocoagulation, photodynamic therapy, and anti-vascular endothelial growth factor injections were not performed. OUTCOMES: Nine months later, a spontaneous large RPE tear occurred sequentially in the left eye. Her final visual acuity was 0.3 and 0.15 in the right and left eye, respectively. LESSONS: Patients may spontaneously develop large RPE tears in both eyes, despite no treatment for acute CSC with non-bullous RD. Large PED and old age may affect this. Therefore, for a CSC patient with a large PED and advanced age, attention must be paid when determining treatment.

Spent Coffee Grounds as Eco-Friendly Additives for Aluminum-Air Batteries.

A new approach to the recycling of spent coffee grounds is described in which lignin, a chemical component of spent coffee, is used as an electrolyte additive in aluminum-air batteries. The effect of lignin on the performance of aluminum-air batteries has been investigated by weight loss measurement, galvanostatic discharge test, and electrochemical impedance spectroscopy (EIS). The corrosion inhibition efficiency is improved up to 37.3% and fuel efficiency up to 21.7% at 500 ppm of lignin molecules. The chemisorption of lignin molecules on the aluminum surface improves battery performance. Adsorption of lignin molecules onto the aluminum surface is driven by the electrostatic interaction between the lignin's hydroxyl group and the aluminum surface. The mechanism for the performance improvement is explained by the chemisorption behavior of lignin molecules. The adsorption behavior has been investigated by scanning electronic microscopy with energy-dispersive spectroscopy (SEM-EDS), laser scanning microscopy (LSM), atomic force microscopy (AFM), Freundlich adsorption isotherm, Fourier-transform infrared (FT-IR) spectroscopy, and the computational calculation of adsorption energies based on the density functional theory (DFT).

Bilateral optic neuropathy following vincristine chemotherapy: A case report with description of multimodal imaging findings.

RATIONALE: A few cases of optic neuropathy presumed to be caused by vincristine have been reported. However, none described multimodal imaging findings. Here, we report abnormal magnetic resonance imaging (MRI) and optical coherence tomography (OCT) findings in a putative case of vincristine-induced optic neuropathy. PATIENT CONCERNS: A 9-year-old boy with Burkett lymphoma who had had no visual problems noticed blurred vision in both eyes 22 days after the first maintenance therapy for lymphoma; the blurred gradually worsened. At that time, the best-corrected visual acuity was 20/200 and 20/100 in the right and left eyes, respectively. DIAGNOSES: Blood and imaging workup, and cerebrospinal fluid and genetic analyses, were performed; these included fundus photography, OCT, and MRI. We found no plausible cause of the optic neuropathy other than vincristine. INTERVENTIONS: The scheduled chemotherapy was stopped, and the patient was managed with high-dose corticosteroids. However, as there was no improvement, plasma exchange was then performed. OUTCOMES: Three days after the initial examination, the visual acuity in both eyes was only light perception and projection. Signal intensity was abnormally high on 3-dimensional T2-weighted turbo spin echo and T2-weighted MRI images. Optic disc atrophy progressed to "total pallor"; thinning of the ganglion cell-inner plexiform and retinal nerve fiber layers also progressed. The patient was followed up for 7 months but showed no improvement in vision. There were no treatment-related complications. LESSONS: We conclude that vincristine can cause optic neuropathy, and clinicians need to be alert to the possibility of optic neuropathy in any patient prescribed this agent.OCT and MRI may help to diagnose optic neuropathy in pediatric patients. Periodic ophthalmologic examinations, including an OCT scan, may be useful.

Long-term repeatability of peripapillary optical coherence tomography angiography measurements in healthy eyes.

This is a prospective observational study to establish the short- and long-term repeatability of measurements of peripapillary optical coherence tomography angiography (OCTA) parameters in healthy eyes and identify factors affecting long-term repeatability. We enrolled 84 healthy eyes. Participants with a history of any ophthalmic disease (except high myopia) or intraocular surgery were excluded from the study. An experienced examiner performed OCTA using disc-centered 6 × 6 mm scans. All examinations were conducted twice at 5-min intervals at the initial visit and repeated at least 6 months later. For short-term repeatability, the coefficient of variation (CV) was 2.94-4.22% and the intraclass correlation coefficient (ICC) was 0.840-0.934. For long-term repeatability, the CV was 2.73-3.84% and the ICC was 0.737-0.934. Multivariate analyses showed that the axial length (AL) (B = 0.970; p = 0.002) and mean signal strength (SS) (B = - 2.028; p < 0.001) significantly affected long-term repeatability. Measurements of peripapillary OCTA parameters exhibited excellent short-term and good long-term repeatability in healthy individuals. The mean SS and AL affected long-term repeatability and should be considered while interpreting peripapillary OCTA images.

Repeatability of Spectral Domain Optical Coherence Tomography Measurements of Bruch's Membrane Opening-Minimum Rim Width in Epiretinal Membrane Patients with Peripapillary Involvement.

The Bruch's membrane opening-minimum rim width (BMO-MRW) is a recently introduced parameter of the neuroretinal rim. We analyzed the repeatability of spectral-domain optical coherence tomography (SD-OCT) measurements of BMO-MRW in epiretinal membrane (ERM) patients with peripapillary involvement, since the surface around the optic disc is distorted in such patients. BMO-MRW and retinal nerve fiber layer (RNFL) thickness measurements were performed using SD-OCT in prospectively enrolled ERM patients and age-matched healthy control individuals. After two consecutive measurements with a 5 min interval, repeatability was analyzed using the intraclass correlation coefficient (ICC), repeatability coefficient (RC), and coefficient of variation (CV). Fifty-two eyes of 52 ERM patients and 62 eyes of 62 healthy controls were included in the study. The ICCs of the mean BMO-MRW/RNFL thickness measurements were 0.999/0.985 in ERM eyes and 0.999/0.999 in normal eyes, respectively. The RC values of mean BMO-MRW/RNFL thickness measurements were 9.0/6.25 µm in ERM eyes and 4.61/0.92 µm in normal eyes, respectively. The CV values were 0.91% and 1.45% for BMO-MRW and RNFL thickness in ERM eyes, and 0.63% and 0.33% in normal eyes, respectively. In ERM eyes, the RC, CV of average BMO-MRW were 1.9 and 1.4 times greater than those of normal eyes, but 6.8 and 4.4 times greater for average RNFL thickness. BMO-MRW and RNFL thickness showed good repeatability in the diseased eyes with peripapillary involvement and healthy control eyes. Based on the ICC, RC, and CV values, the repeatability of BMO-MRW measurements in peripapillary membrane patients was better than that of RNFL thickness.

Highly Sensitive Electrochemical Aptasensor for Detecting the VEGF165 Tumor Marker with PANI/CNT Nanocomposites.

Sensing targeted tumor markers with high sensitivity provides vital information for the fast diagnosis and treatment of cancer patients. A vascular endothelial growth factor (VEGF165) have recently emerged as a promising biomarker of tumor cells. The electrochemical aptasensor is a promising tool for detecting VEGF165 because of its advantages such as a low cost and quantitative analysis. To produce a sensitive and stable sensor electrode, nanocomposites based on polyaniline (PANI) and carbon nanotube (CNT) have potential, as they provide for easy fabrication, simple synthesis, have a large surface area, and are suitable in biological environments. Here, a label-free electrochemical aptasensor based on nanocomposites of CNT and PANI was prepared for detecting VEGF165 as a tumor marker. The nanocomposite was assembled with immobilized VEGF165 aptamer as a highly sensitive VEGF165 sensor. It exhibited stable and wide linear detection ranges from 0.5 pg/mL to 1 µg/mL, with a limit of detection of 0.4 pg/mL because of the complementary effect of PANI/CNT. The fabricated aptasensor also exhibited good stability in biological conditions, selectivity, and reproducibility after several measurement times after the dissociation process. Thus, it could be applied for the non-invasive determination of VEGF, in biological fluid diagnosis kits, or in an aptamer-based biosensor platform in the near future.

Effect of axial length on peripapillary microvasculature: An optical coherence tomography angiography study.

OBJECTIVE: To investigate the effects of axial length (AL) on the peripapillary microvascular density acquired from optical coherence tomography angiography (OCTA). METHODS: Retrospective observational study. A total of 111 eyes from 111 normal healthy subjects were examined. The subjects were divided into three groups according to the AL: Group 1 (AL: < 24.0 mm; 35 eyes), Group 2 (AL: 24.0-25.99 mm; 37 eyes), and Group 3 (AL: ≥ 26 mm; 39 eyes). Peripapillary OCTA images were acquired using 6× 6 mm angiography scans, and vessel density (VD) and perfusion density (PD) of the superficial capillary plexus were calculated automatically. VD and PD were compared among the three groups according to the distance from the optic disc (inner and outer rings). Linear regression analyses were also performed to identify clinical factors associated with average VD. RESULTS: The average ALs of Groups 1-3 were 23.33± 0.57, 25.05± 0.60, and 27.42± 0.82, respectively. Average VD (P = 0.009) and PD (P = 0.029) in the inner ring increased with increasing AL. However, average VD (P < 0.001) and PD (P < 0.001) in the outer ring decreased with AL increased; the same trends were found for the full areas (VD, p<0.001; PD, p = 0.001). Average VDs in the inner and outer rings were not associated (P = 0.938). CONCLUSIONS: Peripapillary VD and PD were significantly associated with AL. Depending on the distance from the disc, peripapillary VDs and PDs of the inner and outer rings were differentially affected by AL. Physicians should therefore consider the effects of AL in the analyses of peripapillary microvasculature.

Effect of Systemic Hypertension on Peripapillary RNFL Thickness in Patients With Diabetes Without Diabetic Retinopathy.

Type 2 diabetes mellitus (T2DM) and hypertension (HTN) are both relatively common systemic diseases and cause damage to the retina, such as inner retina reduction and microvascular impairment. The purpose of this study was to identify peripapillary retinal nerve fiber layer (pRNFL) damage by diabetic neurodegeneration and the effects of HTN on the pRNFL thickness in patients with T2DM without clinical diabetic retinopathy. Subjects were divided into three groups: healthy control subjects (group 1), patients with T2DM (group 2), and patients with both diabetes and HTN (group 3). The pRNFL thickness was measured using optical coherence tomography and compared among each group. Linear regression analyses were performed to identify factors associated with pRNFL thickness. A total of 325 eyes were included: 143 eyes in the group 1, 126 eyes in group 2, and 56 eyes in group 3. The mean pRNFL thicknesses of each group were 96.1 ± 7.7, 94.4 ± 8.6, and 91.6 ± 9.6 µm, respectively (P = 0.003). In multivariate linear analyses, diabetes duration (ß = -0.236; P = 0.018) and HTN (ß = -3.766; P = 0.008) were significant factors affecting the pRNFL thickness in groups 2 and 3. Additionally, the HTN duration was significantly correlated with pRNFL thickness in group 3 (R 2 = 0.121; P = 0.008). In conclusion, patients with T2DM with HTN showed thinner pRNFL thickness than those with T2DM only. Additionally, the duration of HTN was significantly correlated with pRNFL thickness in patients with both diabetes and HTN.

Integrative analysis of the choroid by quantifying Haller vessel and choriocapillaris parameters in different drusen subtypes.

This study aimed to quantify the Haller vessel and choriocapillaris (CC) parameters in drusen subtypes in nonexudative age-related macular degeneration (AMD) and pachydrusen. Ninety-five eyes of 80 patients and 28 control eyes were categorized into soft drusen, subretinal drusenoid deposit (SDD), soft drusen plus SDD, pachydrusen, and control groups. The diameter, length and intersections of Haller vessels and the total area, size and number of CC flow voids were quantified using en face optical coherence tomography (OCT) or OCT angiography. The pachydrusen group showed the largest Haller vessel area and diameter and shortest total length but similar CC parameters to those in the control group. The soft drusen plus SDD group showed the largest CC flow void area and size, while the Haller parameters were similar to those in the control group. The area and size of the flow voids in the SDD group were smaller than those in the soft drusen plus SDD group. Based on unsupervised machine learning, the eyes were classified into 4 clusters-the control, pachydrusen, soft drusen plus SDD and soft drusen plus SDD groups. Cluster 3 showed a larger diameter and shorter total length of the Haller vessels than cluster 4.

Wide-Field Swept-Source OCT Analysis of Interocular Symmetry of Choroidal Thickness in Subjects with Uncomplicated Pachychoroid.

BACKGROUND: We aimed to study the bilateral choroidal thickness (CT) symmetry and difference in uncomplicated pachychoroid subjects using wide-field swept-source optical coherence tomography (SS-OCT). METHODS: All subjects underwent a wide-field 16-mm one-line scan using SS-OCT. Bilateral CT was measured at, and compared among, the following 12 points: three points at 900-µm intervals from the nasal optic disc margin (nasal peripapillary area), one point at the subfovea, six points at 900-µm intervals from the fovea to the nasal and temporal areas (macular area), and two peripheral points 5400 and 8100 µm from the fovea (peripheral area). RESULTS: There were no statistically significant differences in CT between the right and left eyes in any area (all p > 0.05); they all showed significant positive correlations (all p < 0.01). However, the correlation coefficients (ρ) were smaller for the nasal peripapillary and peripheral areas compared to the macular area. CONCLUSIONS: The CTs in each region were bilaterally symmetrical in subjects with uncomplicated pachychoroid. However, interocular difference in CT increased from the center to the periphery, indicating that the anatomical variation of the nasal peripapillary and peripheral choroid was greater than that of the macula.