Comparative Evaluation of Foveal Avascular Zone on Two Optical Coherence Tomography Angiography Devices.

SIGNIFICANCE: This study compares foveal avascular zone (FAZ) geometry in healthy eyes as imaged by two commercially available optical coherence tomography angiography (OCTA) devices. Foveal avascular zone measurements are repeatable and reproducible with each OCTA device, but interdevice agreement was poor. We provide conversion factors between devices. PURPOSE: The purpose of this study was to perform comparative evaluation of FAZ geometry in healthy eyes as imaged by two commercially available OCTA devices. METHODS: Ninety-six eyes of 48 healthy subjects were imaged prospectively on each of two OCTA devices (DRI-OCT [Topcon Corporation, Tokyo, Japan]; Cirrus 5000 [Carl Zeiss Meditec Inc., Dublin, CA]). The FAZ was evaluated in the superficial capillary plexus layer of 6 × 6-mm foveal scans by two masked observers. Intraobserver and interobserver agreement was determined using intraclass correlation by using linear mixed models and Bland-Altman plots. K-means clustering was used to provide conversion values between two devices. Foveal avascular zone acircularity was calculated using scans from each device and compared. RESULTS: The intraobserver repeatability for DRI-OCT was 0.95 (95% confidence interval [CI], 0.90 to 0.98) for observer A and 0.92 (95% CI, 0.83 to 0.96) for observer B. Intraobserver repeatability for Cirrus 5000 was 0.988 (95% CI, 0.972 to 0.995) for observer A and 0.993 (95% CI, 0.983 to 0.997) for observer B. The interobserver variability between observers A and B for DRI-OCT was 0.87 (0.73 to 0.94) and for Cirrus 5000 was 0.984 (95% CI, 0.964 to 0.993). Poor interdevice agreement (0.205 [95% CI, -0.202 to 0.554]) was noted, and conversion formulas were devised to convert FAZ area measurements from one device to another. No significant correlation was found when comparing FAZ acircularity indices between devices (P = .39). CONCLUSIONS: Repeatable and reproducible FAZ area measurements were obtained with each respective OCTA device, but interdevice agreement was poor, yet quantifiable and systematic with calculable conversion factors between devices.

Evaluation of Lag of Accommodation with Full-Field Diffusion Optics Technology™ (DOT) Contrast Management Spectacle Lenses in Emmetropic Children.

Purpose: To evaluate the impact on the lag of accommodation (LOA) in emmetropic children after short-term wear of full-field Diffusion Optics TechnologyTM (DOT) spectacle lenses, designed to modulate retinal contrast to control myopia progression. Patients and Methods: This was a single-visit, prospective, randomized, subject-masked study of emmetropes (ametropes ±1.00D or less in each meridian) with no history of myopia control treatment. Unaided logMAR visual acuity was measured, and ocular dominance was determined using the sighting method. In a randomized order, participants wore plano full-field contrast management (DOT) spectacles (no clear central aperture) or control spectacles (standard single vision spectacle lenses). Each participant was given 5 minutes for adaptation to the respective lenses before open field autorefraction measurements were taken at 6 meters and 40 cm. Ten measurements were taken for each eye. Data were evaluated from the right eye and the dominant eye separately. Results: A total of 30 participants (20 females and 10 males) with a mean age of 10.4 ± 2.8 (7 to 17) years completed the study. There was no significant difference in right eye mean LOA with contrast management spectacles 0.57 ± 0.39D versus control spectacles 0.62 ± 0.34D; Wilcoxon test, p = 0.37. For dominant eyes, LOA values were 0.60 ± 0.40D and 0.68 ± 0.33D with contrast management spectacles and control spectacles, respectively (p = 0.14). Additionally, no significant difference was observed in mean LOA between males and females or between age groups (7-11 years vs 12-17 years) for either right or dominant eyes with contrast management or control spectacles (all p > 0.05). Conclusion: Full-field contrast management spectacle lenses had no significant effect on LOA compared to standard single vision spectacle lenses, indicating no differential impact on accommodative response over the short period of lens wear tested.

Choroidal Vascularity Map in Unilateral Central Serous Chorioretinopathy: A Comparison with Fellow and Healthy Eyes.

BACKGROUND: To map the choroidal vascularity index and compare two eyes in patients with unilateral central serous chorioretinopathy (CSCR). METHODS: This was a retrospective, observational study performed in patients with unilateral CSCR. Choroidal thickness (CT) and Choroidal vascularity index (CVI) were measured and mapped in various zones according to the early treatment diabetic retinopathy (ETDRS) grid. RESULTS: A total of 20 CSCR patients (20 study and 20 fellow eyes) were included in the study. Outer nasal region CT was seen to be significantly lower than central CT (p = 0.042) and inner nasal CT (p = 0.007); outer ring CT was significantly less than central (p = 0.04) and inner ring (p = 0.01) CT in CSCR eyes. On potting all the CVI values against the corresponding CT values, a positive correlation was seen in CSCR eyes (r = 0.54, p < 0.01), which was slightly weaker in fellow eyes (r = 0.3, p < 0.01) and a negative correlation was seen in healthy eyes (r = -0.262, p < 0.01). CONCLUSIONS: Correlation between CVI and CT was altered in CSCR eyes as compared to fellow and normal eyes with increasing CVI towards the center of the macula and superiorly in CSCR eyes.

Evaluation of Choroidal Layer Thickness in Central Serous Chorioretinopathy.

PURPOSE: To evaluate medium and large choroidal vessel layer thickness (MCVT and LCVT, respectively) in eyes with acute and chronic central serous chorioretinopathy (CSC) in comparison with age-matched controls. METHODS: The study included 96 eyes of 96 patients with CSC, including 53 eyes with acute CSC, 43 eyes with chronic CSC, and 30 eyes of 30 age-matched normal subjects. Manual measurements of subfoveal choroidal thickness (SFCT), MCVT, and LCVT at subfoveal and 750 µm nasal and temporal to the fovea locations were made on enhanced depth imaging optical coherence tomography (EDI-OCT) of the macula in all subjects using ImageJ software (National Institutes of Health, Bethesda, MD, USA). RESULTS: SFCT in acute CSC was significantly larger than that in healthy eyes (P = 0.0001). SFCT in acute CSC did not differ significantly from that in chronic CSC eyes. Subfoveal LCVT and MCVT in acute CSC eyes were greater than those in healthy eyes (P = 0.02 and P = 0.03, respectively). Mean SFCT and MCVT in chronic CSC eyes were significantly larger than those in control eyes (P = 0.01 and P = 0.04, respectively). No significant difference in LCVT was observed between chronic and control eyes. CONCLUSION: Choroidal vasculature is altered in both acute and chronic CSC. SFCT, MCVT, and LCVT are higher in eyes with acute CSC. The thickening of medium choroidal vessels is still detectable in chronic CSC compared to control eyes.

Comparison of choroidal vessel thickness in children and adult eyes by enhanced-depth imaging optical coherence tomography imaging.

AIM: To evaluate choroidal thickness, medium choroidal vessel thickness (MCVT) and large choroidal vessel thickness (LCVT) in normal children and adult subjects. METHODS: Manual measurements of subfoveal choroidal thickness (SFCT), MCVT and LCVT at subfoveal and 750 µm nasal and temporal to fovea locations were completed on enhanced-depth imaging optical coherence tomography (EDI-OCT) scans of normal children and adult subjects. RESULTS: Fifty adult and fifty-seven child subjects were included in the study (including 80 adult and 103 child eyes). Mean (±SD) SFCT of adult and children eyes in the study was 309.3±95.7 µm and 279.3±50.4 µm respectively. SFCT and subfoveal MCVT in adult eyes were significantly more than children (P=0.01 and P≤0.0001 respectively). CONCLUSION: There is choroidal thickening with associated thickening of medium choroidal vessels in adults, suggesting that there is alteration in choroidal vasculature with ageing.

In vivo evaluation of retinal ganglion cells degeneration in eyes with branch retinal vein occlusion.

PURPOSE: To analyse the topographic changes in retinal ganglion cells (RGCs) in eyes with unilateral naive branch retinal vein occlusion (BRVO) in comparison to normal fellow eyes and to healthy control eyes. METHODS: We performed a retrospective analysis of 66 eyes (33 subjects) with naive unilateral BRVO who underwent spectral-domain optical coherence tomography using Cirrus HD-OCT. We also included 67 eyes of 48 age-matched healthy volunteers as control group. Average, minimum and sectoral macular ganglion cell-inner plexiform layer (GCIPL) thickness, macular retinal nerve fibre layer (RNFL) thickness and outer retinal thickness were collected. Comparison of the GCIPL, RNFL and outer retinal thicknesses among study eyes, normal fellow eyes and control groups was performed. RESULTS: The average and minimum macular GCIPL thicknesses were constantly and diffusely reduced in BRVO compared with normal fellow eyes and healthy controls (p<0.001 for each GCIPL sector). The average macular RNFL thickness was reduced in BRVO eyes compared with normal fellow eyes (p=0.01) and tended to be lower than controls (p=0.07). The minimum RNFL thickness in eyes with BRVO was significantly reduced when compared with fellow eyes (p<0.001) and control eyes (p<0.001). The average outer retina thickness was thicker in BRVO eyes compared with both fellow eyes (p<0.001) and controls (p<0.001). CONCLUSIONS: A significant reduction of the macular GCIPL and RNFL thicknesses was observed in eyes with BRVO. This finding is suggestive of RGCs degeneration; the neuroprotective effect of current therapeutic options might be an important consideration when evaluating treatment strategies and prognosticating visual outcome in BRVO eyes.