Variation of vortex veins at the horizontal watershed in normal eyes.

PURPOSE: To assess the vascular pattern of choroidal vortex veins at the horizontal watershed zone in normal eyes using optical coherence tomography (OCT). METHODS: We retrospectively studied 207 normal eyes of 207 patients whose fellow eyes were diagnosed with unilateral retinal diseases without choroidal involvement. Venous anastomosis between the superior and inferior vortex veins and deviation of the horizontal watershed zone were evaluated using 12 × 12-mm en face OCT images. Central choroidal thickness (CCT) was measured on B-mode OCT images. RESULTS: Vortex vein anastomosis was observed in 92 eyes (44.4%) at the horizontal watershed zone. Superior or inferior deviation of the horizontal watershed was ascertained in 69 eyes (33.3%). The frequency of the anastomosis and deviation did not differ significantly between age groups (P = 0.56 and 0.96, respectively). Mean CCT of all eyes was 221 ± 80 µm. CCT was significantly greater in eyes with anastomosis than in those without (233 ± 73 µm vs 210 ± 83 µm, P < 0.05). However, CCT did not differ significantly between eyes with and without deviation of the horizontal watershed zone (223 ± 74 µm vs 219 ± 82 µm). CONCLUSIONS: Venous anastomosis at the horizontal watershed zone as well as superior or inferior deviation of the zone were frequently observed in normal eyes. CCT was greater in eyes with than in those without anastomosis, suggesting subclinical vortex vein congestion.

Observation of the far peripheral retina of normal eyes by ultra-wide field fluorescein angiography.

PURPOSE: The appearance of the far peripheral retina in normal eyes was observed using an Optos ultra-wide field fluorescein angiography imaging system. METHODS: A cross-sectional study of ultra-wide field pseudocolor and angiography images obtained using the Optos 200Tx. Four different non-vascular and six vascular-associated fluorescence features in far peripheral retina were analyzed. RESULTS: A total of 166 eyes in 83 patients met the inclusion criteria. The mean patient age was 40.78 ± 10.94 years (range: 20-65 years) with a female-to-male ratio of 0.98. Slight cataract were present in 64 eyes (38.55%), low to moderate myopia in 50 eyes (30.12%), and unspecified visual disturbances in 52 eyes (31.33%). Far peripheral retinas were found to have mottled florescent band in 42.17% eyes, ground glass hyperfluorescence in 84.34% eyes, granular hyperfluorescence in 12.65% eyes, local mottled fluorescence in 10.84% eyes, vascular anastomosis with a peripheral avascular area in 36.23% eyes, invisible capillary details in 50.67% eyes, vessels passing through the ora serrata in 16.98% eyes, late-phase slight leakage in 32.53% eyes, angiectasis in 18.67% eyes, and microaneurysm in 34.94% eyes. CONCLUSION: Ultra-wide field fluorescein angiography revealed various fluorescence features in the periphery of normal eyes, providing a basis for interpreting normal and pathological changes in peripheral retina and an important reference for clinical work.

Peripheral retinal fluorescence features of ultra-wide fundus fluorescein angiography in normal fundus eyes / 中华实验眼科杂志

Objective:To analyze the peripheral retinal fluorescence characteristics of normal fundus on ultra-wide field fluorescein angiography (UWFA) images.Methods:A cross-sectional study was conducted.Ninety-five patients (190 eyes) who underwent normal UWFA in Renmin Hospital of Wuhan University from July 2016 to January 2019 were enrolled.There were 94 (49.47%) male eyes and 96 (50.53%) female eyes.Among them, there were 72 (37.89%) mild cataract eyes, 60 (31.58%) moderate and low myopia eyes and 58 (30.53%) subjective blurred vision eyes.The peripheral retinal fluorescence characteristics were divided into vascular-associated feature or non-vascular feature according to whether the retinal vessel involved or not.The subjects were divided into ≤40 years old group and >40 years old group, and the differences in various features between the two groups were compared and analyzed.The study protocol adhered to the Declaration of Helsinki and was approved by an Ethics Committee of Renmin Hospital of Wuhan University (No.WDRY2019-K037). Written informed consent was obtained from each patient prior to any examination.Results:Four non-vascular and five vascular-associated fluorescence features were found in normal peripheral retina.Non-vascular features contained glass hyperfluorescence in 158 (83.16%) eyes, far peripheral retina with mottled florescent band in 82 (43.16%) eyes, granular ground hyperfluorescence in 24 (12.63%) eyes and local mottled fluorescence in 21 (11.05%) eyes.Vascular-associated fluorescence features included peripheral avascular area in 92 (48.42%) eyes, vessels passing through the ora serrata in 66 (34.74%) eyes, microaneurysm in 60 (31.58%) eyes, slight leakage within 10 minutes after angiography in 56 (29.47%) eyes and angiotelectasis in 30 (15.79%) eyes.There were 19.61% (20/102) of eyes with peripheral retinal vessels passing through the ora serrata and 43.10% (44/102) of eyes with microaneurysm and 19.61% (20/102) of eyes with angiotelectasis in >40 years old group, and there were 52.27% (46/88), 18.23% (16/88) and 11.36% (10/88) correspondingly in ≤40 years old group, and the differences were statistically significant ( χ2=22.235, 10.451, 9.259; all at P<0.01). Conclusions:UWFA reveals four non-vascular and five vascular-associated fluorescence characteristics of normal fundus and age might be associated with the distribution of microaneurysm and angiotelectasis.

Inter-relationship between retinal and choroidal vasculatures using optical coherence tomography angiography in normal eyes.

PURPOSE: To quantify vascular and structural macular variables in healthy eyes and to investigate correlations between these variables and age using optical coherence tomography angiography. MATERIALS AND METHODS: A total of 261 eyes of 261 subjects with normal fundus were included. Central macular thickness, ganglion cell layer to inner plexiform layer thickness, outer retina layer thickness, subfoveal choroidal thickness, and choroidal vascularity index were measured using optical coherence tomography. Foveal avascular zone area, vascular density, and flow void area were measured using optical coherence tomography angiography. RESULTS: Vascular density in the superficial capillary plexus was correlated with central macular thickness, ganglion cell layer to inner plexiform layer thickness, and outer retina layer thickness (P < 0.001, P = 0.004, and P < 0.001, respectively). Vascular density in the deep capillary plexus was correlated with central macular thickness and outer retina layer thickness (P = 0.003 and P = 0.001, respectively). Vascular density of choriocapillaris was correlated with vascular density of superficial capillary plexus and deep capillary plexus (P < 0.001 and P = 0.001, respectively). CONCLUSION: Vascular density of choriocapillaris varies with retinal vascular density rather than the structure of choroid using optical coherence tomography angiography. In contrast, retinal vascular density changes as the retinal structure. Our results provide more information about the relationship between retina and choroid.

The quantitative measurements of foveal avascular zone using optical coherence tomography angiography in normal volunteers.

PURPOSE: To provide normative data of foveal avascular zone (FAZ) and thickness. METHODS: In this cross-sectional study both eyes of each normal subject were scanned with optical coherence tomography angiography (OCTA) for foveal superficial and deep avascular zone (FAZ) and central foveal thickness (CFT) and parafoveal thickness (PFT). RESULTS: Out of a total of 224 eyes of 112 volunteers with a mean age of 37.03 (12-67) years, the mean superficial FAZ area was 0.27 mm2, and deep FAZ area was 0.35 mm2 (P < 0.001), with no difference between both eyes. Females had a larger superficial (0.32 ± 0.11 mm2 versus 0.23 ± 0.09 mm2) and deep FAZ (0.40 ± 0.14 mm2 versus 0.31 ± 0.10 mm2) (P < 0.001) than males. By multivariate linear regression analysis, in normal eyes, superficial FAZ area varied significantly with the gender, CFT, and deep FAZ. Deep FAZ varied with the gender and CFT. CONCLUSION: The gender and CFT influence the size of normal superficial and deep FAZ of capillary network.

Multimodal Imaging of the Normal Eye.

Multimodal imaging is the concept of "bundling" images obtained from various imaging modalities, viz., fundus photograph, fundus autofluorescence imaging, infrared (IR) imaging, simultaneous fluorescein and indocyanine angiography, optical coherence tomography (OCT), and, more recently, OCT angiography. Each modality has its pros and cons as well as its limitations. Combination of multiple imaging techniques will overcome their individual weaknesses and give a comprehensive picture. Such approach helps in accurate localization of a lesion and understanding the pathology in posterior segment. It is important to know imaging of normal eye before one starts evaluating pathology. This article describes multimodal imaging modalities in detail and discusses healthy eye features as seen on various imaging modalities mentioned above.

Interleukin 11 expression in the normal canine eye.

OBJECTIVES: The purpose of this study was to characterize the expression of interleukin-11 (IL-11), a cytokine with anti-inflammatory, cytoprotective, and immune-modulating characteristics, in the canine eye. PROCEDURES: Normal canine eyes were collected from clinically healthy dogs that had been euthanized for reasons unrelated to this study. The distribution of IL-11 expression in the different ocular layers was evaluated by immunofluorescence (eight eyes). Expression levels were quantified (based on fluorescence intensity) using pixel density analysis. Primary cell cultures were derived from all three corneal cell layers. IL-11 mRNA expression was assessed in these cultures using quantitative RT-PCR before and after treatment with TGF-ß1, a known inducer of IL-11 expression. IL-11 protein expression was also assessed in the media of these cells by Western blot analysis. RESULTS: IL-11 protein was detected in the corneal epithelium, keratocytes, and the corneal endothelium of the normal canine eyes examined using immunofluorescence. Baseline IL-11 mRNA expression was noted in the corneal epithelium, fibroblasts, and endothelium using quantitative RT-PCR. Treatment of canine corneal cell lines with TGF-ß1 resulted in statistically significant increases in IL-11 expression in the corneal epithelium, endothelial and fibroblast cell lines with strongest induction noted in the fibroblasts and endothelium. CONCLUSION: This is the first description of IL-11 expression in the canine eye. The protein and mRNA appear to be constitutively present throughout all layers of the cornea and are increased by TGF-ß1, a cytokine important in ocular inflammation and disease.

Comparison of Aberrations in Korean Normal Eyes Measured With Two Different Aberrometers

PURPOSE: To compare ocular higher order aberrations measured by two different aberrometers in a sample of normal eyes. METHODS: We included 41 normal eyes of Koreans in this study. Ocular aberration data were obtained through three measurements per eye using Zywave and OPD-Scan devices. Spherical equivalent and higher order aberrations calculated in the central 6 mm zone and expressed as root mean square (RMS) values were analyzed. RESULTS: A comparison of measurements between the Zywave and OPD-Scan devices demonstrated no statistically significant differences in the RMS values of total higher order aberration (p=0.11), but significant differences were detected in the RMS values of total spherical aberration, total coma and total trefoil (p<0.01). CONCLUSIONS: The two different aberrometers that we tested are suitable for taking repeated measurements and are internally consistent, but not interchangeable.

Factors Influencing Optic Disc and Retinal Nerve Fiber Layer Parameters Measured by Optical Coherence Tomography

PURPOSE: To determine the factors influence retinal nerve fiber layer (RNFL) and optic nerve head (ONH) parameters measured by Stratus optical coherence tomography (OCT). METHODS: Topographic RNFL thickness and optic disc parameters of 129 healthy Korean subjects of aged 14 to 87 were measured using the fast retinal nerve fiber layer thickness and fast optic disk algorithms of Stratus OCT. One eye of each subject was randomly selected for statistical analysis. Using multiple linear regression, the effect of optic disc area, age, refractive error, and zone beta on each parameter was analyzed. RESULTS: Large discs had large horizontal integrated rim width (HIRW), cup area, rim area, C/D area ratio, and vertical C/D ratio. The thickness of average, superior, inferior, and nasal quadrant RNFL increased significantly with an increase in optic disc area. Average and superior quadrant RNFL thickness, and HIRW decreased with age. Refractive error showed a correlation with the vertical integrated rim area, horizontal C/D ratio, and temporal quadrant RNFL thickness. Gender and zone beta had no statistically significant influence on ONH and RNFL parameters. CONCLUSIONS: This study shows that optic disc size affects most RNFL thickness and ONH parameters. Because of the relationships revealed in this study, optic disc area in addition to age should be considered when the Stratus OCT RNFL thickness and ONH parameters are interpreted.