Optic Disc Rotation Research Articles

Analysis of the relationship between axial length, optic disc morphology, and regional variations in retinal vessel density in young adults with healthy eyes.

To investigate the relationship between optic disc morphology, axial length, and regional distribution of retinal vessels in healthy eyes of young adults. Nine hundred and two healthy eyes were enrolled in this university-based, cross-sectional study. Spectral-domain optical coherence tomography angiography was used to measure the parapapillary retinal vessel density. We automated the process of calculating optic disc tilt and rotation by using a program written in Python. Relationships between optic disc rotation, optic disc tilt, parapapillary vessel density, and other ocular parameters were analyzed using regression models. As axial length increased, optic disc morphology became more tilted and rotated inferiorly. The superficial vessel density (SVD) and radial peripapillary capillary density (RPCD) gradually decreased in all regions except for the temporal quadrant. Increased temporal SVD (OR [95% CI] = 1.081 [1.039, 1.124], p < 0.001), reduced nasal SVD (OR [95% CI] = 0.898 [0.861, 0.937], p < 0.01), and short relative lens position (OR [95% CI] = 0.126 [0.032, 0.495], p = 0.003) were significantly associated with the presence of a tilted optic disc. Inferior disc rotation was associated with decreased superior deep vessel density (DVD) and increased inferior DVD and temporal DVD after adjusting for sex and axial length. The tilted and rotated optic discs were associated with the distribution of SVD and DVD, respectively. We should fully consider the influence of optic disc morphology on parapapillary vessel density in eyes with myopia.

Optic disc tilt and rotation effects on positions of superotemporal and inferotemporal retinal nerve fibre layer peaks in myopic Caucasians

ABSTRACT Clinical relevance In myopic eyes, the optic disc may become tilted and rotated, making glaucoma diagnosis more difficult. Background To determine the presence of tilted optic disc, the degree of optic disc rotation, and their effects on the angular location of superotemporal and inferotemporal retinal nerve fibre layer (RNFL) peaks in healthy myopic Caucasians. Methods Non-glaucomatous healthy myopic Caucasian eyes with an axial length > 24 mm were evaluated. ImageJ was used to quantify optic disc tilt and torsion on red-free fundus photography. The RNFL was scanned using spectral-domain optical coherence tomography. The angle of the superotemporal and inferotemporal peaks with the vertical-horizontal meridian was measured. Results Fifty-four eyes of 54 individuals were evaluated. The axial length was correlated with the angular location for both the superotemporal (r = −0.549, p < 0.001) and inferotemporal (r = −0.415, p = 0.002) RNFL peaks; they were placed more temporally in eyes with higher axial lengths. For each 1 mm increase in axial length, the angle between the superotemporal peak and the temporal horizontal meridian decreased by 3.976°, and the angle between the inferotemporal apex and the temporal horizontal meridian decreased by 3.028°. The angle between the inferotemporal peak and the temporal horizontal meridian decreased by 0.231° for each 1° increase in optical disc torsion (R2 = 0.09 Regression coefficient = −0.231, p = 0.027). Conclusions The temporal shift of superior and inferior peaks, the thickening of temporal and nasal RNFL, the presence of tilted optic disc, and optic disc rotation may cause misinterpretation of the RNFL in myopic Caucasians. When evaluating peripapillary RNFL thickness in myopic individuals, it would be better to consider these to avoid misinterpretation.

Comparison of Optic Disc Ovality Index and Rotation Angle Measurements in Myopic Eyes Using Photography and OCT Based Techniques.

PurposeTo compare optic nerve head (ONH) ovality index and rotation angle measurements based on semi-automated delineation of the clinical ONH margin derived from photographs and automated BMO configuration derived from optical coherence tomography (OCT) images in healthy and glaucomatous eyes with high-, mild- and no axial myopia.MethodsOne hundred seventy-five healthy and glaucomatous eyes of 146 study participants enrolled in the Diagnostic Innovations in Glaucoma Study (DIGS) with optic disc photographs and Spectralis OCT ONH scans acquired on the same day were stratified by level of axial myopia (non-myopic [n = 56, axial length (AL) <24 mm], mild-myopic [n = 58, AL 24–26 mm] and high-myopic [n = 32, AL >26 mm]. The clinical disc margin of each photograph was manually annotated, and semi-automated measurements were recorded of the ovality index and rotation angle based on a best-fit ellipse generated using ImageJ software. These semi-automated photograph-based measurements were compared to ovality index and rotation angle generated from custom automated BMO-based analysis using segmented OCT ONH volumes. R2 values from linear mixed effects models were used to describe the associations between semi-automated, photograph-based and automated OCT-based measurements.ResultsAverage (95% CI) axial length was 23.3 (23.0, 23.3) mm, 24.8 (24.7, 25.0) mm and 26.8 (26.6, 27.0) mm in non-myopic, mild-myopic and high-myopic eyes, respectively (ANOVA, p ≤ 0.001 for all). The R2 association (95% CI) between semi-automated photograph-based and automated OCT-based assessment of ONH OI for all eyes was [0.26 (0.16, 0.36); p < 0.001]. This association was weakest in non-myopic eyes [0.09 (0.01, 0.26); p = 0.02], followed by mild-myopic eyes [0.13 (0.02, 0.29); p = 0.004] and strongest in high-myopic eyes [0.40 (0.19, 0.60); p < 0.001]. No significant associations were found between photography- and OCT-based assessment of rotation angle with R2 values ranging from 0.00 (0.00, 0.08) in non-myopic eyes to 0.03 (0.00, 0.21) in high-myopic eyes (all associations p ≥ 0.33).ConclusionsAgreement between photograph-based and automated OCT-based ONH morphology measurements is limited, suggesting that these methods cannot be used interchangeably for characterizing myopic changes in the ONH.

Morphological parameters of the posterior pole in a high myopia population aged over 40 years: a 10-year follow-up study

Objective To study the long-term changes of the morphological parameters of the posterior pole in highly myopic patients over 40 years old in Chinese natural population. Methods A population-based follow-up study. The study included 71 patients (27 males, 44 females; 110 eyes) with high myopia who completed the Beijing Eye Study in 2001 and 2011 and had assessable color fundus photographs. The age of the patients in 2011 was 56.2±9.5 years old. According to the definition of pathological myopia by the meta-analysis of the Pathological Myopia Research Group, the fundus photos in 2001 were interpreted, and 110 eyes were divided into groups of simple high myopia (79 eyes) and pathological myopia (31 eyes). The morphological parameters during the 2 follow-up visits in 2001 and 2011 were measured in the color fundus photos, including optic disc tilt ratio, optic disc rotation degree, β zone area, disc-fovea distance, disc-outer β zone border distance, fovea-outer β zone border distance, and vertical distance between temporal arterial arcades, and compared in all the subjects, patients with simple high myopia and patients with pathological myopia. Correlations between the 10-year changes of these parameters and other parameters were analyzed using multiple linear regression analysis. Results In all subjects, the incidence of optic disc tilt and rotation was 41.1% (44/107) and 63.3% (68/107), respectively. The optic disc tilt ratio in 2001 and 2011 was 1.34±0.31 and 1.34±0.33, respectively. The optic disc rotation degree was 30.4±26.3° and 30.0±25.3 in 2001 and 2011, respectively. The differences in optic disc tilt ratio (Z=-0.317, P>0.05) and optic disc rotation degree (t=0.159, P>0.05) were not statistically significant. The β zone area [1.34 (0.45,3.73)mm2, Z=-7.295, P<0.05], disc-fovea distance [(5.18±0.54)mm, t=-3.523, P<0.05], and disc-outer β zone border distance [1.55 (0.24,2.16)mm, Z=-6.825, P<0.05] in 2011 were significantly increased compared to those in 2001 [1.05 (0.23,1.88)mm2, 5.08±0.43, 1.39 (0.77,1.93)mm]. There was no statistically significant difference in the vertical distance between temporal arterial arcades (Z=-1.858, P>0.05). The fovea-outer β zone border distance in the simple high myopia group in 2011 was significantly shorter than that in 2001 (Z=-3.221, P<0.05), while there was no significant change in this parameter in the pathological myopia group (t=0.655, P<0.05). In multivariate analysis, larger β zone area was significantly correlated with longer corneal curvature (r=0.462, P<0.05) and longer axial length (P<0.05). Longer disc-fovea distance was significantly correlated with lower best corrected visual acuity (r=0.348, P<0.05) and longer axial length (P<0.05). Similarly, longer disc-outer β zone border distance was related to lower best corrected visual acuity (r=0.538, P<0.05) and longer axial length (P<0.05). In addition, the progression of myopic maculopathy (Z=-3.425, P<0.05) and the progression from simple high myopia to pathological myopia (Z=-2.911, P<0.05) were both related to enlargement of the β zone. Conclusion For patients with high myopia aged over 40 years, the optic disc morphology is relatively stable, while the disc-fovea distance and β zone area will continue to increase with the progression of myopia. This may be due to the elongation of axial length. Enlargement of the β zone may be a predictor for the progression of myopic maculopathy. (Chin J Ophthalmol, 2021, 57:908-915).

Research advance in optic disc tilt and rotation in high myopia and its implications for glaucoma and visual field defects.

High myopia is of worldwide concern due to its high prevalence, and myopia is an independent risk factor for glaucoma. The purpose of this paper is to review the mechanism and clinical manifestations of optic disc tilt and rotation in high myopia and its relationship with glaucoma, to provide clues for monitoring fundus changes in high myopia and the early diagnosis of high myopia with glaucoma.

Optic disc morphology and peripapillary atrophic changes in diabetic children and adults without diabetic retinopathy or visual impairment.

PurposeTo investigate the changes in optic disc morphology and peripapillary atrophy (PPA) in diabetic children and adults without diabetic retinopathy (DR) or visual impairment (VI).MethodsThis cross‐sectional study included two groups of subjects. One group included 91 children with type 1 diabetes mellitus (T1DM) and 86 healthy children, and the other group included 444 adults with T2DM and 442 healthy controls. The optic disc parameters including major and minor axis lengths, optic disc ovality (ODO), optic disc tilt, optic disc area and β‐PPA area were analysed in all subjects. Optic disc rotation and the Bergmeister papilla were analysed only in children. Patients with diabetes and healthy controls were compared in each group of the study population.ResultsIn both groups, patients with diabetes and healthy controls were matched for age, sex and axial length (AL). Among the children, β‐PPA area was significantly smaller in those with diabetes (0.29 ± 0.43 mm2) than in the healthy controls (0.46 ± 0.58 mm2, p < 0.05). Multiple linear regression analysis showed that diagnosis of DM was negatively associated with β‐PPA area. Longer AL and higher body mass index (BMI) were positively associated with β‐PPA area. Among adults, ODO was significantly larger in those with diabetes (1.14 ± 0.09) than in healthy controls (1.12 ± 0.06, p < 0.05). Multiple linear regression analysis showed that the BMI and DM were potential risk factors affecting ODO.ConclusionHyperglycaemia had different effects on the optic disc in children and adults. Unlike in healthy controls, hyperglycaemia had an impact on the peripapillary tissue in children and on optic disc shape in adults before DR and VI development.

The influence of axial myopia on optic disc characteristics of glaucoma eyes

This study characterizes differences in glaucomatous eyes with and without high axial myopia using custom automated analysis of OCT images. 452 eyes of 277 glaucoma patients were stratified into non (n = 145 eyes), mild (n = 214 eyes), and high axial myopia (axial length (AL) > 26 mm, n = 93 eyes). Optic disc ovality index, tilt and rotation angle of Bruch´s membrane opening (BMO) and peripapillary choroidal thickness (PCT) were calculated using automated and deep learning strategies. High myopic optic discs were more oval and had larger BMO tilt than mild and non-myopic discs (both p < 0.001). Mean PCT was thinnest in high myopic eyes followed by mild and non-myopic eyes (p < 0.001). BMO rotation angle, global retinal nerve fiber layer (RNFL) thickness and BMO-minimum rim width (MRW) were similar among groups. Temporal RNFL was thicker and supranasal BMO-MRW was thinner in high myopic eyes. BMO tilt and PCT showed moderate and temporal RNFL and nasal BMO-MRW showed weak but significant associations with AL in multivariable analyses (all p < 0.05). Large BMO tilt angle and thin PCT are characteristics of highly myopic discs and were not associated with severity of glaucoma. Caution should be exercised when using sectoral BMO-MRW and RNFL thickness for glaucoma management decisions in myopic eyes.

A case of tractional retinal detachment associated with congenital retinal vascular hypoplasia in the superotemporal quadrant treated by vitreous surgery

BackgroundHere we report a case of traction retinal detachment (TRD) associated with congenital retinal vascular hypoplasia localized in the superotemporal quadrant that was treated with vitrectomy.Case presentationsA 58 year-old female presented with a gradual decrease of visual acuity (VA) and distorted vision in her left eye. She had a past history of amblyopia in her left eye from early childhood, and a previous examination performed at a nearby hospital revealed that the corrected visual acuity (VA) in that eye was 0.15. Upon initial examination, no abnormal findings were observed in her right eye, yet optic-disc traction and macular rotation with a folded TRD extending superotemporally from the macular region was observed in her left eye. Fluorescein fundus angiography showed a retinal nonperfused area localized in the superotemporal quadrant surrounded by a retinal avascular area. The optic disc in her left eye was smaller than that in her right eye. Vitrectomy was performed to remove the proliferative membrane and created an artificial posterior vitreous detachment (PVD). Following surgery, the patient’s corrected VA improved from 0.04 to 0.1.ConclusionsThe present case was likely to be TRD caused by PVD in the presence of localized congenital retinal vascular hypoplasia secondary to optic-disc hypoplasia.

Association between morphological characteristics of the optic disc and other anatomical features of the fundus in highly myopic eyes

To investigate associated factors with optic disc characteristics in high myopia patients. According to the meta-analysis of pathologic myopia study, patients were divided into groups from categories 1 (C1) to C4. The diameters, tilt ratio, and rotation degree of optic disc, and the diameters of parapapillary atrophy were measured among other morphometric variables. Totally 147 eyes (84 patients) were included. Longer horizontal optic disc diameter was associated with smaller tilt ratio (p < 0.001, unstandardized regression coefficient B: -0.59), greater rotation degree (p < 0.001, B: 0.01), and longer horizontal delta zone diameter (p < 0.001, B: 0.09). Longer vertical optic disc diameter was associated with smaller rotation degree (p < 0.001, B: 0.01), longer vertical delta zone diameter (p < 0.001, B: 0.16), and longer disc-fovea distance (DFD; p < 0.024, B: 0.14). Generally, the horizontal optic disc diameter of C3 and C4 groups was smaller than C1 and C2, while vertical diameter and tilt ratio was greater than in C1 and C2. After setting axial length (AL) as an independent variable, horizontal diameters and tilt ratio still showed significant differences, while vertical diameters did not show significant differences. Axial elongation was associated with an increase of vertical optic disc diameter that was correlated with an reduction of optic disc rotation degree. By contrast, horizontal optic disc diameter elongation was correlated with an reduction of optic disc tilt ratio and an increase of optic disc rotation degree, which was independent of axial elongation.

Early transient intraocular pressure spike after cataract surgery in highly myopic cataract eyes and associated risk factors

PurposeTo investigate the incidence of the early transient intraocular pressure (IOP) spike after cataract surgery in eyes with highly myopic cataract (HMC) and associated risk factors.MethodsConsecutive patients treated with phacoemulsification...

Fixation Characteristics in Highly Myopic Eyes: the Shanghai High Myopia Study

We enrolled 500 highly myopic eyes and 50 controls in this hospital-based prospective cohort study. The fixation ellipse angle and area in terms of the bivariate contour ellipse area (BCEA) were measured with Macular Integrity Assessment microperimetry. Optic disc tilt and rotation were evaluated with retinal images. The associations between fixation and optic disc changes were assessed. Both 63% and 95% BCEA correlated positively with axial length (AL) (both r = 0.230, P = 0.001) in highly myopic group, and were significantly higher than the control group (both P < 0.001). The direction of fixation ellipse presented clockwise rotation in the right eyes and anti-clockwise rotation in the left eyes with the increase of AL in highly myopic group (AL ≥30 vs <30 mm: OD 76.12 ± 51.17°: vs 90.60° ± 51.28°, P = 0.029; OS 94.73 ± 57.45° vs 87.82 ± 55.15°, P = 0.371). The angle between the long axis of the fixation ellipse and the long axis of the optic disc (AngleF−D) distributed in various directions: 0–30° (34.6% almost parallel) ≈60–90° (34.4% almost vertical) >30–60° (31% oblique). AngleF−D increased slightly with the AL (r = 0.105, P = 0.024). In highly myopic eyes, fixation stability decreased with the AL, and superior rotation of the fixation ellipse increased with AL. The long axis of fixation ellipse and the long axis of optic disc became less parallel to each other with increasing AL. Our data may provide clues for improvement of fixation evaluation designs of biometric instruments.

Interocular Symmetry of Fixation, Optic Disc, and Corneal Astigmatism in Bilateral High Myopia: The Shanghai High Myopia Study.

PurposeWe investigate the interocular symmetry of fixation, optic disc, and corneal astigmatism in bilateral high myopia, and evaluate the predictive relationships between them.MethodsWe enrolled 202 cases with bilateral high myopia. Fixation, in terms of the bivariate contour ellipse area (BCEA), was evaluated with the Macular Integrity Assessment microperimetry. Optic disc features, including orientation, tilt, and rotation, were evaluated with ultrawide-field retinal photographs. Corneal topography was performed with Pentacam. Interocular symmetry of fixation, optic disc, and corneal astigmatism was assessed, and the predictive relationships between these parameters were investigated.ResultsAxial length differences between the two eyes were: ≥0 to ≤1 mm, 67.8%; 1 to ≤2 mm, 20.3%; 2 to ≤3 mm, 9.4%; and >3 mm, 2.5%. Axial length, 95% BCEA, and magnitude of corneal astigmatism showed good interocular symmetry, whereas the optic disc tilt, rotation, and axis of corneal astigmatism (mirror axes) showed less symmetry (all P < 0.05). No interocular symmetry was observed in the direction of the fixation ellipse. In both eyes, the corneal steep meridian more often was consistent with the optic disc orientation than inconsistent (right eye [OD], P < 0.001; left eye [OS], P = 0.029).ConclusionsAs different parameters presented different degrees of symmetry, cautions are needed when including both eyes or only one lateral eye in cases of bilateral high myopia for clinical investigations. The optic disc orientation, to some extent, may indicate the steep meridian of the cornea.Translational RelevanceOur study provided evidences for selection of eye laterality in clinical investigations of highly myopic eyes.

The relationship between optic nerve head deformation and visual field defects in myopic eyes with primary open-angle glaucoma.

PurposeTo investigate the relationship between the morphologic features of myopic optic nerve head (ONH) and visual field (VF) defects in myopic subjects with primary open-angle glaucoma (POAG) by intraindividual comparison.MethodsMyopic POAG subjects with unilateral glaucomatous VF defect were recruited. The morphologic features of myopic ONH, including optic disc tilt, optic disc rotation, and β-zone parapapillary atrophy (PPA) were measured from color fundus photographs. The comparisons were performed between the eyes with VF defects and the contralateral eyes without VF defects. Logistic regression analysis was performed to investigate the relationship between various ocular parameters and the presence of VF defects.ResultsWe retrospectively included 100 eyes of 50 myopic POAG subjects. (Mean age: 50.1 ± 10.0 years). The tilt ratio was similar between the paired eyes. The degree of optic disc rotation (12.96 ± 7.21°) in eyes with VF defects were statistically greater than the contralateral eyes (6.86 ± 4.30°; P < 0.001) without VF defect. The β-zone PPA-to-disc area ratio was significantly greater in eyes with VF defects than the contralateral eyes (P = 0.024) without VF defect. In multivariate logistic regression analysis, the greater degree of optic disc rotation was significantly associated with the presence of VF defects (P < 0.001). However, tilt ratio, β-zone PPA-to-disc area ratio, refractive error, and axial length were not associated with the presence of VF defects.ConclusionsAmong the morphologic features of myopic ONH, only the greater degree of the optic disc rotation was associated with the presence of VF defects in myopic subjects with POAG.

Parapapillary Beta Zone and Gamma Zone in a Healthy Population: The Beijing Eye Study 2011.

To assess prevalence and size of the parapapillary beta zone and gamma zone in a healthy population. Within the population-based Beijing Eye Study, individuals without retinal or optic nerve disease were selected. Using optical coherence tomography (OCT), we measured the parapapillary beta zone (defined by presence of Bruch's membrane and absence of RPE) and gamma zone (region between Bruch's membrane end and optic disc border). The study included 723 individuals (mean age: 59.5 ± 7.6 years; range: 50-90 years). The beta zone was detected in 525 eyes (72.6%; 95% confidence interval [CI]: 69.4, 75.9). A larger maximum width of the beta zone (mean: 253 ± 225 μm) was associated (multivariate analysis; regression coefficient r2: 0.36) with older age (P < 0.001; standardized regression coefficient beta: 0.28), thinner temporal parapapillary choroidal thickness (P < 0.001; beta: -0.21), longer axial length (P < 0.001; beta: 0.14), longer vertical Bruch's membrane opening (BMO) length (P < 0.001; beta: 0.32), shorter horizontal BMO length (P = 0.003; beta: -0.12), and more pronounced vertical optic disc rotation of (P < 0.001; beta: 0.15). The gamma zone was detected in 190 eyes (26.3 ± 1.6%; 95% CI: 23.1, 29.5). A larger maximal width of the gamma zone (mean: 86 ± 187 μm) was (r2: 0.49) associated with longer axial length (P < 0.001; beta: 0.46), thinner central corneal thickness (P < 0.001; beta: 0.10), thinner temporal parapapillary choroidal thickness (P < 0.001; beta: -0.11), longer vertical (P < 0.001; beta: 0.15), and horizontal (P = 0.02; beta: 0.08) BMO length, and more pronounced vertical rotation of optic disc (P < 0.001; beta: 0.32). As measured by OCT in this healthy adult Chinese population, the gamma zone was mainly associated with longer axial length but not with age, while the beta zone was correlated mainly with older age and also with axial length. Both zones were largest in the temporal parapapillary region and smallest in the nasal region.

Optic Disc Features in Highly Myopic Eyes: The ZOC-BHVI High Myopia Cohort Study.

Some studies reported that optic disc tilt and rotation might be risk factors for the susceptibility of high myopic eyes to develop glaucoma. However, data regarding optic disc manifestations in high myopia participants are few. It is crucial to characterize the features of optic disc manifestations among high myopes. To describe optic disc characteristics of Chinese highly myopic eyes and to investigate associated factors. This cross-sectional, observational study included 890 Chinese with bilateral high myopia (defined as ≤-6.00 diopters spherical power) in 2012. All subjects underwent cycloplegic autorefraction, ocular biometry, and fundus photography. The optic disc tilt ratio, degree of rotation, and β-zone peripapillary atrophy area were measured from the 45°optic disc-centered fundus photographs. Optic disc tilt was defined as optic disc tilt ratio, the ratio of maximum to minimum diameter of optic disc, exceeding 1.3. The definition of optic disc rotation was using optic disc rotation degree, the angle from long diameter and the vertical meridian, of >15°. Among 890 participants, 2 were excluded by ungradable optic disc-centered fundus photographs. In the 888 studied right eyes, the mean spherical power was -9.36 ± 3.46 diopters with a mean axial length of 27.51 ± 1.63 mm. The proportion of optic disc tilting, rotation, and β-zone peripapillary atrophy were 81.2%, 48.3%, and 92.8%, respectively. The mean ratio of optic disc tilting and rotation degree was 1.78 ± 0.53 and 21.08 ± 19.91°; the mean area of β-zone peripapillary atrophy/optic disc head was 1.11 ± 1.22. A multiple linear regression showed that older age (P < .001), female (P = .02), and more myopic spherical equivalent (P = .005) were related to the greater optic disc tilting ratio. Beta-zone peripapillary atrophy, optic disc tilting, and rotation are very common in highly myopic eyes in Chinese population. Older age, female, and more myopic spherical equivalent are risk factors of higher degree of optic disc tilting.

Optic disc-fovea distance and myopia progression in school children: the Beijing Children Eye Study.

To assess changes in the optic disc-fovea distance (DFD) with progressing myopia in school children. The school-based, prospective, longitudinal study included grade-1 children in 2011 who were yearly re-examined until 2016. We measured DFD, optic disc diameters and width of parapapillary gamma zone (parapapillary region without Bruch's membrane (BM)) on fundus photographs. Of 382 grade-1 children examined in 2011, 294 (77.0%) children (mean age in 2011: 6.4±0.5years) returned to be examined in 2016. In relative terms, the increase in DFD (1.15±0.33mm) was more due to an increase in gamma zone width (+300% or 0.29±0.30mm) than an increase in macular BM length (+18% or 0.74±0.21mm). In multivariate regression analysis, longer increase in DFD was correlated (regression coefficient r2 =0.79) with longer axial elongation during the study period (p<0.001; standardized regression coefficient β: 0.61; non-standardized regression coefficient B: 0.30; 95% confidence interval (CI): 0.26, 0.33), larger increase in gamma zone width (p<0.001; β: 0.35; B: 0.40; 95%CI: 0.32, 0.48) and longer axial length in 2011 (p=0.01; β:0.07; B:0.03; 95%CI:0.01, 0.06). Larger increase in gamma zone width was associated (r2 =0.73) with larger increase in DFD (p<0.001; β: 0.51; B: 0.46; 95%CI: 0.39, 0.53), larger increase in the vertical-to-horizontal disc diameter ratio (p<0.001; β: 0.43; B:1.21; 95%CI: 1.00, 1.42) and longer vertical disc diameter (p<0.001; β: 0.15; B:0.24; 95%CI: 0.14, 0.34). In adolescent school children, axial elongation-associated increase in DFD was mainly due to an enlargement (+300%) of parapapillary gamma zone, while macular BM length increased to minor degree (+18%). Gamma zone enlargement was correlated with axial elongation-associated vertical optic disc rotation, potentially due to an increased backward pull of the optic nerve on the temporal optic disc border.

Parapapillary Gamma Zone and Progression of Myopia in School Children: The Beijing Children Eye Study.

To assess the development and enlargement of the parapapillary gamma zone in school children. This school-based prospective longitudinal study included Chinese children attending grade 1 in 2011 and returning for yearly follow-up examinations until 2016. These examinations consisted of a comprehensive ocular examination with biometry and color fundus photographs. The parents underwent a standardized interview. The parapapillary gamma zone was defined as the area with visible sclera at the temporal optic disc margin, and the optic disc itself was measured on fundus photographs. The study included 294 children (mean age in 2016, 11.4 ± 0.5 years [range, 10-13 years]; mean axial length, 24.1 ± 1.1 mm [range, 21.13-27.29 mm]). In multivariate analysis, larger increases in the gamma zone area during the study period were correlated (coefficient of determination for bivariate analysis [r2], r2 = 0.69) with larger increases in the vertical-to-horizontal disc diameter ratios (P < 0.001; standardized regression coefficient beta [beta], 0.53; nonstandardized regression coefficient B [B], 4.05; 95% confidence intervals [CI], 3.37-4.73), larger axial elongation (P < 0.001; beta, 0.32; B, 0.37; 95% CI, 0.26-0.47), a larger vertical disc diameter at baseline (P < 0.001; beta, 0.22; B, 0.98; 95% CI, 0.62-1.33), a larger gamma zone area at baseline (P < 0.001; beta, 0.14; B, 0.41; 95% CI, 0.17-0.64), and more time spent indoors studying (P = 0.015; beta, 0.10; B, 0.09; 95% CI, 0.02-0.17). The development and enlargement of the gamma zone in the temporal parapapillary region were associated with an optic disc rotation around the vertical disc axis as indicated by an increasing vertical-to-horizontal disc diameter ratio. These morphologic findings fit with the notion of a backward pull of the temporal peripapillary sclera through the optic nerve dura mater in axially elongated eyes.

Clinical features of superficial and deep peripapillary microvascular density in healthy myopic eyes.

PurposeTo evaluate the clinical features of peripapillary microvasculature in myopic eyes and investigate the association between the superficial and deep peripapillary microvascular density and the myopic optic disc characteristics.Materials and methodsThis cross-sectional study included one hundred and fifty healthy myopic eyes with β-peripapillary atrophy (β-PPA). Ovality index, degree of optic disc rotation, and the area of β-PPA were measured. Superficial and deep peripapillary microvascular density was measured using optical coherence tomography angiography. Logistic regression analysis was performed to look for the factors associated with peripapillary microvascular reduction.ResultsThe mean superficial peripapillary microvascular density was 62.14 ± 5.47%; 33 (22.0%) participants were found to have decreased microvascular density. Increased axial length (p < 0.001) and decreased average peripapillary retinal nerve fiber layer thickness (p = 0.027) were associated with the superficial peripapillary microvascular reduction. The mean deep peripapillary microvascular density was 73.76 ± 4.02%; 26 (17.33%) participants were found to have decreased microvascular density. Larger ovality index (p = 0.028) and more inferiorly rotated optic disc (p = 0.021) were associated with the deep peripapillary microvascular reduction.ConclusionsAxial elongation was significantly associated with microvascular reduction in the superficial peripapillary retina, whereas it was not associated with deep peripapillary microvascular reduction. The deep peripapillary microvascular density was independently associated with myopic optic disc characteristics such as ovality index and optic disc rotation.

Horizontal and vertical optic disc rotation. The Beijing Eye Study.

PurposeTo measure the optic disc rotation around the vertical and horizontal disc axis and to evaluate associations with general and ocular parameters.DesignPopulation-based studyMethodsIn the Beijing Eye Study, 3468 participants (mean age:64.6±9.8 years; range:50–93 years) underwent an ophthalmological examination which included spectral-domain optical coherence tomography (OCT) with enhanced depth imaging. Using the OCT images, we determined the amount of the rotation of the optic disc (defined as Bruch´s membrane opening (BMO)) around the vertical axis and horizontal axis.ResultsOptic disc rotation measurements were available for 3037 (87.6%) individuals. In multivariate analysis, larger optic disc rotation around the vertical axis (range:-4.90° to 41.0°) was associated (regression coefficient r:0.27) with high axial myopia (axial length ≥26.5 mm) (P<0.001;standardized regression coefficient beta beta:0.09), longer disc-fovea distance (P = 0.001;beta:0.09) and wider parapapillary beta/gamma zone (P<0.001;beta0.12). Larger optic disc rotation around the horizontal axis (range:-7.10° to 26.4°) was associated (r:0.32) with high axial myopia (P = 0.001;beta:0.08), larger optic disc-fovea angle (P<0.001;beta:0.13), thinner superior nasal retinal nerve fiber layer (RNFL) thickness (P<0.001;beta:-0.19) and thicker inferior nasal RNFL thickness (P<0.001;beta:0.17).ConclusionsVertical optic disc rotation was associated with highly myopic axial elongation, increased disc-fovea distance and development or enlargement of parapapillary, Bruch´s membrane free, gamma zone, while macular Bruch´s membrane length is not affected. Horizontal optic disc rotation was associated with inferior dislocation of the fovea, in addition to a thinner superior nasal RNFL and thicker inferior nasal RNFL. The latter association may be taken into account in the interpretation of RNFL thickness profiles.

Myopic glaucomatous eyes with or without optic disc shape alteration: a longitudinal study

AimsTo compare the clinical courses of patients with myopic primary open angle glaucoma (POAG) with and without optic disc shape alterations.MethodsIn this longitudinal retrospective study, 146 eyes from 146 patients...