Morphological Characteristics of the Optic Nerve Head and Choroidal Thickness in High Myopia

Assessment of optic disc morphological characteristics and related factors of highly myopic eyes in Chinese school-aged children

CLINICAL RELEVANCE

The morphological characteristics of the optic nerve head (ONH) in myopic eyes are a clinically significant issue, especially for high myopia in school-aged children, and this can be monitored using optical coherence tomography.

BACKGROUND

The purpose of this study is to investigate the morphological characteristics of ONH, and the factors associated with peripapillary choroidal thickness in Chinese school-aged high myopia children.

METHODS

A total of 48 patients, possessing 48 high myopia eyes and 48 contralateral low myopia eyes were enrolled. The ONH characteristic parameters, including peripapillary retinal nerve fibre layer thickness, peripapillary choroidal thickness, peripapillary choroidal blood flow density, Bruch's membrane opening (BMO) characteristic parameters were measured on optical coherence tomography scans.

RESULTS

Eyes with high myopia had a larger disc size, higher peripapillary atrophy area proportion, larger peripapillary atrophy area, larger BMO minimum rim width, lower peripapillary choroidal thickness compared with those contralateral low myopia eyes (all P < 0.001). The BMO distance and border length were longer, and border tissue angle was smaller in the high myopia eyes. The multivariate regression analysis revealed that border length, axial length, and border tissue angle were independently associated with peripapillary choroidal thickness (all P < 0.05); axial length was associated with peripapillary retinal nerve fibre layer thickness (P = 0.007).

CONCLUSION

The peripapillary atrophy area, BMO area, border length, BMO distance, and BMO minimum rim width increased, but peripapillary choroidal thickness, retinal nerve fibre layer thickness decreased with axial elongation of the globe in young myopia children. Longer axial length and border length were positively correlated with lower peripapillary choroidal thickness, and a smaller border tissue angle was positively correlated with lower peripapillary choroidal thickness were found in this study. Monitoring of border length and border tissue angle is essential in the early stages of myopia in children.

Risk factors of non-arteritic anterior ischaemic optic neuropathy and central retinal artery occlusion

AIM

To investigate the difference in risk factors between non-arteritic anterior ischaemic optic neuropathy (NAION) and central retinal artery occlusion (CRAO) and develop a predictive diagnostic nomogram.

METHODS

The study included 37 patients with monocular NAION, 20 with monocular CRAO, and 24 with hypertension. Gender, age, and systemic diseases were recorded. Blood routine, lipids, hemorheology, carotid and brachial artery doppler ultrasound, and echocardiography were collected. The optic disc area, cup area, and cup-to-disc ratio (C/D) of the unaffected eye in the NAION and CRAO group and the right eye in the hypertension group were measured.

RESULTS

The carotid artery intimal medial thickness (C-IMT) of the affected side of the CRAO group was thicker (P=0.039) and its flow-mediated dilation (FMD) was lower (P=0.049) than the NAION group. Compared with hypertension patients, NAION patients had higher whole blood reduced viscosity low-shear (WBRV-L) and erythrocyte aggregation index (EAI; P=0.045, 0.037), and CRAO patients had higher index of rigidity of erythrocyte (IR) and erythrocyte deformation index (EDI; P=0.004, 0.001). The optic cup and the C/D of the NAION group were smaller than the other two groups (P<0.0001). The diagnostic prediction model showed high diagnostic specificity (83.7%) and sensitivity (85.6%), which was highly related to hypertension, the C-IMT of the affected side, FMD, platelet (PLT), EAI, and C/D.

CONCLUSION

CRAO patients show thicker C-IMT and worse endothelial function than NAION. NAION and CRAO may be related to abnormal hemorheology. A small cup and small C/D may be involved in NAION. The diagnostic nomogram can be used to preliminarily identify NAION and CRAO.

Peripapillary atrophy area predicts the decrease of macular choroidal thickness in young adults during myopia progression

OBJECTIVE

This study aimed to investigate the influence of peripapillary atrophy (PPA) area and axial elongation on the longitudinal changes in macular choroidal thickness (ChT) in young individuals with myopia.

METHODS AND ANALYSIS

In this longitudinal investigation, 431 eyes-342 categorised as non-high myopia (non-HM) and 89 as HM-were examined for 2 years. Participants were examined with swept-source optical coherence tomography. The macular ChT, PPA area and axial length (AL) were measured at baseline and follow-up visits. Multiple regression analysis was performed to identify factors associated with ChT changes. The areas under the receiver operating characteristic curves were analysed to ascertain the predictive capacity of the PPA area and axial elongation for the reduction in macular ChT.

RESULTS

Initial measurements revealed that the average macular ChT was 240.35±56.15 µm in the non-HM group and 198.43±50.27 µm in the HM group (p<0.001). It was observed that the HM group experienced a significantly greater reduction in average macular ChT (-7.35±11.70 µm) than the non-HM group (-1.85±16.95 µm, p=0.004). Multivariate regression analysis showed that a greater reduction of ChT was associated with baseline PPA area (β=-26.646, p<0.001) and the change in AL (β=-35.230, p<0.001). The combination of the baseline PPA area with the change in AL was found to be effective in predicting the decrease in macular ChT, with an area under the curve of 0.741 (95% CI 0.694 to 0.787).

CONCLUSION

Over 2 years, eyes with HM exhibit a more significant decrease in ChT than those without HM. Combining the baseline PPA area with the change in AL could be used to predict the decrease of macular ChT.

Association of macular outward scleral height with axial length, macular choroidal thickness and morphologic characteristics of the optic disc in Chinese adults

PURPOSE

To identify the relationship of macular outward scleral height (MOSH) with axial length (AL), macular choroidal thickness (ChT), peripapillary atrophy (PPA), and optic disc tilt in Chinese adults.

METHODS

In this cross-sectional study, 1088 right eyes of 1088 participants were enrolled and assigned into high myopia (HM) and non-HM groups. MOSH was measured in the nasal, temporal, superior, and inferior directions using swept-source optical coherence tomography images. The clinical characteristics of MOSH and the association of MOSH with AL, macular ChT, PPA, and tilt ratio were analysed.

RESULTS

The mean age of participants was 37.31 ± 18.93 years (range, 18-86 years), and the mean AL was 25.78 ± 1.79 mm (range, 21.25-33.09 mm). MOSH was the highest in the temporal direction, followed by the superior, nasal, and inferior directions (all p < 0.001). The MOSH of HM eyes was significantly higher than that of non-HM eyes, and it was positively correlated with AL in the nasal, temporal, and superior directions (all p < 0.001). Macular ChT was independently associated with the average MOSH (B = -0.190, p < 0.001). Nasal MOSH was positively associated with the PPA area and the presence of a tilted optic disc (both p < 0.01). Eyes with a higher MOSH in the superior (odds ratio [OR] = 1.008; p < 0.001) and inferior directions (OR = 1.006; p = 0.009) were more likely to have posterior staphyloma.

CONCLUSION

MOSH is an early indicator of scleral deformation, and it is correlated positively with AL and negatively with ChT. A higher nasal MOSH is associated with a larger PPA area and the presence of a tilted optic disc. Higher MOSH values in the superior and inferior directions were risk factors for posterior staphyloma.

CLINICAL TRIAL REGISTRATION

The study was registered at www.

CLINICALTRIALS

gov (Reg. No. NCT03446300).

Optic neuropathy in high myopia: Glaucoma or high myopia or both?

Due to the increasing prevalence of high myopia around the world, structural and functional damages to the optic nerve in high myopia has recently attracted much attention. Evidence has shown that high myopia is related to the development of glaucomatous or glaucoma-like optic neuropathy, and that both have many common features. These similarities often pose a diagnostic challenge that will affect the future management of glaucoma suspects in high myopia. In this review, we summarize similarities and differences in optic neuropathy arising from non-pathologic high myopia and glaucoma by considering their respective structural and functional characteristics on fundus photography, optical coherence tomography scanning, and visual field tests. These features may also help to distinguish the underlying mechanisms of the optic neuropathies and to determine management strategies for patients with high myopia and glaucoma.

Using a combination of peripapillary atrophy area and choroidal thickness for the prediction of different types of myopic maculopathy

PURPOSE

To analyse the topographic characteristics in macular choroidal thickness (mChT) and ocular biometry in myopic maculopathy and to explore the potential cut-off value for prediction of myopic maculopathy (MM).

METHODS

All participants underwent detailed ocular examinations. MM was subdivided into thin choroid, Bruch's membrane (BM) defects, choroidal neovascularization (CNV), and myopic tractional maculopathy (MTM) according to OCT-based classification system. Peripapillary atrophy area (PPA), tilt ratio, torsion, and mChT were individually measured.

RESULTS

A total of 1947 participants were included. In multivariate logistics models, older age, longer axial length, larger PPA area, and thinner average mChT were more likely to have MM and different type of MM. Female participants were more likely to have MM and BM defects. A lower tilt ratio was more likely to be associated with CNV and MTM. The area under the curve (AUC) of single tilt ratio, PPA area, torsion, and topographic of mChT for MM, thin choroid, BM Defects, CNV, and MTM were 0.6581 to 0.9423, 0.6564 to 0.9335, 0.6120 to 0.9554, 0.5734 to 0.9312, 0.6415 to 0.9382, respectively. After combining PPA area and average mChT for predicting MM, thin choroid, BM defects, CNV, and MTM, the AUC of the combination were 0.9678, 0.9279, 0.9531, 0.9213, 0.9317, respectively.

CONCLUSION

Progressive and continuous PPA area expanding and thin choroid play a role in the development of myopic maculopathy. The present study showed that a combination of peripapillary atrophy area and the choroidal thickness could be used to predict MM and each type of MM.

Longitudinal Changes of Bruch's Membrane Opening, Anterior Scleral Canal Opening, and Border Tissue in Experimental Juvenile High Myopia

Purpose

To investigate the relative positional changes between the Bruch's membrane opening (BMO) and the anterior scleral canal opening (ASCO), and border tissue configuration changes during experimental high myopia development in juvenile tree shrews.

Methods

Juvenile tree shrews were assigned randomly to two groups: binocular normal vision (n = 9) and monocular -10 D lens treatment starting at 24 days of visual experience to induce high myopia in one eye while the other eye served as control (n = 12). Refractive and biometric measurements were obtained daily, and 48 radial optical coherence tomography B-scans through the center of the optic nerve head were obtained weekly for 6 weeks. ASCO and BMO were segmented manually after nonlinear distortion correction.

Results

Lens-treated eyes developed high degree of axial myopia (-9.76 ± 1.19 D), significantly different (P < 0.001) from normal (0.34 ± 0.97 D) and control eyes (0.39 ± 0.88 D). ASCO-BMO centroid offset gradually increased and became significantly larger in the experimental high myopia group compared with normal and control eyes (P < 0.0001) with an inferonasal directional preference. The border tissue showed a significantly higher tendency of change from internally to externally oblique configuration in the experimental high myopic eyes in four sectors: nasal, inferonasal, inferior, and inferotemporal (P < 0.005).

Conclusions

During experimental high myopia development, progressive relative deformations of ASCO and BMO occur simultaneously with changes in border tissue configuration from internally to externally oblique in sectors that are close to the posterior pole (nasal in tree shrews). These asymmetric changes may contribute to pathologic optic nerve head remodeling and an increased risk of glaucoma later in life.

Update on the Utility of Optical Coherence Tomography in the Analysis of the Optic Nerve Head in Highly Myopic Eyes with and without Glaucoma

Glaucoma diagnosis in highly myopic subjects by optic nerve head (ONH) imaging is challenging as it is difficult to distinguish structural defects related to glaucoma from myopia-related defects in these subjects. Optical coherence tomography (OCT) has evolved to become a routine examination at present, providing key information in the assessment of glaucoma based on the study of the ONH. However, the correct segmentation and interpretation of the ONH data employing OCT is still a challenge in highly myopic patients. High-resolution OCT images can help qualitatively and quantitatively describe the structural characteristics and anatomical changes in highly myopic subjects with and without glaucoma. The ONH and peripapillary area can be analyzed to measure the myopic atrophic-related zone, the existence of intrachoroidal cavitation, staphyloma, and ONH pits by OCT. Similarly, the lamina cribosa observed in the OCT images may reveal anatomical changes that justify visual defects. Several quantitative parameters of the ONH obtained from OCT images were proposed to predict the progression of visual defects in glaucoma subjects. Additionally, OCT images help identify factors that may negatively influence the measurement of the retinal nerve fiber layer (RNFL) and provide better analysis using new parameters, such as Bruch’s Membrane Opening-Minimum Rim Width, which serves as an alternative to RNFL measurements in highly myopic subjects due to its superior diagnostic ability.

Clinical characteristics and risk factors of myopic retinoschisis in an elderly high myopia population

PURPOSE

To investigate the clinical characteristics, internal correlations and risk factors for different locations of retinoschisis (RS) in an elderly high myopia (HM) population.

METHODS

A total of 448 eyes (304 participants) were analysed and classified into no retinoschisis (no-RS), paravascular retinoschisis (PVRS), peripapillary retinoschisis (PPRS) and macular retinoschisis (MRS) groups. Each participant underwent comprehensive ophthalmic examinations, and posterior scleral height (PSH) was measured in swept-source optical coherence tomography images. PSH, vitreoretinal interface abnormities and myopic atrophy maculopathy (MAM) were compared among groups.

RESULTS

Retinoschisis was found in 195 (43.5%) eyes, among which 170 (37.9%) had PVRS, 123 (27.5%) had PPRS, and 103 (23.0%) had MRS. MRS was found to be combined with PVRS in 96 of 103 (93.2%) eyes. MAM was one of the risk factors for RS (odds ratio [OR], 2.459; p = 0.005). Higher nasal PSH was the only risk factor for PVRS (OR, 9.103; p = 0.008 per 1-mm increase). Elongation of axial length (AL) (OR, 1.891; p < 0.001 per 1-mm increase), higher PSH in nasal (OR, 5.059; p = 0.009 per 1-mm increase) and temporal (OR, 13.021; p = 0.012 per 1-mm increase), epiretinal membrane (ERM; OR, 2.841; p = 0.008) and vitreomacular traction (VMT; OR, 7.335; p = 0.002) were risk factors for MRS.

CONCLUSIONS

Paravascular retinoschisis is the most common type of RS in HM and MRS is mostly combined with PVRS. MAM is one of the risk factors for RS. In addition to longer AL and higher PSH, the presence of VMT and ERM also play an important role in the formation of MRS.

Identification of ocular refraction based on deep learning algorithm as a novel retinoscopy method

BACKGROUND

The evaluation of refraction is indispensable in ophthalmic clinics, generally requiring a refractor or retinoscopy under cycloplegia. Retinal fundus photographs (RFPs) supply a wealth of information related to the human eye and might provide a promising approach that is more convenient and objective. Here, we aimed to develop and validate a fusion model-based deep learning system (FMDLS) to identify ocular refraction via RFPs and compare with the cycloplegic refraction. In this population-based comparative study, we retrospectively collected 11,973 RFPs from May 1, 2020 to November 20, 2021. The performance of the regression models for sphere and cylinder was evaluated using mean absolute error (MAE). The accuracy, sensitivity, specificity, area under the receiver operating characteristic curve, and F1-score were used to evaluate the classification model of the cylinder axis.

RESULTS

Overall, 7873 RFPs were retained for analysis. For sphere and cylinder, the MAE values between the FMDLS and cycloplegic refraction were 0.50 D and 0.31 D, representing an increase of 29.41% and 26.67%, respectively, when compared with the single models. The correlation coefficients (r) were 0.949 and 0.807, respectively. For axis analysis, the accuracy, specificity, sensitivity, and area under the curve value of the classification model were 0.89, 0.941, 0.882, and 0.814, respectively, and the F1-score was 0.88.

CONCLUSIONS

The FMDLS successfully identified the ocular refraction in sphere, cylinder, and axis, and showed good agreement with the cycloplegic refraction. The RFPs can provide not only comprehensive fundus information but also the refractive state of the eye, highlighting their potential clinical value.

Morphological characteristics of the optic nerve head and impacts on longitudinal change in macular choroidal thickness during myopia progression

PURPOSE

The aim of this study was to investigate the association between morphological characteristics of Bruch's membrane opening distance (BMOD), border length (BL), border tissue angle (BTA), peripapillary atrophy (PPA) as well as axial length (AL) and incident decreased macular choroidal thickness (mChT) in young healthy myopic eyes.

METHODS

A total of 323 participants aged 17-30 years were included in the current 2-year longitudinal study. Each participant underwent detailed ocular examinations at baseline and follow-up. Data of AL, refraction error, PPA area, BMOD, BL, BTA and mChT were measured individually. Incident decreased mChT was defined as follow-up mChT of participants decreased into the lowest quartile of baseline mChT.

RESULTS

Subjects with longer AL, longer BMOD were more likely to have incident decreased mChT (odds ratio [OR], 1.56; 2.09, respectively, per 1 Z-score increment), whereas larger BTA was less likely to develop decreased mChT (odds ratio [OR], 0.51, per 1 Z-score increment). The area under the receiver operating curve (AUROC) of basic risk model for incident decreased mChT was 0.6284. After adding BMOD, BTA and AL separately to the basic risk model, the AUROC of the combination could reach 0.6967, 0.6944 and 0.7383, respectively. After combining BMOD, BTA and AL to the basic model, the AUROC of the combination showed the highest AUROC of 0.7608.

CONCLUSIONS

Bruch's membrane opening distance and AL are significant risk factors for incident decreased mChT, whereas BTA played protective role in the deterioration of mChT. In addition, a combination of BMOD, BTA and AL could serve as earlier predictors of the attenuation of mChT in myopia progression.

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

PURPOSE

To investigate the changes in optic disc morphology and peripapillary atrophy (PPA) in diabetic children and adults without diabetic retinopathy (DR) or visual impairment (VI).

METHODS

This 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.

RESULTS

In 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.

CONCLUSION

Hyperglycaemia 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.

Wide-field swept source optical coherence tomography evaluation of posterior segment changes in highly myopic eyes

BACKGROUND

To investigate the features in the posterior pole of highly myopic (HM) eyes using a wide-field high-resolution swept source optical coherence tomography (SS OCT).

METHODS

This observational cross-sectional study involved 262 eyes of 139 patients, who were diagnosed as HM and had consecutively been examined by SS OCT in the Ophthalmology Department of the Peking Union Medical College Hospital between March 2019 and December 2019. The characteristics of OCT images were documented and analyzed.

RESULTS

In our study, SS OCT could demonstrate the entire layer of the choroid and detect the sclera in all eyes. The mean subfoveal retinal/choroidal/scleral thickness were 204.84 ± 119.86 μm, 92.80 ± 75.78 μm and 394.734 ± 123.09 μm, respectively. 138 eyes (52.67%) had posterior precortical vitreous pocket. Myopic foveoschisis was detected in 110 eyes (41.98%), and significantly associated with the presence of posterior staphyloma. 36 eyes (13.74%) had DSM in our study, of which 8 eyes (22.22%) showed a round dome, 16 (44.44%) were horizontal oval-shaped, 9 (25%) were vertical oval-shaped and 3 (8.34%) were oblique oval-shaped. Both SFCT and SFST were inversely and significantly associated with age and refractive errors. Macular neovascularization was significantly correlated with intrascleral vessels. Different deformation of the sclera and posterior staphyloma were vividly identified on SS OCT images.

CONCLUSIONS

This study provided a relatively comprehensive picture of posterior pole in HM eyes. Such good visualization of ocular fundus provided by wide-field SS OCT could be useful for the therapy option, disease condition monitoring and pathogenesis investigation.

Associations between optic disc characteristics and macular choroidal microvasculature in young patients with high myopia

BACKGROUND

This study aimed to examine changes to optic disc characteristics and macular choroidal microvasculature, and their relationships in young patients with high myopia (HM).

METHODS

A total of 90 patients were enrolled in this cross-sectional study. Based on their refractive power, the patients were divided into three groups: 27 in the control group, 34 in the HM group and 29 in the extremely high myopia group. Images of each patient's macula and optic disc were taken by ocular coherence tomography angiography. The macular choroidal and retinal thickness, capillary vessel density and capillary flow area were measured using Matlab software. Parapapillary atrophy (PPA) and the ovality index (OI) obtained from the scanning laser ophthalmoscopy images and the degree of optic disc tilt obtained from the optic nerve head ocular coherence tomography B-scans were analysed by Image J and Matlab software.

RESULTS

The PPA area, OI and degree of optic disc tilt were significantly different among the three groups (all p ≤ 0.001). The macular choroidal thickness and microvasculature were significantly different among the three groups (all p < 0.05). Macular choroidal thickness was significantly correlated with PPA area and the degree of optic disc tilt (r = -0.331, p = 0.003; r = -0.394, p = 0.001, respectively). Macular choroidal capillary vessel density and choriocapillaris flow area were associated with PPA area (r = -0.251, p = 0.047; r = -0.326, p = 0.009, respectively).

CONCLUSIONS

PPA area, OI and the degree of optic disc tilt were increased in patients with HM, and these changes were correlated with macular choroidal thickness and choroidal microvasculature.

Imaging Features by Machine Learning for Quantification of Optic Disc Changes and Impact on Choroidal Thickness in Young Myopic Patients

Purpose: To construct quantifiable models of imaging features by machine learning describing early changes of optic disc and peripapillary region, and to explore their performance as early indicators for choroidal thickness (ChT) in young myopic patients.

Methods: Eight hundred and ninety six subjects were enrolled. Imaging features were extracted from fundus photographs. Macular ChT (mChT) and peripapillary ChT (pChT) were measured on swept-source optical coherence tomography scans. All participants were divided randomly into training (70%) and test (30%) sets. Imaging features correlated with ChT were selected by LASSO regression and combined into new indicators of optic disc (IODs) for mChT (IOD_mChT) and for pChT (IOD_pChT) by multivariate regression models in the training set. The performance of IODs was evaluated in the test set.

Results: A significant correlation between IOD_mChT and mChT (r = 0.650, R² = 0.423, P < 0.001) was found in the test set. IOD_mChT was negatively associated with axial length (AL) (r = −0.562, P < 0.001) and peripapillary atrophy (PPA) area (r = −0.738, P < 0.001) and positively associated with ovality index (r = 0.503, P < 0.001) and torsion angle (r = 0.242, P < 0.001) in the test set. Every 1 × 10 μm decrease in IOD_mChT was associated with an 8.87 μm decrease in mChT. A significant correlation between IOD_pChT and pChT (r = 0.576, R² = 0.331, P < 0.001) was found in the test set. IOD_pChT was negatively associated with AL (r = −0.478, P < 0.001) and PPA area (r = −0.651, P < 0.001) and positively associated with ovality index (r = 0.285, P < 0.001) and torsion angle (r = 0.180, P < 0.001) in the test set. Every 1 × 10 μm decrease in IOD_pChT was associated with a 9.64 μm decrease in pChT.

Conclusions: The study introduced a machine learning approach to acquire imaging information of early changes of optic disc and peripapillary region and constructed quantitative models significantly correlated with choroidal thickness. The objective models from fundus photographs represented a new approach that offset limitations of human annotation and could be applied in other areas of fundus diseases.