Association of Myopic Deformation of Optic Disc with Visual Field Progression in Paired Eyes with Open-Angle Glaucoma

Morphological differences of the neuroretinal rim between temporally tilted and non-tilted optic discs in healthy eyes

This study aimed to compare morphological differences of the neuroretinal rim between the temporally tilted and non-tilted optic discs in healthy eyes. We prospectively enrolled participants aged 20-40 years with temporally tilted or non-tilted optic discs. The optic nerve head parameters were analyzed using spectral domain-optical coherence tomography. The angle between the Bruch's membrane opening (BMO) plane and BMO-minimum rim width (BMO-MRW) was termed "BMO-MRW angle". Peripapillary retinal nerve fiber layer thickness (pRNFLT) and BMO-based parameters were compared between the temporally tilted and non-tilted disc groups. As a result, 55 temporally tilted disc eyes and 38 non-tilted disc eyes were analyzed. Global pRNFLT, global BMO-MRW, and total BMO-minimum rim area (BMO-MRA) were similar between the two groups (p = 0.138, 0.161, and p = 0.410, respectively). In the sectoral analysis, temporally tilted disc group exhibited thicker BMO-MRW in the temporal sector (p = 0.032) and thinner in the nasal superior and nasal sectors (p = 0.025 and p = 0.002, respectively). Temporally tilted disc group showed larger BMO-MRA in the temporal, temporal superior, and temporal inferior sectors (p < 0.001, p < 0.001, and p < 0.016, respectively), alongside a higher BMO-MRW angle in the temporal sector and lower in the nasal superior and nasal sectors. In conclusion, the neuroretinal rim, represented by BMO-MRW and BMO-MRA, showed morphological differences between temporally tilted and non-tilted optic discs in healthy eyes. BMO-MRW and BMO-MRA showed temporalization in the same manner as pRNFLT in the temporally tilted disc eyes. The BMO-MRW angle showed that in temporally tilted disc eyes, optic nerve fibers met the BMO plane steeply in the nasal sector and gently in the temporal sector than in non-tilted disc eyes, suggesting potential stress region of optic nerve fibers in temporally tilted disc eyes.

Distribution of the Retinal Microcirculation Based on the Morphology of Peripapillary Atrophy in High Myopia

INTRODUCTION

The objective of this study was to evaluate the retinal microvasculature of the optic nerve head and macula in high myopia (HM), investigate the association between the vascular parameters and peripapillary atrophy (PPA) deformation, and assess and identify the PPA morphology changes during the development of HM.

METHODS

One hundred sixty-seven right eyes from 167 HM patients were enrolled in this cross-sectional study. Using the optical coherence tomography angiography (OCTA) and fundus camera, we evaluated the following parameters: radian and type of PPA, intrapapillary vascular density (IVD), peripapillary vascular density (PVD), macular vascular density (MVD), and foveal avascular zone (FAZ). Based on the PPA radian, subjects were divided into four groups: the non-PPA, temporal PPA, advanced PPA, and annular PPA. At the same time, the above parameters were compared between the groups using analysis of variance (ANOVA) and least significant difference test.

RESULTS

Total enrolled patients were divided into the non-PPA group (22 eyes), temporal-PPA group (70 eyes), advanced-PPA group (60 eyes), and annular-PPA group (15 eyes). The results showed that the PVD in the annular-PPA group was smaller than that in the non-PPA group, especially in the superonasal, nasosuperior, nasoinferior, inferotemporal, temporoinferior, and superotemporal directions (F = 4.059, 5.014, 2.830, 4.798, 5.892, 3.439; p < 0.05). Notably, the PVD showcased the highest value in temporal, followed by that in superior and inferior, and the lowest in the nasal. Concerning the fovea deep macular vascular density, FAZ area, and subfoveal choroidal thickness in the annular-PPA group, they were less than those of the rest of the groups (p < 0.05).

CONCLUSION

The retinal microvasculature differed significantly in HM according to the PPA morphology. In addition to PVD and SFCT, the PPA can also affect FAZ. Finally, we speculated that PVD demonstrated better predictability of myopic progression than MVD.

Progress in clinical characteristics of high myopia with primary open-angle glaucoma

High myopia (HM) is a significant risk factor for the occurrence and progression of primary open-angle glaucoma (POAG). Identification with POAG in the HM population is an emergent challenge. Patients with HM have a significantly higher probability of complicating POAG than those without HM. When HM is associated with POAG, the changes to the fundus caused by both of them are confused with each other, making the diagnosis of early glaucoma difficult. This article reviews available researches on HM with POAG, summarizing the characteristics of the fundus structure such as epidemiology, intraocular pressure, optic disc, ganglion cell layer, retinal nerve fiber layer, vascular density, and visual field.

Myopic tilted disc: Mechanism, clinical significance, and public health implication

Myopic tilted disc is a common structural change of myopic eyes. With advancing ocular imaging technology, the associated structural changes of the eye, particularly the optic nerve head, have been extensively studied. These structural changes may increase patients' susceptibility to axonal damage and the risk of developing serious optic neuropathies including glaucoma. They also lead to diagnostic difficulties of disease suspects and treatment dilemmas of patients, which implicate clinical practice and subsequently the health care system. In the context of the mounting prevalence of myopia worldwide and its implications to irreversible visual impairment and blindness, it is essential to gain a thorough understanding of the structural changes of myopia. Myopic tilted disc has been extensively investigated by different study groups. However, generalizing the knowledge could be difficult because of the variable definitions of myopic tilted disc utilized in these studies and the complexities of the changes. The current review aimed to clarify the concepts and discuss various aspects of myopic tilted disc, including the definitions, association with other myopia-related changes, mechanism of tilted disc development, structural and functional changes, and clinical implications.

Distribution of the Retinal Microcirculation Based on the Morphology of the Optic Nerve Head in High Myopia

PURPOSE

To explore the retinal microvasculature of the optic nerve head and macula and their associations with the optic nerve head deformation in high myopia.

METHODS

One hundred sixty-seven eyes from patients with high myopia (HM) were enrolled in a cross-sectional study. We have evaluated and measured characteristics like the tilt ratio of the optic disc, interpupillary vascular density (IVD), peripapillary vascular density (PVD), macular vascular density (MVD), subfoveal choroidal thickness (SFCT) and foveal avascular zone (FAZ). The subjects were classified as a non-tilt group (control group) and a tilt group based on the tilt index. The above parameters were utilized to compare the two groups. In addition, we collected the data from the subjects' right eyes to analyze variance, the Kruskal-Wallis test, and the least significant difference.

RESULTS

The patients were divided into the non-tilt group of ninety-one eyes and the tilt group of seventy-six eyes. We found that the IVD in the tilt group was more significant than in the non-tilt group (t = -2.794, P = .006). On the other hand, the PVD was less in the tilt group than in the non-tilt, especially in the NS, NI and IN directions (t_NS = 3.782; t_NI = 3.07; t_IN = 2.086; P < .05). Interestingly, the values of PVD were the highest in temporal, second in superior and inferior and lowest in nasal. Concerning the fovea-DMVD (including fovea, parafovea and perifovea), we characterized them as more minor in the tilt group when compared to those in the non-tilt group (P < .05).

CONCLUSION

Herein, we discovered that the retinal microvasculature differed significantly in patients with HM according to the ONH morphology. In this population, lower PVD and thinner SFCT were associated with higher odds of the tilted optic disc. In addition, the other two characteristics, the IVD and DMVD, were affected by the ONH deformation. Finally, we showed that PVD demonstrated better predictability of rapid myopic progression than MVD.

Prevalence and Factors Associated with Optic Disc Tilt in the Primary Open-Angle African American Glaucoma Genetics Study

PURPOSE

To investigate the prevalence and factors associated with optic disc tilt in the eyes of Black Americans with glaucoma.

DESIGN

Cross-sectional.

PARTICIPANTS

Subjects with glaucoma participating in the Primary Open-Angle African American Glaucoma Genetics (POAAGG) study.

METHODS

Stereo pairs of optic disc images were assessed independently by POAAGG-certified nonphysician graders for quantitative features including maximum and minimum linear disc diameters, and qualitative features including gradeability of images, shape of the cup, rim plane position, β-peripapillary atrophy, sloping region adjacent to the outer disc margin, and rim pallor. Discrepancies were adjudicated by an ophthalmologist. Descriptive statistics and P values were generated for associations of tilt with demographic and ocular characteristics. Stepwise multivariable analysis was performed with logistic regression using Generalized Estimating Equations (GEEs) to account for inter-eye correlation within subjects.

MAIN OUTCOME MEASURES

Tilt Ovality Index (TOI) of >1.30 and Stereoscopically Identified optic disc Tilt (SIT).

RESULTS

Among 1251 subjects with data on both eyes, 104 (8.3%) had TOI. Subjects with TOI were less likely to be male (adjusted odds ratio [aOR], 0.46, 95% confidence interval [CI], 0.29-0.74, P < 0.001). Eyes with TOI were less likely to have large cup disc ratios (aOR, 0.18, 95% CI, 0.06-0.53, P < 0.001) and less likely to have cylinder-shaped cups compared with conical-shaped cups (aOR, 0.31, 95% CI, 0.19-0.49, P < 0.001). Among 1007 subjects with data on both eyes, 254 (25.2%) had SIT. Subjects with SIT were younger (aOR, 0.95, 95% CI, 0.93-0.96, P < 0.001), and eyes with SIT were more likely to have oval-shaped discs compared with round discs (aOR, 1.82, 95% CI, 1.32-2.52, P < 0.001), more likely to have a sloping region adjacent to the outer disc margin instead of being flat (aOR, 3.26, 95% CI, 2.32-4.59, P < 0.001), and less likely to have cylinder-shaped cups compared with conical-shaped cups (aOR, 0.59, 95% CI, 0.41-0.85, P < 0.001). Both TOI and SIT were not associated with myopia.

CONCLUSIONS

There are substantial numbers of tilted optic discs in glaucoma patients with African ancestry. They occur more frequently in female subjects and younger subjects and are associated with several ocular features but not with myopia.

Association of Optic Disc Tilt and Torsion with Open-Angle Glaucoma Progression Risk: Meta-Analysis and Meta-Regression Analysis

PURPOSE

To evaluate the association of optic disc deformation with open-angle glaucoma (OAG) progression risk.

DESIGN

Meta-analysis and meta-regression analysis.

METHODS

Reports on the association of optic disc tilt and/or torsion with OAG progression published to June 2020 were identified in the PubMed, EMBASE, and Cochrane databases. Tilt ratio was measured as the longest-to-shortest diameter ratio of the optic disc. The angle (in degrees) between the vertical meridian and the disc's long axis was defined as the torsional angle. We used random-effects models to combine the pooled effects. Random-effects meta-regression was used to quantify the study characteristics' potential moderating influences. The protocol was registered in the PROSPERO International Database (CRD42020201151).

RESULTS

Eleven longitudinal studies (1100 participants) were included. For 10 of them evaluated for tilt ratio and glaucoma progression, the pooled hazard ratio (HR) was 0.988 (95% confidence interval [CI] 0.921-1.059; I² = 59%) per 0.1-unit increase. In the meta-regression-based subgroup analysis, risk tended to decrease as the patients' mean age increased (P = .08). For 7 of the studies (605 patients) reporting data on torsion and glaucoma progression, the pooled HR was 0.936 (95% CI 0.860-1.018; I² = 32%) per 10-degree increase. The meta-regression analyses showed that the glaucoma progression assessment methods had a modulating influence (P = .01). In studies assessing just functional glaucomatous progression, the pooled HR was 0.890 (95% CI 0.831-0.952; I² = 0%).

CONCLUSION

Evidence for the effects of optic nerve deformation on glaucoma progression is still lacking. Future research using stratified analysis according to age and tailored diagnostic criteria will allow for more rigorous analyses for this topic.

Characteristics of progressive temporal visual field defects in patients with myopia

Temporal visual field damage (VFD) is the common type of non-glaucomatous VF defects found in eyes with myopia. However, little is known about the factors associated with its progression. We investigated the characteristic of myopic eyes with progressive temporal VF defects. This retrospective, observational study included a total of 116 eyes: 39 eyes with temporal VFDs and an axial length greater than 24.5 mm, 77 eyes with typical glaucomatous VFDs who were followed up more than 5 years. VF progression was evaluated with Trend-based global progression analysis. In the temporal VFD group, the greater tilt ratios, the higher prevalence of β-zone peripapillary atrophy (β-PPA), the substantial increase in β-PPA were found, compared to the typical glaucomatous VFD groups (all P-values ≤ 0.001). The temporal VFD group had the slower progression than the typical glaucomatous VFD group on trend-based GPA (P = 0.047). In the multivariate linear regression analysis, the change of β-PPA area over years was related to temporal VFD progression (B, − 0.000088, P = 0.003). In conclusion, myopic eyes with the temporal VFD, which come with growing β-PPA area, should be monitored with extra caution.

Clinical Assessment of Scleral Canal Area in Glaucoma Using Spectral-Domain Optical Coherence Tomography

PURPOSE

To investigate anterior scleral canal (ASC) area in the eyes with glaucoma using spectral-domain optical coherence tomography (SDOCT).

DESIGN

Cross-sectional study.

METHODS

This study included 206 eyes of 103 patients with glaucoma, classified as 66 eyes of 33 patients with unilateral glaucoma and 140 eyes of 70 patients with bilateral glaucoma. Radial scan enhanced depth imaging SDOCT centered on the optic disc was performed, and parameters that present ASC area such as ASC opening and the largest ASC area were obtained in each eye. The largest ASC area was the largest cross-sectional area of the ASC region identified between the ASC opening and anterior lamina cribrosa insertion. These parameters were compared between eyes with and without glaucoma in unilateral glaucoma, and eyes with worse and better visual field defect (VFD) in bilateral glaucoma.

RESULTS

In the patients with unilateral glaucoma, ASC opening and largest ASC area were significantly larger in the eyes with glaucoma than in those without glaucoma (both P < .001). In bilateral glaucoma, these parameters were significantly larger in the eyes with worse VFD than in those with better VFD (P = .0080 and P = .0018, respectively). Intereye differences of the ASC parameters in the glaucoma patients were significantly greater than that in the normal subjects.

CONCLUSIONS

Significantly larger ASC area was first observed in the living human eyes with glaucoma compared to the normal eyes. Further longitudinal studies are required to determine if the ASC area is useful in the prevention and treatment of glaucoma.

Association between Information and Communication Technology use and Ocular Axial Length Elongation among Middle-Aged Male Workers

The use of Information and Communication Technology devices (ICT) has spread globally; therefore, increasing exposure to these display devices is an important health issue in the workplace. The association between ocular axial length (AL) elongation and ICT use was investigated among 7334 middle-aged Japanese male workers. Detailed ICT use information was obtained using a self-administered questionnaire. The high AL group was defined as the group with AL above the 75th percentile for each 5-year age interval. Logistic analysis showed that the odds ratio (OR) for the high AL group of >8 hours/day, adjusted for potent confounding factors, was significantly elevated relative to <1 hour/day. Notably, there was a strong association in the older groups (OR = 6.60, 95% CI = 3.92–11.12), based on work-related uses: word processing, sending e-mails, preparation of presentation materials, and browsing websites. In addition, among workers with extended ICT use for these work-related purposes, a significant lateral difference was observed in AL. However, these associations were not observed for private use, such as playing games. The results of our prospective cross-sectional study show that increased time spent on work-related ICT uses was associated with AL elongation, particularly in older workers.

EFFECT OF GEOMETRICAL PARAMETERS ON THE DEFORMATIONS OF THE HUMAN OPTIC NERVE HEAD BASED ON INDIVIDUAL-SPECIFIC MODELS

The elevated intraocular pressure (IOP) is one of the important risk factors of glaucomatous optic nerve damage. The deformations of glaucomatous optic nerve head (ONH) due to the elevated IOP might lead to further damage to the optic nerve. The ONH deformations due to the elevated IOP depend on their geometry. Therefore, it is meaningful to investigate the relationship between geometrical parameters and the deformation of ONH. Firstly, the geometrical parameters of ONH were obtained by in vivo using spectral domain optical coherence tomography. Then, individual-specific three-dimensional (3D) models of ONH for glaucoma and normal subjects were established and the deformations of ONH were acquired by using finite element method. Furthermore, the thickness changes of retina and lamina cribrosa were calculated under different IOPs. Finally, correlations between geometrical parameters and the relative deformations of the human ONH were researched by using Spearman correlation. It was found that the relative thickness change of patient’s retina was larger than that of normal subjects under the same condition. The correlation of several parameters, including cup area, and lamina cribrosa depth, with relative deformations of ONH had statistical significance.

Association Between Optic Nerve Head Deformation and Retinal Microvasculature in High Myopia

PURPOSE

To evaluate the retinal microvasculature of peripapillary and macular regions in highly myopic eyes and investigate the association between the vascular parameters and optic nerve head (ONH) deformation.

DESIGN

Cross-sectional study.

METHODS

Seventy-one subjects with highly myopic eyes and 26 subjects with emmetropic eyes were included. Horizontal B-scan images of the ONH were obtained using optical coherence tomography (OCT) and horizontal tilt angles were measured. Integrated automated algorithms in the Avanti OCT angiography were used to quantify the peripapillary vessel density and area of the foveal avascular zone (FAZ) at the level of superficial and deep vascular networks. Association between horizontal disc tilt and the vascular parameters was evaluated.

RESULTS

The mean axial length and horizontal tilt angle were 26.73 ± 0.63 mm and 9.77 ± 3.00 degrees in the highly myopic group and 23.46 ± 0.55 mm and 5.95 ± 3.48 degrees in the emmetropic group, respectively. Highly myopic eyes exhibited significantly lower average peripapillary vessel density (P = .010) and larger superficial and deep FAZs (P = .001 and P < .001, respectively) compared with emmetropic eyes. Linear regression analyses showed that horizontal tilt angle significantly correlated the average peripapillary vessel density (P = .037) and the areas of superficial (P < .001) and deep (P < .001) FAZs.

CONCLUSIONS

The retinal microvasculature was significantly different in highly myopic eyes according to the degree of horizontal optic disc tilt. In addition to peripapillary vessel density, FAZ can be affected by the degree of optic disc tilt.

Increased Incidence of Visual Field Abnormalities as Determined by Frequency Doubling Technology Perimetry in High Computer Users Among Japanese Workers: A Retrospective Cohort Study

Background

This retrospective cohort study primarily aimed to investigate the possible association of computer use with visual field abnormalities (VFA) among Japanese workers.

Methods

The study included 2,377 workers (mean age 45.7 [standard deviation, 8.3] years; 2,229 men and 148 women) who initially exhibited no VFA during frequency doubling technology perimetry (FDT) testing. Subjects then underwent annual follow-up FDT testing for 7 years, and VFA were determined using a FDT-test protocol (FDT-VFA). Subjects with FDT-VFA were examined by ophthalmologists. Baseline data about the mean duration of computer use during a 5-year period and refractive errors were obtained via self-administered questionnaire and evaluations for refractive errors (use of eyeglasses or contact lenses), respectively.

Results

A Cox proportional hazard analysis demonstrated that heavy computer users (>8 hr/day) had a significantly increased risk of FDT-VFA (hazard ratio [HR] 2.85; 95% confidence interval [CI], 1.26–6.48) relative to light users (<4 hr/day), and this association was strengthened among subjects with refractive errors (HR 4.48; 95% CI, 1.87–10.74). The computer usage history also significantly correlated with FDT-VFA among subject with refractive errors (P < 0.05), and 73.1% of subjects with FDT-VFA and refractive errors were diagnosed with glaucoma or ocular hypertension.

Conclusions

The incidence of FDT-VFA appears to be increased among Japanese workers who are heavy computer users, particularly if they have refractive errors. Further investigations of epidemiology and causality are warranted.

Progressive Deformation of the Optic Nerve Head and Peripapillary Structures by Graded Horizontal Duction

Purpose

We investigated the effect of graded range of horizontal duction on the shape of the peripapillary Bruch's membrane (ppBM) and optic nerve head (ONH).

Methods

In 50 eyes of 25 normal subjects, the ONH and peripapillary retina were imaged by optical coherence tomography (OCT) in central gaze and incremental angles of add- and abduction. Displacements of the Bruch's membrane opening (BMO), optic cup (OC), and change in ONH angle in eccentric gazes were compared to those of central gaze, in add- and abduction.

Results

With increasing duction, the nasal edge of the BMO (nBMO) shifted progressively anteriorly in adduction and posteriorly in abduction, while the temporal edge of the BMO (tBMO) shifted posteriorly in adduction and anteriorly in abduction. The summed absolute nBMO and tBMO displacements in 30° and 35° adduction significantly exceeded those in comparable abduction angles (P < 0.005 for both). The ONH progressively tilted temporally in adduction and nasally in abduction; absolute ONH tilt in adduction was significantly greater than that in abduction for 30° and 35° ductions (P < 0.005 for both). BMO displacement and ONH tilt in adduction exhibited bilinear behavior, with greater effects for both at angles exceeding 26°. The OC shifted significantly farther anteriorly in abduction than adduction at every angle from 10° to 35°.

Conclusions

Horizontal duction deforms the ONH and ppBM, but more in adduction than in abduction, and increasingly so for angles greater than 26°. This behavior is consistent with optic nerve sheath tethering for adduction exceeding 26°.