Assessing Glaucoma Severity and Progression in Individuals with Asymmetric Axial Length: An Intra-Patient Comparative Study.

PURPOSE: To investigate whether there is a difference in inter-eye glaucoma severity and progression in patients with asymmetric axial length DESIGN: Long-term observational study PARTICIPANTS: Patients over 20 years of age who had been diagnosed with glaucoma at Seoul National University Hospital, Seoul, Korea, between 2010 and 2020. METHODS: Patients diagnosed with glaucoma in both eyes with an axial length difference of more than 1.0 mm were included. Each individual's eyes were classified into "longer eye" and "shorter eye," and the baseline and follow-up clinical data were analyzed using the paired test. MAIN OUTCOME MEASURES: Differences in clinical characteristics in patients with asymmetric axial length RESULTS: A total of 190 eyes of 95 glaucoma patients with asymmetric axial length were included in the study. The patients' mean age was 51.2 ± 12.3 years, and the mean follow-up period was 10.1 ± 3.9 years. There was no difference in the baseline intraocular pressure (IOP) or central corneal thickness (CCT) between longer eyes and shorter eyes. Among the baseline disc parameters, ovality index, beta-zone and gamma-zone parapapillary atrophy (PPA) area were larger in the longer eyes. In the baseline OCT data, the retinal nerve fiber layer (RNFL) thickness and ganglion cell-inner plexiform layer (GCIPL) thickness were thinner in the longer eyes. According to a baseline visual field (VF) test, the mean deviation (MD) and visual field index (VFI) values were significantly lower in the longer eyes. Based on an analysis of glaucoma progression, the rate of change of superior GCIPL (longer eyes : -0.65 µm/yr, shorter eyes : -0.40 µm/yr) , MD (longer eyes : -0.40 dB/yr, shorter eyes : -0.21 dB/yr) , and VFI (longer eyes : -0.92 %/yr, shorter eyes : -0.46 %/yr) were larger in the longer eyes. The greater the difference between the mean IOP and beta-zone PPA area between inter-eyes, the greater the difference in the rate of change of RNFL and GCIPL. Additionally, the greater the difference in IOP fluctuation, the greater the difference in the rate of change between MD and VFI. CONCLUSIONS: When there was an axial length difference of more than 1.0 mm, glaucoma tended to be more severe and to progress faster in the longer eyes. The inter-eye difference in glaucoma progression rate is related to both mean IOP and IOP fluctuation.

Can Baseline Parapapillary Atrophy Morphology Predict Future Glaucoma Progression?-An OCT Glaucoma Imaging Study.

PURPOSE: To investigate glaucoma progression based on Optical Coherence Tomography (OCT) Guided Progression Analysis (GPA) according to baseline ß-zone parapapillary atrophy (PPA) morphology in glaucoma patients. DESIGN: Retrospective cohort study. METHODS: Patients over 20 years of age who had been diagnosed with primary open-angle glaucoma (POAG) at Seoul National University Hospital, Seoul, Korea between 2010 and 2020. This study included POAG patients with a minimum of 5 years of follow-up. We quantitatively measured the baseline ß-zone PPA parameters, classified ß-zone PPA morphology according to new classification standard we created and analyzed the corresponding GPA progression of the retinal nerve fiber layer (RNFL). RESULTS: A total of 210 patients with POAG (mean age: 53.8 years) were enrolled in the study. The mean follow-up period was 9.8 years. The average value of the baseline mean deviation in visual field perimetry was -2.48 dB. Longer radial extent and larger angular extent of ß-zone PPA were significantly associated with progression on GPA, as was the presence of disk hemorrhage. Among the 4 classified ß-zone PPA morphologies (Crescent type 1 & 2, Solar-eclipse type 1 & 2), the Solar-eclipse type 2 group showed the highest progression. A Kaplan-Meier survival analysis demonstrated significant differences among the 4 types. CONCLUSIONS: The larger the radial and angular extents of ß-zone PPA, the more progression that was shown on OCT GPA. Furthermore, significant differences in progression were noted based on the morphological type of ß-zone PPA. Our findings indicate that baseline ß-zone PPA parameters and morphology are valuable predictors of future glaucoma progression.

Age-related changes of intraocular pressure in Dutch belted rabbits.

This study investigated intraocular pressure (IOP) in Dutch belted rabbits using two different tonometers, rebound tonometry (TonoVet Plus; TVP) and a Tonopen (Tono-Pen AVIA Vet; TPA). Post-pubescent male Dutch belted rabbits aged 36 weeks (n = 10 animals) were used in the study. IOP measurements were conducted every 2 weeks for 22 weeks using TVP and TPA on both eyes of each rabbit. The average IOP measurements were compared by the paired Student's t-test. Pairwise Pearson's correlation coefficients and Bland-Altman statistics were used. The overall mean IOP measured with TPA was significantly higher than that with TVP (23.5 ± 4.9 vs. 21.8 ± 2.4 mmHg for the right eyes; P = 0.045, and 23.0 ± 4.7 vs. 21.5 ± 2.4 mmHg for the left eyes; P = 0.047). Both tonometers tended to show increased IOP readings with age, and positive correlations between IOP and age were observed with both TPA (r = 0.95, P < 0.001 for right eyes; r = 0.95, P < 0.001 for left eyes) and TVP (r = 0.91, P < 0.001 for right eyes; r = 0.64, P = 0.024 for left eyes). The average bias calculated by subtracting TPA from TVP was - 1.60 (95% confidence intervals - 1.927, - 1.281) mmHg. IOP in post-pubescent Dutch belted rabbits tended to increase with age throughout the 22 week study.

Long-Term Follow-Up of Myopic Glaucoma: Progression Rates and Associated Factors.

PRCIS: In the group of glaucoma patients with myopia, the more severe the degree of myopia, the faster the loss of visual acuity and central visual field defect. DESIGN: Longitudinal observational study. OBJECTIVE: To investigate the progression rate of myopic glaucoma and associated factors by long-term analysis of its clinical course. METHODS: Patients who had had at least 5 years of follow-up and a spherical equivalent of -0.5 diopters or less were included in this study. They were divided into 3 myopia groups according to myopic grade, namely mild myopia (-0.5 to -3.0 diopters), moderate myopia (-3.0 to -6.0 diopters), and high myopia (-6.0 diopters or more), and the clinical course, progression rate, and associated factors were compared among the groups and analyzed. RESULTS: A total of 121 eyes of 121 patients with glaucoma with myopia were included in the study. The average follow-up period was 10.4 ± 2.9 years. In the analysis of progression rate, the change rate of average retinal nerve fiber layer (RNFL) thickness (-0.75 µm/y in mild myopia, -0.82 µm/y in moderate myopia, -0.84 µm/y in high myopia) and the mean deviation change (-0.30 dB/y in mild myopia, -0.37 dB/y in moderate myopia, -0.39 dB/y in high myopia) both tended to be faster as the myopic grade increased. In a Kaplan-Meier survival analysis, the high myopia groups demonstrated a significantly faster VA loss (of more than 3 lines) and a higher incidence of newly developed central visual field defect (CVFD) than did the mild and moderate myopia groups. Longer axial length (odds ratio: 1.72, CI: 1.03-3.07, P = 0.047) and RNFL defect extending to the macula (odds ratio: 4.14, CI: 1.54-12.30, P = 0.007) were significantly associated with newly developed CVFD. CONCLUSIONS: In patients with myopic glaucoma, the higher the degree of myopia, the faster the rate of visual acuity loss and CVFD occurrence. Occurrence of CVFD was associated with longer axial length and widening of RNFLr defect to the macula.

Hemifield-based analysis of pattern electroretinography in normal subjects and patients with preperimetric glaucoma.

This prospective cross-sectional study investigated the visual function of preperimetric glaucoma (PPG) patients based on hemifield (HF) pattern electroretinogram (PERG) amplitudes. Thirty-two (32) normal subjects and 33 PPG patients were enrolled in control and PPG groups, respectively. All of the participants had undergone full ophthalmic examinations, including spectral-domain optical coherence tomography (SD-OCT), visual field (VF) examination and pattern electroretinography (PERG). The PERG parameters along with the HF ratios of SD-OCT and PERG were compared between the control and PPG groups. Pairwise Pearson's correlation coefficients and linear regression models were fitted to investigate the correlations. The PERG N95 amplitudes were significantly lower in the PPG group (P < 0.001). The smaller/larger HF N95 amplitude ratio of the PPG group was found to be smaller than that of the control group (0.73 ± 0.20 vs. 0.86 ± 0.12; P = 0.003) and showed positive correlations with affected HF average ganglion cell-inner plexiform layer (GCIPL) thickness (r = 0.377, P = 0.034) and with average GCIPL thickness (r = 0.341, P = 0.005). The smaller/larger HF N95 amplitude ratio did not significantly change with age (ß = - 0.005, P = 0.195), whereas the full-field N95 amplitude showed a negative correlation with age (ß = - 0.081, P < 0.001). HF analysis of PERG N95 amplitudes might be particularly useful for patients with early glaucoma.

Clinical Significance of Optic Disc Hemorrhage Size in Visual Field Progression in Glaucoma.

PURPOSE: To investigate the correlation between optic disc hemorrhage (DH) size and glaucoma progression. DESIGN: A retrospective observational cohort study METHODS:   SETTING: A single tertiary hospital in South Korea STUDY POPULATION: Two hundred and fifty (250) open-angle glaucoma (OAG) patients with DH. Participants were followed for 5 years or longer, with a minimum of 5 visual field (VF) tests. OBSERVATION PROCEDURE: The DH area was calculated by comparing the pixel numbers of the DH area with the disc area based on optical coherence tomography (OCT). For recurrent DH cases, we calculated the average DH area. DH size was classified as large or small based on the median value. Rates of mean deviation (MD) loss were determined using guided progression analysis (GPA). Univariable and multivariable regression analyses were performed to identify significant predictors of MD loss. MAIN OUTCOME MEASURES: DH size and longitudinal VF progression RESULTS: The mean follow-up period was 11.1 ± 3.6 years. The group with large DH showed faster global MD loss relative to the group with small DH (-0.51±0.48 dB/y vs -0.36 ± 0.42 dB/y, P = .01). In the multivariable model, mean DH size, maximum DH size, and initial MD were all significantly associated with the overall rate of MD loss (all P < .05). CONCLUSIONS: DH size was associated with the rate of VF deterioration. Eyes with larger DH showed more pronounced VF progression.

Intraocular pressure reduction and progression of highly myopic glaucoma: a 12-year follow-up cohort study.

AIMS: To investigate any association between intraocular pressure (IOP) reduction amount and open-angle glaucoma (OAG) progression in highly myopic eyes and to determine the associated risk factors. METHODS: One hundred and thirty-one (131) eyes of 131 patients with highly myopic OAG, all of whom had received topical medications and been followed for 5 years or longer, were enrolled. Based on the IOP reduction percentage, patients were categorised into tertile groups, and subsequently, the upper-tertile and lower-tertile groups were compared for the cumulative probability of glaucoma progression. Kaplan-Meier survival analysis and log-rank testing were applied in the comparison, and multivariate analysis with Cox's proportional hazard model, additionally, was performed to identify progression risk factors. RESULTS: Throughout the average 11.6±4.4 year follow-up on the 131 eyes (mean age, 41.2 years at initial visit; baseline IOP, 16.4 mm Hg), 72 eyes (55.0%) showed glaucoma progression. The upper-tertile group (IOP reduction percentage>23.7%) showed a high cumulative probability of non-progression relative to the lower-tertile group (IOP reduction percentage<11.0%; p=0.034), according to the Kaplan-Meier analysis. Presence of disc haemorrhage (DH; HR=2.189; p=0.032) was determined by the multivariate Cox's proportional hazard model to be significantly associated with glaucoma progression. For progressors, the average rate of retinal nerve fibre layer thickness thinning was -0.88±0.74 µm/year, while the MD change was -0.42±0.36 dB/year. CONCLUSIONS: Glaucoma progression is associated with amount of IOP reduction by topical medications in highly myopic eyes, and DH occurrence is a glaucoma progression risk factor.

Longitudinal evaluation of advanced glaucoma: ten year follow-up cohort study.

This study focused on patients with advanced open-angle glaucoma (OAG) and aimed to identify key factors for monitoring them. We included 127 such patients who were followed for seven years or more, undergoing annual ophthalmic examinations. Glaucoma progression was defined as a deterioration in either structure or function. The progression rates and risk factors were evaluated. The patients were divided into upper- and lower-half subgroups based on the reduction in intraocular pressure (IOP) from the baseline. Over an 11-year period, glaucoma progression was detected in 59 eyes (46.5%). The rate of change in mean deviation (MD) was - 0.43 dB/year for the entire population; - 0.67 dB/year for progressors; and - 0.20 dB/year for non-progressors. Hypertension and disc hemorrhage (DH) were more common in progressors compared to non-progressors (45.8 vs. 23.5%, 11.9 vs. 1.5%; P = 0.008 and P = 0.016). Multivariate Cox's proportional hazard model revealed that the presence of DH and a better baseline MD were associated with glaucoma progression. Additionally, patients with a higher percentage reduction in IOP (> 20.94%) had a lower risk of progression compared to those with less reduction. Inadequate IOP reduction, better baseline MD, presence of DH, and lower central corneal thickness were identified as risk factors for progression in advanced OAG patients.

Nighttime Outdoor Artificial Light and Risk of Age-Related Macular Degeneration.

Importance: Light pollution's impact on human health is increasingly recognized, but its link to exudative age-related macular degeneration (EAMD) remains unclear. Objective: To investigate the association between exposure to outdoor artificial light at night (OALAN) and the risk of incident EAMD. Design, Setting, and Participants: In this nationwide population-based case-control study, all individuals 50 years or older with newly diagnosed EAMD between January 1, 2010, and December 31, 2011, were identified with reference to the Korean National Health Insurance Service registration program database for rare and intractable diseases. Birth year- and sex-matched controls (with no EAMD diagnosis until 2020) were selected at a 1:30 ratio. Data were acquired from May 1 to December 31, 2021, and analyzed from June 1 to November 30, 2022. Exposures: Mean levels of OALAN at participants' residential addresses during 2008 and 2009 were estimated using time-varying satellite data for a composite view of persistent nighttime illumination at an approximate scale of 1 km2. Main Outcomes and Measures: The hazard ratios (HRs) and 95% CIs of the association between residential OALAN and risk of incident EAMD were determined based on maximum likelihood estimation after adjusting for sociodemographic characteristics, comorbidities, and area-level risk factors (ie, nighttime traffic noise and particulate matter of aerodynamic diameter ≤10 µm in each participant's administrative district of residence). Results: A total of 126 418 participants were included in the analysis (mean [SD] age, 66.0 [7.9] years; 78 244 men [61.9%]). Of these, 4078 were patients with newly diagnosed EAMD and 122 340 were EAMD-free matched controls. In fully adjusted models, an IQR (55.8 nW/cm2/sr) increase in OALAN level was associated with an HR of 1.67 (95% CI, 1.56-1.78) for incident EAMD. The exposure-response curve demonstrated a nonlinear, concave upward slope becoming more pronounced at higher levels of light exposure (ie, at approximately 110 nW/cm2/sr). In a subgroup analysis, an IQR increase in OALAN was associated with increased risk of incident EAMD in urban areas (HR, 1.46 [95% CI, 1.33-1.61]) but not in rural areas (HR, 1.01 [95% CI, 0.84-1.22]). Conclusions and Relevance: In this nationwide population-based case-control study, higher levels of residential OALAN were associated with an increased risk of incident EAMD. Future studies with more detailed information on exposure, individual adaptive behaviors, and potential mediators are warranted.

Incidence of and Risk Factors for Fellow-Eye Involvement in Sturge-Weber Syndrome Children With Unilateral Glaucoma.

PRCIS: Among children with unilateral glaucoma associated with Sturge-Weber syndrome (SWS), 7 of 47 demonstrated involvement in the fellow eye, and that group had had earlier first-eye surgery relative to the noninvolvement group. PURPOSE: The aim of this study was to determine the incidence of and risk factors for fellow-eye involvement in children with unilateral SWS-associated glaucoma. MATERIALS AND METHODS: Children diagnosed with a unilateral facial port-wine stain and ipsilateral glaucoma before the age of 5 and followed up for at least 5 years were enrolled. The incidence rates of fellow-eye glaucoma involvement were estimated per 100 person-years, and factors associated with a higher incidence of fellow-eye involvement were investigated. RESULTS: A total of 47 children [24 (51.1%) girls] with unilateral SWS-associated glaucoma were included. All of them had facial port-wine stain involving ophthalmic division of the trigeminal nerve, and 18 (38.3%) had neurological comorbidities. The mean age at glaucoma diagnosis was 0.8±1.2 years [range, 0.08 (1 mo)-4.0 y]. Over a median follow-up of 8.4 years, glaucoma was diagnosed in the fellow eye of 7 of the children (14.9%; incidence rate of 1.8 per 100 person-years), 6 of whom were girls ( P =0.097) and 5 of whom were diagnosed before the age of 4 years ( P =0.508). The fellow-eye-involvement group showed significantly higher mean follow-up intraocular pressure in the fellow eye, older age at first-eye surgery (both P <0.005), and higher frequency of choroidal hemangioma both at first onset and in fellow eyes ( P =0.026 and 0.019, respectively). CONCLUSIONS: In this cohort of SWS children diagnosed with unilateral glaucoma, the risk of fellow-eye involvement was higher in girls, within the first 4 years, and in cases with choroidal hemangioma. The fellow-eye-involved children underwent surgery on the first eye earlier than those without fellow-eye involvement.

Prevalence Ratio of Primary Angle-Closure and Primary Open-Angle Glaucoma in Asian Population: A Meta-Analysis and Multiple Meta-Regression Analysis.

PURPOSE: To investigate the prevalence ratio of primary angle-closure glaucoma (PACG) and primary open-angle glaucoma (POAG) in the Asian population. METHODS: Systematic searches of PubMed, Embase, and Cochrane databases for population-based studies in Asia published until August 5, 2022. We conducted a meta-analysis for PACG to POAG prevalence ratio using inverse variance-weighted random-effects meta-analyses so as to combine the study-specific measures of association. Between-study outcome variation (i.e., heterogeneity) was quantified with the I2 statistic. The multiple meta-regression analyses were performed in order to further account for the reasons for heterogeneity. RESULTS: Twenty studies, with a total study population of 52,522 individuals, had been conducted in 13 countries. The pooled PACG to POAG prevalence ratio was 2.204 (95% confidence interval, 1.617-3.004) with high heterogeneity (p < 0.001). In multiple meta-regression model, prevalence of POAG is the most important predictor for heterogeneity (model importance, 0.954), followed continent (0.508), and publication year (0.222). For every additional elevation of POAG prevalence (i.e., increase of 1.0%), the PACG to POAG prevalence ratio is expected to rise by 0.471. CONCLUSIONS: We estimated the pooled PACG to POAG prevalence ratio in the Asian population. The POAG prevalence is the most important factor to determine the PACG to POAG prevalence ratio.

Papillomacular bundle defect (PMBD) in glaucoma patients with high myopia: frequency and risk factors.

Little is known about the papillomacular bundle defect (PMBD) in glaucoma. As such, we investigated the frequency of PMBD in glaucoma patients with high myopia, and its risk factors. In this retrospective, cross-sectional study, retinal nerve fiber layer (RNFL) defect was analyzed in 92 glaucomatous eyes with high myopia (axial length of 26.0 mm or more or an average spherical value of - 6.0 diopters or less). After dividing them into two groups with and without PMBD, the clinical characteristics of the groups were compared and analyzed. The mean age of the patients was 52.1 ± 10.5 years, and there were 53 males and 39 females. PMBD were observed in 55 eyes (59.8%). There was no significant intergroup difference in baseline or follow-up intraocular pressure (IOP). Parapapillary atrophy (PPA)-to-disc-area ratio (OR 3.83, CI: 1.58-10.27, p = 0.010), lamina cribrosa defect (LCD; OR 2.92, CI: 1.14-8.13, p = 0.031) and central visual field defect (CVFD; OR 3.56, CI: 1.38-9.58, p = 0.010) were significantly associated with the PMBD..

Bleb Morphology on Anterior-Segment Optical Coherence Tomography after XEN Gel Stent Implantation.

We investigated the internal morphology of filtration blebs after XEN gel stent implantation using anterior segment optical coherence tomography (AS-OCT) and identified factors related to intraocular pressure (IOP) postoperatively. Eighteen eyes of 18 patients who had undergone XEN gel stent implantation were analyzed. Blebs were imaged using Visante OCT (Carl Zeiss Meditec AG, Germany) at 6 months and 1 year after surgery and evaluated for quantitative parameters including bleb height, maximum height of internal cavity, maximum bleb wall thickness, and maximum bleb epithelial thickness. Subjects were classified into two groups according to the presence or absence of a definite internal cavity between the conjunctiva and sclera using AS-OCT imaging. Nine eyes (50%) were assigned to the internal cavity group and 9 (50%) to the uniform group. Postoperative IOP was significantly lower in the internal cavity group than in the uniform group both at 6 months and 1 year after surgery (p = 0.024 and p = 0.040). Postoperative IOP showed statistically significant negative correlations with bleb height and the height of the internal cavity (Spearman correlation coefficient r = -0.518, p = 0.028 and r = -0.453, p = 0.034, respectively). AS-OCT facilitates analysis of bleb morphology after XEN gel stent implantation. A larger height of the internal cavity of the bleb appeared to correlate with lower IOP after XEN implantation.

Relative Risks for Dementia among Individuals with Glaucoma: A Meta-Analysis of Observational Cohort Studies.

PURPOSE: To investigate the relative risks (RRs) for dementia among individuals with glaucoma. METHODS: We conducted a search of PubMed, Web of Science, Scopus, and Cochrane databases for observational cohort studies examining the association between glaucoma and dementia until March 2023. Two authors independently screened all titles and abstracts according to predefined inclusion and exclusion criteria. Pooled RR and 95% confidence intervals (CIs) were generated using random-effect models. RESULTS: The meta-analysis included 18 cohort studies conducted in eight countries and involving 4,975,325 individuals. The pooled RR for the association between glaucoma and all-cause dementia was 1.314 (95% CI, 1.099-1.572; I2 = 95%). The pooled RRs for the associations of open-angle glaucoma with Alzheimer dementia and Parkinson disease were 1.287 (95% CI, 1.007-1.646; I2 = 96%) and 1.233 (95% CI, 0.677-2.243; I2 = 73%), respectively. The pooled RRs for the associations of angle-closure glaucoma with all-cause dementia and Alzheimer dementia were 0.978 (95% CI, 0.750-1.277; I2 = 17%) and 0.838 (95% CI, 0.421-1.669; I2 = 16%), respectively. No evidence of publication bias was detected in the Begg-Mazumdar adjusted rank correlation test (p = 0.47). CONCLUSIONS: Based on current observational cohort studies, there is evidence supporting that glaucoma is a risk factor for dementia in the adult population.

Surgical Outcome of Refixation versus Exchange of Dislocated Intraocular Lens: A Retrospective Cohort Study.

We compared the surgical outcomes and complications of refixation vs. exchange of dislocated intraocular lenses (IOLs) in patients who underwent transscleral suture fixation combined with pars plana vitrectomy for the treatment of IOL dislocation. A total of 83 eyes (n = 83 patients) with postoperative follow-up of ≥6 months were evaluated: 40 received refixation of dislocated IOL (refixation group) while 43 received IOL exchange (exchange group) treatment. Treatment outcomes, including best-corrected visual acuity (BCVA), spherical equivalent, corneal cylinder, intraocular pressure (IOP), central macular thickness (CMT), and corneal endothelial cell density (ECD), and postoperative complications were retrospectively reviewed. BCVA improvement at 6 months after surgery was comparable between the groups. Postoperative decrease in corneal ECD was significantly greater in the exchange group than in the refixation group, but no significant differences were found in spherical equivalent, corneal cylinder, IOP, or CMT changes. The exchange group experienced significantly more frequent postoperative vitreoretinal complications, such as retinal detachment, choroidal effusion, cystoid macular edema, and secondary epiretinal membrane, than the refixation group. Without any reason to extract the dislocated IOL, reuse of the dislocated IOL would be a better surgical option for transscleral suture fixation to protect corneal endothelial cells and prevent postoperative vitreoretinal complications.

Short foveo-disc distance in situs inversus of optic disc.

Situs inversus of optic disc (SIOD) is thought to be a congenital optic disc abnormality that is caused by dysversion of optic nerve insertion. SIOD, however, has many additional features that cannot be explained by abnormal optic-nerve-insertion directionality. In this study, we measured the distance between the fovea and disc in 22 eyes of 15 SIOD patients. For comparison, two control eyes were matched with each SIOD eye by age and axial length. The vertical distance between the temporal vascular arcades also was measured. The foveo-disc distance was shorter in the SIOD eyes than in the control eyes, while the inter-arcade distance did not differ. Further, we measured the circumpapillary retinal nerve fiber layer thickness, which showed nasal crowding of two humps in the SIOD eyes. This nasal crowding disappeared when we shifted the circle scan by the mean difference (465 µm) of the foveal-disc distance between the two groups. Our findings suggest that the optic disc was located closer to the fovea than it would have been normally. Thus, SIOD might reflect incomplete expansion of the posterior pole in the direction of the fovea-disc axis.