Vertical Disc Diameter Research Articles

PM2.5 Exposure as a Risk Factor for Optic Nerve Health in Type 2 Diabetes Mellitus

(1) Objective: This study investigated the relationship between long-term particulate matter (PM2.5) exposure and optic disc parameters—vertical cup-to-disc ratio (vCDR), vertical optic disc diameter (vDD), and vertical optic cup diameter (vCD)—in patients with type 2 diabetes mellitus (T2DM). (2) Methods: A cross-sectional analysis was conducted using data from 65,750 T2DM patients in the 2017–2018 Shanghai Cohort Study of Diabetic Eye Disease (SCODE). Optic disc parameters were extracted from fundus images, and PM2.5 exposure was estimated using a random forest model incorporating satellite and meteorological data. Multivariate linear regression models were applied, adjusting for confounders including age, gender, body mass index, blood pressure, glucose, time of T2DM duration, smoking, drinking, and physical exercise. (3) Results: A 10 μg/m3 increase in PM2.5 exposure was associated with significant reductions in vCDR (−0.008), vDD (−42.547 μm), and vCD (−30.517 μm) (all p-values < 0.001). These associations persisted after sensitivity analyses and adjustments for other pollutants like O3 and NO2. (4) Conclusions: Long-term PM2.5 exposure is associated with detrimental changes in optic disc parameters in patients with T2DM, suggesting possible optic nerve atrophy. Considering the close relationship between the optic nerve and the central nervous system, these findings may also reflect broader neurodegenerative processes.

Longitudinal changes of funduscopic optic disc size, color and cup-to-disc ratio in school children

BackgroundTo investigate the relationship between changes in the optic disc size and color, cup-to-disc (C/D) ratio, and axial elongation in schoolchildren.MethodsA prospective cohort study was performed in 75 right eyes of elementary school students for six years (from 8.5 to 14.5 years old). In the first and last year, all participants underwent optical axial length measurement and color fundus photography. The optic disc color was calculated by dividing the intensity of red by the sum of the intensity of red, green, and blue. The optic disc area was calculated by modifying the number of pixels according to Bennett’s formula. The C/D ratio was calculated by dividing the vertical cup diameter by vertical optic disc diameter. Wilcoxon signed rank test was used to compare these optic disc parameters and axial length in the first and last year.ResultsMean axial length in the last year (24.82 mm) was significantly longer than that in the first year (23.34 mm). Likewise, the mean optic disc size was significantly smaller in the last year (41,946 pixels) than that in the first year (46,144 pixels). The mean optic disc color in the last year (0.49) was significantly more reddish than that in the first year (0.46), while the mean C/D ratio in last year (0.50) was significantly smaller than that in first year (0.52).ConclusionsDuring the period from 8.5 years to 14.5 years of age, both the optic disc size and C/D ratio became smaller, while the color became more red.

Quantitative assessment of colour fundus photography in hyperopia children based on artificial intelligence

ObjectivesThis study aimed to quantitatively evaluate optic nerve head and retinal vascular parameters in children with hyperopia in relation to age and spherical equivalent refraction (SER) using artificial intelligence (AI)-based...

Optic nerve head dimension as biomarker in Leber hereditary optic neuropathy

Aims/Purpose: To study the optic nerve head (ONH) dimension in symptomatic and asymptomatic patients with Leber hereditary optic neuropathy (LHON) and to correlate ONH parameters with genotype and clinical phenotype.Methods: Seventy‐eight affected patients, 175 asymptomatic carriers, and 29 age‐matched healthy controls were enrolled in the study. All patients underwent ONH optical coherence tomography (OCT) measurements by DRI OCT Triton (Topcon, Japan) and were analysed with the Orion custom software (Volexeron, CA, USA). The following parameters were obtained for each eye: disc area, horizontal and vertical diameter; retinal nerve fibre layer (RNFL) and ONH volume. For the comparison of the different parameters the ANOVA with Bonferroni post‐hoc test was performed.Results: LHON‐affected patients appeared to have smaller ONH size parameters compared to control cases, but only the vertical disc diameter of patients with mutations 11 778 and 14 484 were statistically significant. Also, carrier patients with the mutation 11 778 presented a statistical significantly smaller vertical disc diameter compared to controls, instead 14 484 carriers presented a bigger diameter. ONH volume of all affected patients was significantly smaller. Moreover, asymptomatic 11 778 carriers older than 35 years were significantly smaller. Linear regression sustained the relationship between age, volume, and RNFL, unlike between age and disc area.Conclusions: This study exposed the differences of ONH size in LHON‐affected and ‐carrier patients with different mutations: smaller disc in 11 778 affected and unaffected patients and larger disc in 14 484 carriers. A strong correlation was found between ONH volume both in affected patients and carriers older than 35 years old. These results highlight the importance of the 3D ONH structure as a potential biomarker to support clinicians in the characterization of symptomatic LHON patients and possibly at‐risk mutation carriers with different genetic mutations and clinical course.

Comparison of optic disc head vascular density status between crowded and normal discs: An optical coherence tomography angiography study.

To compare the optic disc capillary vascular status between crowded and normal optic discs using optical coherence tomography angiography (OCT-A). A total of 101 eyes were included in this cross-sectional, comparative study. Fifty-one eyes with crowded optic discs (Group 1) were compared with 50 eyes with normal discs (Group 2). Peripapillary and optic disc head capillary vascular density measurements were obtained quantitatively with OCT-A. Mean ages were 46.2±6.2 years in Group1 and 45.9±6.0 years in Group2 (p=0.796).Vertical disc diameters were 1.52±0.2mm in Group 1 and 1.61±0.16mm in Group 2 (p=0.022) whereas horizontal disc diameters were 1.53±0.17mm in Group 1 and 1.61±0.13mm in Group 2(p˂0.014). OCT-A findings were as follows: radial peripapillary capillary, vascular density whole image measurements (%); 49.6±2.3 in Group 1 and 49.1±2.3 in Group 2 (p=0.292), peripapillary capillary density; 53.3±2.8 in Group 1 and 52.6±2.6 in Group 2 (p=0.176), inside disc measurements 52.4 (48.7-54.7) in Group 1 and 46.5 (42.6-49.6) in Group 2 (p˂0.001). RNFL was 118.2±12.2µm in Group 1 and 110.8±11.4µm in Group 2(p=0.002). The vascular density of the disc circumference in individuals with healthy crowded optic discs is not different from those with normal discs. However, inside disc measurements differ between crowded and normal size discs. This finding suggests that when the disc size is reduced, the amount of vessels in it does not decrease in a way that correlates with the size. Therefore, the vascular structures are suitable for compression in the narrow optic nerve head.

Size and position of the optic disc crescent in a white European population with myopia.

SignificanceOne of the first clinically observed changes in the retina with progressing myopia is in the form of optic disc crescents. If such a change is predictive of myopia progression, it could aid in myopia management interventions to target those at greatest risk of progression and subsequent ocular morbidity.PurposeTo investigate the type, dimension and appearance of optic disc crescents and how they relate to the level of myopia.MethodsRetrospective data collection analysing retinal photographs of healthy children and adults with a refractive error of ≤−0.50 D sphere and astigmatism ≤2.00 D. Crescent location, maximum crescent width and vertical disc diameter were measured from retinal images of right eyes only.ResultsFour‐hundred eyes with a mean spherical error (SER) of −0.50 to −14.00 D (aged 7–81 years) were included (83.5% exhibited a discernible crescent). Mean (SD) maximum crescent width was 0.24 (0.24) mm. Univariate analysis showed a significant correlation between crescent width and age (r = 0.26, p < 0.001). SER was correlated with crescent width when controlling for age (r = −0.45, p < 0.001) and to the ratio of crescent width to vertical disc diameter (r = −0.43, p < 0.001). Temporal crescents were the most frequently observed (74%), followed by inferior temporal crescents (17%). One‐way between‐groups analysis of variance showed a significant difference between crescent locations (F = 5.2, p < 0.001). Post‐hoc analysis revealed significant differences in SER between those with no crescent versus an inferior‐temporal crescent, as well as differences between those with temporal versus inferior‐temporal crescents. Other crescent locations did not differ significantly in the level of myopia. Participants not exhibiting a crescent had the lowest level of myopia (mean [SD] −3.03 [1.97)] D), while those with inferior temporal crescents had a mean (SD) SER of −5.01 (2.37) D.ConclusionIn this white European population, higher levels of SER were associated with increasing crescent size. Eyes with inferior temporally located crescents were more myopic.

Inter-eye Comparison of the Lamina Cribrosa Depth in Patients with Bilateral Normal-tension Glaucoma with Asymmetrical Damage

Purpose: To evaluate the association between lamina cribrosa depth (LCD) and the severity of glaucomatous damage in patients with normal-tension glaucoma (NTG).Methods: The optic nerve heads (ONHs) of patients with bilateral NTG showing asymmetrical damage were scanned using spectral-domain optical coherence tomography. LCDs were measured on ONH horizontal B-scan images at three locations equidistant across the vertical optic disc diameter and compared between the more damaged and contralateral eyes. Conditional logistic regression analysis was performed to identify ocular risk factors associated with more severe damage between the eyes.Results: One hundred and four eyes of 52 patients with bilateral NTG were included. The mean age was 66.0 ± 15.0 years; there were 31 males and 21 females. The more damaged eyes exhibited a higher baseline intraocular pressure (IOP) (p &lt; 0.001), a thinner global retinal nerve fiber layer thickness (p &lt; 0.001), and worse visual field mean deviation (p &lt; 0.001) and a pattern standard deviation (p &lt; 0.001), than the contralateral eyes. In contrast, we found no significant inter-eye difference in either the spherical equivalent or the axial length. The average LCD was significantly larger in the more damaged eyes (529.4 ± 116.7 vs. 482.9 ± 107.5 μm, p &lt; 0.001). On conditional logistic regression analysis, the higher the baseline IOP (p = 0.006) and the larger the LCD (p = 0.003), the higher the risk of having more severe damage compared to the contralateral eye under similar systemic conditions.Conclusions: The LCD was significantly larger in the more damaged eyes of patients with bilateral NTG, suggesting that LC deformation might be associated with glaucomatous ONH damage in NTG eyes.

Morphologic Changes in the Lamina Cribrosa Upon Intraocular Pressure Lowering in Patients With Normal Tension Glaucoma.

PurposeThe purpose of this study was to investigate whether the lamina cribrosa (LC) curve changes in response to intraocular pressure (IOP) reduction following administration of topical ocular hypotensive eye drops in eyes with normal tension glaucoma (NTG).MethodsNinety-three eyes of 93 patients with treatment naïve NTG at initial examination and with ≥20% reduction from baseline IOP following administration of topical ocular hypotensive eye drops were included. Serial horizontal B-scan images of the optic nerve head (ONH) were obtained from each eye using enhanced depth imaging spectral domain optical coherence tomography (OCT) before and 1 year after IOP-lowering treatment. The LC curvature in each eye was assessed by measuring the LC curvature index (LCCI) in horizontal OCT B-scan images obtained at three (superior, central, and inferior) locations spaced equidistantly across the vertical optic disc diameter before and after IOP-lowering treatment. We evaluated the OCT detectible change in the LC curvature based on the interval change of LCCI to exceed the intersession standard deviation of 1.96 times and factors associated with the magnitude of the LCCI change in the eyes showing significant LC change.ResultsIOP decreased from 15.7 ± 2.5 mm Hg at baseline to 11.2 ± 1.7 mm Hg after topical glaucoma medication. Among the 93 subjects, 62 (66.7%) eyes showed the significant reduction of the LCCI (interssetional change over 1.5) after the treatment; greater interssessional change of the LCCI after IOP reduction was associated with younger age (P = 0.020) and larger baseline LCCI (P < 0.001).ConclusionsThe OCT detectible changes in LC curvature occurred in response to a modest decrease in the IOP in the naïve NTG eyes. The therapeutic benefit of these changes need to be assessed in longitudinal studies.

Combining spectral domain optical coherence tomography of retinal nerve fiber layer and noncontact tonometry in mass glaucoma screening during the World Glaucoma Week

This study reports the combination of noncontact tonometry and spectral domain optical coherence tomography (SD-OCT) in mass glaucoma screening in the Lebanese population. This cross-sectional study included Lebanese individuals who participated in a glaucoma screening campaign in March 2018 and March 2019 for World Glaucoma Week. Intraocular pressure (IOP) was measured by noncontact tonometry. Optic nerve head (ONH) and retinal nerve fiber layer (RNFL) scans were obtained using SD-OCT. Glaucoma suspects were defined as individuals having an IOP above 21mmHg in at least one eye and/or RNFL thinning in either the superior or the inferior quadrant. Among the 1116 individuals who were examined, 15.5% were found to be glaucoma suspects based upon their IOP readings, 15.5% based on OCT, and 3.0% based on both criteria combined. The mean vertical and horizontal disc diameter was 1.75±0.23mm and 1.57±0.22mm, respectively. Eyes that were suspects by OCT with normal IOP had thinner corneas when compared to eyes with normal OCT and high IOP (512.25μm vs. 559.12μm, P<0.0001). SD-OCT can be an easy and relatively fast component of mass glaucoma screening in addition to IOP measurement. Further studies are needed to establish this combination as a valid glaucoma screening method.

Optic disc morphology in preterm children. Influence of gestational age and birth weight

The characteristics of the optic disc and the development of the optic nerve can affect visual function in children. The purpose of our study was to assess optic disc morphology in preterm infants and to determine whether it is influenced by gestational age, birth weight and the presence of a retinopathy of prematurity. In a retrospective study, RetCam fundus images of 109 premature newborns admitted to our tertiary-level neonatal intensive care unit were reviewed. We evaluated the cup to disc ratio (C/D), optic disc diameter, cup diameter, shape of the optic disc, adherence to the ISNT rule, and presence of a peripapillary atrophy. Of 218 photos, we found the following results: mean±SD gestational age 28.5±2.7 weeks, mean±SD birth weight 1122±394g, mean C/D 0.32. There was no significant correlation between C/D and gestational age or birth weight. Vertical disc diameter was greater than horizontal disc diameter, with a mean ratio (horizontal/vertical) of 4/5, lending an oval shape to the optic disc. Nineteen infants had retinopathy of prematurity in both eyes; ninety-three percent had peripapillary atrophy. In our study, optic disc morphology in premature newborns was not influenced by gestational age, birth weight or presence of premature retinopathy.

Automated AI labeling of optic nerve head enables insights into cross-ancestry glaucoma risk and genetic discovery in >280,000 images from UKB and CLSA

Cupping of the optic nerve head, a highly heritable trait, is a hallmark of glaucomatous optic neuropathy. Two key parameters are vertical cup-to-disc ratio (VCDR) and vertical disc diameter (VDD). However, manual assessment often suffers from poor accuracy and is time intensive. Here, we show convolutional neural network models can accurately estimate VCDR and VDD for 282,100 images from both UK Biobank and an independent study (Canadian Longitudinal Study on Aging), enabling cross-ancestry epidemiological studies and new genetic discovery for these optic nerve head parameters. Using the AI approach, we perform a systematic comparison of the distribution of VCDR and VDD and compare these with intraocular pressure and glaucoma diagnoses across various genetically determined ancestries, which provides an explanation for the high rates of normal tension glaucoma in East Asia. We then used the large number of AI gradings to conduct a more powerful genome-wide association study (GWAS) of optic nerve head parameters. Using the AI-based gradings increased estimates of heritability by ∼50% for VCDR and VDD. Our GWAS identified more than 200 loci associated with both VCDR and VDD (double the number of loci from previous studies) and uncovered dozens of biological pathways; many of the loci we discovered also confer risk for glaucoma.

Optic disc morphometry using spectral domain optical coherence tomography in a Nigerian population.

To assess morphological optic disc dimensions using spectral-domain optical coherence tomography (OCT) in a Nigerian population. Good quality SD-OCT scans of the optic disc of 147 eyes of 88 participants were selected, enrolled, and retrospectively reviewed. All subjects had optic nerve head and retinal nerve fibre layer OCT imaging, as well as analysis, done using the Topcon 3D OCT-1 Maestro®. The age, sex, and some OCT-generated optic disc dimensions namely disc area (DA), vertical disc diameter (VDD), horizontal disc diameter (HDD) were retrieved from the database and analyzed. The mean age of the study subjects was 52.6±20.9 years with a range of 8-90 years; male to female ratio was 1:1.3. The right eye and left eye accounted for 75 and 72 of the 147 scans respectively. The mean DA, VDD, and HDD were 2.54 ± 0.48 mm2, 1926.5 ± 189.6 μm and 1673.9 ± 173.9 μm, respectively. Males had significantly larger DA than females (2.56 ± 0.53 mm2 vs 2.51 ± 0.44 mm2, p = 0.043). The mean DA and VDD of eyes of subjects aged 21-40 years were significantly higher compared to subjects aged 60 years and more (p = 0.008 and 0.001, respectively). The mean optic disc area and diameters are larger than those reported in similar studies involving blacks and other races. The mean disc area reduces with increasing age.

Association between Topographic Features of the Retinal Nerve Fiber Bundle and Good Visual Acuity in Patients with Glaucoma

ABSTRACT Purpose: Maintaining visual acuity in glaucoma patients is an important part of preventing the deterioration of quality of vision. We identified specific areas of the papillomacular bundle (PMB) that were strongly associated with visual acuity, based on en-face images derived from optical coherence topography (OCT) wide scans. Methods: The study recruited 23 eyes of 21 glaucoma patients (age: 61.3 ± 13.0 years, M: F = 9:12, Humphrey field analyzer-measured mean deviation: -19.9 ± 6.5 dB) with good best-corrected visual acuity (20/20 or more) and a remaining PMB with a maximum width no more than half that of the vertical disc diameter. En-face images were derived from 12 × 9 mm wide-scan images made with DRI-OCT (Triton, Topcon). Averaged en-face images were created by identifying the disc center and fovea line (DFL) and aligning it between images. We then measured the frequency of remaining PMB at 10 µm intervals along a vertical line intersecting the DFL at its midpoint. Finally, we used a logistic analysis in a much larger group of patients to identify cases of glaucoma with low BCVA (<20/20). Results: In the averaged en-face image, the residual PMB area appeared as a high-intensity region above the DFL. Analysis showed that residual PMB was most common in an area 830–870 µm above the DFL. The correlation coefficient of residual PMB in this area to BCVA was -0.57 (p < .01), and among OCT parameters in this residual PMB area, the AUC to identify decreased BCVA was highest for ganglion cell complex thickness (0.85, p < .01), with a cutoff of 87.5 µm. Conclusions: This study identified specific areas of the PMB that were associated with BCVA in wide-scan, en-face OCT images from glaucoma patients. This suggests that it may be possible to identify visual impairment during glaucoma treatment by measuring this area.

Correlation between optic disc deformation and retinal vasculature in non-pathological high myopia.

The aim of the current study was to investigate the correlation between optic disc deformation and retinal vasculature in high myopia. A total of 130 eyes with non-pathological high myopia were included in the current cross-sectional study. β-zone parapapillary atrophy (β-PPA), optic disc tilt ratio, and horizontal and vertical disc diameters were analyzed using fundus color photography. A 3x3 mm grid and a 4.5x4.5 mm grid were used to scan parafoveal and peripapillary regions, respectively, using optical coherence tomography angiography. Vessel flow density (VFD) and fractal dimension of the retina, as well as the foveal avascular zone (FAZ), were analyzed and quantified using en face projection images. Optic disc parameters that were associated with vascular changes were determined using multiple linear regression analysis. The results from the multivariate analysis revealed that β-PPA was negatively correlated with the VFD of the superficial retinal plexus (R=-2.805; P=0.006), deep retinal plexus (R=-2.801; P=0.006), radial parapapillary capillaries (R=-3.936; P<0.001) and enhanced-depth imaging of the fovea (R=-2.161; P=0.034). Additionally, FAZ was not significantly correlated with any factors in the current study. Age was negatively correlated with the VFD of the retina (R=-4.234; P<0.001), while the optic tilt ratio (R=-2.291; P=0.025) was negatively correlated with three sectors in the deep layer. Overall, the present results demonstrated that optic disc deformation was negatively correlated with the retinal microvasculature in non-pathological high myopia, particularly in the radial peripapillary capillaries and the deep retinal plexus. Therefore, optic disc deformation may be used to predict the retinal vasculature in high myopia.

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.

Long term change of the optic disc and OCT parameters during myopic shift in children with large cup to disc ratio.

PurposeThis observational case series was to determine long term optic disc changes in eyes with large cup to disc ratio (CDR) and compare the changes induced by myopic shift during childhood with normal control eyes.MethodsChildren under 15 years of age who developed myopia with serial optic disc photographs and spectral domain (SD)-optical coherence tomography (OCT) images with a minimal interval of three years were evaluated. Children with average CDR ≥ 0.6 on SD-OCT were classified as having large CDR. The ratios of vertical disc diameter (VDD), horizontal disc diameter (HDD), and maximum peripapillary atrophy (PPA) width (PPW) were measured to quantify morphologic changes of optic discs and SD-OCT parameters, such as peripapillary retinal nerve fiber layer (RNFL) thickness and macular ganglion cell and inner plexiform layer (GCIPL) thickness were measured.ResultsOf the 82 eyes (82 patients) analyzed, 42 eyes had large CDR and 40 eyes were normal controls. The mean age and refractive error at initial examination were not different between groups (P = 0.33, P = 0.76, respectively). The changes in HDD/VDD and PPW/VDD ratios during follow-up showed no significant difference among the groups (P = 0.45, P = 0.62, respectively). No statistical significance was found in changes in RNFL and GCIPL thickness between the two groups (P = 0.74, P = 0.79, respectively).ConclusionsChildren with enlarged CDR showed changes in optic disc morphology and RNFL/GCIPL thickness similar to normal children during myopic shift.

Prevalence of glaucoma in the elderly population in Taiwan: The Shihpai Eye Study.

Background:This study aimed to evaluate the prevalence, characteristics, and the awareness status of glaucoma in an elderly Chinese population.Methods:A total of 460 individuals aged ≥72 years were enrolled in this cross-sectional community-based eye disease screening program. Glaucoma was diagnosed according to the diagnostic criteria proposed by the International Society of Geographical and Epidemiological Ophthalmology. Characteristics of subjects with primary open-angle glaucoma (POAG) and primary angle-closure glaucoma (PACG) were described and compared between groups using Mann-Whitney U and Fisher’s exact tests.Results:Forty subjects were diagnosed with glaucoma, including 17 subjects with POAG, 22 with PACG, and one with secondary glaucoma. The estimated prevalence of glaucoma, POAG, and PACG was 8.7%, 3.7%, and 4.8%, respectively. In total, 71% of the subjects with PACG and 77% of POAG subjects presented with a normal intraocular pressure (IOP) of <19 mmHg. The demographic and ocular characteristics were similar between the two groups; however, subjects with POAG had a longer axial length and smaller vertical disc diameter than those with PACG. Further, 95% of the glaucoma subjects ever visited the eye clinic, but only 32.5% of them were aware of the disease.Conclusion:Glaucoma is prevalent in the elderly population in Taiwan, but the diagnostic rate and disease awareness are low. Since most subjects with glaucoma presented with normal IOPs, optic disc evaluation is critical for diagnosing glaucoma in the elderly in Taiwan

Differentiation of Nonarteritic Anterior Ischemic Optic Neuropathy from Normal Tension Glaucoma by Comparison of the Lamina Cribrosa.

PurposeTo compare lamina cribrosa (LC) morphology between eyes with nonarteritic anterior ischemic optic neuropathy (NAION) and eyes with normal tension glaucoma (NTG) in the Korean population.MethodsThis retrospective study included 48 eyes with NAION, 48 eyes with NTG, and 48 healthy control eyes matched by age, intraocular pressure, axial length, and optic disc area. Eyes with NAION and NTG were also matched by retinal nerve fiber layer (RNFL) thickness in the affected sector. Optic nerve heads were scanned using enhanced depth imaging spectral-domain optical coherence tomography. LC depth (LCD) and the LC curvature index (LCCI) were measured at seven locations spaced equidistantly across the vertical optic disc diameter. LCD and the LCCI were compared in the three groups.ResultsRNFL thicknesses of the matched affected sectors did not differ between the NAION and NTG groups (P = 0.347). LCD and the LCCI were significantly larger in the NTG group than in the NAION and healthy control groups at all seven planes (P < 0.001 each), but were comparable in the NAION and healthy control groups. The LCCI was larger in the affected than in the unaffected sector of NTG eyes (P = 0.010) but did not differ in NAION eyes (P = 1.000). LCD did not differ between affected and unaffected sectors in either NAION (P = 0.600) or NTG (P = 0.098) eyes.ConclusionsLC morphology differed in eyes with NAION and NTG, despite a similar degree of RNFL damage. Evaluation of LC morphology may help to understand the distinctive pathophysiology of NAION and to differentiate NAION from NTG eyes.

Disc-fovea Angle Is Associated With Visual Field Defect Location in Patients With Glaucoma.

The current study showed that glaucomatous eyes from patients with central visual field defects presented less negative disc-fovea angle compared with patients with peripheral defects. The purpose of this study was to investigate the relationship between disc-fovea angle and visual field defect location in patients with glaucoma. This was a cross-sectional study including glaucoma patients divided into isolated central and isolated peripheral scotoma groups. The main outcome measure was disc-fovea angle measurement between groups. Secondary outcomes included disc-fovea distance, vertical disc diameter, and fovea vertical deviation. We included 50 glaucoma patients (50 eyes; 27 with central scotoma and 23 with peripheral scotoma). Mean deviation from visual fields was -3.05±1.67 and -2.95±1.49 dB (P=0.829) (central and peripheral scotoma groups, respectively). We found that eyes in the central group had lower values of disc-fovea angle (-5.85±2.67 vs. -7.97±2.26 degrees, P=0.004), shorter disc-fovea distance (4.38±0.70 vs. 4.98±0.78 mm, P=0.006), and shorter fovea vertical deviation (-0.43±0.19 vs. -0.68±0.22 mm, P<0.001) compared with eyes in the peripheral group. This study showed an association between disc-fovea angle and central visual field defects in patients with glaucoma. Our findings suggest that eyes with a less negative disc-fovea angle should undergo a more careful investigation of the central visual field, even at early stages of the disease.

Lamina Cribrosa Moves Anteriorly After Trabeculectomy in Myopic Eyes.

PurposeThe purpose of this study was to investigate changes in lamina cribrosa (LC) depth after trabeculectomy in myopic eyes using enhanced depth imaging (EDI) spectral-domain optical coherence tomography (SD-OCT).MethodsSerial horizontal B-scans of the optic nerve head of 41 myopic eyes with primary open-angle glaucoma (POAG) were obtained before and 3 months after trabeculectomy using EDI SD-OCT. LC depth, defined as the distance from the opening plane of Bruch's membrane to the level of the anterior LC surface, was measured before and 3 months after trabeculectomy at 7 locations spaced equidistantly across the vertical optic disc diameter on B-scan images. The mean of the measurements at these seven planes was defined as the average LC depth. Factors associated with changes in LC depth were identified by linear regression.ResultsIntraocular pressure (IOP) decreased from 26.3 ± 9.3 millimeters of mercury (mm Hg) preoperatively to 10.6 ± 3.5 mm Hg 3 months after trabeculectomy. LC depth was significantly lower 3 months after trabeculectomy than preoperatively (P < 0.001, all planes). The magnitude of LC depth reduction was significantly associated with younger age, higher preoperative LC depth, and greater magnitude of IOP reduction (all P ≤ 0.016).ConclusionsLC depth reduction was observed after trabeculectomy in myopic eyes. The degree of LC depth reduction was not related to the degree of myopia.