Association between localized retinal nerve fiber layer defects in nonglaucomatous eyes and metabolic syndrome: a propensity score-matched analysis.

Background: We investigated the association between metabolic syndrome and localized retinal nerve fiber layer (RNFL) defects in nonglaucomatous subjects. Methods: We examined 20,385 adults who visited the Health Promotion Center of Seoul St. Mary's Hospital between May 2015 and April 2016. After excluding those with known glaucoma or glaucomatous optic discs, subjects with and without localized RNFL defects were 1:5 propensity score matched. Metabolic syndrome components, including central obesity, elevated triglyceride, reduced high-density lipoprotein (HDL) cholesterol, elevated blood pressure (BP), and elevated fasting glucose, were compared between two groups. We performed logistic regression to investigate the association between RNFL defects and each component of metabolic syndrome and the number of metabolic syndrome components. Results: Subjects with RNFL defects showed higher waist-to-hip ratios, systolic BP (SBP) and diastolic BP (DBP), fasting blood glucose, and hemoglobin A1c (HbA1c) levels than did those without RNFL defects both before and after propensity score matching. The number of metabolic syndrome components was significantly greater in those with RNFL defects (1.66±1.35) than in those without (1.27±1.32, P<0.01). In multivariate logistic regression, the odds ratio (OR) of RNFL defects was significantly increased in subjects with central obesity [OR =1.53, 95% confidence interval (CI): 1.11-2.13], elevated BP (OR =1.50, 95% CI: 1.09-2.05), and an elevated fasting glucose level (OR =1.42, 95% CI: 1.03-1.97). An increased number of metabolic syndrome components was associated with a higher risk of RNFL defects. Conclusions: Localized RNFL defects in nonglaucomatous subjects are associated with metabolic syndrome components, including central obesity, elevated BP, and an elevated fasting glucose level, suggesting that comorbid metabolic syndrome should be considered when evaluating subjects with RNFL defects.

Characteristics of diffuse retinal nerve fiber layer defects in red-free photographs as observed in optical coherence tomography en face images.

BACKGROUD: To determine whether diffuse retinal nerve fiber layer (RNFL) defects, identified on red-free fundus photographs, could be identified on optical coherence tomography (OCT) en face structural images and to evaluate which factors are related to the different recognition patterns on en face images. METHODS: This retrospective, cross-sectional study included open-angle glaucoma eyes with diffuse RNFL defects in the inferior hemifield, identified in red-free photographs. The corresponding OCT en face structural images were divided into 3 groups: (1) no defect, (2) localized defect, and (3) diffuse defect. We compared the demographic and clinical ocular characteristics among the groups. RESULTS: A total of 209 eyes from 157 patients were included. The distribution of OCT en face images was: no defect, 25 eyes (11.96%); localized defect, 106 eyes (50.72%); diffuse defect, 78 eyes (37.32%). Logistic regression analysis revealed that eyes with greater mean deviation (P = 0.004) and thicker inferior RNFL (P = 0.008) would be included in the no defect and localized defect groups based on OCT en face images, rather than in the diffuse defect group. CONCLUSION: Around half of diffuse RNFL defects identified in the red-free photographs appeared as localized defects in OCT en face images. Mild glaucomatous damage was related to no defect and localized defect groups, classified based on the OCT en face images, in eyes with diffuse photographic RNFL defects. OCT en face images may be helpful in further assessing diffuse RNFL defects seen in red-free photographs in eyes with open-angle glaucoma.

Relationship between Plasma Homocysteine Level and Glaucomatous Retinal Nerve Fiber Layer Defect.

AIMS: To investigate the association between plasma homocysteine levels and glaucomatous retinal nerve fiber layer (RNFL) defect in South Korean population. MATERIALS AND METHODS: This retrospective cross-sectional study included subjects who underwent screening at Kangbuk Samsung Hospital Health Screening Center between August 2012 and July 2013. Subjects underwent physical examination and provided samples for laboratory analysis of homocysteine. Subjects were divided equally into four quartiles (Qs) based on plasma homocysteine level. Digital fundus photographs of both eyes were obtained. Determination of glaucomatous disc appearance was based on criteria set forth by the International Society of Geographical and Epidemiological Ophthalmology and based on the appearance of the RNFL and optic disc. Multivariate logistic regression models were used to define elevated glaucoma risk with P < 0.2 on univariate analysis. RESULTS: A total of 78,049 subjects were included; 76,093 subjects were male, and 1956 subjects were female. When analyzed by gender, the mean homocysteine level in the male group with glaucomatous RNFL defects (11.05 ± 3.80 µmol/L) was higher than those without RNFL defects (10.81 ± 4.12 µmol/L (P = 0.000, χ2 test). Upon multifactorial logistic regression analysis adjusted for age, gender, creatinine, diabetes mellitus, hypertension, and hyperlipidemia, glaucomatous RNFL defects had a significant correlation with plasma homocysteine level. Based on the Q2 level, the odds ratio (OR) of Q3 was 1.267, while the OR of Q4 was 1.285 (95% CI = 1.067-1.505, 1.081-1.529, respectively, P for trend = 0.001). CONCLUSION: Our results suggest that homocysteine level is associated with the presence of glaucomatous RNFL defects.

Utility of Heidelberg retinal tomography as a screening tool for analyzing retinal nerve fiber layer defects.

CONTEXT: Although Heidelberg retinal tomography (HRT)-generated topographic images have been studied extensively for the detection of retinal nerve fiber layer (RNFL) defects, little is known about the role of HRT-generated surface reflectivity images in the detection of RNFL defects in either patients with glaucoma or glaucoma suspects. AIMS: To evaluate the effectiveness of HRT version II (HRT II) optic nerve reflectivity images in uncovering RNFL defects in an outpatient population evaluated for glaucoma. STUDY DESIGN/MATERIALS AND METHODS: In 102 consecutive eyes from 60 patients evaluated for glaucoma in an academic-based practice, HRT II optic nerve images were prospectively imaged and compared with clinical optic nerve exam techniques to see if HRT II was able to detect RNFL defects overlooked in clinical practice. RESULTS: Nine eyes (8.8%) were found to have RNFL defects recognized by screening with HRT II. Of these nine eyes, eight (88.9%) were recognized to demonstrate RNFL defects by conventional examination techniques. One additional eye had an RNFL defect seen on physical exam that was not detected by HRT. CONCLUSION: In academic practice, HRT II may be helpful in complementing conventional exam techniques in the recognition and documentation of acquired RNFL loss.

Diffuse retinal nerve fiber layer defects identification and quantification in thickness maps.

PURPOSE: To report retinal nerve fiber layer (RNFL) defect identification and quantification in RNFL thickness maps according to the structural RNFL loss, and to evaluate diffuse RNFL defects. METHODS: A total of 170 patients with glaucoma and 186 normal subjects were consecutively enrolled. We defined RNFL defects in an RNFL thickness map by the degree of RNFL loss. The reference level for RNFL defect determination was set as a 20% to 70% degree of RNFL loss with a 1% interval. To identify RNFL defects, each individual RNFL thickness map was compared to the normative database map by using MATLAB software, and the region below the reference level was detected. The area, volume, location, and angular width of each RNFL defect were measured. Diffuse RNFL defects were defined as having an angular width > 30°. RESULTS: The optimal reference level for glaucomatous RNFL defects identification was 42% loss of RNFL. Retinal nerve fiber layer defects were identified in all (100%) of the 170 glaucoma patients and false-positive RNFL defects were detected in 16 (8.16%) cases among the 186 normal subjects. In all, 64.1% of glaucoma patients had diffuse RNFL defects, and 47.7% of diffuse RNFL defects were associated with mild glaucoma patients. The volume of diffuse RNFL defects was significantly associated with the severity of glaucomatous damage (P = 0.009). Diffuse RNFL defects were located closer to the center of the optic disc than localized RNFL defects (P < 0.001). CONCLUSIONS: Retinal nerve fiber layer thickness map analysis is an effective method for analyzing RNFL defects. Quantitative measurements (area, volume, location, and width) were useful to understanding diffuse RNFL defects.

Comparison of the Detection Rate, Location and Amount of Retinal Nerve Fiber Layer Defect

PURPOSE: To compare the detection rate of the patients with retinal nerve fiber layer (RNFL) defect and the amount of RNFL defect according to the patients' age. METHODS: Retrospective chart reviews of 22,811 subjects, who visited the health care center from January 2009 to December 2009 were performed. The detection rate, location and average amount of RNFL defect and the proportions of the patients who were diagnosed with glaucoma through Humphrey visual field (HVF) test or determined as a glaucomatous optic disc were compared according to the patients' age. RESULTS: The proportions of the patients whose RNFL defect were detected was highest in the patients 60 years old or older (2.3%) and was statistically significant (p = 0.012). However, there was no significant difference among the other age groups (under 40 years: 1.7%, 40 thru 49 years: 1.5%, 50 thru 59 years: 2.0%). The proportions of the patients who were determined as glaucoma through the HVF test or glaucomatous optic disc were also highest in the patients 60 years old or older (1.4%), however, there was no statistically significant difference (p = 0.070) among the age groups (under 40 years: 1.1%, 40 thru 49 years: 0.9%, 50 thru 59 years: 1.2%). CONCLUSIONS: The RNFL defect is likely to be detected in subjects less than 40 years of age and the detection rate is similar to subjects in their 40's and 50's. The use of fundus photography to detect RNFL defect in a health care center is recommended in subjects under 40 years of age.

Analysis of Localized Retinal Nerve Fiber Layer Defects not Detected by Optical Coherence Tomography

PURPOSE: To analyze localized RNFL defect cases that were identified in retinal nerve fiber layer (RNFL) fundus photographs but not in optical coherence tomography (OCT). METHODS: Analysis of OCT scans and images was performed for 14 eyes (17 locations) that showed localized RNFL defects in RNFL fundus photographs but not in RNFL thickness average analysis. RESULTS: With respect to the range of RNFL defects, 41.2% were less than 10degrees, 47.0% were 11 to 20degrees, and 11.8% were 21 to 30degrees. In 71.4% of the RNFL cases the defects were less than 10degrees and the decrease of RNFL thickness was not readily observable on the OCT scan images. In all cases of RNFL defects in the 11 to 30degrees range the decrease in RNFL thickness could be assessed on the OCT scan images. Nonetheless, the decrease of RNFL thickness could not be seen on the OCT analysis images in which the results of the RNFL thickness made through an automated computer algorithm were displayed. CONCLUSIONS: The range of localized RNFL defects that were difficult to detect with OCT consisted of those cases that were almost less than 20degrees. The limitations of the OCT scan itself in patients with RNFL with an angular width defect less than 10degrees and the problems of RNFL thickness analysis processing in patients with an angular width of 11 to 30degrees may decrease the sensitivity of OCT in diagnosing RNFL defects.

Retinal Nerve Fiber Layer Thickness Analysis in Early Glaucoma

PURPOSE: To investigate the difference between superior and inferior peripapillary retinal nerve fiber layer (RNFL) thickness in early glaucoma patients who have RNFL defect in either superior quadrant or inferior quadrant and to determine if it can be useful to detect early glaucomatous change. METHODS: Eighty eight patients with early glaucoma who have RNFL defect in either the superior quadrant or the inferior quadrant as confirmed by red free photograph (40 eyes with normal standard automated perimetry and 48 eyes with early glaucomatous visual field loss) were divided into the superior RNFL defect group and the inferior RNFL defect group. The average RNFL thickness was measured in the superior and inferior quadrants using optical coherence tomography and the thickness differences between the superior and the inferior quadrants (S-I difference) were compared among early glaucoma eyes and 59 normal controls. Then, discriminative power of the S-I difference was assessed by area under ROC (AUROC). RESULTS: The average thickness of the RNFL showed a statistically significant difference between early glaucoma eyes and normal controls (P<0.05). S-I differences of the superior RNFL defect group and inferior RNFL defect group in preperimetric patients and in early perimetric patients were -20.5+/-16.4 micrometer and 15.0+/-14.2 micrometer, -24.0+/-17.2 micrometer and 18.4+/-16.7 micrometer, respectively, which were significantly greater than that of the normal control group (-8.2+/-17.1 micrometer). AUROC of S-I difference in the superior and inferior defect groups of preperimetric patients were 0.691, 0.872, respectively. CONCLUSIONS: The difference in RNFL thickness between the superior and inferior quadrants (S-I difference) in early glaucoma patients was larger than in normal controls. We expect that this parameter of RNFL analysis using OCT can be useful in detecting early glaucoma.

Assessment of Retinal Ganglion Cell using Retinal Nerve Fiber Layer Photography in Age-related Macular Degeneration

PURPOSE: To determine the loss of ganglion cell layer (GCL) neurons in patients with age-related macular degeneration (AMD) with choroidal neovascularization (CNV). METHODS: Retinal nerve fiber layer (RNFL) photography was taken in patients with AMD with CNV to assess the presence of RNFL defects in the papillomacular bundle area. Patients with other ocular disorders or a history of previous intraocular surgery or laser treatment were excluded from this study. RESULTS: Eighty-five eyes in 65 patients were included, of which only one (1.2%) showed papillomacular bundle defects in association with CNV. CONCLUSIONS: From this study, the majority of the patients with AMD with CNV had no papillomacular bundle defect, which demonstrates that considerable amount of GCL is maintained in AMD.