Study of retinal nerve fiber layer thickness in diabetic patients using optical coherence tomography

Purpose: This study aimed to assess and compare the changes in peripapillary retinal nerve fiber layer (RNFL) thickness in nondiabetics and diabetics with various stages of diabetic retinopathy (DR). Methods: The study subjects were divided into four groups based on their diabetic status and findings, namely, controls (normal subjects without diabetes [NDM]), diabetics without retinopathy (NDR), nonproliferative DR (NPDR), and proliferative DR (PDR). Peripapillary RNFL thickness was assessed using optical coherence tomography. One?way analysis of variance (ANOVA) with the post?Tukey HSD test was done to compare RNFL thickness in different groups. The Pearson coefficient was used to determine the correlation. Results: There was statistically significant difference in measured average RNFL (F = 14.8000, P < 0.05), superior RNFL (F = 11.7768, P < 0.05), inferior RNFL (F = 12.9639, P < 0.05), nasal RNFL (F = 12.2134, P < 0.05), and temporal RNFL (F = 4.2668, P < 0.05) across the different study groups. Pairwise comparison showed that there was a statistically significant difference in RNFL measured (average and all quadrants) in patients with DR (NPDR and PDR) and the NDM control group (P < 0.05). In diabetics without retinopathy, the RNFL measured was reduced compared to controls, but it was statistically significant only in the superior quadrant (P < 0.05). Average RNFL and RNFL in all quadrants showed a small negative correlation with the severity of DR and it was statistically significant (P < 0.001). Conclusion: In our study, peripapillary RNFL thickness was reduced in diabetic retinopathy compared to normal controls and the thinning increased with the severity of DR. This was evident in the superior quadrant even before the fundus signs of DR set in

Changes in retinal nerve fiber layer and macular retinal thickness and predictive value of outcome in children with abnormal refractive amblyopia / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To investigate the changes in retinal nerve fiber layer(RNFL)and macular retinal thickness(MRT)in children with refractive abnormalities and amblyopia, and their predictive value of outcome.METHODS: A total of 168 children with myopic refractive abnormalities and monocular amblyopia admitted to our hospital from January 2020 to October 2022 were selected as the observation group, with 118 cases of mild to moderate amblyopia and 50 cases of severe amblyopia, and 168 children with normal vision were included as the control group in a 1:1 ratio during the same period. The changes of RNFL and MRT in two groups of children were statistically counted, and the correlation between the severity of refractive abnormalities and RNFL and MRT in children with amblyopia was analyzed. Additionally, the observation group was divided into effective subgroup and ineffective subgroup based on the therapeutic effect. The general information, as well as RNFL and MRT of the effective subgroup and the ineffective subgroups before and after treatment were compared. Logistic was used to analyze the factors influencing efficacy, and ROC curves was plotted to analyze the predictive value of RNFL and MRT alone or in combination for efficacy.RESULTS: RNFL and MRT of cases of severe amblyopia were higher than those of the mild to moderate amblyopia and the control groups(all P&#x0026;#x003C;0.05); the severity of amblyopia in children with refractive abnormalities is positively correlated with RNFL and MRT(rs=0.745 and0.724, both P&#x0026;#x003C;0.001); among patients of mild to moderate and severe, there were statistically significant differences between the effective and ineffective subgroups in terms of initial treatment age, fixation form, treatment compliance, as well as RNFL, MRT, and their differences before and 1mo postoperatively(all P&#x0026;#x003C;0.05). Logistic analysis showed that initial treatment age, fixation nature, treatment compliance, RNFL and MRT before and 1mo postoperatively were all factors influencing the therapeutic effect of amblyopia with refractive abnormalities in children(all P&#x0026;#x003C;0.05); after 1mo of treatment, the combined prediction of RNFL and MRT was significantly better than that of single prediction in children with mild to severe amblyopia.CONCLUSION:There are differences in RNFL and MRT in children with abnormal refractive amblyopia, and they are closely related to the different degrees and curative effects of children. The combination of RNFL and MRT after 1mo of treatment has certain value in predicting children with different degrees of abnormal refractive amblyopia.

Comparison of peripapillary capillary plexus using optical coherence tomography angiography and retinal nerve fibre layer analysis using spectral domain optical coherence tomography in glaucoma patients, glaucoma suspects, and healthy subjects

Purpose: To assess the association between radial peripapillary capillary (RPC) plexus using optical coherence tomography angiography (OCTA) and retinal nerve fibre layer (RNFL) thickness using spectral domain OCT (SD?OCT) in primary open?angle glaucoma (POAG) patients, glaucoma suspects, and healthy subjects. Methods: In this single?centre cross?sectional observational study, POAG, glaucoma suspects, and healthy patients underwent OCT?RNFL and optic nerve head angiography scans. The RNFL thickness and the vascular parameters obtained from RPC plexus, including perfusion density (PD), flux index (FI), and vessel density (VD), were analysed. Results: In all, 120 eyes of 120 patients, including 40 POAG patients, 40 glaucoma suspects, and 40 healthy subjects, were included. The pairwise comparison of mean RNFL thickness, FI, and VD showed significant difference (P < 0.001) in all sectors between POAG, glaucoma suspects, and healthy eyes. However, PD showed no significant difference between glaucoma suspects and healthy eyes. The average RNFL thickness was found to have a better diagnostic ability than VD to distinguish POAG eyes from healthy eyes and glaucoma suspects based on receiver operating characteristics curve and area under the curve. VD had better diagnostic accuracy than RNFL when glaucoma suspects and healthy were compared. Conclusion: OCT?RNFL has better diagnostic capability in differentiating glaucoma from healthy eyes compared to OCTA. However, OCTA was found to be better in screening out glaucoma suspects from healthy eyes. The VD is a better OCTA parameter than FI and PD to differentiate POAG and glaucoma suspects from healthy eyes

Evaluation of visual field changes with retinal nerve fiber layer thickness in primary congenital glaucoma

Purpose: To evaluate visual field changes in primary congenital glaucoma (PCG) with retinal nerve fiber layer thickness on optical coherence tomography. Methods: In this cross?sectional, observational study, consecutive PCG children who underwent combined trabeculotomy with trabeculectomy and on regular follow?up were enrolled. All patients were aged over four years and co?operative for RNFL OCT and visual field examination. Perimetry was done on Humphrey visual field (HVF) analyzer using 30?2 and 10?2 SITA standard algorithms as appropriate. If a reliable automated perimetry was not feasible, kinetic perimetry was done. The following were noted at baseline and every follow?up: age, sex, visual acuity, intraocular pressure (IOP), cup–disc ratio (CDR), corneal diameters, refraction, any topical antiglaucoma medications, surgeries underwent, age at surgery and duration between surgery and final examination. Results: Forty?eight eyes of 34 children operated for PCG and 19 eyes of 17 controls were analyzed. A statistically significant thinner average RNFL thickness of 87.2 ± 28 ?m was noted in PCG eyes as compared to controls with 100.6 ± 7.2 ?m (P = 0.04). The mean cup–disc area ratio on OCT in PCG eyes was 0.43 ± 0.2 (0.02–0.93) and in control eyes was 0.23 ± 0.07 (0.1–0.4) (P < 0.001). On RNFL OCT, there was significant focal RNFL loss in temporal superior (P = 0.003), nasal inferior (P = 0.037) and temporal inferior (P < 0.001) quadrants compared to controls. Among PCG eyes, 20/48 eyes (41.7%), had definitive, reproducible glaucomatous VF defects. Mean baseline IOP in PCG eyes with VF defect was 28.7 ± 5.7 mmHg and in eyes with normal VF was 24.6 ± 5.9 mmHg (P = 0.03). On univariate regression analysis, higher baseline IOP was significantly associated with both RNFL loss (odds ratio (OR): ?2.17) and VF defects (OR: 3.35). Fluctuation in follow?up IOP (OR: 3.33) was also significantly associated with the presence of VF defects. On multivariable regression analysis maximum, IOP was significantly associated with RNFL loss and VF defects. Conclusion: Peripapillary RNFL thickness could be used to identify PCG eyes having visual field loss and possibly poor visual function from PCG eyes without visual field defects. Baseline and follow?up IOP, significantly correlated with RNFL thickness in PCG eyes

Optical coherence tomography features and correlation of functional and structural parameters in patients of idiopathic intracranial hypertension

Purpose: To determine the correlation between functional parameters and optical coherence tomography (OCT) features in patients of idiopathic intracranial hypertension (IIH). Methods: A prospective observational study in early and established cases of papilledema in IIH presenting from December 2017 to February 2019. Functional parameters (visual acuity, contrast sensitivity, mean deviation, VER, and MfERG) and structural parameters (RNFL, GCL?IPL, and optic disc height) were measured at baseline and every 6 weeks for 6 months. Results: At baseline, average RNFL had a moderate negative correlation with mean deviation (r = ?0.45; P = 0.0007) and a positive correlation with logMAR visual acuity (r = 0.18; P = 0.17). On the contrary, baseline GCL and logMAR visual acuity had a negative correlation (r = ?0.4, P = 0.02). Optic disc height (ODH) had a negative correlation with visual field mean deviation (r = ?0.046; P = 0.0005). At 6 months, ODH and GCL?IPL complex had a statistically significant correlation with functional parameters. However, RNFL values did not show any significant correlation with any of the functional parameters. Baseline GCL?IPL and optic disc height values had a moderate and significant correlation with final functional parameters. However, RNFL did not show any correlation with final functional parameters. Correlation between GCL?IPL thickness at 6 weeks and final functional parameters were stronger than that with baseline GCL values. Conclusion: In the setting of severe papilledema, RNFL can misguide the prognosis. GCL?IPL can be a valuable tool for an objective evaluation of the integrity of the optic nerve in IIH and ODH may be used as an alternative or in combination with GCL?IPL in these cases.

Patterns of Visual Field Defects in Malay Population with Myopic Eyes

@#Introduction: Myopia is an emerging vision problem that causes public health and economic burden worldwide and associated with increased risk to many ocular conditions leading to blindness. This study aimed to evaluate patterns of visual field defects in Malay population with myopia. Methods: A retrospective study was conducted between January 2018 until June 2018 at MSU Eye Centre and data was obtained from patient records of Malay subjects with myopia and free from any ocular and systemic diseases. The spherical equivalent (SE) of the refractive errors and the global indices (mean deviation, MD and pattern of standard deviation, PSD) of OCULUS Twinfield® 2 with SPARK strategy were recorded for this study. Results: A total of 90 eyes with the mean age of 29.16 (SD: 10.27) years old and SE (M= -2.92 D, SD:2.94 D) were selected. The mean of MD was -1.71 dB (SD 3.95 dB) and PSD was 1.81 dB (SD:1.82 dB) respectively. Significant differences was found in MD (p=0.012) and PSD (p=0.01) between the three groups. The localised field defect was observed in the moderate to high myopic eyes in all quadrants (p=0.01) for PP2, and also more prevalent pattern found in all quadrants for PP1 except at superior quadrant (p=0.08). Conclusions: There is a localised visual field defect found in a higher degree of myopia particularly at temporal, nasal and inferior quadrants. Thus, the visual field test is recommended as a routine procedure in moderate to high myopic eyes and need to be interpreted with caution.

Analysis of macular, foveal, and retinal nerve fiber layer thickness in children with unilateral anisometropic amblyopia and their changes following occlusion therapy

Purpose: To analyze macular thickness (MT), foveal thickness (FT), and retinal nerve fibre layer thickness (RNFLT) in children with unilateral anisometropic amblyopia and their changes following occlusion therapy. Methods: A prospective, longitudinal, and comparative study of 60 children aged between 5 and 18 years consisted of two groups, group 1: 30 children with unilateral anisometropic amblyopia; group 2: 30 normal children. Best corrected visual acuity (BCVA), a detailed ocular examination, spectral domain optical coherence tomography for MT, FT, and RNFLT in both eyes were done at visit one (baseline) and every 3 months for a year following occlusion therapy (initiated one month after first visit) in group 1. Results: Mean BCVA, MT, FT, and RNFLT in amblyopic eyes at first visit were 0.63 ± 0.405, 286.9 ± 6.522 ?m, 195.90 ± 8.462 ?m, and 100.87 ± 6.240 ?m, respectively and at last visit after occlusion therapy were 0.50 ± 0.318, 248.9 ± 11.681 ?m, 169.47 ± 10.941 ?m, and 99.43 ± 5.722 ?m, respectively. At first visit, mean BCVA, MT, FT, and RNFLT in nonamblyopic eyes (group 1) were 0 ± 0, 240 ± 10.447 ?m, 159.27 ± 9.285 ?m, 98.63 ± 4.723 ?m and in normal eyes (group 2: average of right and left eyes) were 0 ± 0, 239.8 ± 4.294 ?m, 143.6 ± 4.61 ?m, 100.5 ± 2.895 ?m, respectively. Conclusion: MT and FT, which were more in amblyopic eyes as compared to normal fellow eyes and group 2, decreased with improvement in BCVA after occlusion therapy. However, there was no difference in RNFLT between amblyopic eyes and normal fellow eyes and group 2 before and after occlusion therapy.

Relationship between Changes in RNFL thickness of optic discs and visual field defects / 中国法医学杂志

Objective To discuss the relationship between thickness of RNFL and visual field, and its application in forensic identification. Methods Using the GDxVCC and Octopus automatic perimeter to check on 52 optic nerve lesion cases. The data is grouped according to valid value of visual field (Group1- severe injury group, Group2-minor injury group, Group3- slight and following slight injury group) , calculated for the averaged RNFL thickness, and analyzed by ANOVA. Meanwhile, the correlation between RNFL thickness and visual field indices(effective value of visual field, MD, MS, sLV) was analyzed with Pearson's correlation and described in scattered plot. Results Group 1 to 3 average RNFL thickness was 60.9036±9.53514μm, 53.6474±15.45306μm, 36.3±8.45695μm accordingly. Through ANOVA we can see that differences wer significant between every group. The valid value of visual field and MS were positively with the average RNFL thickness with a correlation of 0.543, 0.400, respectively(P<0.05). The MD and sLV were negatively correlated with the average RNFL thickness with correlation -0.450、-0.440, respectively(P<0.05). Linear relationship between the average RNFL thickness and effective value of visual field, MD, MS, sLV were Y=0.967X+19.508, Y=0.095X-10.858, Y=0.175X+9.187, Y=-0.205X+20.215accordingly. Nonlinear relationship between the average RNFL thickness and effective value of visual field, MD, MS, sLV were Y=-0.037X2+5.208X-93.795, Y=0.010X2-1.325X+50.111, Y=-0.008X2+1.103X-15.606, Y=0.004X2 -0.520X+22.232. Conclusion RNFL thickness measurement is expected to be an objective assessment in visual field, a new morphological methods.

Retinal nerve fibre layer analysis in primary open angle glaucoma

Background: POAG occurs in elderly, rarely seen earlier than 40 years of age and tends to run in families. Glaucoma is a neurodegenerative disease characterized by the slow, progressive degeneration of retinal ganglion cells. Aim: To study the changes, in retinal nerve fibre layer thickness in primary open angle glaucoma (POAG). Materials and methods: The present cross sectional study was carried out at a tertiary care hospital in North India. 100 patients of primary open angle glaucoma were matched with 100 controls and evaluated with the aim to assess their RNFL thickness and compare with each other. Results: The data distribution analysis of retinal nerve fibre layer thickness in different optic nerve head quadrants in POAG group in relation to overall severity of glaucoma shows that in superior quadrant maximum number of patients in preperimetric group 6 (50%) cases, in mild 9 (45%) cases and in moderate group 25 (44.6%) were in the range 100±10μm. But in severe glaucoma cases majority 7 (58.3%) cases had the RNFL thickness in the range of 60±10 μm. The temporal quadrant RNFL thickness was least in all grades of severity of glaucoma i.e. preperimetric 6 (50%), in mild cases 9 (45%), in moderate 25 (44.6%) cases and in severe 8 (66.7%) cases. Conclusion: Overall RNFL thickness variation, regardless of severity of glaucoma, follow the normal pattern of thickness being thicker in superior and inferior quadrant compared to nasal and temporal quadrant. It was interesting to note that the RNFL thickness in all the quadrants of optic nerve head area continues to become thinner as the severity of glaucoma increases.

The Analysis of Retinal Nerve Fiber Layer in Amblyopia Using Spectral Domain Optical Coherence Tomography

PURPOSE: To determine whether retinal nerve fiber layer (RNFL) thickness and optic nerve head parameters differ in the amblyopic and normal fellow eyes of hyperopic anisometropic amblyopic patients using spectral domain optical coherence tomography (SD-OCT). METHODS: This study included 30 patients with hyperopic anisometropic amblyopia; patient eyes were divided into 30 anisometropic amblyopic eyes and 30 normal fellow eyes. RNFL thickness, disc area, rim area, average cup-to-disc ratio, and cup volume were obtained using SD-OCT. Axial length was obtained using the IOL Master®, and the interocular differences between group were analyzed. RESULTS: Nasal quadrant RNFL thickness of amblyopic eyes was significantly thicker than that of normal fellow eyes in amblyopic patients (p = 0.010). Among optic nerve parameters, cup volume of amblyopic eyes was significantly smaller than that of normal fellow eyes (p = 0.021). No significant relationship between refractive error and RNFL thickness was observed, and a significant positive linear relationship was observed between neural rim area and RNFL thickness (rho = 0.426, p = 0.005). CONCLUSIONS: SD-OCT analysis of hyperopic anisometropic amblyopic eyes demonstrated a significant increase in nasal RNFL thickness compared to fellow non-amblyopic eyes. No optic nerve head parameters except cup volume showed significant change.

Study on ageing changes of the optic nerve head in a group of normal subjects.

Introduction: Thickness of RNFL around the different quadrants of the optic disc margin progressively increases. Macular fibers occupying the lateral quadrant are the most resistant to glaucomatous damage and explain the retention of the central vision till end. This study was undertaken to determine the age related changes in the optic nerve head (ONH) and retinal nerve fiber layer (RNFL) in a group of normal subjects. Material and Methods: This prospective cross sectional hospital based study consisted of 150 healthy eyes of 75 subjects whom underwent ONH measurement using the Optovue optical coherence tomography (OCT) and examined the result of optic nerve head parameters and RNFL. Results- Mean cup disc ratio was found to be higher with increasing age. And the average RNFL thickness was found to decrease with increasing age. Conclusion: There are changes in optic disc parameters and RNFL with increasing age and the changes were measurable and significant.

Retinal Nerve Fiber Layer Thickness in a Subset of Karachi (Pakistan) Population.

Aim: To provide the normal range of retinal nerve fiber layer (RNFL) thickness in a subset of Karachi population by Spectralis OCT and to evaluate the effects of age and gender on it. Methodology: 300 eyes from 150 healthy subjects aged 40 years and above with no ocular pathologies were examined using standard protocols by a single examiner. Subjects with high myopia, history of diabetic or hypertensive retinopathy, raised intraocular pressure (> 21 mmHg) and previous intraocular or laser surgery were excluded from the study. The mean retinal nerve fiber layer thickness was calculated and was correlated with age and gender difference. Results: The mean global retinal nerve fiber layer thickness was found to be 99.02±9.08 μm in our set of population. Out of four quadrants the maximum RNFL thickness was found in inferior quadrant (126.45±16.23 μm) followed by the thickness of 121.50±15.03 μm in superior quadrant, 78.99±13.99 μm in nasal quadrant and 68.90±13.10 μm in temporal quadrant. We found strong negative correlation of RNFL thickness with age (P= 0.001) and not significant relation with gender (P= 0.8). Conclusions: Keeping in mind the variations in RNFL thickness with ethnic differences, this study provides the normal values of RNFL thickness according to our set of population. It is concluded that RNFL thickness decreases significantly with increasing age but gender had no significant effect on it.

Difference of GCIPL Thickness of Diabetes and Normal Eyes in Spectral Domain OCT

PURPOSE: To analyze the difference of the ganglion cell-inner plexiform layer (GCIPL) thickness in diabetic and normal eyes of patients using spectral domain optical coherence tomography (OCT) (Carl Zeiss Meditec, Dublin, CA, USA). METHODS: The authors compared and analyzed the difference of the GCIPL thickness measured with spectral domain optical coherence tomography (OCT) in 42 diabetic and 92 normal subjects. RESULTS: The study subjects were divided into 3 groups: 92 normal subjects, 22 diabetic patients without diabetic retinopathy, and 26 diabetic patients with diabetic retinopathy. Presence of diabetes mellitus (DM) or diabetic retinopathy did not influence the retinal nerve fiber layer (RNFL) thickness. The GCIPL thickness tended to be thinner especially in the superior sector GCIPL. The GCIPL thickness of normal subjects, diabetes patients without diabetic retinopathy, and diabetic retinopathy patients was 82.24 +/- 7.21 microm, 81.86 +/- 9.53 microm, and 76.77 +/- 14.13 microm, respectively, especially in the superior sector GCIPL (p = 0.029). CONCLUSIONS: Retinal ganglion cell layer thinning was induced by diabetes and diabetic retinopathy, and originated specifically from the superior part of the retina.

Changes of Peripapillary Retinal Nerve Fiber Layer Thickness Profile According to Aging in Myopic Eyes

PURPOSE: To evaluate the effects of age on the distributional variability of peripapillary retinal nerve fiber layer (RFNL) thickness measured by optical coherence tomography (OCT) in myopia. METHODS: Only the right eye of 64 myopic patients with long axial length (> or =24.5 mm) was included in the present study. The patients were divided into 2 age groups, 20 to 39 years of age and 40 to 59 years of age. Eventually, 42 subjects were selected and matched based on the difference of axial length not exceeding 0.5 mm between subjects in each group. The RFNL thickness was measured using Stratus OCT and average thickness, angular locations of double humps, and false-positive rate were compared. RESULTS: In both groups, the distribution of RNFL thickness in a double hump pattern was observed, which had a deviation to the temporal side only in the younger myopic eye group, but not in the middle-aged group. The middle-aged group had significantly thinner RNFL in 1, 7, and 8 clock-hour sectors compared to the younger myopic eyes (p < or = 0.02). Probability of abnormal OCT parameters at the 5% level of the 2 groups with the built-in RNFL normative database was not significantly different. CONCLUSIONS: The variability of RFNL thickness distribution related to axial length was less observed in the middle-aged group than the younger-aged group. These results should be considered in glaucoma diagnosis when using OCT.

Retinal Nerve Fiber Layer Thickness and Optic Disc Parameters in Dominant Compared with Non-Dominant Eyes

PURPOSE: To investigate the comparison of retinal nerve fiber layer (RNFL) thickness and optic disc parameters measured by optical coherence tomography (Cirrus HD-OCT(R)) in dominant and non-dominant eyes. METHODS: Seventy-one subjects without underlying ocular disease were recruited for the present study. Ocular dominance was determined using the hole-in-the-card test. Comprehensive standardized eye examinations were performed. Scans of the optic disc and RNFL were performed using OCT. RESULTS: The mean intraocular pressure (IOP) of the dominant eye was higher than its counterpart (p = 0.025). No significant differences were observed in uncorrected visual acuity, refractive error and axial length between dominant and non-dominant eyes (p = 0.235, 0.180, 0.850). No RNFL and optic disc features were identified in the dominant from non-dominant eyes. CONCLUSIONS: Although dominant eyes tended to have higher IOP than non-dominant eyes, no consistent ocular structural differences between dominant and non-dominant eyes with the use of OCT were found.

Regularity on change of retinal nerve fiber layer thickness with acute high intraocular pressure / 医用生物力学

Objective To measure the rabbit retinal nerve fiber layer(RNFL) thickness in vivo under different intraocular pressures (IOP) and at different time intervals after acute high IOP, and to obtain the regularity on change of RNFL thickness with acute high IOP. Methods Four groups of acute high IOP model were formed by perfusing the saline water into the anterior chamber of rabbit eyes, then RNFL thickness under different IOPs was measured by optical coherence tomography with radial scanning mode whose center was optical papilla and diameter was 6 mm. Results The absolute change values of RNFL thickness were(-27.16±14.24), (-33.33±6.74), (-48.75±5.24), (-67.29±3.89) μm under different IOPs of (4.50±0.35), (6.07±0.31), (7.74±0.26), (10.71±0.07) kPa, respectively. The linear relationship was found between the relative change of RNFL thickness and IOP. IOP could return to the normal level within two days after acute high IOP, while the RNFL thickness could be restored at the second week, and it was easier to restore if the IOP was lower than 6.65 kPa. Conclusions The acute high IOP could cause RNFL thickness to decrease significantly with the increased acute high IOP, but it will be restored after some time.

Correlation of average RNFL thickness using the STRATUS OCT with the perimetric staging of glaucoma

Objective@#To determine the correlation between average peripapillary retinal nerve fiber layer (RNFL) thickness measured with time domain optical coherence tomography (TD-OCT) in normal and glaucoma eyes. @*Methods@#This was a cross-sectional study of 281 eyes randomly selected from a previous study. Assessment of glaucomatous damage was done by glaucoma specialists who based their diagnosis on the visual field tests and optic disc photos, independent of OCT results. Eyes were classified into the following groups: normal, mild, moderate, or severe glaucoma. Severity of glaucoma was based on visual field abnormalities following a modified HodappAnderson-Parish criteria for staging. Average RNFL thickness of normal and glaucoma subgroups, as measured with STRATUS–OCT, were analyzed using single ANOVA test. Association between average RNFL thickness and severity of glaucomatous visual field loss was evaluated using the Pearson’s correlation coefficient analysis. @*Results@#183 eyes had no glaucoma; 27 had mild, 32 had moderate, and 39 had severe glaucoma. Mean average peripapillary RNFL thickness (μm) in the normal, mild, moderate, and severe glaucoma groups were 98.05(±13.46), 76.27(±11.79), 76.42(±16.01), and 56.17(±14.92) respectively. Significant differences were seen in the average RNFL thickness among the groups (P<0.05), except in eyes with mild to moderate glaucoma. A moderately strong correlation of -0.57 (P<0.05) was observed between average RNFL thickness and the stage of glaucoma. @*Conclusion@#TD-OCT showed moderately strong correlation between the average RNFL thickness and perimetric stages of glaucoma. Average RNFL thickness is a good parameter to discriminate normal from glaucoma eyes.

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.

Quantitative Analysis of Retinal Nerve Fiber Layer Thickness Profile in Myopic Eyes

PURPOSE: To investigate peripapillary retinal nerve fiber layer (RNFL) thickness profiles associated with myopia. METHODS: One hundred and twenty-seven normal eyes of 67 Korean adults were divided into three groups by spherical equivalent. All subjects were tested with fast RNFL scans of Stratus optical coherence tomography. The angular locations of superior and inferior maximal thickness points in relationship to a reference line drawn horizontally though the center of the scan circle were calculated from the raw data of scanned images (angle alpha, angle beta). Differences of angle alpha and angle beta were compared among the three groups. RESULTS: Angle alpha and angle beta were significantly different in three groups (ANOVA, p<0.001, respectively). Angle alpha and angle beta were also significantly different among the three groups for excluded eyes with tilted discs. CONCLUSIONS: The points of superior and inferior maximal peripapillary RNFL thickness were significantly different in three groups divided by spherical equivalent. As myopia becomes more severe, superior and inferior maximal peripapillary RNFL thickness points are located closer to the fovea.

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.