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

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.

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.

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.

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 Retinal Nerve Fiber Layer Thickness in Patients With Superior Segmental Optic Hypoplasia

PURPOSE: To analyze the thickness of the peripapillary retinal nerve fiber layer (RNFL) in patients with superior segmental optic hypoplasia (SSOH) using optical coherence tomography (OCT). METHODS: Ten eyes of 10 patients with SSOH and 20 eyes of 20 subjects as normal control were evaluated. The peripapillary RNFL thickness measured by Stratus OCT was compared between the two groups. RESULTS: The mean RNFL thickness was significantly different between SSOH patients (72.35+/-14.77 micrometer) and normal subjects (111.61+/-6.62 micrometer) (p<0.001). The extent to which the RNFL thickness was below 5 percentile of normal subjects on the TSNIT graph was from the 41.7+/-15.53 to 110.1+/-7.47 scan number, which corresponded mainly with the superior nasal region. Moreover, in a clock-hour analysis, the peripapillary RNFL thic kness of the SSOH patients decreased significantly from 10 o'clock to 6 o'clock compared to normal subjects (p<0.01). CONCLUSIONS: Peripapillary RNFL thickness in patients with SSOH was reduced in the superior, nasal, and inferior regions. Further studies involving larger populations of patients should be performed to verify these findings.

Changes in RNFL Thickness According to the Myopia in Patients with Glaucoma and Ocular Hypertension

PURPOSE: To evaluate the changes in retinal nerve fiber layer (RNFL) thickness according to the degree of myopia in patients with glaucoma and ocular hypertension. METHODS: Ninety-eight patients (165 eyes) diagnosed with glaucoma or ocular hypertension underwent optical coherence tomography (OCT) and scanning laser polarimetry using variable corneal compensation (GDx-VCC) to analyze the correlation between the degree of myopia and the thickness of the RNFL. A partial correlation coefficient analysis was performed to adjust for various factors such as age, laterality, intraocular pressure, and the mean deviation from visual field test, which can influence the RNFL thickness. RESULTS: The average, nasal, superior, and inferior sectorial RNFL thicknesses measured by OCT significantly decreased with increasing myopia (p<0.05). However, RNFL thickness measured by GDx-VCC was not significantly correlated with the degree of myopia. CONCLUSIONS: The RNFL thickness measured by OCT decreased with increasing myopia in eyes with glaucoma and ocular hypertension.

Analysis of RNFL Thickness and Optic Nerve Head Measured with OCT in Children

PURPOSE: To analyze peripapillary retinal nerve fiber layer (RNFL) thickness and optic nerve head (ONH) parameters with regard to age in children by using optical coherence tomography (OCT). METHODS: We analyzed RNFL thickness and ONH parameters by using Stratus OCT Model 3000 (Zeiss-Humphrey) in two-hundred eyes of 100 children ranging in age from 5 to 14 years, with 5 males and 5 females for each age. RESULTS: The RNFL thicknesses for 100 children (200 eyes) in total were as follows: Mean 104.67+/-9.07 micrometer, superior 131.84+/-18.71 micrometer, temporal 78.49+/-12.91 micrometer, nasal 73.85+/-14.26 micrometer, and Inferior 133.87+/-18.58 micrometer. The parameters of ONH for 100 children (200 eyes) in total were as follows: optic disc area 2.80+/-0.21 mm2, rim area 1.85+/-0.28 mm2, cup to disc area ratio 0.34+/-0.08, horizontal cup to disc diameter ratio 0.47+/-0.11, and vertical cup to disc diameter ratio 0.49+/-0.11. In analyzed RNFL thickness and ONH according to age, there was a significant negative correlation among mean RNFL, inferior RNFL, and age (r=-0.258, p=0.000, r=-0.464, p=0.000). There was a significant positive correlation between nasal RNFL and age (r=0.135, p=0.028). There was a significant positive correlation between disc area and age (r=0.528, p=0.000). There was a significant negative correlation among the cup to disc area ratio, the horizontal cup to disc diameter ratio, the vertical cup to disc diameter ratio, and age (r=-0.170, p=0.008, r=-0.266, p=0.000, r=-0.155, p=0.014). CONCLUSIONS: OCT can be used to measure RNFL thickness and ONH parameters in children. Age had an effect on RNFL thickness and ONH parameters in children.

Normal Retinal Nerve Fiber Layer Thickness in the Peripapillary Region of Koreans Measured by Scanning Laser Polarimeter

PURPOSE: To measure normal retinal nerve fiber layer thickness (RNFLT) in the peripapillary region of Koreans using a scanning laser polarimeter, the nerve fiber analyzer (GDx VCC). METHODS: Two hundred ninety-nine eyes of 299 healthy subjects (156 men, 143 women) were recruited for this study. No subject had diabetes mellitus, hypertension, or any other neurologic disorders. All subjects were normal at ophthalmologic examination, which was assessed by slit-lamp biomicroscopy using a 90-diopter lens, Goldmann applanation tonometry, and Humphrey visual field analysis. Using the GDx VCC, we analyzed the mean value of each parameter in GDx VCC (average at global, superior, inferior, superior maximum and inferior maximum) and evaluated the difference between men and women and each decade of age. RESULTS: Mean RNFLT parameters in GDx VCC were global 56.42 +/- 6.84 micrometer, superior 70.51 +/- 8.70 micrometer, inferior 67.55 +/- 9.04 micrometer, superior maximum 83.52 +/- 12.38 micrometer, and inferior maximum 82.64 +/- 12.70 micrometer. The parameters which showed a difference between men and women were superior average and superior and inferior maximum average RNFLT. The superior RNFLT was thicker than the inferior ones. RNFLT was not statistically different in each decade of age. CONCLUSIONS: We can make good use of the normal parameters of GDx VCC in Koreans for early diagnosis and follow-up of glaucoma.

Interocular comparison of nerve fiber layer thickness and its relation with optic disc size in normal subjects

We conducted an investigation of the relation between RNFL thickness and optic disc size along with an interocular comparison of optic disc size, RNFL thickness, and RNFL density in healthy subjects. A total of 64 normal eyes from 32 Korean volunteers were enrolled in this study. A GDx Nerve Fiber Analyzer with software version 2.0.09 was used to image all subjects. Optic disc size was measured by pi x (horizontal radius) x (vertical radius). The RNFL density of each quadrant was calculated by dividing each quadrant integral by the total integral. Optic disc size was positively correlated with the total RNFL thickness (r = 0.615, p < 0.01). Optic disc size and RNFL density were inversely related in the superior quadrant (r = -0.248, p < 0.05). There was a significant positive correlation between optic disc size and RNFL density in the nasal quadrant (r = 0.439, p < 0.01) and the temporal quadrant to a certain degree. A significant positive correlation was found between the right and left eyes in terms of total RNFL thickness in and that of each quadrant. Interocular RNFL density was positively correlated in both the temporal and nasal quadrants. These findings must be considered when one evaluates and compares RNFL measurements between two eyes as is often the case where both eyes are usually affected in the course of glaucomatous RNFL damage.

The Parameters of the Retinal Nerve Fiber Layer Measured with Confocal Scanning Laser Ophthalmoscope & Nerve Fiber Analyzer

Assessment of the optic nerve head or the retinal nerve fiber layer is essential for the early diagnosis and monitoring of glaucoma. We compared mean retinal nerve fiber layer[RNFL]thickness with Average, and compared RNFL CSA with Integral between Heidelberg Retina Tomograph[HRT] and GDx nerve fiber analyzer[GDx]at global, superior, inferior, nasal and temporal area. Mean RNFL thickness in HRT was significantly greater than Average in GDx at all quadrants[p<0.001], and correlated with Average at global, superior and inferior area[p<0.05]. RNFL CSA in HRT was significantly greater than Integral in GDx at superior, inferior and nasal quadrants[p<0.001], and correlated with Integral at superior and inferior quadrants[p<0.05]. In conclusion, the two parameters related to nerve fiber layer in HRT were measured greater than those in GDx. Correlations of the above parameters between HRT and GDx were mainly present at superior and inferior quadrant. These results may come from regional difference in measurement between HRT and GDx, and uncorrected disc tilting in HRT appears to have adverse effects on the correlations of the above parameters between HRT and GDx at nasal or temporal quadrant.