Retinal nerve fiber layer and macular inner retina measurements by spectral domain optical coherence tomograph in Indian eyes with early glaucoma

Purpose

To compare the diagnostic abilities of peripapillary retinal nerve fiber layer (RNFL) and macular inner retina (MIR) measurements by spectral domain optical coherence tomography (SD–OCT) in Indian eyes early glaucoma.

Methods

In an observational, cross-sectional study, 125 eyes of 64 normal subjects and 91 eyes of 59 early glaucoma patients underwent RNFL and MIR imaging with SD–OCT. Glaucomatous eyes had characteristic optic nerve and RNFL abnormalities and correlating visual field defects and a mean deviation of better than or equal to -6 dB on standard automated perimetry. Areas under the receiver operating characteristic curves (AUC), sensitivities at a fixed specificity and likelihood ratios (LRs) were estimated for all RNFL and MIR parameters.

Results

The AUCs for the RNFL parameters ranged from 0.537 for the temporal quadrant thickness to 0.821 for the inferior quadrant RNFL thickness. AUCs for the MIR parameters ranged from 0.603 for the superior minus inferior MIR thickness average to 0.908 for ganglion cell complex focal loss volume (GCC–FLV). AUC for the best MIR parameter (GCC–FLV) was significantly better (P<0.001) than that of the best RNFL parameter (inferior quadrant thickness). The sensitivities of these parameters at high specificity of 95%, however, were comparable (52.7% vs58.2%). Evaluation of the LRs showed that outside normal limits results of most of the RNFL and MIR parameters were associated with large effects on the post-test probability of disease.

Conclusion

MIR parameters with RTVue SD–OCT were as good as the RNFL parameters to detect early glaucoma.     

Measurement of macular ganglion cell layer and circumpapillary retinal nerve fiber layer to detect paracentral scotoma in early glaucoma

Background

Glaucoma patients with paracentral scotoma are at higher risk of losing central vision than those without glaucoma. The purpose of this study was to determine whether macular inner retinal layer (MIRL) measurements with spectral-domain optical coherence tomography (SD-OCT) outperform circumpapillary retinal nerve fiber layer (cpRNFL) measurements in discriminating between eyes with and without paracentral scotoma.

Methods

This retrospective study included 63 early glaucomatous eyes of 63 patients with (PSI group) or without (PSF group) paracentral visual field (VF) defects. MIRL thicknesses, including macular ganglion cell complex (mGCC), macular ganglion cell layer + inner plexiform layer (mGCL+), macular RNFL (mRNFL), and cpRNFL thickness were measured using a SD-OCT instrument (3D OCT-2000). The MIRL and cpRNFL were divided into 50 grid cells and 36 sectors, respectively, which were numbered from center/temporal to periphery/nasal. Discriminating ability of the methods for number of cells/sectors with abnormal thickness (<5 % of normal) and average thickness in the hemisphere corresponding to the VF defects (termed hemi-thickness) was compared by area under the receiver operating characteristics curves (AROCs).

Results

The number of abnormal nearest sectors of cpRNFL and all MIRL parameters were significantly smaller in the PSI group than in the PSF group (P?≤?0.001–0.047), whereas no significant differences were found for average or hemi-cpRNFL thickness. The AROCs of the number of abnormal nearest cells for mGCC and mGCL+ and average hemi-thickness for mGCC, mGCL+, and mRNFL were comparable and significantly higher than those of the number of abnormal nearest sectors/cells for cpRNFL (P?=?0.0002–0.0063) and mRNFL (P?=?0.0003–0.0267) parameters.

Conclusions

Regional assessment of MIRL thickness as measured by SD-OCT may potentially be an effective method for predicting central involvement of VF defects in early glaucoma.     

Pattern electroretinogram association with spectral domain-OCT structural measurements in glaucoma

Purpose

To describe the association between pattern electroretinogram (PERG) amplitude and spectral domain-optical coherence tomography (SD-OCT) macular thickness, retinal nerve fibre layer (RNFL) thickness and optic disc topography measurements.

Subjects and methods

Both eyes (n=132) of 66 glaucoma patients (mean age=67.9 years) enroled in the University of California, San Diego, CA, USA, Diagnostic Innovations in Glaucoma Study (DIGS) were included. Eyes were tested with PERG (Glaid PERGLA, Lace Elettronica, Pisa, Italy), RTVue SD-OCT (Optovue Inc., Fremont, CA, USA) GCC, and NHM4 protocols on the same day. Of the 66 enroled patients, 43 had glaucoma defined by repeated abnormal standard automated perimetry (SAP) results in at least one eye and 23 were glaucoma suspects defined by a glaucomatous-appearing optic disc by physicians'' examination in at least one eye and normal SAP results in both eyes. Associations (R ²) were determined between PERG amplitude (μV) and SD-OCT macular ganglion cell complex (GCC) thickness (μm), macular thickness (μm), macular outer retinal thickness (macular thickness minus GCC thickness) (μm), RNFL thickness (μm), neuroretinal rim area (mm²), and rim volume (mm³).

Results

PERG amplitude was significantly associated with GCC thickness (R ²=0.179, P<0.001), RNFL thickness (R ²=0.174, P<0.001), and macular thickness (R ²=0.095, P<0.001). R ² associations with other parameters were not significant (all P>0.624). Significant associations remained for GCC and average RNFL thickness when age and intraocular pressure at the time of testing were included in multivariate models (both P≤0.030).

Conclusions

PERG amplitude is significantly (but weakly) associated with macular GCC thickness, RNFL thickness, and macular thickness. The lack of association between PERG amplitude and macular outer retinal thickness supports previous results, possibly suggesting that that the PERG is driven primarily by retinal ganglion cell (inner retinal) responses.     

Unilateral amblyopia: Optical coherence tomography findings

Purpose

This study was performed to measure the macular and the retinal nerve fiber layer (RNFL) thicknesses using optical coherence tomography (OCT) in patients with unilateral amblyopia.

Methods

Measurement of the Retinal nerve fiber layer and Macular Retinal Layer thickness for both amblyopic and normal fellow eyes by (OCT) was carried out at king Abdulaziz University Hospital, Riyadh, Saudi Arabia.

Results

Ninety-three patients with unilateral amblyopia between the ages of 5 years and 12 years were included. The macular retinal thickness and the RNFL thickness were measured using OCT. The mean macular retinal thickness was 259.3 μm and 255.6 μm, and the mean RNFL thickness was 112.16 μm and 106 μm, in the amblyopic eye and the normal eye, respectively. OCT assessment of RNFL thickness revealed a significantly thicker RNFL in amblyopic eye (P < 0.0001), but no statistically significant difference was found in macular retinal thickness (P = 0.195).

Conclusion

The amblyopic process may involve the RNFL, but not the macula. However, further evaluation is needed.     

Macular and peripapillary retinal nerve fiber layer thickness in children with hyperopic anisometropic amblyopia

AIM:To compare the retinal nerve fiber layer (RNFL) thickness and macular thickness in the amblyopic eye with that in the sound eye of children with hyperopic anisometropic amblyopia using optical coherence tomography (OCT).METHODS: A prospective, nonrandom, intraindividual comparative cohort study includes 72 children with hyperopic anisometropic amblyopia in a single center. Macular thickness, macular foveola thickness, and peripapillary RNFL thickness were compared between the amblyopia eyes and the contralateral sound eyes.RESULTS:There were 38 male and 34 female patients, with a mean age as 9.7±1.9 years (range, 5–16 years). Hyperopic was +3.62±1.16D (range +2.00D to +6.50D) in the amblyopic eyes, which was significantly higher in the control eyes with +0.76±0.90D (range 0D to +2.00D) (P < 0.01). The mean peripapillary RNFL thickness was 113.9±7.2µm and 109.2±6.9µm in the amblyopic eye and the normal eye, respectively, reaching statistical significance (P = 0.02). The mean macular foveola thickness was significantly thicker in the amblyopic eyes than the contralateral sound eyes (181.4±14.2µm vs 175.2±13.3µm, P < 0.01), but the 1mm, 3mm or 6mm macular thickness central macular thickness was not significantly different. Degree of anisometropia in the contralateral eyes was not significantly correlated with differences of peripapillary RNFL, macular foveola thickness or central macular thickness.CONCLUSION:Eyes with hyperopic anisometropic amblyopia are found thicker macular foveola and peripapillary RNFL than the contralateral eyes in children.     

Discriminating ability of spectral domain optical coherence tomography in different stages of glaucoma

Purpose

To determine the discriminating ability of retinal nerve fiber layer (RNFL) thickness measured with spectral-domain optical coherence tomography (SD-OCT) in different stages of glaucoma.

Patients and methods

Thirty normal, 150 glaucomatous eyes were included. Glaucomatous eyes were graded into early, moderate and severe stages according to one of the global indices called visual field index (VFI). Complete ophthalmic examination, white on white perimetry and SD-OCT were done for all patients. RNFL thickness of quadrants and average thickness were recorded. Area under receiver operating characteristic curves (AUCs) were used to assess the performance of OCT parameters.

Results

Average, inferior and superior RNFL thickness were the best parameters to discriminate normal from early glaucoma (AUC: 0.91–86), early from moderate (AUC: 0.77–0.70) and moderate from severe (AUC: 0.85–83). Average RNFL loss was 18% in early glaucoma, 28% in moderate glaucoma and 41% in severe glaucoma. Early damage tends to be focal and in the lower quadrant. A significant correlation was detected between mean VFI and mean RNFL loss. Glaucoma was restaged according to average RNFL loss into early: ⩾97.5 μ, moderate: <97.5–72.5 μ and severe: <72.5 μ.

Conclusion

RNFL thickness measured with SD-OCT could discriminate the three stages of glaucoma. RNFL loss can be correlated to visual field loss. Future OCT-based staging of glaucoma, adjunctive to perimetry is possible.     

Macular and peripapillary retinal nerve fibre layer thickness in patients with cyanotic congenital heart disease

Purpose

To evaluate macular and retinal nerve fibre layer (RNFL) measurements in patients with cyanotic congenital heart disease (cCHD) using spectral domain optical coherence tomography (OCT).

Patients and methods

Thirty patients with cCHD (18 females and 12 males, mean age 10.9 years) and 60 healthy controls (35 females and 25 males, mean age 11.2 years) underwent complete ophthalmologic examination and OCT measurements of macular and peripapillary RNFL thickness.

Results

Patients with cCHD had significantly thinner measurements in all macular subfields compared with healthy controls (P<0.001). There was no significant difference in peripapillary RNFL thickness between the two groups, with the exception of the upper quadrant, for which thickness measurements were higher in patients with cCHD (P=0.021).

Conclusions

Patients with cCHD showed a significant decrease in macular thickness and a thickened superior quadrant RNFL thickness when compared with healthy controls. This may represent the damage caused by the effect of hypoxia.     

Diagnostic accuracy of posterior pole asymmetry analysis parameters of spectralis optical coherence tomography in detecting early unilateral glaucoma

Purpose:

To report the diagnostic ability of posterior pole asymmetry analysis (PPAA) parameters of spectralis optical coherence tomography (OCT) in detecting early unilateral glaucoma.

Methods:

A prospective, cross-sectional study which included 80 eyes of 80 normal subjects and 76 eyes of 76 patients with unilateral early primary open-angle glaucoma by Hodapp-Anderson-Parrish classification. All subjects were of age more than 18 years, best-corrected visual acuity 20/40 or better, and a refractive error within ± 5 diopter (D) sphere and ± 3 D cylinder. Control subjects had a normal ocular examination, intraocular pressure (IOP) <22 mmHg, no past history of high IOP, no family history of glaucoma, normal optic disc morphology, and visual field in both eyes. One eye of the control subject was randomly included. All eyes underwent OCT for retinal nerve fiber layer (RNFL) analysis and PPAA. The number of continuous black squares was noted in the asymmetry analysis (right-left + hemisphere asymmetry). The area under curve (AUC) was calculated for all OCT parameters.

Results:

The best value for AUC for RNFL analysis was 0.858 for the inferotemporal quadrant thickness. This was similar to the best value for AUC for PPAA which was 0.833 for the inferior macular thickness parameter (P = 0.5). The AUC for the right-left and the hemisphere asymmetry part of PPAA was 0.427 and 0.499, respectively.

Conclusion:

The macular thickness PPAA parameters were equally good as the RNFL parameters. However, the asymmetry analysis parameters performed poorly and need further refinement before its use in early unilateral glaucoma diagnosis.     

Macular findings on optical coherence tomography in cat-scratch disease neuroretinitis

Purpose

To describe the macular findings on optical coherence tomography (OCT) in patients with cat-scratch disease (CSD) neuroretinitis.

Methods

Medical records of all patients diagnosed with CSD neuroretinitis at the Tel Aviv Medical Center between April 2006 and May 2010 were retrospectively reviewed. All patients underwent Stratus OCT macular examination.

Results

Eight eyes of seven patients with confirmed CSD neuroretinitis, (mean age 33±9.9 years, range 6–48 years) were included in the study. All patients presented clinically with optic nerve swelling and macular edema or macular exudates. OCT demonstrated flattening of the foveal contour, thickening of the neurosensory retina, and accumulation of subretinal fluid (SRF) in all studied eyes. Retinal exudates appeared as multiple hyper-reflective foci in the outer plexiform layer. The average central macular thickness was 460 μm (range 170–906 μm) and the average maximal retinal thickness was 613 μm (range 387–1103 μm), at presentation. The macula appeared normal on repeated exams during follow-up.

Conclusion

Similar OCT findings were demonstrated in patients with CSD neuroretinitis. SRF was found in all eyes, although was not visible on clinical examination or fluorescein angiography. OCT may be used as an adjunct imaging tool in the diagnosis and follow-up of patients with CSD neuroretinitis.     

Chorio-retinal thickness measurements in patients with acromegaly

Purpose

To compare choroidal, foveal, and peripapillary retinal thickness between patients with acromegaly and healthy adults.

Methods

This prospective, cross-sectional, and comparative study included 30 patients with acromegaly (study group) and 30 healthy subjects (control group). The subfoveal choroidal thickness (SFCT), foveal thickness, and peripapillary retinal nerve fibre layer thickness were measured with spectral domain optical coherence tomography.

Results

The mean SFCT in the study group and in the control eyes was 374.4±98.1 and 308.6±77.3 μm, respectively (P<0.001). The mean thinnest foveal thickness value was 233.2±22.4 μm in the acromegaly group and 222.8±13.9 μm in the control group (P=0.003). The mean peripapillary retinal nerve fibre layer thickness did not differ significantly between the groups (P=0.34).

Conclusion

The SFCT and foveal thickness were significantly higher in patients with acromegaly, whereas peripapillary retinal nerve fibre layer thickness was similar between the groups.     

OCT测量视盘及黄斑区相关参数在早期原发性开角型青光眼中的诊断价值

目的：分析光学相干断层扫描技术(OCT)测量黄斑区神经节细胞复合体(mGCC)、视盘周围视网膜神经纤维层(pRNFL)、黄斑区视网膜神经纤维层(mRNFL)和黄斑区神经节细胞层+内丛状层(GCIP)厚度对早期原发性开角型青光眼(POAG)的诊断价值。

方法：采用病例对照研究设计,收集2019-01/2020-01于我院收治的早期POAG患者82例82眼,选择同期健康志愿者40例40眼(左右眼各20眼)为对照组,所有受检者均检查裸眼视力(UCVA)及最佳矫正视力(BCVA)及等效球镜度数,比较两组受检者上方、下方、鼻侧、颞侧及平均的pRNFL厚度及上、下方、平均的mGCC、黄斑区视网膜神经纤维层(mRNFL)、黄斑区神经节细胞层+内丛状层(GCIP)厚度,采用Spearman分析各指标平均厚度之间的相关性,采用ROC曲线分析mGCC、pRNFL、mRNFL和GCIP厚度参数诊断早期POAG的价值。

结果：早期POAG组患者上方、鼻侧、下方、颞侧、平均pRNFL厚度和上方、下方及平均mGCC、mRNFL、GCIP厚度均低于对照组(均P<0.05)。平均pRNFL厚度与平均mGCC厚度、平均mRNFL厚度及平均GCIP厚度正相关(r_s=0.582、0.632、0.456,均P<0.05); 平均mGCC厚度与平均mRNFL厚度及平均GCIP厚度正相关(r_s=0.583、0.851,均P<0.05); 平均mRNFL厚度与平均GCIP厚度正相关(r_s=0.528,均P<0.01)。ROC曲线分析得出不同部位mGCC厚度及平均值AUC值均在0.8以上,其诊断效能最高。

结论：OCT测量mGCC诊断早期POAG具有一定价值。     

Changes in retinal nerve fibre layer, optic nerve head morphology, and visual field after acute primary angle closure

Aims/Purpose

To determine and correlate the long-term changes in retinal nerve fibre layer (RNFL) thickness, optic nerve head (ONH) morphology, and visual fields after a single episode of acute primary angle closure (APAC).

Methods

This was a cross-sectional comparative study of patients at National University Hospital (Singapore) from 2000 to 2006 after an episode of unilateral APAC. The peripapillary and macular RNFL were measured using Stratus optical coherence tomography (OCT) and ONH configuration was assessed using Heidelberg Retina Tomography (HRT)-III. Humphrey perimetry was also performed, and the presence of disc pallor was noted. APAC eyes were compared with fellow eyes as matched controls.

Results

Twenty-five patients were assessed at a median of 33 months (range, 11–85 months) after APAC. OCT showed that there was a reduction in the peripapillary and outer macular RNFL thickness in APAC eyes compared with controls. Humphrey perimetry revealed significantly reduced mean deviation (P=0.006) and increased pattern standard deviation (P=0.045) in APAC eyes compared with controls. HRT-III showed no difference in mean rim area, rim volume, or cup–disc ratio between APAC eyes and controls. Disc pallor was present in nine APAC eyes (36%) but was absent in fellow eyes (P=0.002), and was associated with peripapillary RNFL thinning, visual field loss, and an increased interval between the onset of symptoms and normalization of intraocular pressure (P=0.023).

Conclusion

APAC results in peripapillary and outer macular RNFL loss, visual field defects, and optic disc pallor, even in cases in which the ONH configuration remains unchanged.     

Structural and functional correlates in color vision deficiency

Purpose

The aim of this study is to assess the photoreceptor integrity, using spectral domain optical coherence tomography (SD-OCT), and to measure the retinal sensitivity of patients with congenital red–green color vision deficiency (CVD).

Methods

In all, 14 eyes from 7 patients with congenital red–green CVD (diagnosed by Farnsworth Munsell 100 hue test), and 14 eyes from 7 control subjects were examined by SD-OCT and microperimetry. Radial scans (7-mm) were taken of the macula. The center of the fovea was defined. The thickness of different retinal layers, at the foveal center, and at multiple defined points along all six radial scans, was measured. The median readings were compared between the two groups using Mann–Whitney U-test.

Results

SD-OCT demonstrated normal total retinal thickness, normal thickness of the photoreceptor layer, normal thickness of the outer nuclear layer, normal vertical thickness of the outer segments (OSs), and normal vertical thickness of the inner segments. OS horizontal diameter was less in left eye in cases with CVD when compared with controls. The mean retinal and foveal sensitivity was similar between cases and controls.

Conclusions

In subjects with congenital red–green CVD, there are no discernible anatomical abnormalities seen on SD-OCT in various retinal layers, except for a narrower foveal pit. However, further studies with larger sample size are required.     

Measurement of Retinal Nerve Fiber Layer Thickness and Macular Volume for Glaucoma Detection Using Optical Coherence Tomography

Purpose

To evaluate retinal nerve fiber layer (RNFL) thickness and macular volume in normal eyes and in the eyes of patients with glaucoma, and to compare the usefulness of these measurements in diagnosing glaucomatous eyes.

Methods

Eighty-one eyes were divided into three groups: normal control (n = 31), early glaucoma [n = 31, mean deviation (MD) ≥ ?6?dB], and advanced glaucoma (n = 19, MD < ?6?dB). The RNFL thickness and macular volume were measured using Stratus OCT (optical coherence tomography). Then, the diagnostic power of these parameters was evaluated.

Results

In eyes with early glaucoma, RNFL thickness was decreased significantly in eight of the 12 peripapillary sectors, and macular volume was decreased significantly in six of the nine macular sectors, compared with normal eyes. In the advanced glaucoma eyes, RNFL and macular volume were decreased throughout, except in RNFL thickness in the papillomacular region, and in retinal thickness in the foveal region. The area under the receiver-operating characteristic curve (AUROC) of the average RNFL (0.963) was larger than the macular volume (0.919).

Conclusions

Both peripapillary RNFL thickness and macular volume were decreased even in the early stage of glaucoma. Average RNFL thickness had greater diagnostic power than macular volume.?Jpn J Ophthalmol 2007;51:197–203 © Japanese Ophthalmological Society 2007

     

Use of systemic steroid after successful macular surgery in eyes with epiretinal membrane: a randomized, controlled clinical study

Purpose

To evaluate the functional and morphological outcomes of postoperative systemic steroid therapy after successful macular surgery in eyes with macular edema due to idiopathic macular epiretinal membranes (ERMs).

Design

Prospective, randomized, investigator-masked, controlled clinical study.

Methods

Twenty-eight patients scheduled for 23-gauge vitrectomy combined with ERM and inner limiting membrane (ILM) peeling for macular edema due to ERM were included in this single center trial. Patients were randomized to receive oral steroid therapy (Prednisolone, 100 mg per day for 5 days) or no oral steroid (control group) after surgery. Main outcome measures included best corrected visual acuity (BCVA; Early Treatment Diabetic Retinopathy Study), central retinal thickness (CRT), retinal volume (RV), and macular morphology as determined by spectral domain optical coherence tomography (SD-OCT, Cirrus). Examinations were carried out preoperatively and at week 1, at months 1 and 3, postoperatively.

Results

At month 3, mean BCVA improved to a eight-letter gain in each study group (P<0.01 compared with baseline for both groups), showing no statistically significant difference between both the groups (P=0.19). Morphologically, retinal surface folds resolved within 1 month after surgery in both treatment groups, followed by a progressive recovery of retinal layer integrity and a statistical significant (P<0.01) decrease in CRT and RV without significant differences between both groups (P=0.62, P=0.13, respectively, ANOVA between the groups).

Conclusion

The early postoperative use of systemic steroid treatment after successful vitrectomy combined with ERM and ILM peeling does not seem to improve significantly the anatomic and functional outcomes in eyes with ERM.     

Detecting the Progression of Normal Tension Glaucoma: A Comparison of Perimetry,Optic Coherence Tomography,and Heidelberg Retinal Tomography

Purpose

We compared the abilities of Stratus optical coherence tomography (OCT), Heidelberg retinal tomography (HRT) and standard automated perimetry (SAP) to detect the progression of normal tension glaucoma (NTG) in patients whose eyes displayed localized retinal nerve fiber layer (RNFL) defect enlargements.

Methods

One hundred four NTG patients were selected who met the selection criteria: a localized RNFL defect visible on red-free fundus photography, a minimum of five years of follow-up, and a minimum of five reliable SAP, Stratus OCT and HRT tests. Tests which detected progression at any visit during the 5-year follow-up were identified, and patients were further classified according to the state of the glaucoma using the mean deviation (MD) of SAP. For each test, the overall rates of change were calculated for parameters that differed significantly between patients with and without NTG progression.

Results

Forty-seven (45%) out of 104 eyes displayed progression that could be detected by red-free fundus photography. Progression was detected in 27 (57%) eyes using SAP, 19 (40%) eyes using OCT, and 17 (36%) eyes using HRT. In early NTG, SAP detected progression in 44% of eyes, and this increased to 70% in advanced NTG. In contrast, OCT and HRT detected progression in 50 and 7% of eyes during early NTG, but only 30 and 0% of eyes in advanced NTG, respectively. Among several parameters, the rates of change that differed significantly between patients with and without progression were the MD of SAP (p = 0.013), and the inferior RNFL thickness (p = 0.041) and average RNFL thickness (p = 0.032) determined by OCT.

Conclusions

SAP had a higher detection rate of NTG progression than other tests, especially in patients with advanced glaucoma, when we defined progression as the enlargement of a localized RNFL defect. The rates of change of the MD of SAP, inferior RNFL thickness, and average RNFL thickness differed between NTG patients with and without progression.     

Variability of subfoveal choroidal thickness measurements in patients with age-related macular degeneration and central serous chorioretinopathy

Purpose

To evaluate the variability in subfoveal choroidal thickness measurements in patients with age-related macular degeneration (AMD) and central serous chorioretinopathy using enhanced depth imaging optical coherence tomography (EDI-OCT).

Methods

One hundred and sixty eyes of 160 patients who were diagnosed with early AMD (N=40), exudative AMD (N=40), polypoidal choroidal vasculopathy (PCV, N=40), or central serous chorioretinopathy (CSC, N=40) were included in this retrospective observational study. In addition, we included 40 normal eyes of 40 subjects. Subfoveal choroidal thickness was measured manually by two masked observers based on EDI-OCT images. The correlation of choroidal thickness with the absolute value of the difference in the choroidal thickness measurement was estimated for all 200 eyes. Intraobserver and interobserver coefficients of repeatability (CRs) were calculated.

Results

There was a significant positive correlation between subfoveal choroidal thickness and both intraobserver (P<0.001) and interobserver (P<0.001) difference in choroidal thickness measurements. The mean intraobserver CRs in nonexudative AMD, exudative AMD, PCV, CSC, and normal eyes were ∼15–21, 23–29, 24–35, 32–38, and 19–25 μm, respectively. The mean interobserver CRs were ∼24–28, 30–36, 39–45, 46–57, and 26–35 μm, respectively.

Conclusions

Relatively great measurement variability should be considered when investigating eyes with pathologic conditions related to a thick choroid, including PCV or CSC.     

The effect of various factors on variability of retinal nerve fiber layer thickness measurements using optical coherence tomography

Purpose

To evaluate the effects of various factors on the variability of retinal nerve fiber layer (RNFL) thickness measurements using the Stratus optical coherence tomography (OCT) in normal and glaucomatous eyes.

Methods

Four hundred seventy-four subjects (103 normal eyes and 371 glaucomatous eyes) were scanned to determine the RNFL thickness measurements using the Stratus OCT. Measurements were obtained twice during the same day. The standard deviation (SD) was used to compare the variability in RNFL thickness measurements of the normal subjects to that of the glaucomatous patients. Multivariate regression analysis was used to evaluate which covariates were independent predictors of SD in overall mean RNFL thickness.

Results

The mean SD of all RNFL thickness measurements was larger in the glaucoma group except in one sector. In the multivariate regression analysis, the average signal strength (SS) and the relative SS change (difference in SS between initial and repeat scans, divided by initial SS) were independent predictors of the SD in the RNFL thickness measurements (partial R² = 0.018, 0.013; p = 0.016, 0.040, respectively).

Conclusions

Glaucomatous eyes tend to be more variable than normal eyes in RNFL thickness measurement using the Straus OCT. The average SS and the relative SS changes appear to correlate with the variability in RNFL thickness measurement. Therefore, the results of the RNFL analysis should not be interpreted independently of these factors.     

Analysis of peripapillary retinal nerve fiber layer and inner macular layers by spectral-domain optical coherence tomography for detection of early glaucoma

AIM: To analyze the diagnostic capabilities of peripapillary retinal nerve fiber layer (pRNFL) thickness and segmented inner macular layer (IML) thickness measured by spectral-domain optical coherence tomography for detection of early glaucoma. METHODS: Fifty-three patients with primary open angle glaucoma (POAG), 60 patients with normal tension glaucoma (NTG) and 32 normal control subjects were enrolled. Thicknesses of pRNFL, total macular layers (TML), and the IML, including macular RNFL (mRNFL) and macular ganglion cell layer (mGCL) were assessed. The areas under the receiver operating characteristic curves (AROC) were calculated to compare the diagnostic power of different parameters. RESULTS: There were no differences in the parameters of pRNFL, TML, and IML between POAG and NTG groups. The thicknesses of superior and inferior mGCL showed significant correlation with mean deviation of visual field (R2=0.071, P=0.004; R2=0.08, P=0.002). The mGCL thickness significantly correlated with the pRNFL thickness in the superior and inferior quadrants (R2=0.156, P<0.001; R2=0.407, P<0.001). The thickness of the inferior-outer sector of macula had greater AROCs than those in the inferior-inner sector of macula. The AROCs for superior (0.894) and inferior (0.879) pRNFL thicknesses were similar with the AROCs for superior (0.839) and inferior mGCL (0.864) thicknesses. Sensitivities at 80% specificity for global pRNFL, inferior-outer mGCL and inferior-outer mRNFL thicknesses were 0.938, 0.867, and 0.725, respectively. CONCLUSION: The diagnostic capability of the mGCL thickness is comparable to that of the pRNFL thickness in patients with early glaucoma. The inferior-outer sector of IML has a better diagnostic capability than the inferior-inner sector of IML for detection of early glaucoma.     

Foveal Thickness between Stratus and Spectralis Optical Coherence Tomography in Retinal Diseases

Purpose

To compare the foveal thickness (FT) parameters measured by Stratus optical coherence tomography (OCT) and Spectralis OCT in various retinal diseases and to construct conversion formulas between the two types of OCT devices.

Methods

We examined 366 consecutive patients (475 eyes) with retinal diseases and 13 normal controls (13 eyes). The patients were categorized into eight retinal disease groups. The mean amount and distribution of foveal thickness differences (FTD) measured by Stratus and Spectralis OCT were determined, and conversion formulas were constructed for Stratus OCT FT from Spectralis OCT FT for each retinal disease group.

Results

Among retinal diseases, the mean FTD was significantly larger in exudative age-related macular degeneration (AMD) patients (mean ± SD, 94.0 ± 55.0 µm) compared to normal subjects (66.2 ± 11.7 µm; p < 0.0001). The proportion of eyes with a mean FTD outside 1.96 standard deviations of normal subject FTD was greatest in the exudative AMD (50.0%) group and smallest in the macular hole (18.2%) group. The predicted FTs obtained through the conversion formulas showed lower variance than the actual FTD values, especially in the exudative AMD group. The prediction line for exudative AMD deviated most from that of normal subjects.

Conclusions

FTD shows diverse values and variances among various retinal diseases, especially in exudative AMD, which indicates that Stratus OCT FT cannot be predicted from Spectralis OCT FT by FTD value alone. We constructed statistically significant conversion formulas, which provided more reliable methods to predict Stratus OCT-measured FT from Spectralis OCT measurements for different retinal disease groups.