Pattern ERG and RNFL thickness in hypertensive eyes with normal blue-yellow visual field

Purpose

To evaluate the transient pattern electroretinogram (t-PERG) and the retinal nerve fiber layer (RNFL) thickness in eyes with ocular hypertension (OH) and normal short-wavelength automated perimetry (SWAP).

Methods

In 26 patients with bilateral OH with normal SWAP, and in 26 age and sex matched healthy controls, t-PERG recording and RNFL thickness measurement were performed. Mean deviation (MD) and pattern standard deviation (PSD) of a reliable full threshold 24-2 SWAP were considered. RNFL thickness was determined by OCT3. Monocular PERG were recorded by using a black and white checkerboard pattern (check size 0.9°, contrast 100 %, mean luminance 80 cd/m2) generated on a monitor and reversed in contrast (four reversals per second, 2 Hz) at a distance of 70 cm. Patients had optimal correction at viewing distance; no mydriatic or miotic eye drops were used. Silver/silver chloride skin electrodes were placed over the lower eyelids in the stimulated eye (active electrode) and in the patched eye (reference electrode); ground electrode was in the Fpz scalp. Peak-to peak amplitude of P50 (N35-P50) and N95 (P50-N95) waves, and implicit time of P50, were considered.

Results

Compared to controls, in OH eyes, a reduction of N35-P50 amplitude (2.86?±?1.49 vs. 3.77?±?1.08 microvolts, ?24.1 %, t-test p?=?0.015), of average RNFL thickness (88?±?11 vs. 96?±?10 μm, ?9.5 %, t-test p?=?0.002), and of RNFL thickness in superior (p?=?0.015) and inferior quadrant (p?<?0.001), were found. Multivariate analysis showed that in OH eyes, N35-P50 amplitude was inversely related to intraocular pressure (IOP) (p?=?0.001); no correlation was found between N35-P50 amplitude and MD, PSD, CCT or RNFL thickness.

Conclusions

In OH eyes, both PERG and RNFL thickness changes occur in hypertensive eyes with undamaged SWAP; the correlation of PERG amplitude with IOP, but not with RNFL thickness, suggests that such PERG changes are an effect of the IOP on retinal ganglion cells, rather than a sign of their loss.     

Correlation between multifocal pattern electroretinography and Fourier-domain OCT in eyes with temporal hemianopia from chiasmal compression

Purpose

To evaluate the correlation between multifocal pattern electroretinography (mfPERG) and Fourier-domain optical coherence tomography (FD-OCT) with regard to macular and retinal nerve fiber layer (RNFL) thickness in eyes with temporal hemianopia from chiasmal compression.

Methods

Twenty-five eyes from 25 patients with permanent temporal visual field defects from chiasmal compression and 25 healthy eyes were submitted to mfPERG using a stimulus pattern of 19 rectangles, standard automated perimetry and FD-OCT measurements. The mfPERG response was determined for groups of three rectangles for the nasal and temporal hemifields and for each quadrant. Macular thickness measurements were registered according to an overlaid OCT-generated checkerboard with 36 checks and averaged for the central area, and for each scanned quadrant and hemifield. RNFL thickness was determined for all twelve 30-degree segments around the disc, and averaged for the segments corresponding to the 6, 7, 8, 9, 10, 11 and 12 o’clock position. Correlations were verified with Pearson’s correlation coefficients and linear regression analysis.

Results

Both mfPERG amplitudes and OCT measurements were significantly smaller in eyes with temporal visual field defects than in normals. A significant and strong correlation was found between most mfPERG and macular or RNFL thickness OCT parameters.

Conclusions

mfPERG amplitudes and OCT measurements are significantly correlated in patients with chiasmal compression. Both technologies can quantify neuronal loss and, if used in combination, may help clarify structure–function relationships in this patient population.     

Evaluation of relationship between retinal nerve fiber layer thickness progression and visual field progression in patients with glaucoma

Purpose

To evaluate the capability of optical coherence tomography (OCT), retinal nerve fiber layer (RNFL) thickness, and visual field (VF) measurements in glaucoma progression detection.

Methods

The study examined 62 eyes of 37 glaucoma patients observed over a 3-year period. All eyes underwent at least four serial RNFL measurements performed by Cirrus OCT, with the first and last measurements separated by at least 3 years. VF testing was performed by using the Swedish interactive threshold algorithm (SITA) Standard 30-2 program of the Humphrey field analyzer (HFA) on the same day as the RNFL imaging. Both serial RNFL thicknesses and VF progression were assessed by the guided progression analysis (GPA) software program. RNFL thickness progression was evaluated by event analysis. Total deviation (TD) in the superior or inferior hemifield was also examined.

Results

A total of 295 OCT scans and 295 VFs were analyzed. Five eyes exhibited progression by OCT only and 8 eyes exhibited progression by VF GPA only. When the analysis was based on the combined measurement findings, progression was noted in 6 eyes. The average of the progressive hemifield TD at baseline for combined RNFL and VF progression was ?3.21 ± 1.38 dB, while it was ?2.17 ± 1.14 dB for RNFL progression and ?9.12 ± 3.75 dB for VF progression. The average of the progressive hemifield TD indicated a significant advancement of VF progression as compared to RNFL progression (P = 0.002).

Conclusions

When a mild VF defect is present, OCT RNFL thickness measurements are important in helping discern glaucoma progression.     

A comparison of false positives in retinal nerve fiber layer,optic nerve head and macular ganglion cell-inner plexiform layer from two spectral-domain optical coherence tomography devices

Background

The incidence of false positive (FP) results of optic coherence tomography (OCT) retinal nerve fiber layer (RNFL) color code in healthy subjects can be very high with Cirrus OCT. Recent evidence has shown that OCT parameters derived from macular ganglion cell-inner plexiform layer (GCIPL) have excellent ability to discriminate between normal eyes and eyes with early glaucoma.

Methods

This was a prospective, cross-sectional study. One hundred eyes from 50 healthy volunteers underwent circumpapillary scanning by Cirrus and Spectralis OCT and macular scanning using Cirrus OCT. FP rates for each of the OCT parameters, using predefined criteria for an abnormal test were calculated. Comparative analysis was performed using the McNemar test. A generalized estimating equations model (GEE) was used to compare demographic and clinical factors between the eyes with normal findings and eyes with abnormal results.

Results

The overall RNFL color-code FP rate was significantly higher for Cirrus (39 %) than for Spectralis (18 %) (P?=?0.000). The Spectralis RNFL FP rate showed no significant difference when compared to the FP rate by Cirrus GCIPL (13 %) and ONH (11 %) analysis. Axial length, mean spherical equivalent, presence of peripapillary atrophy, and tilted disc were significantly related to the RNFL FP occurrence displayed by both devices.

Conclusions

Spectralis might be more specific than Cirrus when evaluating the RNFL thickness for Caucasians and moderate myopic population. GCIPL and ONH analysis might be more useful than RNFL thickness to evaluate this population using Cirrus OCT.     

Macular thickness measurements with frequency domain-OCT for quantification of axonal loss in chronic papilledema from pseudotumor cerebri syndrome

Purpose

To evaluate the ability of frequency domain-optical coherence tomography (FD-OCT)-measured macular thickness parameters to differentiate between eyes with resolved chronic papilledema and healthy eyes and to evaluate the correlation between FD-OCT measures and visual field (VF) loss on standard automated perimetry (SAP).

Methods

Fifty-two eyes from 29 patients suffering from pseudotumor cerebri syndrome (PTC) and 62 eyes from 31 normal controls underwent FD-OCT scanning and ophthalmic evaluation including VF with SAP. All patients had previously been submitted to treatment of PTC and had clinically resolved papilledema and stable VF for at least 6 months before the study. Macular and peripapillary retinal nerve fiber layer (RNFL) thickness measurements were determined for both groups. Comparisons were made using Generalized Estimated Equations. Correlations between FD-OCT and VF measurements were verified.

Results

In eyes with resolved papilledema, the macular thickness parameters corresponding to the inner and outer superior, temporal, inferior and nasal segments, average macular thickness and most RNFL thickness measurements were significantly reduced when compared with controls. The discrimination ability was similar for macular thickness measurements and RNFL thickness measurements. Both sets of OCT measurements correlated well with VF sensitivity loss.

Conclusions

Eyes with resolved chronic papilledema show a significant reduction in macular thickness, which is well correlated with the severity of VF loss. Macular thickness measurements can potentially be used to estimate and monitor the amount of ganglion cell loss in eyes with papilledema from patients with PTC.     

Structural and functional comparison of the persistent and resolved amblyopia

Purpose

To assess structural or functional differences of the retina among subjects with persistent and resolved amblyopia.

Methods

Fourteen eyes with persistent amblyopia that did not reach normal visual acuity (VA) levels (≤0.1 LogMAR) despite amblyopia treatment, 18 eyes with resolved amblyopia, and 16 eyes of 16 normal subjects were included. All subjects underwent optical coherence tomography (OCT), pattern visual evoked potential (PVEP), and pattern electroretinography (PERG) evaluation.

Results

There was no significant difference in foveal thickness, foveal volume, macular volume, ganglion cell layer thickness, and total and sectorial retinal nerve fiber layer measurements among three groups (p > 0.05). Foveolar thickness was significantly increased in both resolved and persistent amblyopia groups compared with the control group (p = 0.031). However, there was no difference between amblyopic groups (p = 0.98). Although, in the PVEP study, N75 implicit time was found significantly prolonged in both amblyopia groups (p = 0.046), there were no significant differences in P100 implicit time and amplitude among the groups (p > 0.05). PERG amplitude of the persistent group was significantly lower than that of the control group (p = 0.003). There were no significant differences in P50, N95 implicit times among groups (p > 0.05).

Conclusions

In our study, the only significant difference between persistent and resolved amblyopia groups was the initial VA. Neither OCT nor electrophysiological examinations were found to be useful in order to explain why some cases were resistant to the treatment for amblyopia.     

Reproduzierbarkeit der Messung der peripapillären Nervenfaserschichtdicke

Purpose

The aim of this study was to compare the intra- and inter-examiner reproducibility of measurements obtained by optical coherence tomography (OCT) and retinal thickness analyzer (RTA).

Patients and methods

During a period of 2 months, 22 eyes of 16 patients and 6 healthy subjects were included. Two examiners (EMH, RK) successively performed three measurements of the peripapillary retinal nerve fibre layer (RNFL) thickness with RTA and OCT. The reproducibility of three individual measurements of one examiner (intra-examiner) as well as the reproducibility of the measurements between both examiners (inter-examiner) was evaluated using the Friedman test and sign test.

Results

The average thickness of the peripapillary RNFL was 154.4 µm for the first investigator (EMH) and 155.1 µm for the other investigator (RK) measured with RTA. The results obtained by OCT were 137.3 µm (EMH) and 138.9 µm (RK), respectively, generally indicating a threefold smaller range. Comparing the three measurements of one single examiner, no appreciable intra-observer dependency neither for RTA (EMH: p=0.19, RK: p=0.95) nor for OCT (EMH: p=0.51, RK: p=0.62) was observed. Inter-examiner analysis for RTA and OCT also revealed an acceptable reproducibility.

Conclusions

Measurements of peripapillary RNFL thickness using RTA and OCT exhibited intra- and inter-observer agreement.     

Measurement of retinal nerve fiber layer and macular ganglion cell–inner plexiform layer with spectral-domain optical coherence tomography in patients with optic nerve head drusen

Purpose

To evaluate the effect of optic nerve head drusen (ONHD) on the retinal nerve fiber layer (RNFL) and macular ganglion cell–inner plexiform layer (GCIPL) using Cirrus optical coherence tomography (OCT).

Methods

Fifty-seven eyes of thirty patients with ONHD and thirty-eight eyes of twenty age-matched and sex-matched control subjects underwent circumpapillary and macular scanning using Cirrus OCT. The percentages of eyes with abnormal GCIPL and RNFL values according to the Cirrus normative data were analysed and compared.

Results

Overall, eyes with ONHD showed abnormally reduced values for average and minimum GCIPL thicknesses in 35 % and 45 % of cases compared to 2 % for both values in control eyes (P?p?=?0.002). The percentage of abnormal thinning increased with higher grades of ONHD for all the parameters evaluated, so that in grade III drusen, values were abnormally reduced in 80 % of eyes in all three analyses. Regarding buried ONHD, 30 % and 4 % of eyes had an abnormally reduced minimum GCIPL and average RNFL thickness, respectively. Furthermore, 26 % of these eyes had abnormal GCIPL exams with a normal or increased RNFL thickness.

Conclusions

Both RNFL and GCIPL analysis reveal significant thinning in eyes with ONHD directly correlated with drusen severity. In buried ONHD, the abnormality rate was significantly higher with GCIPL compared to RNFL evaluation, suggesting that GCIPL analysis might be an early structural indicator of neuronal loss in the setting of thickened RNFL.     

Time-domain-OCT versus Frequency-domain-OCT

Background

When changing from previously used time domain OCTs (TD-OCT) to frequency domain OCTs (FD-OCT) the question arises how to evaluate the progress of macular disease.

Methods

OCT examinations and calculation (mapping) of the central retinal thickness were carried out in 40 healthy eyes with the Stratus OCT® (Carl Zeiss Meditec Inc.; TD-OCT) as well as the Spectralis-OCT® (Heidelberg Engineering GmbH 2008; FD-OCT).

Results

The average central macular thickness was 218 µm in the Stratus OCT® and 282 µm in the Spectralis-OCT®. The average difference was 69 µm (p < 0.001). The mean value of single measurements showed a macular thickness of 195 µm when performed with the Stratus OCT® and of 235 µm with the Spectralis-OCT®. The difference of 40 µm was statistically significant (p < 0.001).     

Comparison of two different spectral domain optical coherence tomography devices in the detection of localized retinal nerve fiber layer defects

Purpose

To compare the detection of localized retinal nerve fiber layer (RNFL) defects by two different spectral domain optical coherence tomography (SD-OCT) devices.

Methods

Eyes of 42 normal control subjects and 48 patients with a localized RNFL defect on red-free fundus photographs were imaged by the Cirrus (Carl Zeiss Meditec, Dublin, CA, USA) and 3D OCT (Topcon, Tokyo, Japan) devices. We compared sensitivities, specificities, and area under the receiver operating characteristic curves (AUCs) of circumpapillary RNFL (cpRNFL) thickness and ganglion cell complex (GCC) parameters between the two devices.

Results

The devices provided different cpRNFL thickness measurements. The highest sensitivities at fixed specificities of 80 % (Cirrus: 83.3 %; 3D OCT: 77.1 %) and 95 % (Cirrus: 69.8 %; 3D OCT: 68.8 %) and the largest AUCs (Cirrus: 0.90; 3D OCT: 0.88) obtained by the cpRNFL parameters of the two devices were similar. Based on the internal normative database, the deviation-from-normal map of the Cirrus OCT device and the 36-segment map of the 3D OCT device had the highest sensitivity (89.6 and 91.7 %, respectively). Among the macular GCC parameters of the 3D OCT device, inferior macular RNFL thickness had the highest sensitivity (81.2 % at a specificity of 80 %) and the largest AUC (0.89).

Conclusions

Although the two SD-OCT devices have different measurement protocols, they showed similar abilities for the detection of a localized RNFL defect.     

Investigation of retinal nerve fiber layer thickness in patients with neurofibromatosis-1

Purpose

To compare the optical coherence tomography (OCT) findings of neurofibromatosis-1 (NF-1) patients with/without optic pathway glioma (OPG) with those of healthy controls.

Methods

Ten patients with NF-1, 17 patients with NF-1-associated OPGs, and 17 control subjects were included in the study. Retinal nerve fiber layer (RNFL) and macular thickness findings measured with Stratus OCT were compared between the groups.

Results

The average RNFL thickness was significantly lower in the OPG group (76.72 ± 22.16 μm) than in the controls (108.89 ± 9.92 μm) and NF-1 patients without OPGs (111.17 ± 12.13 μm) (p < 0.001). The macular volume was also found to be lower in NF-1 patients with OPG (6.41 ± 0.66 mm³) than in the healthy controls (7.19 ± 0.36 mm³; p = 0.001) and NF-1 patients without OPGs (7.25 ± 0.26 mm³; p = 0.005). Following this analysis the OPG group was further subdivided into two categories: OPG patients with normal visual acuity (VA) and OPG patients with decreased VA. The statistical analysis was repeated for these four subgroups, revealing that while the decrement in the average RNFL thickness was significant for both OPG groups that in the macular volume was only significant for OPG patients with decreased VA.

Conclusion

The results of our study suggest that RNFL thinning can be a helpful marker for the detection of OPGs in NF-1 patients. Larger studies with longitudinal data are required to confirm the role of OCT in the diagnosis and follow-up of these patients.     

Inner retinal layer comparisons of eyes with exudative age-related macular degeneration and eyes with age-related macular degeneration and glaucoma

Background

The incidence of glaucoma increases with age, as does age-related macular degeneration (AMD), with the reported incidence of glaucoma among AMD subjects being 5.4 %. Optical coherence tomography (OCT) can detect glaucomatous changes in the inner retina with high sensitivity. The purpose of this study was to compare ganglion cell complex (GCC) parameters and the thickness of the peripapillary retinal nerve fiber layer (RNFL) in normal eyes to that observed in eyes with age-related macular degeneration (AMD) and eyes with both AMD and glaucoma.

Methods

The GCC components [GCC thickness, focal loss volume (FLV), and global loss volume (GLV)] and peripapillary RNFL thickness were measured using RTVue spectral-domain OCT (SD-OCT). The GCC and RNFL parameters of normal eyes, AMD eyes treated with different types of therapy, and AMD eyes with and without glaucoma were evaluated using nonparametric tests. Univariate and multivariate analyses were used to determine whether the GCC and RNFL parameters could be used to differentiate AMD eyes with glaucoma from those without glaucoma.

Results

Seventy-one normal eyes, 120 eyes with AMD, and 23 eyes with AMD and glaucoma were studied. The values of all GCC components were significantly different in the normal eyes from those observed in the eyes with AMD, except for the RNFL thicknesses. The GCC and RNFL parameters were not significantly different between the eyes receiving different types of therapy among the AMD groups. The RNFL thickness was significantly correlated with glaucoma diagnosis in AMD eyes.

Conclusions

These findings indicate that there is damage to the inner retinal layers in eyes with AMD. The RNFL thickness can be a useful parameter for differentiating eyes with AMD from eyes with both AMD and glaucoma.     

Optic disc rim area to retinal nerve fiber layer thickness correlation: comparison of diabetic and normal tension glaucoma eyes

Purpose

To compare the correlation between optic disc rim area and retinal nerve fiber layer thickness (rim-RNFL correlation) in diabetic eyes with non-progressive RNFL defects and normal tension glaucoma (NTG) eyes.

Methods

Seventy-three eyes of 73 patients with preperimetric or early NTG and 25 eyes of 25 type II diabetes patients with a non-progressive RNFL defect for ≥5 years were enrolled in this retrospective cohort study. Rim areas and RNFL thicknesses were measured by Heidelberg retina tomography (HRT II) and by optical coherence tomography (Cirrus OCT), in global and 12 clock-hour parameters. Diabetic eyes were evaluated whether they were above the 95 % prediction interval (PI) for the rim-RNFL correlation of NTG.

Results

A significant linear rim-RNFL correlation was observed in NTG eyes globally and at all clock-hours, except in the 4 and 9 o’clock areas, (0.08 < r ² < 0.56, P < 0.05). Eighty-four percent of the diabetic eyes were above the 95 % PI of the rim-RNFL correlation of NTG in ≥2 clock-hours, as compared with 36 % of the eyes in the global parameter.

Conclusions

The eyes of diabetic patients with non-progressive RNFL were well-differentiated from NTG eyes by the rim-RNFL correlation.     

Visual function and inner retinal structure correlations in aquaporin-4 antibody-positive optic neuritis

Purpose

To investigate the correlation between visual function and thinning of the retinal nerve fiber layer (RNFL) and the macular ganglion cell-inner plexiform layer (GCIPL) as measured by optical coherence tomography (OCT) in eyes with aquaporin-4 IgG-positive optic neuritis (AQP4-IgG-positive ON).

Study design

Prospective study.

Methods

Patients with a history of ON were categorized into 2 groups: the AQP4-IgG-positive group and the AQP4-IgG-negative group. Patients with multiple sclerosis were excluded. All patients underwent ophthalmologic examination and OCT imaging at least 6 months after the last episode of acute ON. Visual function and inner retinal structure correlations were analyzed using Pearson correlation and regression analyses.

Results

Thirty-one previous ON eyes of 17 AQP4-IgG-positive patients and 21 previous ON eyes of 15 AQP4-IgG-negative patients were registered. Visual function, especially the visual field, was better correlated with RNFL than with macular GCIPL. The best correlation between visual function and RNFL was the linear model, whereas the best correlation between visual function and GCIPL was the nonlinear model (inverse regression). Regression models revealed worse visual function in AQP4-IgG-positive ON than in AQP4-IgG-negative ON, whereas no differences in RNFL and GCIPL were found between the 2 groups.

Conclusions

RNFL measured by OCT can be a useful retinal structure for estimating and monitoring visual field loss in AQP4-IgG-positive ON patients, particularly in patients whose visual field cannot be quantitated. The correlation between visual function and the inner retinal structure of eyes with AQP4-IgG is unique and differs from that of eyes without AQP4-IgG.

     

Development of a new strategy of visual field testing for macular dysfunction in patients with open angle glaucoma

Purpose

To explore methods of automated visual field (VF) examination for the assessment of macular function.

Method

We used a VF examination (AP-7000 automatic perimeter, Kowa, Japan) to examine macular function in 53 eyes from 29 patients with open angle glaucoma. We measured the mean total deviation (c-MD) of 16 points in the central VF located in a 2-degree-interval 4 × 4 array with various stimulus sizes (Goldmann sizes III, II, and I). The retinal nerve fiber layer (RNFL) thickness, ganglion cell complex (GCC), and ganglion cell layer plus inner plexiform layer (GCL + IPL) were measured with the 3D OCT-2000 System (Topcon, Japan). The c-MDs of various stimulus sizes were compared with the OCT parameters using the Spearman rank correlation.

Results

The average examination time was 93.5 ± 23.5 s and the c-MD values were ?11.8 ± 8.2 (stimulus size III), ?11.9 ± 9.5 (stimulus size II), and ?12.3 ± 9.6 dB (stimulus size I). The c-MD (stimulus size III) and averaged total deviations of the Humphrey Field Analysis 10-2 program were significantly correlated (ρ = 0.91). The C-MD values for stimulus size III were significantly correlated with the OCT parameters (RNFL: ρ = 0.59; GCC: ρ = 0.65; and GCL + IPL: ρ = 0.64). The correlation coefficient between the c-MD and the GCC was better for stimulus sizes II and I (ρ = 0.69) than for stimulus size III (ρ = 0.65).

Conclusion

The C-MD values for the 16 measured central VF points were significantly correlated with macular structure, and the smaller stimulus sizes of the automated VF test had a higher correlation coefficient of within 8°.     

Comparative study of macular ganglion cell complex thickness measured by spectral-domain optical coherence tomography in healthy eyes,eyes with preperimetric glaucoma,and eyes with early glaucoma

Purpose

To evaluate the diagnostic accuracy of Topcon 3D spectral-domain optical coherence tomography (SD-OCT) for measuring the macular inner retinal layers and the circumpapillary retinal nerve fiber layer (cpRNFL) in order to detect preperimetric glaucoma.

Methods

Two hundred four eyes, including 64 healthy eyes, 68 eyes with preperimetric glaucoma, and 72 eyes with early glaucoma were analyzed. Patients had a comprehensive ocular examination including visual field testing and SD-OCT imaging (3D OCT-2000; Topcon Corporation, Tokyo, Japan) in the macular and peripapillary regions. OCT macular scans were segmented into the macular nerve fiber layer (mNFL), ganglion cell layer with the inner plexiform layer (GCIP), and ganglion cell complex (GCC) (composed of the mNFL and GCIP). Ability to discriminate preperimetric glaucoma was assessed using the area under the receiver operating curve for all macular parameters and the cpRNFL.

Results

The median visual field MD was ?0.78 ± 1.19 dB for the healthy group, ?1.02 ± 1.29 dB for the preperimetric glaucoma group, and ?3.08 ± 1.61 dB for the early glaucoma group. There were significant differences between the preperimetric and healthy groups for GCIP and GCC and for almost all cpRNFL thickness parameters (P < 0.05), except for the mNFL and cpRNFL (nasal, 3, 4, 8, 9, and 10 o’clock sectors). The comparisons among the AUCs of the cpRNFL parameters (0.772), the GCIP parameters (0.727) and the GCC parameters (0.720) showed no significant differences in their abilities to detect preperimetric glaucoma.

Conclusions

The capacity of Topcon 3D-OCT macular intraretinal parameters (GCIP and GCC measurements, not mNFL measurements) to diagnose preperimetric glaucoma is similar to that of the cpRNFL.     

Retinal and optic nerve evaluation by optical coherence tomography in adults with obstructive sleep apnea–hypopnea syndrome (OSAHS)

Objective

To assess the peripapillary retinal nerve fiber layer (RNFL) thickness, optic nerve head (ONH) morphologic parameters, and macular thickness and volume in patients affected by obstructive sleep apnea–hypopnea syndrome (OSAHS).

Methods

This prospective, observational case-control study consisted of 96 eyes of 50 OSAHS patients (mean age of 50.9?±?12.4 years, best-corrected visual acuity ≥20/20, refractive error less than 3 spherocylindrical diopters, and intraocular pressure <21 mmHg) who were enrolled and compared with 64 eyes of 33 age-matched controls. Peripapillary RNFL thickness, ONH parameters, macular thickness and volume were measured by optical coherence tomography (OCT).

Results

OSAHS patients showed a significant reduction of the nasal quadrant RNFL thickness (74.7?±?15.8 μm) compared with those values observed in control patients (81.1?±?16.6 μm, p?=?0.047, Student's t-test). No differences in peripapillary RNFL thickness were observed when dividing the OSAHS group in accordance with disease severity. Vertical integrated rim area (VIRA) (0.67?±?0.41 mm³ in OSAHS vs 0.55?±?0.29 mm³ in controls; p?=?0.043, Student's t-test), horizontal integrated rim width (HIRW) (1.87?±?0.31 mm² in OSAHS vs 1.8?±?0.25 mm² in controls; p?=?0.039, Student's t-test) and disc area (2.74?±?0.62 mm² in OSAHS vs 2.48?±?0.42 mm² in controls; p?=?0.002, Student's t-test) showed significant differences, all of them being higher in the OSAHS group. Severe OSAHS had significant higher disc area (2.8?±?0.7 mm²) than controls (2.5?±?0.4 mm²; p?=?0.016, ANOVA test). Temporal inner macular thickness was significantly higher in mild–moderate OSAHS patients (270?±?12 μm) than in severe OSAHS patients (260?±?19 μm; p?=?0.021, ANOVA test).

Conclusions

OSAHS patients showed decreased peripapillary nasal RNFL thickness, and increased ONH area and volume parameters when they were evaluated by OCT. These findings suggest that neuronal degeneration might be present in the retina of OSAHS patients, as previously observed in some neurodegenerative disorders     

Discrepancy between optic disc and nerve fiber layer assessment and optical coherence tomography in detecting glaucomatous progression

Purpose

To compare the outcomes of Cirrus spectral-domain optical coherence tomography (OCT) and optic disc/retinal nerve fiber layer (RNFL) photographic assessment in detecting glaucomatous progression.

Methods

Two-hundred twenty-six eyes of 130 glaucoma patients (mean follow-up: 2.5 years) with at least 5 OCT examinations were included. Eyes were classified into one of four groups (diffuse RNFL defect; localized RNFL defect; no RNFL defect; unidentifiable RNFL status) based on baseline RNFL photographs. After performing the entire series of optic disc/RNFL photographic assessments, the eyes were classified into one of three groups: stable, progressed, and undetermined. Progression was divided into one of four categories (optic disc rim thinning; widening RNFL defect; deepening RNFL defect; new disc hemorrhage). OCT progression was determined using guided progression analysis (GPA) software.

Results

One-hundred thirty-nine eyes had diffuse RNFL defects, 34 eyes had localized RNFL defects, 42 eyes had no RNFL defects, and 11 eyes had unidentifiable RNFL at baseline. Forty-six eyes showed at least one category of progression upon expert assessment of optic disc/RNFL photographs, while OCT GPA detected progression in 35 eyes. Among the 34 eyes in which progression was observed in photographs only, 15 showed a new disc hemorrhage, 12 presented deepening of an RNFL defect, 10 showed optic disc rim change, and 6 had widening of an RNFL defect. Among the 23 eyes processed only by OCT GPA, 18 had a diffuse RNFL defect at baseline.

Conclusion

OCT GPA was more sensitive in eyes with a diffuse RNFL defect whereas photographic assessment was better for detecting optic disc hemorrhage and deepening of an RNFL defect when evaluating structural progression.     

Assessment of serous macular detachment in eyes with diabetic macular edema by use of spectral-domain optical coherence tomography

Background

The introduction of optical coherence tomography (OCT) has brought new potentialities for an objective evaluation of macular diseases. The purpose of the present study was to assess the serous macular detachment (SMD) in eyes with diabetic macular edema (DME) by use of spectral-domain OCT.

Methods

In this prospective study were included 79 eyes of 46 patients with diabetic retinopathy and DME. All patients underwent examination of best-corrected visual acuity (BCVA), non-contact slit-lamp fundus biomicroscopy, fluorescein angiography and OCT. Spectral-domain OCT (OCT/SLO Combination Imaging System, OPKO/OT Inc., Toronto, Ontario, Canada) was used to evaluate retinal morphology and the presence of macular traction (vitreomacular and/or from epiretinal membranes) on B-scans, C-scans and C-scan OCT/SLO fundus image overlays. With OCT were measured retinal thickness, volume, diameter of intraretinal cystoid spaces, diameter and height of SMD. The correlation of retinal thickness and volume with BCVA in all eyes with DME and the relation of SMD to retinal thickness, volume, BCVA, macular traction and ischemia were assessed.

Results

The SMD was diagnosed only by means of OCT in nine eyes (11.4%) of five patients. In eight of nine eyes it was combined with intermediate (300–600 µm) or severe (>600 µm) cystoid spaces, and in one eye with simple macular edema. Retinal thickness and volume correlated with BCVA (r?=?0.464, P?<?0.0001 and r?=?0.480, P?<?0.0001). The SMD height did not correlate with retinal thickness, volume or BCVA. Six eyes with SMD had macular ischemia, and five eyes had severe ischemia in retinal periphery. Macular traction was: absent in three eyes, questionable (without distortion of retinal contour from partial posterior vitreous detachment and/or epiretinal membrane) in three eyes, and definite (with distortion of retinal contour) in three eyes.

Conclusions

Spectral-domain OCT provided valuable information on retinal morphology and was particularly useful in diagnosing sub-clinical SMD in eyes with DME. It disclosed the presence and strength of macular traction either by partially detached posterior hyaloid or by epiretinal membranes. C-scans and C-scan OCT/SLO fundus image overlays added complementary information for the extent and location of the pathological features. Larger studies which follow subjects longitudinally are needed to explain the pathogenesis and determine the prognosis of SMD.     

Extrafoveal changes following intravitreal bevacizumab injections for macular edema secondary to branch retinal vein occlusion: an mfERG and OCT study

Purpose

To evaluate the functional and structural changes of extrafoveal macula after intravitreal bevacizumab (IVB) injection in patients with macular edema due to branch retinal vein occlusion (BRVO) using multifocal electroretinogram (mfERG) and optical coherence tomography (OCT).

Methods

A total of 19 eyes of 19 patients with macular edema due to BRVO received three consecutive IVB injections with a 6-week interval. Spectral domain optical coherence tomography (SD-OCT), mfERG, and fluorescein angiography (FA) were performed at baseline. The macular area was divided into four quadrants (Q1–Q4) based on FA. The mean retinal thickness (MRT) and mfERG parameters in each of the four quadrants were measured at baseline and 4 weeks after the third injection.

Results

The MRT in the four quadrants improved significantly after IVB injections (p < 0.01 for Q1 and Q2, p < 0.05 for Q3 and Q4) compared to baseline. The significant improvements in mfERG responses were seen in Q1 and Q2. In Q1, there were 68 and 56 % improvement in N1 and P1 amplitude, respectively (p < 0.01). N1 and P1 amplitude in Q2 increased significantly by 43 and 46 %, respectively, compared to baseline (p < 0.05). The MRT and P1 amplitude were significantly correlated at baseline in Q1 and Q2, but no significant correlations were found after three IVB injections.

Conclusions

The injection of IVB improved functional and structural outcomes in the primarily affected half of the extrafoveal macula effectively. The measurements of structural and functional changes using mfERG and OCT may be appropriate for monitoring the effects of IVB injection in BRVO patients.