Luciana Virgínia Ferreira Costa-Cunha

Comparison of Fourier-Domain and Time-Domain Optical Coherence Tomography in the Detection of Band Atrophy of the Optic Nerve

PURPOSE To compare the ability of Fourier-domain (FD) optical coherence tomography (3D OCT-1000; Topcon, Tokyo, Japan) and time-domain (TD) OCT (Stratus; Carl Zeiss Meditec Inc, Dublin, California, USA) to detect axonal loss in eyes with band atrophy (BA) of the optic nerve. DESIGN Cross-sectional study. METHODS Thirty-six eyes from 36 patients with BA and temporal visual field (VF) defect from chiasmal compression and 36 normal eyes were studied. Subjects were submitted to standard automated perimetry and macular and retinal nerve fiber layer (RNFL) measurements were taken using 3D OCT-1000 and Stratus OCT. Receiver operating characteristic (ROC) curves were calculated for each parameter. Spearman correlation coefficients were obtained to evaluate the relationship between RNFL and macular thickness parameters and severity of VF loss. Measurements from the two devices were compared. RESULTS Regardless of OCT device, all RNFL and macular thickness parameters were significantly lower in eyes with BA compared with normal eyes, but no statistically significant difference was found with regard to the area under the ROC curve. Structure-function relationships were also similar for the two devices. In both groups, RNFL and macular thickness measurements were generally and in some cases significantly smaller with 3D OCT-1000 than with Stratus OCT. CONCLUSIONS The introduction of FD technology did not lead to better discrimination ability for detecting BA of the optic nerve compared with TD technology when using the software currently provided by the manufacturer. 3D OCT-1000 FD OCT RNFL and macular measurements were generally smaller than TD Stratus OCT measurements. Investigators should be aware of this fact when comparing measurements obtained with these two devices.

Relationship between optical coherence tomography, pattern electroretinogram and automated perimetry in eyes with temporal hemianopia from chiasmal compression.

PURPOSE To evaluate the relationship between pattern electroretinogram (PERG) amplitude, macular and retinal nerve fiber layer (RNFL) thickness by optical coherence tomography (OCT), and visual field (VF) loss on standard automated perimetry (SAP) in eyes with temporal hemianopia from chiasmal compression. METHODS Forty-one eyes from 41 patients with permanent temporal VF defects from chiasmal compression and 41 healthy subjects underwent transient full-field and hemifield (temporal or nasal) stimulation PERG, SAP and time domain-OCT macular and RNFL thickness measurements. Comparisons were made using Students t-test. Deviation from normal VF sensitivity for the central 18 degrees of VF was expressed in 1/Lambert units. Correlations between measurements were verified by linear regression analysis. RESULTS PERG and OCT measurements were significantly lower in eyes with temporal hemianopia than in normal eyes. A significant correlation was found between VF sensitivity loss and full-field or nasal, but not temporal, hemifield PERG amplitude. Likewise a significant correlation was found between VF sensitivity loss and most OCT parameters. No significant correlation was observed between OCT and PERG parameters, except for nasal hemifield amplitude. A significant correlation was observed between several macular and RNFL thickness parameters. CONCLUSIONS In patients with chiasmal compression, PERG amplitude and OCT thickness measurements were significant related to VF loss, but not to each other. OCT and PERG quantify neuronal loss differently, but both technologies are useful in understanding structure-function relationship in patients with chiasmal compression. (ClinicalTrials.gov number, NCT00553761).

Correlation between macular and retinal nerve fibre layer Fourier-domain OCT measurements and visual field loss in chiasmal compression.

PurposeThe aim of this study was to test the correlation between Fourier-domain (FD) optical coherence tomography (OCT) macular and retinal nerve fibre layer (RNFL) thickness and visual field (VF) loss on standard automated perimetry (SAP) in chiasmal compression.MethodsA total of 35 eyes with permanent temporal VF defects and 35 controls underwent SAP and FD-OCT (3D OCT-1000; Topcon Corp.) examinations. Macular thickness measurements were averaged for the central area and for each quadrant and half of that area, whereas RNFL thickness was determined for six sectors around the optic disc. VF loss was estimated in six sectors of the VF and in the central 16 test points in the VF. The correlation between VF loss and OCT measurements was tested with Spearmans correlation coefficients and with linear regression analysis.ResultsMacular and RNFL thickness parameters correlated strongly with SAP VF loss. Correlations were generally stronger between VF loss and quadrantic or hemianopic macular thickness than with sectoral RNFL thickness. For the macular parameters, we observed the strongest correlation between macular thickness in the inferonasal quadrant and VF loss in the superior temporal central quadrant (ρ=0.78; P<0.001) whereas for the RNFL parameters the strongest correlation was observed between the superonasal optic disc sector and the central temporal VF defect (ρ=0.60; P<0.001).ConclusionAlthough FD-OCT RNFL and macular thickness measurements were both correlated with VF loss, the correlation was stronger with quadrantic macular than with RNFL thickness measurements in patients with temporal hemianopia. Such measurements could potentially be used to quantify neuronal loss in patients with chiasmal compression.

Evaluation of Inner Retinal Layers in Eyes With Temporal Hemianopic Visual Loss From Chiasmal Compression Using Optical Coherence Tomography

PURPOSE We measured macular inner retinal layer thicknesses using frequency-domain optical coherence tomography (fd-OCT) and correlated these measures with visual field (VF) in eyes with temporal hemianopia from chiasmal compression and band atrophy (BA) of the optic nerve. METHODS Macular fd-OCT scans and VFs were obtained from 33 eyes of 33 patients with temporal hemianopia and 36 control eyes. The macular retinal nerve fiber layer (mRNFL), combined retinal ganglion cell and inner plexiform layers (RGCL+), and the inner nuclear layer (INL) were segmented. Measurements were averaged for each macula quadrant. Scans were assessed qualitatively for microcysts in the INL. The VF was estimated from the central 16 test points. The two groups were compared. Correlations between VF and OCT measurements were assessed. RESULTS The mRNFL, RGCL+, and total retinal (TR) macular thickness measurements were significantly smaller in BA eyes than controls. In the nasal quadrants, INL measurements were significantly greater in BA eyes than controls. The mRNFL and RGCL+ measurements had greater discrimination ability than TR measurements in the temporal quadrants. A significant correlation was found between most OCT parameters and their corresponding VF parameters. The strongest association was observed between RNFL and RGCL+ thickness, and VF loss in the corresponding area. The INL microcysts were found in seven eyes with BA, but not in controls. CONCLUSIONS Band atrophy leads to mRNFL and RGCL+ thinning, and INL thickening, and mRNFL and RGCL+ measurements are correlated strongly with VF loss. Segmented macular thickness measurements may be useful for quantifying neuronal loss in chiasmal compression.

Comparison between retinal nerve fiber layer and macular thickness measured with OCT detecting progressive axonal loss following traumatic optic neuropathy

PURPOSE To compare the optical coherence tomography retinal nerve fiber layer and macular thickness measurements for detection of progressive axonal loss following acute traumatic optic neuropathy in a longitudinal study. METHODS Three patients with unilateral traumatic optic neuropathy were evaluated sequentially after trauma. Macular and retinal nerve fiber layer thickness measurements were obtained using optical coherence tomography weekly for five weeks and around the twelfth week after trauma. RESULTS All patients showed progressive macular and retinal nerve fiber layer thickness reduction. The mean retinal nerve fiber layer thickness on the first week was 114 microm and reduced sequentially over the first five weeks and was 46 microm on the twelfth week. For macular parameters, the mean average thickness on the first week was 248 microm and also reduced over the first five weeks and was 218 microm on the twelfth week. When compared to the initial measurement, macular thickness average reduction rate at the 12th week was 14% while peripapillary retinal nerve fiber layer thickness average reduction rate was 59%. CONCLUSIONS Although both measurements reduce significantly after trauma, retinal nerve fiber layer thickness measurements show greater and faster retinal neural reduction if compared to macular thickness measurements in traumatic optic neuropathy.

Macular Thickness Measurements with Frequency Domain-OCT for Quantification of Retinal Neural Loss and its Correlation with Cognitive Impairment in Alzheimerʼs Disease

Purpose To evaluate the ability of frequency domain optical coherence tomography (fd-OCT) to estimate retinal neural loss in eyes with Alzheimer’s disease (AD). We also verified the existence of a correlation between AD-related cognitive impairment and macular and peripapillary retinal nerve fiber layer (RNFL) thickness measurements. Methods fd-OCT scans were obtained from 45 eyes of 24 patients with AD and 48 control eyes. Peripapillary RNFL, macular full-thickness and segmented inner macular thickness parameters were calculated. The inner macular parameters included macular retinal nerve fiber layer (mRNFL) thickness, ganglion cell layer (GCL) plus inner plexiform layer thickness (GCL+), and RNFL plus GCL+ thickness (GCL++). The Mini-Mental State Examination (MMSE) was used to assess cognition in all subjects. The two groups were compared and the relationship between MMSE scores and fd-OCT measurements was verified. Results Average, superior and inferior quadrant RNFL thickness parameters and all but one of the nine full-thickness macular measurements were significantly reduced in AD patients compared to controls. The segmented layers, GCL+ and GCL++ were significantly reduced in AD eyes. A significant correlation was found between most fd-OCT parameters (especially macular thickness measurements) and MMSE scores. Conclusions Most fd-OCT peripapillary RNFL and macular full-thickness and segmented inner retinal layers parameters were reduced in AD eyes compared to controls. Moreover, neuronal loss, especially as reflected in macular parameters, correlated well with cognitive impairment in AD. Our results suggest that fd-OCT could be a potentially useful diagnostic tool in the evaluation and follow-up of AD patients.

The role of optical coherence tomography in Alzheimer’s disease

BackgroundAlzheimer’s disease (AD) is the most common cause of dementia and its incidence is increasing worldwide along with population aging. Previous clinical and histologic studies suggest that the neurodegenerative process, which affects the brain, may also affect the retina of AD patients.Main bodyOptical coherence tomography (OCT) is a non-invasive technology that acquires cross-sectional images of retinal structures allowing neural fundus integrity assessment. Several previous studies demonstrated that both peripapillary retinal nerve fiber layer and macular thickness measurements assessed by OCT were able to detect neuronal loss in AD. Moreover, recent advances in OCT technology, have allowed substantial enhancement in ultrastructural evaluation of the macula, enabling the assessment not only of full-thickness retinal measurements but also of inner retinal layers, which seems to be a promising approach, mainly regarding the assessment of retinal ganglion cell layer impairment in AD patients. Furthermore, retinal neuronal loss seems to correlate with cognitive impairment in AD, reinforcing the promising role of OCT in the clinical evaluation of these patients.ConclusionThe purpose of this article is to review the main findings on OCT in AD patients, to discuss the role of this important diagnostic tool in these patients and how OCT technology may be useful in understanding morphological retinal changes in AD.

Relationship between visual field sensitivity loss and quadrantic macular thickness measured with Stratus-Optical coherence tomography in patients with chiasmal syndrome

PURPOSE To correlate visual field sensitivity (VFS) loss on standard automated perimetry (SAP) and quadrantic macular thickness on optical coherence tomography (OCT) in patients with permanent temporal hemianopia from chiasmal compression. METHODS Forty eyes from 40 patients with chiasmal compression and 40 healthy eyes were submitted to standard automated perimetry and Stratus-OCT scanning. Raw data of the fast macular thickness scanning protocol were exported and macular thickness measurements were recorded and averaged for each quadrant and half of the central area. The correlation between visual field sensitivity loss and optical coherence tomography measurements was tested with Pearsons correlation coefficients and with linear regression analysis. RESULTS A significant association was found between each macular thickness parameter and the corresponding central VF mean sensitivity. The strongest association was observed between superonasal macular thickness and the inferotemporal mean defect measured both in decibel (R=0.47; p=0.001) and in 1/Lambert (R=0.59; p<0.0001) units. CONCLUSION Stratus-OCT-measured macular thickness was topographically related with visual field sensitivity loss in patients with temporal hemianopia from chiasmal compression. Such measurements could prove clinically useful in the diagnosis and follow-up of patients with chiasmal compression. ClinicalTrial.gov identifier number: NCT0039122.

Intraretinal worm documented by optical coherence tomography in a patient with diffuse unilateral subacute neuroretinitis: case report

Our purpose is to report a case of diffuse unilateral subacute neuroretinitis (DUSN) in which an ophthalmoscopically visible worm was found and optical coherence tomography (OCT) scans allowed the precise localization of the parasite in the intraretinal layers. Our findings suggest that the parasite moves in the inner portions of the retina possibly explaining the severe degenerative neural changes that it causes.

Non-Mydriatic Fundus Retinography in Screening for Diabetic Retinopathy: Agreement Between Family Physicians, General Ophthalmologists, and a Retinal Specialist

Purpose To determine the level of agreement between trained family physicians (FPs), general ophthalmologists (GOs), and a retinal specialist (RS) in the assessment of non-mydriatic fundus retinography in screening for diabetic retinopathy (DR) in the primary health-care setting. Methods 200 Diabetic patients were submitted to two-field non-mydriatic digital fundus camera. The images were examined by four trained FPs, two GOs, and one RS with regard to the diagnosis and severity of DR and the diagnosis of macular edema. The RS served as gold standard. Reliability and accuracy were determined with the kappa test and diagnostic measures. Results A total of 397 eyes of 200 patients were included. The mean age was 55.1 (±11.7) years, and 182 (91%) had type 2 diabetes. The mean levels of serum glucose and glycosylated hemoglobin A1c were 195.6 (±87.3) mg/dL and 8.9% (±2.1), respectively. DR was diagnosed in 166 eyes by the RS and in 114 and 182 eyes by GO1 and GO2, respectively. For severity, DR was graded as proliferative in 8 eyes by the RS vs. 15 and 9 eyes by GO1 and GO2, respectively. The agreement between the RS and the GOs was substantial for both DR diagnosis (GO1 k = 0.65; GO2 k = 0.74) and severity (GO1 k = 0.60; GO2 k = 0.71), and fair or moderate for macular edema (GO1 k = 0.27; GO2 k = 0.43). FP1, FP2, FP3, and FP4 diagnosed DR in 108, 119, 163, and 117 eyes, respectively. The agreement between the RS and the FPs with regard to DR diagnosis was substantial (FP2 k = 0.69; FP3 k = 0.73; FP4 k = 0.71) or moderate (FP1 k = 0.56). As for DR severity, the agreement between the FPs and the RS was substantial (FP2 k = 0.66; FP3 k = 069; FP4 k = 0.64) or moderate (FP1 k = 0.51). Agreement between the FPs and the RS with regard to macular edema was fair (FP1 k = 0.33; FP2 k = 0.39; FP3 k = 0.37) or moderate (FP4 k = 0.51). Conclusion Non-mydriatic fundus retinography was shown to be useful in DR screening in the primary health-care setting. FPs made assessments with good levels of agreement with an RS. Non-mydriatic fundus retinography associated with appropriate general physicians training is essential for the DR screening.