Leonardo Provetti 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.

Predictive factors for the development of visual loss in patients with pituitary macroadenomas and for visual recovery after optic pathway decompression

OBJECTIVE To investigate clinical and MRI findings that are predictive of both visual loss in patients with pituitary adenomas and visual recovery after treatment. DESIGN Cohort study. PARTICIPANTS Thirty patients (60 eyes) with pituitary adenoma. METHODS Patients underwent neuro-ophthalmic examination and MRI before and after optic chiasm decompression. Visual field (VF) was assessed using the mean deviation in standard automated perimetry (SAP) and temporal mean defect, the average of 22 temporal values of the total deviation plot. Tumour size was measured on sagittal and coronal cuts. RESULTS Visual loss was found in 47 eyes; 35 had optic atrophy (subtle in 9, moderate in 14, and severe in 12). Before treatment, the average SAP mean deviation and temporal mean defect were -11.78 (SD 8.56) dB and -18.66 (SD 11.20) dB, respectively. The chiasm was 17.3 (SD 6.2, range 10-34) mm above the reference line on the sagittal and 21.8 (SD 8.3, range 12-39) mm on the coronal images. Tumour size correlated with the severity of VF defect. VF improvement occurred in 80% of eyes after treatment. The degree of optic atrophy, visual loss, and tumour size were significantly associated with improvement after treatment. CONCLUSIONS The best predictive factor for visual loss was tumour size, and factors related to visual recovery were the degree of optic atrophy, the severity of VF defect, and the tumour size. Diagnosing pituitary adenomas before optic atrophy becomes severe may be related to a better prognosis in such patients.

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.

Bilateral visual loss after liposuction: case report and review of the literature

Severe visual loss after a general surgical procedure can be a devastating complication for both surgeon and patient. Although visual loss can be the result of damage to any structure in the eye, most cases of such a complication are the result of ischemic damage to both the anterior and posterior portions of the optic nerve. Ischemic optic neuropathy (ION) is therefore a potentially devastating and untreatable, albeit rare complication of general surgery, usually occurring in the immediate postoperative period. Precipitating factors for such occurrences include prolonged hypotension, anemia, significant intraoperative hydration, surgical trauma, gastrointestinal bleeding, hemorrhage, shock, and long operative times, usually occurring after cardiopulmonary, orthopedic, and neurosurgical procedures. Recently, 3 cases of ION after liposuction, a simple and commonly performed operation, have been reported. The purpose of this paper is to report 1 further case of this unusual event and to review the possible mechanisms and preventive measures for such an occurrence.

Progressive macular thinning after indirect traumatic optic neuropathy documented by optical coherence tomography

Optical coherence tomography (OCT) is a noninvasive optical imaging technique that provides high-resolution, cross-sectional, in vivo imaging of the human retina from which estimates of retinal layers thickness can be made.1 OCT is capable of scanning the peripapillary retina, optic nerve head (ONH), and macular region. Previous studies have documented the ability of OCT to image the retinal nerve fibre layer (RNFL) of patients with glaucoma or other optic neuropathies including indirect optic nerve trauma.2–4 Although OCT has for the most part been used to evaluate RNFL thickness, recent software improvements have made it possible to measure macular thickness as well. The purpose of this paper is to report a case of …

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.

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

PurposeTo 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.MethodsTwenty-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.ResultsBoth 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.ConclusionsmfPERG 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.

Multifocal pattern electroretinography for the detection of neural loss in eyes with permanent temporal hemianopia or quadrantanopia from chiasmal compression

Aims To evaluate the ability of multifocal transient pattern electroretinography (mfPERG) to detect neural loss and assess the relationship between mfPERG and visual-field (VF) loss in eyes with chiasmal compression. Methods 23 eyes from 23 patients with temporal VF defects and band atrophy of the optic nerve and 21 controls underwent standard automated perimetry and mfPERG using a stimulus pattern of 19 rectangles, each consisting of 12 squares. The response was determined for the central rectangle, for the nasal and temporal hemifields (eight rectangles each) and for each quadrant (three rectangles) in both patients and controls. Comparisons were made using variance analysis. Correlations between VF and mfPERG measurements were verified by linear regression analysis. Results Mean±SD mfPERG amplitudes from the temporal hemifield (0.50±0.17 and 0.62±0.32) and temporal quadrants (superior 0.42±0.21 and 0.52±0.35, inferior 0.51±0.23 and 0.74±0.40) were significantly lower in eyes with band atrophy than in controls (0.78±0.24, 0.89±0.28, 0.73±0.26, 0.96±0.36, 0.79±0.26 and 0.91±0.31, respectively). No significant difference was observed in nasal hemifield measurements. Significant correlations (0.36–0.73) were found between VF relative sensitivity and mfPERG amplitude in different VF sectors. Conclusions mfPERG amplitude measurements clearly differentiate eyes with temporal VF defect from controls. The good correlation between mfPERG amplitudes and the severity of VF defect suggests that mfPERG may be used as an indicator of ganglion cell dysfunction. Clinical trial registration number ClinicalTrial.gov identifier number NCT00553761.