The natural history of lamellar macular holes: a spectral domain optical coherence tomography study.

BACKGROUND: To study the evolution of lamellar macular holes (LMHs) using spectral domain-optical coherence tomography (SD-OCT). METHODS: Thirty-four consecutive patients diagnosed with a LMH were followed prospectively at Sacco University Hospital from October 2008 to January 2011. Inclusion criteria were a foveal defect on SD-OCT with residual foveal tissue above the retinal pigment epithelium and corresponding hyperautofluorescence on fundus autofluorescence imaging. Epiretinal membranes (ERMs) were categorized by SD-OCT at baseline as two different types: normal and thicker than normal. Best corrected visual acuity (BCVA) and SD-OCT findings were collected and compared at baseline and every 6 months thereafter. Active eye tracking technology ensured that the same scanning location was identified on follow-up visits. Main outcome measures were visual acuity changes (Early Treatment Diabetic Retinopathy charts) and progression of the lamellar macular defect. The influence of ERM type on disease progression was also evaluated. RESULTS: The patients included 15 males and 19 females with a mean age of 73 years and mean refraction of -0.25 diopters. The mean follow-up period was 18 months (range 6 to 24 months). BCVA at baseline (±standard deviation) was 63 ± 6 letters and did not change significantly during the follow-up period (P = 0.256). Foveal thickness at baseline, 180 ± 29 µm, was also stable (P = 0.592). All eyes had an ERM at baseline. Both thicker and normal ERMs showed similar functional and morphological evolution during follow-up with no significant changes. Two LMHs (5.8 %) developed a full thickness macular hole after 6 and 15 months follow-up respectively. CONCLUSIONS: Lamellar macular holes seem to be a stable macular condition. Vitrectomy should be considered only in the presence of progressive thinning of foveal thickness and/or decrease of visual acuity during the follow-up of the disease.

Repeatability and reproducibility of retinal thickness measurements with spectral-domain optical coherence tomography using different scan parameters.

PURPOSE: To evaluate repeatability (test-retest) and reproducibility of retinal thickness measurements using spectral-domain optical coherence tomography with different densities of A-scans per B-scan and different frames per B-scan for real-time averaging. METHODS: Twelve healthy subjects were analyzed by spectral-domain optical coherence tomography. Raster lines analysis with 19 B-scans over the examined area centered on the macula was performed. Images were acquired both in standard-density (768 A-scans/B-scan) and high-density (1,536 A-scans/B-scan) modalities. Moreover, images were acquired using 2 and 20 frames/B-scan for real-time averaging. Each analysis was repeated twice to test for repeatability. RESULTS: Intersession repeatability was good for all studied analysis protocols, with Lin concordance correlation coefficient values ranging between 0.88 and 1.00. Reproducibility assessment showed consistent retinal thickness measurements using variable scan density, with Bland-Altman limits of agreement of -6 µm to 6 µm in the central area. Reproducibility assessment showed consistent retinal thickness measurements using different number of frames used in the real-time averaging process, with Bland-Altman limits of agreement of -8 µm to 4 µm in the central area. CONCLUSION: Spectral-domain optical coherence tomography is a very reliable tool for central retinal thickness assessment. Changes in the number of A-scans/B-scan and in frames used for real-time averaging do not affect repeatability and reproducibility.

Spectral domain-optical coherence tomography and fundus autofluorescence findings in a case of purtscher-like retinopathy.

PURPOSE: The purpose of this study is to describe spectral domain-optical coherence tomography and autofluorescence images in a case of bilateral Purtscher-like retinopathy. METHODS: This is an observational case report of a 31-year-old man suffering with Purtscher-like retinopathy postpancreatitis. RESULTS: In the acute phase, spectral domain-optical coherence tomography showed hyperreflectivity in the inner retinal layers, corresponding to cotton-wool exudation as a result of precapillary ischemia. The follow-up using spectral domain-optical coherence tomography showed that the inner retina is the most involved layer by ischemic damage in the acute phase. In the regression phase, signs of suffering in the outer retinal layers became visible as well, although after the resolution of the pathology, there was no evident spectral domain-optical coherence tomography abnormality in the photoreceptors layers. Autofluorescence images after resolution showed hyperautofluorescent vessels affected by ischemia as a possible result of long-lasting retention of intraretinal blood. CONCLUSION: Spectral domain-optical coherence tomography and autofluorescence are sensitive and noninvasive imaging modalities to evaluate retinal alterations after Purtscher-like retinopathy. Spectral domain-optical coherence tomography confirms that ischemia causes an alteration primarily in the inner retinal layers, but the process also involves the outer retinal layers.

Reproducibility of retinal thickness measurements on normal and pathologic eyes by different optical coherence tomography instruments.

PURPOSE: To compare retinal thickness measurements produced by different time-domain and spectral-domain optical coherence tomography (TD-OCT and SD-OCT) devices when imaging normal and pathologic eyes. DESIGN: Prospective, observational study in an academic institutional setting. METHODS: A total of 110 eyes were imaged by 6 different OCT devices: Stratus and Cirrus (Carl Zeiss Meditec Inc), Spectralis HRA+OCT (Heidelberg Engineering), RTVue-100 (Optovue Inc), SDOCT Copernicus HR (Optopol Technology S.A.), and 3D OCT-1000 (Topcon Corporation). Eyes were normal or affected by different pathologies of the retina, including exudative and nonexudative age-related macular degeneration, epiretinal membrane, cystoid macular edema, and macular hole. For each instrument we used standard analysis protocols for macular thickness evaluation. Mean retinal thickness values between the instruments in the ETDRS central circular 1000-µm-diameter areas and in the ETDRS midperipheral circular 3000-µm-diameter areas were compared. RESULTS: The 6 different devices produced measurements that differ in variance (Bartlett test, P = .006), and mean values (Friedman test, P < .001). Bland-Altman analysis revealed that the limits of agreement for all the comparisons were not acceptable. Regression was calculated and it was elaborated into a conversion table, despite a high standard error for both intercepts and slope conversion values. CONCLUSIONS: This study suggests that retinal thickness measurements obtained with various OCT devices are different beyond clinical practice tolerance, according to Bland-Altman analysis. Furthermore, regression analysis reveals high standard error values. These differences appear to be primarily attributable to the analysis algorithms used to set retinal inner and outer boundaries.