One-Year Anti-VEGF Therapy Outcomes in Diabetic Macular Edema Based on Treatment Intensity: Data from the Fight Retinal Blindness! Registry.

PURPOSE: To compare 1-year outcomes of eyes with diabetic macular edema (DME) treated in routine clinical practice based on the proportion of visits where intravitreal VEGF inhibitor injections were delivered. DESIGN: Cohort study. PARTICIPANTS: There were 2288 treatment-naive eyes with DME starting intravitreal VEGF inhibitor therapy from October 31, 2015 to October 31, 2021 from the Fight Retinal Blindness! international outcomes registry. METHODS: Eyes were grouped according to the proportion of visits at which an injection was received, Group A with less than the median of 67% (n = 1172) versus Group B with greater than the median (n = 1116). MAIN OUTCOME MEASURES: Mean visual acuity (VA) change after 12 months of treatment. RESULTS: The mean (95% confidence interval [CI]) VA change after 12 months of treatment was 3.6 (2.8-4.4) letters for eyes in Group A versus 5.2 (4.4-5.9) letters for eyes in Group B (P = 0.005). The mean (95% CI) central subfield thickness (CST) change was -69 (-76 to -61) µm and -85 (-92 to -78) µm for eyes in Group A versus Group B, respectively (P = 0.002). A moderate positive correlation was observed between the number of injections received over 12 months of treatment and the change in VA (P < 0.001). Additionally, eyes that received more injections had a moderately greater CST reduction. CONCLUSIONS: This registry analysis found that overall VA and anatomic outcomes tended to be better in DME eyes treated at a greater proportion of visits in the first year of intravitreal VEGF inhibitor therapy. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Gender differences in retinal diseases: A review.

Gender medicine is a medical specialty that addresses gender differences in health and disease. Traditionally, medical research and clinical practice have often been focused on male subjects and patients. As a result, gender differences in medicine have been overlooked. Gender medicine considers the biological, psychological, and social differences between the genders and how these differences affect the development, diagnosis, treatment, and prevention of disease. For ophthalmological diseases epidemiological differences are known. However, there are not yet any gender-based ophthalmic treatment approaches for women and men. This review provides an overview of gender differences in retinal diseases. It is intended to make ophthalmologists, especially retinologists, more sensitive to the topic of gender medicine. The goal is to enhance comprehension of these aspects by highlighting fundamental gender differences. Integrating gender medicine into ophthalmological practice helps promote personalized and gender-responsive health care and makes medical research more accurate and relevant to the entire population.

The Role of Intravitreal Corticosteroids in the Treatment of DME: Predictive OCT Biomarkers.

This work aims to summarize predictive biomarkers to guide treatment choice in DME. Intravitreal anti-VEGF is considered the gold standard treatment for centers involving DME, while intravitreal steroid treatment has been established as a second-line treatment in DME. However, more than 1/3 of the patients do not adequately respond to anti-VEGF treatment despite up to 4-weekly injections. Not surprisingly, insufficient response to anti-VEGF therapy has been linked to low-normal VEGF levels in the serum and aqueous humor. These patients may well benefit from an early switch to intravitreal steroid treatment. In these patients, morphological biomarkers visible in OCT may predict treatment response and guide treatment decisions. Namely, the presence of a large amount of retinal and choroidal hyperreflective foci, disruption of the outer retinal layers and other signs of chronicity such as intraretinal cysts extending into the outer retina and a lower choroidal vascular index are all signs suggestive of a favorable treatment response of steroids compared to anti-VEGF. This paper summarizes predictive biomarkers in DME in order to assist individual treatment decisions in DME. These markers will help to identify DME patients who may benefit from primary dexamethasone treatment or an early switch.

Quality of life impact of eye diseases: a Save Sight Registries study.

BACKGROUND: The objectives of this study were to evaluate the quality-of-life (QoL) impact of eye diseases (keratoconus; neovascular age-related macular degeneration, AMD; retinal vein occlusion, RVO; and diabetic macular edema, DME) using the Impact of Vision Impairment (IVI) questionnaire, and to determine the relationship between the IVI scores and visual acuity. METHODS: This cross-sectional, multicentre, real-world study utilised the prospective, web-based Save Sight Registries. The IVI was completed by 1557 patients: 307 with keratoconus, 1049 with AMD, 148 with RVO and 53 with DME. Statistical analysis included Rasch analysis, Welch t-test, one-way ANOVA, Tukey's test, Pearson correlation, and multiple regression. RESULTS: The IVI scales (Overall; Visual Function, VF; Emotional, EM) had robust psychometric properties. The keratoconus patients had the worst Overall (adjusted mean: 48.2 vs. DME 58.8, RVO 64.6, AMD 67.6 units), VF (47.7 vs. DME 59.4, RVO 65.9, AMD 68.9 units) and EM (50.8 vs. DME 63.1, RVO 69.2, AMD 71.8 units) scores (all p < 0.05). The IVI scales scores weakly correlated with better and worse eye visual acuity (Pearson's r 0.24-0.39, all p < 0.05). The correlations were similar in the better eye (Overall 0.35, VF 0.39, EM 0.24) and the worse eye (Overall 0.31, VF 0.33, EM 0.25) visual acuity. Correlations with visual acuity were stronger for VF than for the EM scores. CONCLUSIONS: The IVI was a psychometrically robust QoL questionnaire. Keratoconus patients had worse IVI scores than patients with retinal diseases. The low strength of correlations between visual acuity and QoL scores, although statistically significant, suggested that a complex relationship exists.

Prevalence and characteristics of macular atrophy in eyes with neovascular age-related macular degeneration. A study from a long-term observational dataset: the Fight Retinal Blindness! project.

BACKGROUND: To assess the prevalence and characteristics associated with macular atrophy (MA) in eyes with neovascular age-related macular degeneration (nAMD) treated with vascular endothelial growth factor (VEGF) inhibitors. METHODS: This was a retrospective, cross-sectional study of nAMD eyes that commenced anti-VEGF between January 2006 and August 2016. MA (absent/extrafoveal/subfoveal) was graded by treating practitioners based on multimodal imaging from April 2016. The prevalence of MA over time and risk factors of MA were assessed. RESULTS: The prevalence of MA in a cohort of 1689 eyes was 9.9% (22/222) in eyes within 1 year of starting treatment, 41.5% (71/171) after 5 years and 48.4% (30/62) after 9 years of treatment. Risk factors for subfoveal MA included the proportion of visits at which the lesion was graded as inactive ((adjusted OR (AOR) 3.72 for the highest vs lowest the quartile of frequency of inactive gradings (95% CI 2.33 to 6.07)), age (AOR 1.05 per year (95% CI 1.02 to 1.07)), baseline visual acuity (AOR 3.9 for ≤35 letters vs ≥70 letters (95% CI 2.4 to 6.4)) and the number of injections received (AOR 1.20 every 10 injections (95% CI 1.08 to 1.33)). Similar associations were observed with extrafoveal MA. CONCLUSIONS: The risk of MA appeared to drop in eyes that had not developed it within 5 years. Low choroidal neovascularisation activity was by far the strongest predictor. We could not determine whether the increased prevalence of MA with time was due to anti-VEGF treatment or the natural history of the condition.

Comparison of Choroidal Thickness Measurements Using Spectral Domain Optical Coherence Tomography in Six Different Settings and With Customized Automated Segmentation Software.

PURPOSE: We investigate which spectral domain-optical coherence tomography (SD-OCT) setting is superior when measuring subfoveal choroidal thickness (CT) and compared results to an automated segmentation software. METHODS: Thirty patients underwent enhanced depth imaging (EDI)-OCT. B-scans were extracted in six different settings (W+N = white background/normal contrast 9; W+H = white background/maximum contrast 16; B+N = black background/normal contrast 12; B+H = black background/maximum contrast 16; C+N = Color-encoded image on black background at predefined contrast of 9, and C+H = Color-encoded image on black background at high/maximal contrast of 16), resulting in 180 images. Subfoveal CT was manually measured by nine graders and by automated segmentation software. Intraclass correlation (ICC) was assessed. RESULTS: ICC was higher in normal than in high contrast images, and better for achromatic black than for white background images. Achromatic images were better than color images. Highest ICC was achieved in B+N (ICC = 0.64), followed by B+H (ICC = 0.54), W+N, and W+H (ICC = 0.5 each). Weakest ICC was obtained with Spectral-color (ICC = 0.47). Mean manual CT versus mean computer estimated CT showed a correlation of r = 0.6 (P = 0.001). CONCLUSION: Black background with white image at normal contrast (B+N) seems the best setting to manually assess subfoveal CT. Automated assessment of CT seems to be a reliable tool for CT assessment. TRANSLATIONAL RELEVANCE: To define optimized OCT analysis settings to improve the evaluation of in vivo imaging.

The impact of ganglion cell layer cysts in diabetic macular oedema treated with anti-vascular endothelial growth factor.

PURPOSE: To investigate the prevalence and impact of ganglion cell layer cysts (GCLC) in patients with diabetic macular oedema (DME) under continuous anti-vascular endothelial growth factor (VEGF) therapy. METHODS: The clinical findings and spectral domain optical coherence devices of baseline visits and follow-up after 12-24 and 36 months of DME patients under continuous anti-VEGF therapy were retrospectively collected and analysed for the impact of GCLC cysts. Previously established prognostic parameters were also assessed. RESULTS: A total of 110 eyes of 110 DME patients (mean age 64 ± 10 years) were included. At baseline, 17% eyes had GCLC. With GCLC, the best-corrected visual acuity (BCVA) improvement was in mean 8.4 ± 2.4 Early-Treatment-Diabetic-Retinopathy-Study (ETDRS) letters less over the course of 36 months compared to the group lacking GCLC (p = 0.0009). Eyes with GCLC showed 68 ± 23.4 µm less central retinal thickness (CRT) decrease than eyes lacking GCLC (p < 0.0001). In the linear mixed effect models including external limiting membrane disruption, disintegration of inner retinal layer and epiretinal membrane, GCLC remained a statistical significant factor for the outcome parameter CRT, but missed statistical significance for BCVA. CONCLUSION: Ganglion cell layer cysts (GCLC) seem to impact outcome in DME in patients receiving long-term treatment. This prognostic factor warrants further evaluation in the context of already well-established outcome parameters.

The Burden of Macular Diseases in Central and Eastern Europe-Implications for Healthcare Systems.

BACKGROUND: Despite the significant impact of retinal diseases such as wet age-related macular degeneration (wAMD) and diabetic macular edema (DME), there is a limited understanding of how these conditions are managed in Central and Eastern Europe (CEE). OBJECTIVES: To provide a comprehensive overview of the clinical and economic burden of wAMD and DME in CEE and the status quo associated with their management. METHODS: A narrative literature review was undertaken to identify existing data on wAMD and DME, including epidemiology, economic burden, clinical guidelines, and available and reimbursed treatments. Data were collected from relevant sources such as PubMed, ophthalmology associations, national statistical offices, and government agency websites; practical viewpoints were provided by local ophthalmologists and healthcare economics experts in CEE. RESULTS: Epidemiological data on wAMD and DME are limited in CEE, and intercountry comparison is difficult because of differences in data collection methodologies. There are effective treatment options for wAMD and DME, and international guidelines advocate the use of intravitreal anti-vascular endothelial growth factor injections as first-line therapy. Local expert organizations broadly support these recommendations; nevertheless, no clinical practice guidelines exist on the treatment of wAMD and DME in CEE. Access to and reimbursement of anti-vascular endothelial growth factor agents vary significantly in the region and, as a result, many patients remain untreated or inadequately treated. CONCLUSIONS: There is an urgent need for the creation of a wAMD/DME treatment program in CEE to ensure that patients have timely access to the most appropriate treatments.

The Impact of the Vitreomacular Interface in Neovascular Age-Related Macular Degeneration in a Treat-and-Extend Regimen with Exit Strategy.

PURPOSE: To evaluate the impact of the vitreomacular interface (VMI) in a treat-and-extend (TREX) regimen with exit strategy in patients with neovascular age-related macular degeneration (nAMD). DESIGN: Retrospective cohort study. PARTICIPANTS: Five hundred ninety-three eyes of 498 patients with nAMD. METHODS: Eyes were treated according to a TREX regimen with an exit criterion, which was defined as no signs of disease activity during 3 consecutive 16-week injection visits. The impact of the VMI and the presence of an epiretinal membrane (ERM) assessed by spectral-domain OCT were evaluated based on the parameters mentioned below. MAIN OUTCOME MEASURES: Effect of vitreomacular adhesion (VMA) and ERM on mean treatment interval, number of injections, likelihood of fulfilling the exit criterion, choroidal neovascularization recurrences, CRT decrease, and BCVA improvement. RESULTS: During the TREX period, posterior vitreous detachment (PVD) eyes needed significantly fewer injections (mean, 10.6 ± 5.9) than VMA eyes (mean, 12.6 ± 6.7; P = 0.0008), and the mean injection interval was shorter in VMA eyes (8.3 ± 3.1 weeks) than in PVD eyes (9.5 ± 3.5 weeks; P = 0.0008). Eyes with PVD at baseline and without an ERM were 9.2 and 11.4 times more likely to fulfill the exit criterion than eyes with VMA and ERM, respectively (P = 0.006 and P = 0.004, respectively, corrected). Although CRT decrease (P = 0.16) and BCVA improvement (P = 0.32) did not differ with respect to the VMI configuration, ERM had a significant impact on CRT decrease (ERM present, +11 ± 198 µm vs. ERM absent, -92 ± 136 µm; P = 0.041). Vitreomacular adhesion at treatment cessation was associated significantly with disease recurrence (likelihood ratio, 7.8; P = 0.013, corrected), whereas the presence of an ERM was not associated with choroidal neovascularization recurrence (P = 0.18). CONCLUSIONS: The configuration of the VMI and the presence of an ERM have a significant impact on the treatment frequency, the chance to meet the exit criterion in this TREX regimen, and the recurrence risk after treatment cessation. This indicates that eyes with VMA should be monitored carefully for new disease activity after treatment cessation.

VISUAL ACUITY OUTCOMES OF RANIBIZUMAB TREATMENT IN PATHOLOGIC MYOPIC EYES WITH MACULAR RETINOSCHISIS AND CHOROIDAL NEOVASCULARIZATION.

PURPOSE: To investigate visual and morphological outcome in eyes with MRS and choroidal neovascularization (CNV) secondary to pathologic myopia treated with intravitreal (IVT) ranibizumab. METHODS: Post hoc analysis of the patients included in the RADIANCE trial (n = 277) was performed to evaluate the impact of MRS on the functional outcome in patients with myopic choroidal neovascularization (mCNV) undergoing intravitreal ranibizumab injections. RESULTS: Prevalence of MRS in pathologic myopia population is 6%. Respective patients were generally older than patients without MRS. Study eyes with MRS at baseline (BL) showed an initially poor treatment response after 3 months (mean change in best corrected visual acuity (BCVA) was 2.8 ± 12.4 letters, P = 0.009). After 12 months of treatment however, the mean change in BCVA was 7.1 ± 14.5 early treatment diabetic retinopathy study (ETDRS) letters (P = 0.025). Patients with MRS at baseline received more intravitreal injections than the other RADIANCE patients without MRS (MRS, n = 15 eyes: 5.8 ± 2.1 vs. RADIANCE non-MRS [n = 207 eyes]: 4.0 ± 2.9; P = 0.0001). CONCLUSION: Improvement of visual acuity is delayed and reduced after 3 months intravitreal ranibizumab in eyes with MRS and myopic choroidal neovascularization compared to eyes without MRS. More ranibizumab injections are needed in eyes with MRS to gain comparable BCVA at Month 12.

Macular atrophy in patients with long-term anti-VEGF treatment for neovascular age-related macular degeneration.

PURPOSE: To identify the prevalence and progression of macular atrophy (MA) in neovascular age-related macular degeneration (AMD) patients under long-term anti-vascular endothelial growth factor (VEGF) therapy and to determine risk factors. METHOD: This retrospective study included patients with neovascular AMD and ≥30 anti-VEGF injections. Macular atrophy (MA) was measured using near infrared and spectral-domain optical coherence tomography (SD-OCT). Yearly growth rate was estimated using square-root transformation to adjust for baseline area and allow for linearization of growth rate. Multiple regression with Akaike information criterion (AIC) as model selection criterion was used to estimate the influence of various parameters on MA area. RESULTS: Forty-nine eyes (47 patients, mean age 77 ± 14) were included with a mean of 48 ± 13 intravitreal anti-VEGF injections (ranibizumab:37 ± 11, aflibercept:11 ± 6, mean number of injections/year 8 ± 2.1) over a mean treatment period of 6.2 ± 1.3 years (range 4-8.5). Mean best-corrected visual acuity improved from 57 ± 17 letters at baseline (= treatment start) to 60 ± 16 letters at last follow-up. The MA prevalence within and outside the choroidal neovascularization (CNV) border at initial measurement was 45% and increased to 74%. Mean MA area increased from 1.8 ± 2.7 mm2 within and 0.5 ± 0.98 mm2 outside the CNV boundary to 2.7 ± 3.4 mm2 and 1.7 ± 1.8 mm2 , respectively. Multivariate regression determined posterior vitreous detachment (PVD) and presence/development of intraretinal cysts (IRCs) as significant factors for total MA size (R2 = 0.16, p = 0.02). Macular atrophy (MA) area outside the CNV border was best explained by the presence of reticular pseudodrusen (RPD) and IRC (R2 = 0.24, p = 0.02). CONCLUSION: A majority of patients show MA after long-term anti-VEGF treatment. Reticular pseudodrusen (RPD), IRC and PVD but not number of injections or treatment duration seem to be associated with the MA size.

Retinal layer measurements after successful macula-off retinal detachment repair using optical coherence tomography.

PURPOSE: Optical coherence tomography (OCT) was used to analyze the thickness of various retinal layers of patients following successful macula-off retinal detachment (RD) repair. METHODS: Optical coherence tomography scans of patients after successful macula-off RD repair were reanalyzed with a subsegmentation algorithm to measure various retinal layers. Regression analysis was performed to correlate time after surgery with changes in layer thickness. In addition, patients were divided in two groups. Group 1 had a follow-up period after surgery of up to 7 weeks (range, 21-49 days). In group 2, the follow-up period was >8 weeks (range, 60-438 days). Findings were compared to a group of age-matched healthy controls. RESULTS: Correlation analysis showed a significant positive correlation between inner nuclear-outer plexiform layer (INL-OPL) thickness and time after surgery (P=0.0212; r2=0.1551). Similar results were found for the ellipsoid zone-retinal pigment epithelium complex (EZ-RPE) thickness (P=0.005; r2=0.2215). Ganglion cell-inner plexiform layer thickness (GCL-IPL) was negatively correlated with time after surgery (P=0.0064; r2=0.2101). For group comparison, the retinal nerve fiber layer in both groups was thicker compared to controls. The GCL-IPL showed significant thinning in group 2. The outer nuclear layer was significantly thinner in groups 1 and 2 compared to controls. The EZ-RPE complex was significantly thinner in groups 1 and 2 compared to controls. In addition, values in group 1 were significantly thinner than in group 2. CONCLUSIONS: Optical coherence tomography retinal layer thickness measurements after successful macular-off RD repair revealed time-dependent thickness changes. Inner nuclear-outer plexiform layer thickness and EZ-RPE thickness was positively correlated with time after surgery. Ganglion cell-inner plexiform layer thickness was negatively correlated with time after surgery.

Nonmydriatic ultra-wide-field scanning laser ophthalmoscopy (Optomap) versus two-field fundus photography in diabetic retinopathy.

The purpose of this study was to investigate the diagnostic properties of a 2-laser wavelength nonmydriatic 200° ultra-wide-field scanning laser ophthalmoscope (SLO) versus mydriatic 2-field 45° color fundus photography (EURODIAB standard) for assessing diabetic retinopathy (DR). A total of 143 consecutive eyes of patients with different levels of DR were graded regarding DR level and macular edema based on 2-field color photographs or 1 Optomap Panoramic 200 SLO image. All SLO images were nonmydriatic and all photographs mydriatic. Grading was performed masked to patient and clinical data. Based on photography, 20 eyes had no DR, 44 had mild, 18 moderate and 42 severe nonproliferative DR, and 19 eyes had proliferative DR. Overall correlation for grading DR level compared to Optomap SLO was moderate with kappa 0.54 (p < 0.001), fair-to-moderate in macular edema grading with kappa 0.39 (p < 0.001), and substantial for grading clinically significant macular edema (kappa 0.77). The wide-field SLO offers a wider field of view and can potentially better differentiate lesions by applying the 2 laser wavelengths. However, these advantages over 2-field fundus photography need to be confirmed in further studies.

Graph-based multi-surface segmentation of OCT data using trained hard and soft constraints.

Optical coherence tomography (OCT) is a well-established image modality in ophthalmology and used daily in the clinic. Automatic evaluation of such datasets requires an accurate segmentation of the retinal cell layers. However, due to the naturally low signal to noise ratio and the resulting bad image quality, this task remains challenging. We propose an automatic graph-based multi-surface segmentation algorithm that internally uses soft constraints to add prior information from a learned model. This improves the accuracy of the segmentation and increase the robustness to noise. Furthermore, we show that the graph size can be greatly reduced by applying a smart segmentation scheme. This allows the segmentation to be computed in seconds instead of minutes, without deteriorating the segmentation accuracy, making it ideal for a clinical setup. An extensive evaluation on 20 OCT datasets of healthy eyes was performed and showed a mean unsigned segmentation error of 3.05 ±0.54 µm over all datasets when compared to the average observer, which is lower than the inter-observer variability. Similar performance was measured for the task of drusen segmentation, demonstrating the usefulness of using soft constraints as a tool to deal with pathologies.

Pathology hinting as the combination of automatic segmentation with a statistical shape model.

With improvements in acquisition speed and quality, the amount of medical image data to be screened by clinicians is starting to become challenging in the daily clinical practice. To quickly visualize and find abnormalities in medical images, we propose a new method combining segmentation algorithms with statistical shape models. A statistical shape model built from a healthy population will have a close fit in healthy regions. The model will however not fit to morphological abnormalities often present in the areas of pathologies. Using the residual fitting error of the statistical shape model, pathologies can be visualized very quickly. This idea is applied to finding drusen in the retinal pigment epithelium (RPE) of optical coherence tomography (OCT) volumes. A segmentation technique able to accurately segment drusen in patients with age-related macular degeneration (AMD) is applied. The segmentation is then analyzed with a statistical shape model to visualize potentially pathological areas. An extensive evaluation is performed to validate the segmentation algorithm, as well as the quality and sensitivity of the hinting system. Most of the drusen with a height of 85.5 microm were detected, and all drusen at least 93.6 microm high were detected.

Management and treatment of bizarre open globe trauma in three steps: a case report.

This is a case presentation of a very bizarre open globe trauma with anterior segment foreign body-fishing hook stuck in the cornea and iris. Complications due to this kind of eye trauma might be very hazardous and with serious impact on visual function. We are representing our approach and experience of three step management of this kind of eye injury: first-extract the foreign body, close and reconstruct the eyeball, second-fight inflammation, and third-restore the visual function by cataract surgery.

Management and treatment of bizarre open globe trauma in three steps: a case report / 国际眼科杂志(Guoji Yanke Zazhi)

This is a case presentation of a very bizarre open globe trauma with anterior segment foreign body-fishing hook stuck in the cornea and iris. Complications due to this kind of eye trauma might be very hazardous and with serious impact on visual function. We are representing our approach and experience of three step management of this kind of eye injury: first-extract the foreign body, close and reconstruct the eyeball, second-fight inflammation, and third-restore the visual function by cataract surgery.

Macular thickness measurements in healthy eyes using six different optical coherence tomography instruments.

PURPOSE: To compare central retinal thickness (CRT) measurements in healthy eyes by different commercially available OCT instruments and to compare the intersession reproducibility of such measurements. METHODS: Six different OCT instruments (Stratus OCT [Carl Zeiss Meditec, Inc. Dublin, CA], SOCT Copernicus [Reichert/Optopol Technology, Inc., Depew, NY], Spectral OCT/SLO [Opko/OTI, Inc., Miami, FL], RTVue-100 [Optovue Corp., Fremont, CA], Spectralis HRA+OCT [Heidelberg Engineering, Inc., Heidelberg, Germany], and Cirrus HD-OCT [Carl Zeiss Meditec, Inc.]) were used to assess CRT in both eyes of healthy subjects. Measurements were performed in two different sessions on the same day with each of the systems. From these measurements, the mean CRT was calculated. For the assessment of the intersession reproducibility of the instruments, we calculated the coefficient of the variation of test-retest variation. RESULTS: Twenty healthy subjects were included in the study. Compared with the Stratus OCT all spectral OCT instruments showed significantly higher CRTs. The Spectralis HRA+OCT and Cirrus HD-OCT showed similar CRT values but significantly higher values than did all other instruments. The coefficients of variation for repeated measurements was 3.33% for the Stratus OCT, 0.46% for the Spectralis HRA+OCT, 3.09% for the Cirrus HD-OCT, 2.23% for the OCT/SLO, 2.77% for the RTVue-100 OCT, and for the SOCT 3.5%, respectively. discussion. The six OCT systems provided different results for CRT. The measurements with the Stratus OCT showed the lowest thicknesses, whereas those with the Cirrus HD-OCT and Spectralis HRA+OCT yielded the highest ones. These discrepancies can be explained by the differences in the retinal segmentation algorithms used by the various OCT systems. Whereas the Spectralis HRA+OCT and Cirrus HD-OCT include the RPE layer in the retinal segmentation, the other instruments do not. The data imply that the different OCT systems cannot be used interchangeably for the measurement of macular thickness.

Optical coherence tomography fast versus regular macular thickness mapping in diabetic retinopathy.

OBJECTIVE: The purpose of the study was to investigate if absolute values and reproducibility of thickness maps obtained from 2 optical coherence tomography (OCT) scanning protocols, regular high-resolution and fast low-density mode, differ in patients with diabetic macular edema. METHODS: A total of 26 consecutive patients undergoing fluorescein angiography and Stratus OCT scanning for the evaluation of diabetic macular edema at the Departments of Ophthalmology in Munich and Vienna were included. RESULTS: Retinal thickness of the central field of the thickness map measured by fast retinal thickness protocol was 287 +/- 97 and 290 +/- 113 microm by the regular protocol. This difference as well as that for all other fields was not statistically significant. Three times repeated measurements applying both OCT scanning modes in 10 patients yielded very good intrasession correlation coefficients between 0.70 and 0.99, with corresponding intrasession standard deviations ranging between 6 and 16 mum. The fast mode yielded slightly less reproducible values than the regular mode. Visual acuity did not influence the results. CONCLUSION: In practice both scanning modes can be interchanged and absolute values can be compared directly. Best reproducibility is obtained with higher sampling density even in patients with reduced visual acuity due to diabetic macular edema.