Reproducibility of Nerve Fiber Layer Thickness Measurements Using 3D Fourier-Domain OCT

PURPOSE. Conventional time-domain optical coherence tomography (OCT) has been shown to provide reproducible retinal nerve fiber layer (RNFL) measurements. Recently, high-speed, high-resolution Fourier-domain 3D-OCT has been introduced to improve OCT quality. It can provide 6-mm 2 high-density scans to provide RNFL thickness measurements. The purpose of this study was to test the reproducibility of 3D-OCT RNFL thickness measurements in healthy volunteers. METHODS. Thirty-eight eyes were included in the study. Highdensity 6-mm 2 3D scans were registered by two independent operators. RNFL thickness was calculated for eight areas corresponding to the ETDRS areas and for two ring areas. The ETDRS grid was centered on the optic disc. Intraclass correlation coefficients (ICC) and coefficients of variation (COV) were calculated. Interobserver reproducibility was visualized by using Bland-Altman analysis. RESULTS. Intrasession reproducibility was good with a mean ICC of 0.90. The mean COV for operator 1 and 2 was 4.2% and 4%, respectively (range, 1.9%-6.7%). Highest reproducibility was found for the two ring areas and the superior and inferior quadrants. Mean differences in RNFL thickness measurements for ring 1 and 2 between operator 1 and 2 were 0.9 m (limits of agreement, Ϫ11.4 to ϩ9.6 m) and 0.1 m (limits of agreement Ϫ4.1 to ϩ3.9 m), respectively. CONCLUSIONS. 3D-OCT RNFL thickness measurements in healthy volunteers showed good intra-and interobserver reproducibility. 3D-OCT provides more RNFL thickness information compared to conventional time-domain OCT measurements and may be useful for the management of glaucoma and other optic neuropathies. (Invest Ophthalmol Vis Sci. 2008;49:5386 -5391) DOI:10.1167/iovs.07-1435 E valuation of the retinal nerve fiber layer (RNFL) is fundamental for diagnosing and managing glaucoma and other optic neuropathies. In the past, RNFL could be assessed subjectively only by slit lamp examination. This method requires clinical experience and offers only qualitative data. In addition, comparisons over time are almost impossible. Successively, other techniques such as color photographs of the optic disc or red-free photographs of the RNFL have become available and have facilitated comparisons over time. Scanning laser ophthalmoscopy and scanning laser polarimetry were the first instruments to allow objective and quantitative evaluation of the RNFL and the optic disc. Studies have been conducted to investigate the reproducibility of OCT RNFL thickness measurements, to assess the value of OCT as a clinical tool for distinguishing between healthy and glaucomatous eyes. Recently, improvements in OCT technology have been introduced. 10 -11 Fourier-domain (FD)-OCT provides increased resolution and scanning speed by recording the interferometric information with a Fourier-domain spectrometric method instead of adjusting the position of a reference mirror. Resolution is up to five times higher, and imaging speed is 60 times faster than in conventional time-domain OCT. 12-13 In addition to high image quality, it is important to have reliable and reproducible software programs to analyze the data acquired by FD-OCT. Previous versions of OCT (Stratus OCT3; Carl Zeiss Meditec, GmbH, Oberkochen, Germany) mostly used a 3.4-mm diameter circle scan centered on the optic disc to generate 512 A-scans. The RNFL thickness profile showed a characteristic curve with two peaks, one in the superior and one in the inferior quadrant. FD-OCT can perform a high-density raster-scan (512 ϫ 128 axial B-scans in a 6 mm 2 area). Recently, the peripapillary nerve fiber layer thickness profile was determined with FD-OCT by using high-density scanning. 14 These raster scans provide considerably more data for RNFL thickness analysis. The purpose of this study was to test the reproducibility of RNFL thickness measurements in healthy subjects by using FD-OCT high-density raster scans (3D OCT1000; Topcon, Tokyo, Japan). METHODS Thirty-eight eyes of 19 healthy subjects (10 women) with a mean age of 26 Ϯ 3 years were included in the study. Exclusion criteria were history of glaucoma, history of any other ocular disease, intraocular pressure greater than 21 mm Hg, or a refractive error of more than Ϫ5 or ϩ5 D. FD-OCT high-density scans were performed with the 3D OCT1000 system. The 3D OCT1000 is an FD-OCT device providing OCT images up to 50 times faster than time-domain OCTs with a sweep-scan technique. The device has a field angle of 45°with a color fundus camera included. The scanning range of the device is from 3 to 6 mm 2 . Horizontal resolution is Յ20 m and depth resolution is up to 5 m. As a light source, the system uses superluminescent diodes with a wavelength of 840 nm. Pupil diameter had to be at least 4 mm for scanning. High-density raster scans (512 ϫ 128 B-scans in a 6 mm 2 area) were centered on the From th

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

Abstract: 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 switc

Volume-rendered optical coherence tomography angiography during ocular interventions: Advocating for noninvasive intraoperative retinal perfusion monitoring.

We aimed to test for feasibility of volume-rendered optical coherence tomography angiography (OCTA) as a novel method for assessing/quantifying retinal vasculature during ocular procedures and to explore the potential for intraoperative use. Thirty patients undergoing periocular anaesthesia were enrolled, since published evidence suggests a reduction in ocular blood flow. Retinal perfusion was monitored based on planar OCTA image-derived data provided by a standard quantification algorithm and postprocessed/volume-rendered OCTA data using a custom software script. Overall, imaging procedures were successful, yet imaging artifacts occurred frequently. In interventional eyes, perfusion parameters decreased during anaesthesia. Planar image-derived and volume rendering-derived parameters were correlated. No correlation was found between perfusion parameters and a motion artifact score developed for this study, yet all perfusion parameters correlated with signal strength as displayed by the device. Concluding, volume-rendered OCTA allows for noninvasive three-dimensional retinal vasculature assessment/quantification in challenging surgical settings and appears generally feasible for intraoperative use

Occurrence and outcome of firework-related ocular injuries in Switzerland: A descriptive retrospective study.

BACKGROUND Firework-related ocular injuries (FWROI) are a major cause of preventable visual impairment. This study aimed to analyze the occurrence and outcome of FWROI in Switzerland. METHODS This retrospective multicenter study included patients with FWROI from seven centers in Switzerland from January 2009 to August 2020. Demographic information, type of injuries, medical and surgical treatments, the best corrected visual acuity (BCVA) at baseline and end of follow-up, occurrence and type of secondary complications, and duration of hospitalization were analyzed. RESULTS A total of 105 patients (119 eyes) with a mean age of 27.1 ± 15.9 years were included in the study (71.4% male patients; 29.5% underage). Most injuries occurred around New Year's Eve (32.4%) and the Swiss national holiday on 1 August (60.9%). The most common anterior segment findings were conjunctival or corneal foreign bodies (58%), whereas Berlin's edema was the most common posterior segment finding (11.4%). Globe ruptures were found in four patients. The mean BCVA in all patients at first presentation was 0.4 ± 0.8 logMAR and improved to 0.3 ± 0.8 logMAR at last follow-up. A primary surgical intervention was performed in 48 eyes (40.3%). Hospitalization directly after the trauma was necessary for 18 patients for a mean of 5.8 ± 4.1 days, and a total of 4.9 ± 7.6 follow-up visits were needed. CONCLUSION This study provides the first data on FWROI in Switzerland, which are helpful for further preventive and educational programs and comparisons with other countries

EFFECT OF AGING ON MACULAR FEATURES OF X-LINKED RETINOSCHISIS ASSESSED WITH OPTICAL COHERENCE TOMOGRAPHY

X-linked retinoschisis (XLRS) is one of the most common causes of macular degeneration in young men. The purpose of this study was to use optical coherence tomography combined with ophthalmoscopy to study the effects of aging on the morphologic changes associated with XLRS

Differentiation between Good and Low-Responders to Intravitreal Ranibizumab for Macular Edema Secondary to Retinal Vein Occlusion.

Background. Ranibizumab is approved for treatment of macular edema in eyes with retinal vein occlusion (RVO). Some eyes show low-response to treatment with regard to visual acuity gain (VA) and OCT central retinal thickness (CRT) reduction. The goal of this study was to quantify the percentage of low-responders. Methods. Treatment of naïve eyes with macular edema secondary to RVO was included and monthly VA and CRT were analyzed. Four weeks after the loading phase, and at the end of the study, eyes were grouped into low- and good responders based on predefined criteria. The responder and low-responder groups were then compared at various time points. Results. Forty-three eyes were included. Regarding VA, 27.9% were low-responders after the loading phase and 30.2% at the end of the study. For CRT, 34.9% were low-responders after the loading phase versus 27.9% at the end of the study. 75% of patients that were VA low-responders and 73.3% of CRT low-responders after loading phase remained low-responders at the end of the study. Conclusion. Approximately 30% of patients showed low response to ranibizumab after the loading phase and after 1 year of treatment. Two-thirds of patients that were low-responders after the loading phase remained low-responders after 1 year

Long-term intraocular pressure changes in patients with neovascular age-related macular degeneration treated with ranibizumab

BACKGROUND/AIMS To investigate the long-term effects of multiple intravitreal injections (IVTs) of ranibizumab (Lucentis) on intraocular pressure (IOP) in patients with neovascular age-related macular degeneration. METHODS In 320 eyes, IOP measurements were performed at baseline prior to injection and compared with IOP measurements of the last visit. Correlations between mean IOP change and total number of IVTs, visual acuity or patient age were tested. RESULTS The mean IOP increase was 0.8 ± 3.1 mm Hg (p < 0.0001). Seven eyes showed final IOP values between 22 and 25 mm Hg. The mean follow-up was 22.7 ± 14.1 months. No further correlations between IOP change and number of IVTs, visual acuity or patient age have been found. CONCLUSIONS This study demonstrated a statistically significant IOP increase in patients treated with repeated injections of ranibizumab. However, IOP increase required no glaucoma treatment during the study. Therefore, repeated injections with ranibizumab can be considered safe with regard to long-term IOP changes in patients without ocular hypertension or glaucoma

Functional and anatomical outcome of eyes with neovascular age-related macular degeneration treated with intravitreal ranibizumab following an exit strategy regimen.

AIMS To assess the functional and morphological outcome of eyes with neovascular AMD treated with intravitreal ranbizumab following an exit strategy treatment regime. METHODS The Bern treatment regime for neovascular AMD has a fixed injection schedule, even in the non-active stage of the disease. The regimen has been adapted from the PIER study treatment protocol. Eyes with non-active AMD will receive 4 injections in the first year, and 2 injections in the second year of follow-up before treatment stops. Patients that received ranibizumab for treatment and reached the exit criteria were identified, and charts were reviewed to assess functional and morphological outcome. RESULTS Only 2.6% of all patients (15 out of 575 patients) reached the exit criteria. Mean change in best corrected ETDRS visual acuity (VA) was 4.5±16.9 letters when comparing baseline VA to 4 weeks after the last injection (p=0.32). OCT mean foveal thickness was significantly thinner after last treatment (247.9±43.0 µm) compared to baseline (332.5±83.1 µm, p=0.002). The mean total number of ranibizumab injections was 15.6±8.0, and the mean total treatment period was 40.9±18.3 months. Twenty percent of eyes had geographic atrophy present at baseline versus 46.6% at the end of treatment. CONCLUSIONS Even with a fixed treatment regime and a defined treatment exit strategy, only a small percentage of patients reach exit criteria. Retinal thickness has been significantly reduced by repeated intravitreal ranibizumab injections, and geographic atrophy became more frequent