The noninvasive retro-mode imaging of confocal scanning laser ophthalmoscopy in myopic maculopathy: a prospective observational study

Retro-mode imaging for the diagnosis of optic disc drusen: a case series

OBJECTIVE

We aimed to compare the detectability of optic disc drusen (ODD), using various non-invasive imaging techniques, including the novel retro-mode imaging (RMI), as well as to analyze the morphological characteristics of ODD on RMI.

METHODS

This study involved seven patients with bilateral ODD, totaling 14 eyes. Multimodal imaging techniques, including multicolor fundus photography (MC), near-infrared reflectance (NIR), green and blue light fundus autofluorescence (G-FAF and B-FAF, respectively), and RMI were used to examine the eyes. FAF was used as the primary method of identifying ODD, and each method's detection rate was compared by two observers. Quantitative measurements of ODD included the number of ODD visualized by the RMI technique, the perimeter (P) and area (A) of ODD were identified.

RESULTS

The average age of the patients included was 49.28 ± 23.16 years, with five of the seven being men. RMI was able to detect ODD in all cases, with a sensitivity of 100%, compared to MC (sensitivity 60.71%), NIR (sensitivity 60.71%), B-FAF (sensitivity 100%), G-FAF (sensitivity 100%). RMI was the only imaging technique capable of assessing ODD morphology and quantifying ODD.

CONCLUSIONS

RMI is a promising imaging modality for diagnosing superficial ODD, providing valuable information on the distribution, location, and size of ODD. We suggest the incorporation of RMI as a complementary tool for diagnosing and monitoring ODD in combination with other multimodal imaging methods.

Retromode imaging in retinal diseases: A systematic review of the literature

Retromode scanning laser ophthalmoscopy imaging captures a pseudo-3-dimensional image of the ocular fundus. Retromode scanning laser ophthalmoscopy imaging was introduced first in 2008 using the Nidek F-10 scanning laser ophthalmoscope (F-10; Nidek Co., Gamagori, Japan). At that time, no major role was described for this imaging modality. The interest in retromode scanning laser ophthalmoscopy imaging is reemerging with the recent advent of the Mirante that combines scanning laser ophthalmoscopy and optical coherence tomography (Nidek Co., Gamagori, Japan) that can capture retromode images of the fundus. We summarize the findings and clinical implications of retromode imaging using the Nidek F-10 and the Mirante in retinal diseases with the aim of helping researchers direct their future studies.

Retromode Scanning Laser Ophthalmoscopy for Choroidal Nevi: A Preliminary Study

The purpose of the present study was to document pathological findings on retromode imaging in choroidal nevi and evaluate its diagnostic validity, using the confocal scanning laser ophthalmoscope Nidek Mirante (cSLO). A total of 41 choroidal nevi from 41 patients were included. All patients underwent multicolor fundus (mCF), infrared reflectance (IR), green fundus autofluorescence (FAF), dark-field (DF) and retromode (RM) imaging and optical coherence tomography (OCT) scans. We investigated retromode images to evaluate choroidal nevus features by comparing the results with those of mCF, IR, FAF, DF and OCT. In 100% of available images, retromode scanning laser ophthalmoscopy was able to detect choroidal nevi with a characteristic "hypo-retro-reflective" pattern, even the cases not visible on mCF, IR and FAF images. It also made it possible to delineate the margins of lesions with the highest rate of sharpness and accuracy among the imaging modalities examined. These findings seem to demonstrate how RM-SLO is an innovative diagnostic tool to detect and follow up choroidal nevi in a fast, reliable and non-invasive way.

Retromode Imaging in Age-Related Macular Degeneration

Background and Objectives: Retromode is a relatively new retinal-imaging technique that is based on the transillumination principle and is obtained with a scanning laser ophthalmoscope that uses light in the infrared spectrum. The laser light penetrates into the deep retinal layers and the choroid. Retromode images are captured with a laterally displaced aperture, and the detector captures only the scattered light. The result is a high-contrast pseudo-three-dimensional image. Age-related macular degeneration (AMD) is a disabling retinal disease. AMD is characterized in its early stage by small and intermediate drusen formation, while the signs of intermediate AMD are large drusen and/or pigmentary abnormalities. Late AMD has two forms, geographic atrophy, which is the advanced form of dry AMD, and wet AMD. Most of the lesions of AMD are located in the outer layers of the retina. This new imaging method can provide a glimpse of the deep retinal layers' topographic changes in a non-invasive, fast, and effective way that can match the other imaging tools available. Materials and Methods: The literature review was performed by searching the PubMed database using the following combination of keywords: retromode imaging and age-related macular degeneration. Relevant images similar to the ones in the literature were identified and used as models. Results: The purpose of this article is to highlight the utility of incorporating retromode imaging into the multimodal evaluation of the retina in patients with AMD and to gather and integrate these findings into a brief but comprehensive paper. Conclusions: Retromode imaging is a good screening, diagnosis, and monitoring tool for patients with AMD.

Diagnostic accuracy of OCTA and OCT for myopic choroidal neovascularisation: a systematic review and meta-analysis

BACKGROUND/OBJECTIVES

The purpose of this project was to systematically review and meta-analyse studies assessing the diagnostic accuracy of optical coherence tomography angiography (OCTA) and optical coherence tomography (OCT) for myopic choroidal neovascularisation (mCNV). Fluorescein angiography (FA) was accepted as the reference standard.

METHODS

PUBMED and EMBASE were searched from inception to March 2021 for studies evaluating the test accuracy of OCTA and/or OCT for diagnosing mCNV. The Preferred Reporting Items for Systematic Reviews and Meta-analyses of Diagnostic Test Accuracy Studies guideline was followed, and the Grading of Recommendations, Assessment, Development and Evaluation approach was used to frame clinical recommendations. Pooled estimates of test accuracy were obtained using a bivariate model.

RESULTS

Of 410 studies assessed for eligibility, 3 studies were identified that compared OCTA to FA and 3 studies were identified that compared spectral domain (SD) OCT to FA. All studies had at least one major methodological flaw leading to an overall high risk of bias. On meta-analysis, the pooled sensitivity of OCTA was 0.89 (95% CI 0.78-0.94) and pooled specificity was 0.93 (95% CI 0.79-0.98). The pooled sensitivity of SD-OCT was 0.99 (95% CI 0.91-1.00). Due to uncertainty in individual studies, the pooled specificity of SD-OCT could not be estimated.

CONCLUSIONS

OCTA can reliably diagnose mCNV in clinically suspected patients, however, SD-OCT may not reliably establish a positive diagnosis of mCNV. Future large, prospective studies with improvements in conduct and reporting are needed to strengthen these clinical recommendations.

Retromode Imaging Modality of Epiretinal Membranes

(1) Purpose: To determine the characteristics of macular epiretinal membranes (ERM) using non-invasive retromode imaging (RMI) and to compare retromode images with those acquired via fundus autofluorescence (FAF) and fundus photography. (2) Methods: Prospective observational case-series study including patients with macular ERM with no other ocular disease affecting their morphology and/or imaging quality. We compared RMI, FAF and fundus photography features by cropping and overlapping images to obtain topographic correspondence. (3) Results: In total, 21 eyes (21 patients) affected by ERM were included in this study. The mean area of retinal folds detected by RMI was significantly higher than that detected by FAF (11.85 ± 3.92 mm2 and 5.67 ± 2.15 mm2, respectively, p < 0.05) and similar to that revealed by fundus photography (11.85 ± 3.92 mm2 and 10.58 ± 3.45 mm2, respectively, p = 0.277). (4) Conclusions: RMI appears to be a useful tool in the evaluation of ERMs. It allows for an accurate visualization of the real extension of the retinal folds and provides a precise structural assessment of the macula before surgery. Clinicians should be aware of RMI’s advantages and should be able to use them to warrant a wide range of information and, thus, a more personalized therapeutic approach.

Morphological Features of Full-Thickness Macular Holes Using Retromode Scanning Laser Ophthalmoscopy

BACKGROUND AND OBJECTIVE

Retromode scanning laser ophthalmoscopy (RM-SLO) is a new imaging modality displaying pseudo-3D retinal images. We assessed the correlation between the morphological features of full-thickness macular holes (FTMHs) when using spectral domain-optical coherence tomography (SD-OCT) and when using RM-SLO.

MATERIALS AND METHODS

This is a prospective observational case series in which patients were examined through SD-OCT and RM-SLO after informed consent was obtained. Intraclass correlation coefficient (ICC) and Pearson correlation coefficient (PCC) were used to assess interobserver agreement and the correlation between the diameters measured with the two techniques.

RESULTS

We enrolled 20 patients (20 eyes) with an average hole aperture size of 426 μm (140-890 μm) on SD-OCT and 56 pixels (19-102 pixels) on RM-SLO. ICC and PCC were 0.999 and 0.992, respectively. "Standard" and "double-ring" FTMH patterns were described on RM-SLO and related well with SD-OCT findings.

CONCLUSIONS

RM-SLO is a reliable method for FTMH-diameter evaluation and identifies unique pseudo-3D morphological features consistent with their B-scan counterparts. [Ophthalmic Surg Lasers Imaging Retina 2022; 53:368-373.].