Scanning Laser Ophthalmoscope Research Articles

Adaptive optics scanning laser ophthalmoscopy may support early diagnosis of glaucoma.

To compare image characteristics of retinal nerve fiber layer (RNFL) between glaucoma patients and healthy controls using adaptive optics scanning laser ophthalmoscopy (AOSLO). This was a cross-sectional pilot study with two groups: a glaucoma group with patients with moderate or severe glaucoma as per the Hodapp-Parrish-Anderson classification system and a control group with healthy individuals. The optic nerve damage in moderate glaucoma was predominantly located in only one hemisphere; the other hemisphere was un- or minimally affected on optical coherence tomography and automated perimetry and is referred to as early glaucoma. The structure of RNFL bundles and gain (%) in RNFL images with mean pixel values between 15 and 35 were analyzed. Imaging was performed one degree away from the optic disc margin at two and four cardinal clock positions in the glaucoma and control groups, respectively. The field of view was 1.3° at 2.3 μ resolution. We studied one eye per participant. There were 11 glaucoma patients and 7 healthy controls. Imaging was successful at 88% of the locations in controls and early glaucoma; the reflectivity differed significantly (0.51 and 0.56, respectively, P < 0.001) but not the structure of RNFL bundles (Cohen's Kappa 0.11) between them. In patients with moderate and severe glaucoma, imaging was successful only at 46% of the locations; RNFL bundles were not discernible, and RNFL reflectivity did not differ from those with early glaucoma (P < 0.11). The recorded gain (%) of RNFL images obtained using AOSLO could be an objective indicator of early glaucoma.

Prediction of visual impairment in retinitis pigmentosa using deep learning and multimodal fundus images

BackgroundThe efficiency of clinical trials for retinitis pigmentosa (RP) treatment is limited by the screening burden and lack of reliable surrogate markers for functional end points. Automated methods to determine...

A-01 Changes in Fixational Eye Movements (FEMs) Following Concussion

Abstract Purpose: Identify changes in fixational eye movement (FEMs) outcomes following concussion and assess the association of FEMs outcomes with clinical outcomes including symptoms, neurocognitive, and vestibular/ocular motor. Methods: Participants included thirty-three individuals (13–27 years old; 54.5% female) diagnosed with concussion within the past 21 days. Concussion diagnosis was determined using current consensus guidelines. A tracking scanning laser ophthalmoscope (TSLO) was used to measure FEMS. Participants completed ImPACT, PCSS, and VOMS. Within-subjects changes in FEMS outcomes were calculated using paired-samples t-tests. A backwards stepwise linear regression to predict days to clearance was utilized with all FEMS outcomes as predictors. Results: MeanDriftH (slope of cumulative drift regression calculated horizontally; mean difference = 0.04; p = 0.03; Cohen’s d = 0.43) and drift proportion significantly changed over time (mean difference = 0.03; p = 0.03, d = 0.44). Average peak velocity of microsaccade (MsPkVel) predicted days to recovery (R = 0.26; p = 0.045; n = 24). MsPkVel and average duration of blink correlated with select reports of nausea on VOMS. Microsaccade frequency (r = −0.36; p = 0.04) correlated with NPC fogginess. Drift amplitude (DriftAmp) correlated with NPC distance (r = −0.41; p = 0.02) and VMS headache (r = 0.35; p = 0.04). MeanDriftH was negatively correlated with verbal memory (r = −0.44; p = 0.01), whereas DriftAmp was positively correlated (r = 0.50; p = 0.003). Bivariate contour ellipse area was correlated (r = 0.43; p = 0.01) with slower reaction time on ImPACT. Conclusions: FEMs outcomes demonstrated significant change and were useful in predicting recovery time following concussion. FEMs measurements may provide brief, objective data to augment current clinical assessment and inform prognosis for recovery. Future researchers should examine FEMS outcomes from pre- to post-concussion and explore age and sex differences.

Progress of Imaging in Diabetic Retinopathy-From the Past to the Present.

Advancement of imaging technology in retinal diseases provides us more precise understanding and new insights into the diseases’ pathologies. Diabetic retinopathy (DR) is one of the leading causes of sight-threatening retinal diseases worldwide. Colour fundus photography and fluorescein angiography have long been golden standard methods in detecting retinal vascular pathology in this disease. One of the major advancements is macular observation given by optical coherence tomography (OCT). OCT dramatically improves the diagnostic quality in macular edema in DR. The technology of OCT is also applied to angiography (OCT angiograph: OCTA), which enables retinal vascular imaging without venous dye injection. Similar to OCTA, in terms of their low invasiveness, single blue color SLO image could be an alternative method in detecting non-perfused areas. Conventional optical photography has been gradually replaced to scanning laser ophthalmoscopy (SLO), which also make it possible to produce spectacular ultra-widefield (UWF) images. Since retinal vascular changes of DR are found in the whole retina up to periphery, it would be one of the best targets in UWF imaging. Additionally, evolvement of artificial intelligence (AI) has been applied to automated diagnosis of DR, and AI-based DR management is one of the major topics in this field. This review is trying to look back on the progress of imaging of DR comprehensively from the past to the present.

Salt-and-pepper retinopathy: multimodal imaging of rubella retinopathy

A 54-year-old female presented with congenital hearing loss and pigmentary retinopathy. She was diagnosed with congenital rubella retinopathy. Visual acuity was 20/25 in both eyes. Fundus examination showed bilateral granular pigmentary mottling in all 4 retinal quadrants in both eyes (Fig. A) corresponding to hypoautofluorescent spots on wide-field imaging (Fig. B). Optical coherence tomography angiography showed increased choroidal vessel rarefaction at the level of the choriocapillaris (left, blue arrows) and nummular hyperreflective lesions on scanning laser ophthalmoscopy near-infrared imaging (right) (Fig.

MULTICOLOR CONFOCAL SCANNING LASER OPHTHALMOSCOPE IMAGING IN POSTERIOR UVEITIS.

To study the utility of MultiColor confocal scanning laser ophthalmoscope imaging (MCI) in identifying the morphology of uveitic lesions compared with conventional color fundus photography (CFP) in patients with posterior uveitis. In this prospective observational study, subjects with posterior uveitis underwent MCI and CFP. The images obtained by the two modalities were analyzed by two independent reviewers for vitreoretinal surface abnormalities, retinal fluid and hemorrhages, and depth/location of lesions. These findings were compared with the clinical findings and other imaging techniques. Sixty-nine eyes of 43 patients (25 men) with mean age of 33.5 ± 13.9 years were studied. MultiColor imaging had better sensitivity and specificity in detecting vitreoretinal interface abnormalities, such as epiretinal membrane and inner retinal striae, compared with CFP. MultiColor imaging failed to detect retinochoroiditis lesions in 5 of 6 eyes (83%) and choroiditis in 9 46 eyes (20%), which were detected on CFP and clinical examination. Also, MCI showed a high false-positive rate of 34% in detecting intraretinal hemorrhages. Retinochoroidal lesions in posterior uveitis may be poorly identified on MCI compared with CFP and clinical examination. One must exercise caution in commenting on disease morphology based on MCI alone.

Lattice Degeneration Imaging with Optical Coherence Tomography Angiography.

To describe a series of cases of lattice degeneration of the retina imaged with optical coherence tomography angiography (OCTA). Four eyes of four patients were included and evaluated with green reflectance using a confocal scanning laser ophthalmoscopy and OCTA. In each case, the microcirculation of the retina and choriocapillaris within the lesion, as well as choroidal thickness beneath the lesion, were assessed. OCTA showed regional loss of retinal perfusion and rarefication of the choriocapillaris network within the lesion and the presence of venous collectors in the choroid beneath the lesion. The choroid was substantially thinner beneath the lesion compared to the adjacent normal region. Cross-sectional OCT scans showed retinal thinning, vitreal adhesion, atrophic holes, and subretinal fluid within the lesions. Lattice degeneration is characterized by significant local changes in retinal and choroidal microcirculation which may play an important role in the pathophysiology of lattice degeneration.

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

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. 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. 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. 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.].

Adaptive optics wavefront correction using a damped transpose matrix of the influence function.

To assess the performance of adaptive optics and predict an optimal wavefront correction, we built a wavefront reconstructor with a damped transpose matrix of the influence function. Using an integral control strategy, we tested this reconstructor with four deformable mirrors in an experimental system, an adaptive optics scanning laser ophthalmoscope, and an adaptive optics near-confocal ophthalmoscope. Testing results proved that this reconstructor could ensure a stable and precise correction for wavefront aberration compared to a conventional optimal reconstructor formed by the inverse matrix of the influence function. This method may provide a helpful tool for testing, evaluating, and optimizing adaptive optics systems.

CSGNet: Cascade semantic guided net for retinal vessel segmentation

Retinal vessels are essential biomarkers for the early diagnosis of ophthalmic diseases. Accurate segmentation of retinal vessels is necessary for further quantitative analysis of fundus images. With the development of deep learning, many deep segmentation models have been proposed and show promising results. Nevertheless, segmentation performance is not satisfactory in tiny vessels and low-contrast vessels. A cascade semantic guided network (CSGNet) is proposed to address this problem. CSGNet follows a low-to-high pipeline, where low-resolution semantic-rich features are first learned. Then, higher-resolution features are learned under the guidance of low-resolution features. In this way, CSGNet is expected to learn both semantic-rich and detail-preserved high-resolution representations to facilitate the segmentation of thin vessels. Meantime, a multi-scale and multi-directional feature learning (M2FL) module is developed, which leverages two strip convolutions and two dilated convolutions to align with the shape of vessels and encode context information. Extensive experiments are conducted to validate the segmentation performance of the proposed method over six public datasets, including four photography datasets (CHASE_DB1, DRIVE, STARE, HRF) and two color scanning laser ophthalmoscopy datasets (IOSTAR, RC-SLO). Also, the proposed method is compared with several popular deep learning-based models. Experimental results show that the proposed method achieves comparable or superior segmentation performance compared with other deep learning-based models with fewer parameters and faster segmentation speed. Meantime, cross-training experiments demonstrate the competitive generalization capability of the proposed method.

Long Term Time-Lapse Imaging of Geographic Atrophy: A Pilot Study.

Geographic atrophy (GA), the late stage of age-related macular degeneration, is a major cause of visual disability whose pathophysiology remains largely unknown. Modern fundus imaging and histology revealed the complexity of the cellular changes that accompanies atrophy. Documenting the activity of the disease in the margins of atrophy, where the transition from health to disease occurs, would contribute to a better understanding of the progression of GA. Time-lapse imaging facilitates the identification of structural continuities in changing environments. In this retrospective pilot study, we documented the long-term changes in atrophy margins by time-lapse imaging of infrared scanning laser ophthalmoscopy (SLO) and optical coherence tomography (OCT) images in 6 cases of GA covering a mean period of 32.8 months (range, 18–72). The mean interval between imaging sessions was 2.4 months (range, 1.4–3.8). By viewing time-lapse sequences we observed extensive changes in the pattern of marginal hyperreflective spots, which associated fragmentation, increase and/or disappearance. Over the entire span of the follow-up, the most striking changes were those affecting hyperreflective spots closest to margins of atrophy, on the non-atrophic side of the retina; a continuum between the successive positions of some of the hyperreflective spots was detected, both by SLO and OCT. This continuum in their successive positions resulted in a subjective impression of a centrifugal motion of hyperreflective spots ahead of atrophy progression. Such mobilization of hyperreflective spots was detected up to several hundred microns away from atrophic borders. Such process is likely to reflect the inflammatory and degenerative process underlying GA progression and hence deserves further investigations. These results highlight the interest of multimodal time-lapse imaging to document cell-scale dynamics during progression of GA.Clinical Trial Registrationclinicaltrials.gov, identifier: NCT04128150 and NCT04129021.

Klasifikasi Citra Glaukoma dengan ANN Berdasarkan Pembuluh Darah Pada Citra Fundus Retina Mengguna

Glaucoma is an eye disease that can lead to permanent blindness caused by increased Intraocular Pressure (IOP). There are several methods to detect glaucoma, namely Optical Nerve Hypoplasia Stereo Photographs (ONHSPs), Optical Coherence Tomography (OCT), Scanning Laser Polarimetry (SLP), and Confocal Scanning Laser Ophthalmoscopy (CSLO). However, these methods require a lot of money and expert supervision. In this paper, glaucoma classification will be carried out using the ANN method with a comparison of the otsu-thresholding segmentation method and canny edge detection with the aim of knowing which method gives better results in diagnosing glaucoma images based on the parameters of accuracy, sensitivity, and specificity. The dataset used is RIM-ONE r2 and r3 which will be extracted using 5 features of GLCM and 6 statistical features, and obtained an accuracy of 76% for the otsu-thresholding method, and 79% for canny edge detection.

Multi-modal and multi-scale clinical retinal imaging system with pupil and retinal tracking

We present a compact multi-modal and multi-scale retinal imaging instrument with an angiographic functional extension for clinical use. The system integrates scanning laser ophthalmoscopy (SLO), optical coherence tomography (OCT) and OCT angiography (OCTA) imaging modalities and provides multi-scale fields of view. For high resolution, and high lateral resolution in particular, cellular imaging correction of aberrations by adaptive optics (AO) is employed. The entire instrument has a compact design and the scanning head is mounted on motorized translation stages that enable 3D self-alignment with respect to the subject’s eye by tracking the pupil position. Retinal tracking, based on the information provided by SLO, is incorporated in the instrument to compensate for retinal motion during OCT imaging. The imaging capabilities of the multi-modal and multi-scale instrument were tested by imaging healthy volunteers and patients.

Near-Infrared Confocal Reflectance Scanning Laser Ophthalmoscopy (SLO) and Short-Wavelength Autofluorescence Imaging in Cystic Diabetic Macular Edema.

Objective To characterize results of short-wavelength autofluorescent (SW-AF) and near-infrared confocal reflectance scanning laser ophthalmoscopy (NIR-cR SLO) imaging in cystic diabetic macular edema (DME). Design Cross-sectional study. Participants: 104 eyes from 52 naïve treatment patients with DME and mild to moderate nonproliferative diabetic retinopathy (NPDR) Methods: complete ocular examination, best-corrected visual acuity (BCVA), and imaging were performed. Results In NIR-cR SLO, small/medium and large-sized cysts presented with decreased and increased reflectance, respectively. In SW-AF, increased and decreased autofluorescence, corresponding to medium-/large- and small-sized cysts were noted. Mainly, the lower NIR reflectance was associated with petaloid edema pattern in SW-AF (P=0.011), BCVA (logMAR) (P=0.056), subretinal fluid (P=0.035), and the involved layers of retina by cysts (P < 0.001) in Pearson chi-square test. Fair agreement of 0.31 (P < 0.001) between NIR-cR SLO and late FA leakage was found by the weighted kappa test. In regression analysis, NIR-cR SLO abnormality is highly correlated with outer and inner nuclear layers location of the cystic changes. Conclusions The size of cysts and involved layers affect presenting features of SW-AF and NIR reflectance.

Редкий случай макулярной телеангиэктазии 1-го типа у ребенка

Macular telangiectasia type 1 is usually characterized by a slowly progressive decrease in visual acuity in the 3–4 decade of life. Although MacTel usually manifests with a slowly progressive decrease in visual acuity in the fifth to seventh decades of life, younger patients may occasionally be diagnosed with the disease. Purpose. To present a clinical case of macular telangiectasia type 1 in an 8-year-old child. Material and methods. During a screening examination in one of the schools in the Kirovsky district of Ufa, an 8-year-old child was diagnosed with low vision in his left eye. The examination included a standard ophthalmological examination, as well as optical coherence tomography technology (Triton Topcon, Nidek Mirante, Japan). Fundus photography was performed on a Visucam fundus camera (Zeiss, Germany). Results. The left eye fundus showed microaneurysms, macular edema in the macular zone. According to OCT and OCT with laser scanning ophthalmoscopy, pathological changes in retinal structures were noted in the form of multiple cystic cavities of the neuroepithelium, deposits of small hyperreflective inclusions, intraretinal aneurysmal structures and violations of microangioarchitectonics and hypoperfusion zones. Conclusion. The clinical case demonstrates a rare form of macular telangiectasia type 1 in a child, complicated by cystic macular edema. For the diagnosis and monitoring of this disease, the use of optical coherence tomography with angio-mode is optimal, which is especially import ant when used in children. Key words: macular telangiectasia, OCT, macular edema, child

Single-capture ultra-widefield guided swept-source optical coherence tomography in the management of rhegmatogenous retinal detachment and associated peripheral vitreoretinal pathology

Background/AimTo assess the utility of single-capture ultra-widefield confocal scanning laser ophthalmoscope with integrated swept-source optical coherence tomography (UWF-SS-OCT) in the management of rhegmatogenous retinal detachment (RRD) and associated peripheral pathology.Methods138...

Non-interferometric volumetric imaging in living human retina by confocal oblique scanning laser ophthalmoscopy.

Three-dimensional (3D) imaging of the human retina is instrumental in vision science and ophthalmology. While interferometric retinal imaging is well established by optical coherence tomography (OCT), non-interferometric volumetric imaging in the human retina has been challenging up to date. Here, we report confocal oblique scanning laser ophthalmoscopy (CoSLO) to fill that void and harness non-interferometric optical contrast in 3D. CoSLO decouples the illumination and detection by utilizing oblique laser scanning and oblique imaging to achieve ∼4x better axial resolution than conventional SLO. By combining remote focusing, CoSLO permits the acquisition of depth signals in parallel and over a large field of view. Confocal gating is introduced by a linear sensor array to improve the contrast and resolution. For the first time, we reported non-interferometric 3D human retinal imaging with >20° viewing angle, and revealed detailed features in the inner, outer retina, and choroid. CoSLO shows potential to be another useful technique by offering 3D non-interferometric contrasts.

Automated Assessment of Photoreceptor Visibility in Adaptive Optics Split-Detection Images Using Edge Detection.

PurposeAdaptive optics scanning laser ophthalmoscopy (AOSLO) is a high-resolution imaging modality that allows measurements of cellular-level retinal changes in living patients. In retinal diseases, the visibility of photoreceptors in AOSLO images is affected by pathology, patient motion, and optics, which can lead to variability in analyses of the photoreceptor mosaic. Current best practice for AOSLO mosaic quantification requires manual assessment of photoreceptor visibility across overlapping images, a laborious and time-consuming task.MethodsWe propose an automated measure for quantification of photoreceptor visibility in AOSLO. Our method detects salient edge features, which can represent visible photoreceptor boundaries in each image. We evaluate our measure against two human graders and two standard automated image quality assessment algorithms.ResultsWe evaluate the accuracy of pairwise ordering (PO) and the correlation of ordinal rankings (ORs) of photoreceptor visibility in 29 retinal regions, taken from five subjects with choroideremia. The proposed measure had high association with manual assessments (Grader 1: PO = 0.71, OR = 0.61; Grader 2: PO = 0.67, OR = 0.62), which is comparable with intergrader reliability (PO = 0.76, OR = 0.75) and outperforms the top standard approach (PO = 0.57; OR = 0.46).ConclusionsOur edge-based measure can automatically assess photoreceptor visibility and order overlapping images within AOSLO montages. This can significantly reduce the manual labor required to generate high-quality AOSLO montages and enables higher throughput for quantitative studies of photoreceptors.Translational RelevanceAutomated assessment of photoreceptor visibility allows us to more rapidly quantify photoreceptor morphology in the living eye. This has applications to ophthalmic medicine by allowing detailed characterization of retinal degenerations, thus yielding potential biomarkers of treatment safety and efficacy.

Blue-light fundus autofluorescence imaging of pigment epithelial detachments

BackgroundPigment epithelial detachments (PEDs) occur in association with various chorioretinal diseases. With respect to the broad clinical spectrum of PEDs we describe fundus autofluorescence (FAF) characteristics of PEDs.MethodsNinety-three eyes of 66 patients (mean age 71.9 ± 11.1) with uni- or bilateral PED ( ≥ 350 µm) were included in a retrospective cross-sectional study. PEDs were secondary to age-related macular degeneration (n = 79), central serous chorioretinopathy (n = 7), polypoidal choroidal vasculopathy (n = 2), pattern dystrophy (n = 3) or idiopathic PED (n = 2). FAF images were recorded using confocal scanning laser ophthalmoscopy (488 nm excitation wavelength, detection of emission >500 nm). Diagnosis of PED was confirmed using spectral-domain optical coherence tomography. A qualitative FAF grading system was established, and grading was performed by two independent readers.ResultsPEDs showed highly variable characteristics on FAF imaging. FAF within the area of PED was found to be irregular/granular (n = 59, 63.4%), increased (n = 28, 30.1%), decreased (n = 3, 3.2 %), or normal (n = 3, 3.2%). Accompanying FAF changes included condensation of macular pigment (n = 67, 72.0%), focally increased FAF at the PED apex (n = 14, 15.1%) or elsewhere (n = 52, 55.9%), focally decreased FAF (n = 23, 24.7%), a cartwheel-like pattern (n = 10, 10.8%), a doughnut sign (n = 6, 6.5%), and a halo of decreased FAF encircling the PED (completely n = 20, 21.5% or incompletely n = 20, 21.5%).ConclusionsPEDs show a variety of abnormal patterns on FAF imaging. These changes in FAF signals may be secondary to morphological and metabolic alterations within corresponding retinal layers and do not necessarily correspond with the underlying PED subtype or a specific pathology.

Atypical chorioretinal lesions in Siberian Husky dogs with primary angle-closure glaucoma: a case series

BackgroundA number of etiologies for different canine chorioretinal lesions have been proved or suggested but some fundic lesions remain unclear in terms of an etiologic diagnosis, treatment options and prognosis. The purpose of this case series is to describe atypical chorioretinal lesions observed in dogs with primary angle-closure glaucoma (PACG).Case presentationTwo spayed-female Siberian Huskies (3- and 4-year-old) and one Siberian Husky/Australian Shepherd mixed breed dog (11-month-old) that had multifocal depigmented retinal lesions and PACG were included. Procedures: Ophthalmic examination, gross, and histopathologic examination findings are described. One of the dogs underwent further clinical diagnostics. Advanced clinical diagnostics on the fellow, presumed to be non-glaucomatous eye of a dog revealed: pectinate ligament dysplasia by gonioscopy, retinal thinning in the depigmented area and wedge shaped retinal thinning with delayed choroidal vascular perfusion by optical coherence tomography, confocal scanning laser ophthalmoscopy, fluorescein and indocyanine green angiography. Quantifiable maze testing for the same eye revealed mild nyctalopia but the full-field electroretinogram showed no generalized decrease of retinal function. Genetic testing for mutations within the retinitis pigmentosa GTPase regulator gene causing X-linked progressive retinal atrophy in Siberian Huskies was negative. Histopathologic evaluations on enucleated eyes in two dogs confirmed goniodysgenesis, PACG with optic nerve head cupping, and diffuse inner retinal atrophy. In addition, segmental profound retinal atrophy, loss of retinal pigment epithelium, and adhesion of the retina to Bruch’s membrane was observed and coincided with multifocal depigmented lesions noted on fundic examination.ConclusionsTo our knowledge, this is the first case series with clinical and histopathologic data of chorioretinal lesions, most likely caused by severely impaired choroidal perfusion. Further studies are warranted to elucidate the etiology and pathophysiology, including its possible association with PACG.