Effectiveness and safety comparison of three eye and orbital reconstruction techniques in facial plastic surgery.

PURPOSE: To compare the effectiveness and the safety of three eye reconstruction techniques with porous bioceramic implantation in facial surgery: the "four petals" eye evisceration (EE) technique, the "russian doll" EE technique and the enucleation with "on-the-table" evisceration technique. METHODS: Retrospective review of patients who underwent surgical orbit reconstruction with primary placement of a porous bioceramic orbital implant using three techniques at Quinze-Vingts National Center (Paris, France). We compared outcomes of three surgical orbit reconstruction techniques: the "four petal" EE technique, the "russian doll" EE technique and the enucleation with "on-the-table" evisceration technique. The primary endpoint was to determine the rate of implant exposure and the facial cosmetic result during the first year after surgery for each technique. The mean of the Numeric Pain Rating Scale (NRS) after surgery at day 1 was also a primary endpoint. In addition, data such as analgesic intake and rate of revision surgery were compared for each technique. RESULTS: One hundred and ten patients were included: 70 patients in the "four petals" procedure group, 31 in the "on-the-table" procedure group and 9 in the "russian doll" procedure group. NRS pain at day 1 was statistically significantly lower in the "four petals" procedure group 0.9 [standard deviation (SD)] (1.8) and in the "russian doll" procedure group 1 (1.7) than in the "on-the-table" procedure group 2.5 (2.4) (P=0.001). Implant exposure was statistically significantly lower in the "four petals" procedure group (2.9%) and in the "on-the-table" procedure group (3.2%) when compared to the "russian doll" procedure group (22.2%) (P=0.03). Rate of revision surgery was lower in the "four petals" procedure group (11.5%) than in the "russian doll" procedure group (33.3%) and the "on-the-table" procedure group (22.6%). "russian doll" evisceration procedure group had the highest orbital lipofilling rate due to the highest rate of enophthalmos. Therefore, the cosmetic result was better in the "four petals" and the "on-the-table" procedure group. CONCLUSION: The "four petals" EE technique for surgical eye and orbital reconstruction seems to be a method that reduce implant extrusion, postoperative pain and improve facial esthetic result.

A novel nonsense variant in REEP6 is involved in a sporadic rod-cone dystrophy case.

Rod-cone dystrophy (RCD), also called retinitis pigmentosa, is the most common form of progressive inherited retinal disorders secondary to photoreceptor degeneration. It is a genetically heterogeneous disease characterized by night blindness, followed by visual field constriction and, in most severe cases, total blindness. The aim of our study was to identify the underlying gene defect leading to severe RCD in a 60-year-old woman. The patient's DNA was investigated by targeted next generation sequencing followed by whole exome sequencing. A novel nonsense variant, c.267G>A p.(Trp89*), was identified at a homozygous state in the proband in REEP6 gene, recently reported mutated in 7 unrelated families with RCD. Further functional studies will help to understand the physiopathology associated with REEP6 mutations that may be linked to a protein trafficking defect.

ARL2BP mutations account for 0.1% of autosomal recessive rod-cone dystrophies with the report of a novel splice variant.

We report a novel ARL2BP splice site mutation after whole-exome sequencing (WES) applied to a Moroccan family including two sisters affected with autosomal recessive rod-cone dystrophy (arRCD). Subsequent analysis of 844 index cases did not reveal further pathogenic chances in ARL2BP indicating that mutations in ARL2B are a rare cause of arRCD (about 0.1%) in a large cohort of French patients.

Multimodal imaging and functional correlations identify unusual cases of macular retinal pigment epithelium hypopigmentation occurring without functional loss.

PURPOSE: Patients with unusual macular retinal pigment epithelium (RPE) hypopigmentation are described and analyzed using retinal multimodal imaging. METHODS: We report three cases of patients with unilateral (2) or bilateral (1) macular lesions discovered incidentally on fundoscopy. A comprehensive ophthalmic examination including visual acuity, fundoscopy, spectral-domain optical coherence tomography (SD-OCT), short-wavelength light and near-infrared autofluorescence, fluorescein angiography, microperimetry, multifocal electroretinogram, adaptive optics (AO), and OCT-angiography (OCT-A) has been performed. RESULTS: Visual acuity was 20/20 in both eyes of all patients. The lesion appeared hyperautofluorescent on short-wavelength light and hypoautofluorescent on near-infrared light. Fluorescein angiography revealed a sharply demarcated macular hyperfluorescence without any leakage, suggesting a window defect. Interestingly, SD-OCT revealed only a choroidal hyperreflectivity in relation to the lesions without any abnormality of the outer retinal layers. Microperimetry was normal except for 1 patient with bilateral lesion and subtle decrease in macular sensitivity. Mf ERG was normal in all three patients. AO showed a well-preserved cone mosaic, suggesting that the abnormality was localized under the photoreceptor layers. OCT-A revealed hyperreflectivity just below the RPE layer, corresponding to the macular lesion observed on fundoscopy and the choroidal hyperreflectivity seen on SD-OCT. CONCLUSIONS: Macular RPE hypopigmentation should be considered in case of an isolated macular lesion without functional visual impairment or anatomical defect on SD-OCT.

Next-generation sequencing confirms the implication of SLC24A1 in autosomal-recessive congenital stationary night blindness.

Congenital stationary night blindness (CSNB) is a clinically and genetically heterogeneous retinal disorder which represents rod photoreceptor dysfunction or signal transmission defect from photoreceptors to adjacent bipolar cells. Patients displaying photoreceptor dysfunction show a Riggs-electroretinogram (ERG) while patients with a signal transmission defect show a Schubert-Bornschein ERG. The latter group is subdivided into complete or incomplete (ic) CSNB. Only few CSNB cases with Riggs-ERG and only one family with a disease-causing variant in SLC24A1 have been reported. Whole-exome sequencing (WES) in a previously diagnosed icCSNB patient identified a homozygous nonsense variant in SLC24A1. Indeed, re-investigation of the clinical data corrected the diagnosis to Riggs-form of CSNB. Targeted next-generation sequencing (NGS) identified compound heterozygous deletions and a homozygous missense variant in SLC24A1 in two other patients, respectively. ERG abnormalities varied in these three cases but all patients had normal visual acuity, no myopia or nystagmus, unlike in Schubert-Bornschein-type of CSNB. This confirms that SLC24A1 defects lead to CSNB and outlines phenotype/genotype correlations in CSNB subtypes. In case of unclear clinical characteristics, NGS techniques are helpful to clarify the diagnosis.

High speed optical holography of retinal blood flow.

We performed noninvasive video imaging of retinal blood flow in a pigmented rat by holographic interferometry of near-infrared laser light backscattered by retinal tissue, beating against an off-axis reference beam sampled at a frame rate of 39 kHz with a high throughput camera. Local Doppler contrasts emerged from the envelopes of short-time Fourier transforms and the phase of autocorrelation functions of holograms rendered by Fresnel transformation. This approach permitted imaging of blood flow in large retinal vessels (∼30 microns diameter) over 400×400 pixels with a spatial resolution of ∼8 microns and a temporal resolution of ∼6.5 ms.

Holographic laser Doppler imaging of microvascular blood flow.

We report on local superficial blood flow monitoring in biological tissue from laser Doppler holographic imaging. In time-averaging recording conditions, holography acts as a narrowband bandpass filter, which, combined with a frequency-shifted reference beam, permits frequency-selective imaging in the radio frequency range. These Doppler images are acquired with an off-axis Mach-Zehnder interferometer. Microvascular hemodynamic components mapping is performed in the cerebral cortex of the mouse and the eye fundus of the rat with near-infrared laser light without any exogenous marker. These measures are made from a basic inverse-method analysis of local first-order optical fluctuation spectra at low radio frequencies, from 0 Hz to 100 kHz. Local quadratic velocity is derived from Doppler broadenings induced by fluid flows, with elementary diffusing wave spectroscopy formalism in backscattering configuration. We demonstrate quadratic mean velocity assessment in the 0.1-10 mm/s range in vitro and imaging of superficial blood perfusion with a spatial resolution of about 10 micrometers in rodent models of cortical and retinal blood flow.

[Influence of screen brightness on reading in dry eye patients]. / Influence de la luminosité de l'écran sur la lecture chez des personnes atteintes du syndrome de l'œil sec.

PURPOSE: This study examines the impact of dry eye on screen reading, with an emphasis on glare and visual comfort for patients. POPULATION AND METHODS: We recruited ten patients with dry eye and nine healthy controls. Clinical signs of dry eye were quantified to determine the quality of the tear film and corneal aberrations. Questionnaires related to quality of life and light sensitivity were administered. All participants underwent a screen reading test under five different levels of brightness. RESULTS: Patients with dry eye presented with more significant ocular inflammation (Oxford score) and reduced tear breakup time (BUT; DED: 4.1s, CO: 11.8s; W=90, P<0.001) compared to the control population. Patients also exhibited impaired quality of life (OSDI score: CO: 15.044±9.16, DED: 38.150±18.66, P=0.004) and increased light sensitivity (Glare test: CO: 96.56±65.5 arc.min, DED: 204.1±82.5 arc.min, W=15, P=0.013; VLSQ score: CO: 16.44±4.85, DED: 22.0±6.34, P=0.049). Reading tests did not show a significant difference between the groups (CO: 155±23.3 words/min and DED: 149±28.0, F=1.935, P=0.169). Brightness did not influence reading speed (F=1.308, P-value=0.275). A correlation was observed between reading speed and the OSDI quality of life questionnaire (R=-0.7, P=0.043). CONCLUSION: Although screen brightness did not have a significant impact on reading speed, glare proved to be a major issue for patients with dry eye. The associations between clinical manifestations of dry eye and reading performance emphasize the importance of comprehensive management of this condition. The results suggest that dry eye can influence both quality of life and screen reading, highlighting the need for dedicated approaches to improve the visual comfort of patients.

[CRISPR/Cas9: From research to therapeutic application]. / CRISPR/Cas9 : de la recherche à l'application thérapeutique.

For several decades, genome engineering has raised interest among many researchers and physicians in the study of genetic disorders and their treatments. Compared to its predecessors, zinc-finger nucleases (ZFN) and transcription activator-like effectors (TALEN), clustered regularly interspaced short palindromic repeats (CRISPR/Cas9) is currently the most efficient molecular tool for genome editing. This system, originally identified as a bacterial adaptive immune system, is capable of cutting and modifying any gene of a large number of living organisms. Numerous trials using this technology are being developed to provide effective treatment for several diseases, such as cancer, cardiovascular and ophthalmic disorders. In research, this technology is increasingly used for genetic disease modelling, providing meaningful models of relevant studies as well as a better understanding of underlying pathological mechanisms. Many molecular tools are now available to put this technique into practice in laboratories, and despite the technical and ethical issues raised by manipulation of the genome, CRIPSR/Cas9 offers a new breath of hope for therapeutic research around the world.

Prosthetic Visual Acuity with the PRIMA System in Patients with Atrophic Age-related Macular Degeneration at 4 years follow-up.

Objective: To assess the efficacy and safety of the PRIMA subretinal neurostimulation system 48-months post-implantation for improving visual acuity (VA) in patients with geographic atrophy (GA) due to age-related macular degeneration (AMD) at 48-months post-implantation. Design: First-in-human clinical trial of the PRIMA subretinal prosthesis in patients with atrophic AMD, measuring best-corrected ETDRS VA (Clinicaltrials.gov NCT03333954). Subjects: Five patients with GA, no foveal light perception and VA of logMAR 1.3 to 1.7 in their worse-seeing "study" eye. Methods: In patients implanted with a subretinal photovoltaic neurostimulation array containing 378 pixels of 100 µm in size, the VA was measured with and without the PRIMA system using ETDRS charts at 1 meter. The system's external components: augmented reality glasses and pocket computer, provide image processing capabilities, including zoom. Main Outcome Measures: VA using ETDRS charts with and without the system. Light sensitivity in the central visual field, as measured by Octopus perimetry. Anatomical outcomes demonstrated by fundus photography and optical coherence tomography up to 48-months post-implantation. Results: All five subjects met the primary endpoint of light perception elicited by the implant in the scotoma area. In one patient the implant was incorrectly inserted into the choroid. One subject died 18-months post-implantation due to study-unrelated reason. ETDRS VA results for the remaining three subjects are reported herein. Without zoom, VA closely matched the pixel size of the implant: 1.17 ± 0.13 pixels, corresponding to mean logMAR 1.39, or Snellen 20/500, ranging from 20/438 to 20/565. Using zoom at 48 months, subjects improved their VA by 32 ETDRS letters versus baseline (SE 5.1) 95% CI[13.4,49.9], p<0.0001. Natural peripheral visual function in the treated eye did not decline after surgery compared to the fellow eye (p=0.08) during the 48 months follow-up period. Conclusions: Subretinal implantation of PRIMA in subjects with GA suffering from profound vision loss due to AMD is feasible and well tolerated, with no reduction of natural peripheral vision up to 48-months. Using prosthetic central vision through photovoltaic neurostimulation, patients reliably recognized letters and sequences of letters,and with zoom it provided a clinically meaningful improvement in VA of up to eight ETDRS lines.

Deep learning based diagnostic quality assessment of choroidal OCT features with expert-evaluated explainability.

Various vision-threatening eye diseases including age-related macular degeneration (AMD) and central serous chorioretinopathy (CSCR) are caused due to the dysfunctions manifested in the highly vascular choroid layer of the posterior segment of the eye. In the current clinical practice, screening choroidal structural changes is widely based on optical coherence tomography (OCT) images. Accordingly, to assist clinicians, several automated choroidal biomarker detection methods using OCT images are developed. However, the performance of these algorithms is largely constrained by the quality of the OCT scan. Consequently, determining the quality of choroidal features in OCT scans is significant in building standardized quantification tools and hence constitutes our main objective. This study includes a dataset of 1593 good and 2581 bad quality Spectralis OCT images graded by an expert. Noting the efficacy of deep-learning (DL) in medical image analysis, we propose to train three state-of-the-art DL models: ResNet18, EfficientNet-B0 and EfficientNet-B3 to detect the quality of OCT images. The choice of these models was inspired by their ability to preserve the salient features across all the layers without information loss. To evaluate the attention of DL models on the choroid, we introduced color transparency maps (CTMs) based on GradCAM explanations. Further, we proposed two subjective grading scores: overall choroid coverage (OCC) and choroid coverage in the visible region(CCVR) based on CTMs to objectively correlate visual explanations vis-à-vis DL model attentions. We observed that the average accuracy and F-scores for the three DL models are greater than 96%. Further, the OCC and CCVR scores achieved for the three DL models under consideration substantiate that they mostly focus on the choroid layer in making the decision. In particular, of the three DL models, EfficientNet-B3 is in close agreement with the clinician's inference. The proposed DL-based framework demonstrated high detection accuracy as well as attention on the choroid layer, where EfficientNet-B3 reported superior performance. Our work assumes significance in bench-marking the automated choroid biomarker detection tools and facilitating high-throughput screening. Further, the methods proposed in this work can be adopted for evaluating the attention of DL-based approaches developed for other region-specific quality assessment tasks.

Ptf1a/Rbpj complex inhibits ganglion cell fate and drives the specification of all horizontal cell subtypes in the chick retina.

During development, progenitor cells of the retina give rise to six principal classes of neurons and the Müller glial cells found within the adult retina. The pancreas transcription factor 1 subunit a (Ptf1a) encodes a basic-helix-loop-helix transcription factor necessary for the specification of horizontal cells and the majority of amacrine cell subtypes in the mouse retina. The Ptf1a-regulated genes and the regulation of Ptf1a activity by transcription cofactors during retinogenesis have been poorly investigated. Using a retrovirus-mediated gene transfer approach, we reported that Ptf1a was sufficient to promote the fates of amacrine and horizontal cells from retinal progenitors and inhibit retinal ganglion cell and photoreceptor differentiation in the chick retina. Both GABAergic H1 and non-GABAergic H3 horizontal cells were induced following the forced expression of Ptf1a. We describe Ptf1a as a strong, negative regulator of Atoh7 expression. Furthermore, the Rbpj-interacting domains of Ptf1a protein were required for its effects on cell fate specification. Together, these data provide a novel insight into the molecular basis of Ptf1a activity on early cell specification in the chick retina.

Optogenetic therapy for retinitis pigmentosa.

Retinitis pigmentosa (RP) refers to a diverse group of progressive, hereditary diseases of the retina that lead to incurable blindness and affect two million people worldwide. Artificial photoreceptors constructed by gene delivery of light-activated channels or pumps ('optogenetic tools') to surviving cell types in the remaining retinal circuit has been shown to restore photosensitivity in animal models of RP at the level of the retina and cortex as well as behaviorally. The translational potential of this optogenetic approach has been evaluated using in vitro studies involving post-mortem human retinas. Here, we review recent developments in this expanding field and discuss the potential and limitations of optogenetic engineering for the treatment of RP.

Simultaneous perception of prosthetic and natural vision in AMD patients.

Loss of photoreceptors in atrophic age-related macular degeneration (AMD) results in severe visual impairment. Since the low-resolution peripheral vision is retained in such conditions, restoration of central vision should not jeopardize the surrounding healthy retina and allow for simultaneous use of the natural and prosthetic sight. This interim report, prespecified in the study protocol, presents the first clinical results with a photovoltaic substitute of the photoreceptors providing simultaneous use of the central prosthetic and peripheral natural vision in atrophic AMD. In this open-label single group feasibility trial (NCT03333954, recruitment completed), five patients with geographic atrophy have been implanted with a wireless 2 x 2 mm-wide 30 µm-thick device, having 378 pixels of 100 µm in size. All 5 patients achieved the primary outcome of the study by demonstrating the prosthetic visual perception in the former scotoma. The four patients with a subretinal placement of the chip demonstrated the secondary outcome: Landolt acuity of 1.17 ± 0.13 pixels, corresponding to the Snellen range of 20/460-20/565. With electronic magnification of up to a factor of 8, patients demonstrated prosthetic acuity in the range of 20/63-20/98. Under room lighting conditions, patients could simultaneously use prosthetic central vision and their remaining peripheral vision in the implanted eye and in the fellow eye.

Volumetric quantification of choroid and Haller's sublayer using OCT scans: An accurate and unified approach based on stratified smoothing.

BACKGROUND AND OBJECTIVE: The choroid, a dense vascular structure in the posterior segment of the eye, maintains the health of the retina by supplying oxygen and nutrients, and assumes clinical significance in screening ocular diseases including age-related macular degeneration (AMD) and central serous chorioretinopathy (CSCR). As a technological assist, algorithmic estimation of choroidal biomarkers has been suggested based on sectional (B-scan) optical coherence tomography (OCT) images. However, most such 2D estimation techniques are compute-intensive, yet enjoy limited accuracy and have only been validated on OCT image datasets of healthy eyes. Not surprisingly, fine-scale analyses, including those involving Haller's sublayer, remain relatively rare and unsophisticated. Against this backdrop, we propose an efficient algorithm to quantify desired biomarkers with improved accuracy based on volume OCT scans. Specifically, we attempted an accurate, computationally light volumetric segmentation method involving stratified smoothing to detect choroid and Haller's sublayer. METHODS: For detecting the various boundaries of the choroid and the Haller's sublayer, we propose a common volumetric method that performs suitable exponential enhancement and maintains smooth spatial continuity across 2D B-scans. Further, we achieve suitable volumetric smoothing by primarily deploying light-duty linear regression, and sparingly using compute-intensive tensor voting, and hence significantly reduce overall complexity. The proposed methodology is tested on five health and five diseased OCT volumes considering various metrics including volumetric Dice coefficient and corresponding quotient measures to facilitate comparison vis-à-vis intra-observer repeatability. RESULTS: On five healthy and five diseased OCT volumes, respectively, the proposed method for choroid segmentation recorded volumetric Dice coefficients of 93.53 % and 93.30 %, which closely approximate the respective reference observer repeatability values of 95.60 % and 95.49 %. In terms of related quotient measures, our method achieved more than 50 % improvement over a recently reported method. In detecting Haller's sublayer as well, our algorithm records statistical performance closely matching that of reference manual method. CONCLUSION: Advancing the state-of-the-art, the proposed volumetric segmentation, tested on both healthy and diseased datasets, demonstrated close match with the manual reference. Our method assumes significance in accurate screening of chorioretinal diseases including AMD, CSCR and pachychoroid. Further, it enables generating accurate training data for developing deep learning models for improved detection of choroid and Haller's sublayer.

Retinitis pigmentosa: rod photoreceptor rescue by a calcium-channel blocker in the rd mouse.

Retinitis pigmentosa is an inherited degenerative disease of photoreceptors leading to blindness. A well-characterized model for this disease is provided by the retinal degeneration mouse, in which the gene for the rod cGMP phosphodiesterase is mutated, as in some affected human families. We report that D-cis-diltiazem, a calcium-channel blocker that also acts at light-sensitive cGMP-gated channels, rescued photoreceptors and preserved visual function in the retinal degeneration mouse. The long record of diltiazem prescription in cardiology should facilitate the design of clinical trials for some forms of retinitis pigmentosa.

En-face analysis of short posterior ciliary arteries crossing the sclera to choroid using wide-field swept-source optical coherence tomography.

To study the topographic distribution of the short posterior ciliary arteries (SPCA) entry sites into the choroid in normal eyes using structural en-face swept source optical coherence tomography (SS-OCT). Retrospective analysis of SS-OCT scans (wide-field structural SS-OCT 12 × 12 mm) of 13 healthy subjects was performed. Cross-sectional swept-source OCT scans derived from a volume scan were represented as en-face image display following the Choroid-Scleral Interface to obtain en-face OCT. SPCAs in their last scleral location before choroidal entrance were identified manually, counted and localized by two masked observers. Correlations between two masked observers were analyzed using inter- and intra-class correlation. Accuracy for the choroidal inner and outer border segmentation was 95-99%. Eighteen eyes from 13 normal subjects were included for SPCA analysis. The mean number of arteries was 13.8 ± 3.5 per eye. Thirty-six percent were in the center of the posterior pole image; however, 21% were in the temporal part of the posterior pole. Median accuracy of the detection is 0.94. The correlation between the two observers was fair (0.54). Our algorithm allows visualization of the SPCA at the posterior pole of the eye using wide-field en-face SS-OCT. It can also help the clinicians to study the SPCAs in numerous ocular diseases, particularly its relationship with focal choroidal diseases.

Vitreous cytokine expression profiles in patients with retinal detachment.

PURPOSE: To compare the expression profiles of various cytokines and chemokines in vitreous samples from patients with retinal detachment (RD) to those from controls and to analyze their association with various clinical features. METHODS: In this prospective study, undiluted vitreous fluid was obtained from 41 patients with primary RD and 33 controls with macular hole or vitreomacular traction. A multiplex bead immunoassay was performed to determine the expression of 27 inflammatory mediators. RESULTS: Eleven mediators were significantly upregulated in the vitreous of RD patients compared with controls, including the following: cytokines IL-1ra, IL-6, IL-7, IL-8, IFN-γ; chemokines CCL2, CCL3, CCL4, CXCL10 and CCL11 and growth factor G-CSF. Correlation analyses showed that levels of IL-1ra, CXCL10, CCL11 and G-CSF were positively correlated to the extent of detachment, while those of IL-1ra and CXCL10 were associated with the duration of detachment. There was also a positive association between the concentrations of CXCL10 and CCL11 and preoperative flare values. Additional analysis revealed that flare values and both CXCL10 and CCL11 levels were significantly higher in eyes with grade B or C proliferative vitreoretinopathy (PVR). CONCLUSION: Our results confirm that RD induces a marked inflammatory response with a complex cytokine network. We identified proteins specifically linked to several clinical features that might contribute to photoreceptor degeneration and PVR-related redetachment. These proteins may represent potential therapeutic targets for improving the anatomical and functional outcomes of RD surgery.

Functional ultrasound imaging of the spreading activity following optogenetic stimulation of the rat visual cortex.

Optogenetics has revolutionized neurosciences by allowing fine control of neuronal activity. An important aspect for this control is assessing the activation and/or adjusting the stimulation, which requires imaging the entire volume of optogenetically-induced neuronal activity. An ideal technique for this aim is fUS imaging, which allows one to generate brain-wide activation maps with submesoscopic spatial resolution. However, optical stimulation of the brain with blue light might lead to non-specific activations at high irradiances. fUS imaging of optogenetic activations can be obtained at these wavelengths using lower light power (< 2mW) but it limits the depth of directly activatable neurons from the cortical surface. Our main goal was to report that we can detect specific optogenetic activations in V1 even in deep layers following stimulation at the cortical surface. Here, we show the possibility to detect deep optogenetic activations in anesthetized rats expressing the red-shifted opsin ChrimsonR in V1 using fUS imaging. We demonstrate the optogenetic specificity of these activations and their neuronal origin with electrophysiological recordings. Finally, we show that the optogenetic response initiated in V1 spreads to downstream (LGN) and upstream (V2) visual areas.

Holographic laser Doppler ophthalmoscopy.

We report laser Doppler ophthalmoscopic fundus imaging in the rat eye with near-IR heterodyne holography. Sequential sampling of the beat of the reflected radiation against a frequency-shifted optical local oscillator is made onto an array detector. Wide-field maps of fluctuation spectra in the 10 Hz to 25 kHz band exhibit angiographic contrasts in the retinal vascular tree without requirement of an exogenous marker.