scholarly journals Persistent Dark Cones in Oligocone Trichromacy Revealed by Multimodal Adaptive Optics Ophthalmoscopy

2021 ◽  
Vol 13 ◽  
Author(s):  
Joanne Li ◽  
Tao Liu ◽  
Oliver J. Flynn ◽  
Amy Turriff ◽  
Zhuolin Liu ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Visual Acuity ◽  
Color Vision ◽  
Adaptive Optics ◽  
Retinal Sensitivity ◽  
Photoreceptor Layer ◽  
Normal Visual Acuity ◽  
Normal Color Vision ◽  
Retinal Disorders ◽  
Cone Density

Dark cone photoreceptors, defined as those with diminished or absent reflectivity when observed with adaptive optics (AO) ophthalmoscopy, are increasingly reported in retinal disorders. However, their structural and functional impact remain unclear. Here, we report a 3-year longitudinal study on a patient with oligocone trichromacy (OT) who presented with persistent, widespread dark cones within and near the macula. Diminished electroretinogram (ERG) cone but normal ERG rod responses together with normal color vision confirmed the OT diagnosis. In addition, the patient had normal to near normal visual acuity and retinal sensitivity. Occasional dark gaps in the photoreceptor layer were observed on optical coherence tomography, in agreement with reflectance AO scanning light ophthalmoscopy, which revealed that over 50% of the cones in the fovea were dark, increasing to 74% at 10° eccentricity. In addition, the cone density was 78% lower than normal histologic value at the fovea, and 20–40% lower at eccentricities of 5–15°. Interestingly, color vision testing was near normal at locations where cones were predominantly dark. These findings illustrate how a retina with predominant dark cones that persist over at least 3 years can support near normal central retinal function. Furthermore, this study adds to the growing evidence that cones can continue to survive under non-ideal conditions.

scholarly journals Lamellar Macular Holes: The Role of Microperimetry in Functional Assessment

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Simone Donati ◽  
Paola Della Valle ◽  
Elias Premi ◽  
Marco Mazzola ◽  
Laura Lo Presti ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Cross Sectional Study ◽  
Retinal Sensitivity ◽  
Ophthalmological Examination ◽  
Foveal Thickness ◽  
Cross Sectional ◽  
Photoreceptor Layer ◽  
Central Foveal Thickness ◽  
Functional Aspects ◽  
Horizontal Diameter

Introduction. The aim of our observational cross-sectional study was to evaluate the association between visual function and anatomical characteristics of LMH, considering in particular different subtypes of LMH and their features. Materials and Methods. This observational clinical study has been conducted in the Ophthalmology Clinic, ASST-Sette Laghi, University of Insubria of Varese-Como, Italy. Included patients underwent a complete ophthalmological examination, as well as MP1 microperimetry evaluation and optical coherence tomography (OCT). Two experienced masked observers evaluated OCT imaging in order to assess the integrity of the photoreceptor layer (interdigitation zone and ellipsoid zone: IZ/EZ) and the external limiting membrane (ELM). Results. Twenty-five patients affected by an LMH were evaluated. Eighteen eyes of 18 patients met the study criteria and were included. Based on morphological and functional data, LMHs were divided into two subgroups: tractional (tLMH) and degenerative (dLMH). We identified 11 tLMHs and seven dLMHs. Functional parameters showed a significative difference in visual acuity and retinal sensitivity between the two groups, respectively: (sample median and the interquartile range) 0.0 (0.0; 0.09) LogMAR vs 0.15 (0.09; 0.52) LogMAR and 16.2 (14.2; 17.7) dB vs 10.0 (7.5; 11.8) dB (p<0.05). Fixation was predominantly central in 90.9% of tLMH vs 71.4% of dLMH and stable in 81.8% tLMH vs 42.9% dLMH, but the differences were not statistically significant. Tractional and degenerative LMHs showed no significant differences in central foveal thickness. Conversely, LMH depth and horizontal diameters appeared different between the two groups. Tractional LMH showed a greater depth 257 (205; 278) μm vs 190 (169; 249) μm, whereas degenerative LMH showed a greater horizontal diameter 653 (455; 750) μm vs 429 (314; 620) μm (p<0.05). IZ/EZ line was unaffected in 81.8% of tLMHs eyes versus 14.3% of dLMHs eyes (p<0.05). Visual acuity and retinal sensitivity were higher in eyes with integrity of both IZ/EZ and ELM compared to those with a disruption of one or both layers (p<0.05). Conclusion. Two different subtypes of LMH showed peculiar functional aspects due to their morphological features. Tractional LMHs revealed higher visual acuity and retinal sensibility due to the relative preservation of the outer retinal layers compared to degenerative LMHs. Moreover, we underlined the importance of microperimetry to better identify functional defects in macular degenerative pathologies.

scholarly journals Human foveal cone photoreceptor topography and its dependence on eye length

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Yiyi Wang ◽  
Nicolas Bensaid ◽  
Pavan Tiruveedhula ◽  
Jianqiang Ma ◽  
Sowmya Ravikumar ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Adaptive Optics ◽  
Axial Length ◽  
Visual Angle ◽  
Cone Photoreceptor ◽  
Foveal Vision ◽  
Cone Mosaic ◽  
New Generation ◽  
Myopic Progression ◽  
Cone Density

We provide the first measures of foveal cone density as a function of axial length in living eyes and discuss the physical and visual implications of our findings. We used a new generation Adaptive Optics Scanning Laser Ophthalmoscope to image cones at and near the fovea in 28 eyes of 16 subjects. Cone density and other metrics were computed in units of visual angle and linear retinal units. The foveal cone mosaic in longer eyes is expanded at the fovea, but not in proportion to eye length. Despite retinal stretching (decrease in cones/mm2), myopes generally have a higher angular sampling density (increase in cones/deg2) in and around the fovea compared to emmetropes, offering the potential for better visual acuity. Reports of deficits in best-corrected foveal vision in myopes compared to emmetropes cannot be explained by increased spacing between photoreceptors caused by retinal stretching during myopic progression.

Analysis of the process of recovery of the foveolar region after surgery of idiopathic macular ruptures by the «temporal inverted VPM flap» method

2021 ◽  
pp. 159-163
Author(s):  
S.D. Stebnev ◽  
◽  
V.S. Stebnev ◽  
N.I. Skladchikova ◽  
T.Y. Vashchenko ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Visual Acuity ◽  
Retinal Thickness ◽  
Outer Boundary ◽  
Optical Coherence ◽  
Photoreceptor Layer ◽  
Corrected Distance Visual Acuity ◽  
One Year ◽  
Boundary Membrane

Purpose. To analyze the recovery of the foveolar region after successful surgery of idiopathic macular rupture (IMR) using the "temporal inverted VPM flap" method. Material and methods. In 33 patients (34 eyes) aged 65.2±8.1 years, operated on for stage II-IV IMR according to J. Gass (1995), in the postoperative period for up to 1 year, changes in the foveolar region were studied by optical coherence tomography (OCT). Results. Recovery of the foveolar area began from the first days after the operation and lasted for 12 months. In the period from 1 week to 1 month, the recovery and approximation to the U-shaped foveolar contour was noted in all patients. At the final follow-up period: the outer boundary membrane and the ellipsoid zone were completely restored in 26/44 (76%) and 23/34 (68%) eyes, respectively; the average central retinal thickness decreased from 396±62.6 microns to 194±66 microns (p<0.05); the corrected distance visual acuity (CDVA) increased from 0.07±0.04 to 0.35±0.21 (p<0.05). Conclusion The "temporal inverted VPM flap" method is highly effective in the surgery of idiopathic macular ruptures. The process of restoring the microstructures of the foveolar zone begins from the first days after the IMR surgery using the "temporal inverted VPM flap" method, is gradual and lasts up to one year from the start of treatment. The main stages of restoration of the microstructures of the foveolar region are: mechanical overlap of the macular rupture with HPV flaps, filling of the IMR lumen with a "glial plug", restoration of the external photoreceptor layer of the fovea. Key words: foveolar region, outer layers of the retina, idiopathic macular rupture, temporal inverted VPM flap, optical coherence tomography.

scholarly journals Optical coherence tomography angiography in patients with retinitis pigmentosa who have normal visual acuity

2018 ◽  
Vol 96 (5) ◽  
pp. e636-e642 ◽  
Author(s):  
Seiji Takagi ◽  
Yasuhiko Hirami ◽  
Masayo Takahashi ◽  
Masashi Fujihara ◽  
Michiko Mandai ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Visual Acuity ◽  
Retinitis Pigmentosa ◽  
Optical Coherence Tomography Angiography ◽  
Optical Coherence ◽  
Normal Visual Acuity

scholarly journals Preoperative and Postoperative Optical Coherence Tomography Findings in Patients with Rhegmatogenous Retinal Detachment Involving the Macular Region

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Asaki Matsui ◽  
Hiroshi Toshida ◽  
Rio Honda ◽  
Takahiko Seto ◽  
Toshihiko Ohta ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Visual Acuity ◽  
Retinal Detachment ◽  
Rhegmatogenous Retinal Detachment ◽  
Outer Nuclear Layer ◽  
Optical Coherence ◽  
External Limiting Membrane ◽  
Photoreceptor Layer ◽  
Before And After ◽  
Morphologic Changes

Purpose. To evaluate morphologic changes of the macula, we observed eyes with rhegmatogenous retinal detachment (RRD) involving the macular region by optical coherence tomography (OCT). Subjects and Methods. We studied 26 eyes with RRD before and after surgery, assessing visual acuity, the height of retinal detachment at the fovea (HRD), and morphologic changes of the macular region. The interval between the onset and surgery was also determined. We examined the external limiting membrane (ELM) after surgery and the continuity of the inner segment-outer segment junction (IS/OS junction) of the photoreceptor layer. Results. Impairment of visual acuity was observed when HRD was over 1,000 μm, when there was outer nuclear layer edema before surgery, and when there was IS/OS junction disruption 3 months after surgery. However, 67% of eyes with a continuous ELM and IS/OS junction disruption 3 months after surgery eventually showed restoration of the continuity of IS/OS junction at 6 months. Conclusions. Impairment of visual acuity was observed in eyes with HRD  μm, preoperative outer nuclear layer edema, and IS/OS junction disruption 3 months postoperatively. It is suggested that continuity of ELM might affect restoration of IS/OS junction after surgery for retinal detachment.

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