Arrangement of the trichromatic cone mosaic in peripheral retina of a color-normal and a deutan Carrier

AbstractDisorder in the packing geometry of the human cone mosaic is believed to help alleviate spatial aliasing effects. To characterize cone packing geometry, we gathered positions of cone inner segments at seven locations along four primary and two oblique meridians in an adult human retina. We generated statistical descriptors based on the distribution of distances and angles to Voronoi neighbors. Parameters of a compressed-jittered model were fit to the actual mosaic. Local anisotropics were investigated using correlograms. We find that (1) median distance between Voronoi neighbors increases with eccentricity, but the minimum distance is constant (6–8 μm) across peripheral retina; (2) the cone mosaic is least compressed and jittered at the edge of the foveal rod-free zone; (3) disorder in the foveal center resembles that described by Pu m et al. (1990); (4) cone spacing is 10–15% less in one direction than in the orthogonal direction; and (5) cone spacing is greater in the radial direction (along meridians) than in the tangential direction (along lines of isoeccentricity). The nearly constant minimum distance implies that high spatial frequencies may be sampled even in peripheral retina. Local anisotropy of the cone mosaic is discussed in relation to the growth of the primate retina during development and to the orientation biases of retinal ganglion cells.

Download Full-text

Faculty Opinions recommendation of Organization of the human trichromatic cone mosaic.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1029120.342549 ◽

2005 ◽

Author(s):

Gordon Fain

Keyword(s):

Cone Mosaic

Download Full-text

Drusen in the Peripheral Retina of the Alzheimer’s Eye

Current Alzheimer Research ◽

10.2174/1567205015666180123122637 ◽

2018 ◽

Vol 15 (8) ◽

pp. 743-750 ◽

Cited By ~ 8

Author(s):

Kresimir Ukalovic ◽

Sijia Cao ◽

Sieun Lee ◽

Qiaoyue Tang ◽

Mirza Faisal Beg ◽

...

Keyword(s):

Peripheral Retina ◽

Amyloid Angiopathy ◽

Temporal Region ◽

Future Studies ◽

Eye Tissues ◽

Neuropathological Diagnosis ◽

Ocular Imaging ◽

Cerebral Amyloid ◽

The Brain ◽

Oil Red O

Background: Recent work on Alzheimer's disease (AD) diagnosis focuses on neuroimaging modalities; however, these methods are expensive, invasive, and not available to all patients. Ocular imaging of biomarkers, such as drusen in the peripheral retina, could provide an alternative method to diagnose AD. Objective: This study compares macular and peripheral drusen load in control and AD eyes. Methods: Postmortem eye tissues were obtained from donors with a neuropathological diagnosis of AD. Retina from normal donors were processed and categorized into younger (<55 years) and older (>55 years) groups. After fixation and dissection, 3-6 mm punches of RPE/choroid were taken in macular and peripheral (temporal, superior, and inferior) retinal regions. Oil red O positive drusen were counted and grouped into two size categories: small (<63 μm) and intermediate (63-125 μm). Results: There was a significant increase in the total number of macular and peripheral hard drusen in older, compared to younger, normal eyes (p<0.05). Intermediate hard drusen were more commonly found in the temporal region of AD eyes compared to older normal eyes, even after controlling for age (p<0.05). Among the brain and eye tissues from AD donors, there was a significant relationship between cerebral amyloid angiopathy (CAA) severity and number of temporal intermediate hard drusen (r=0.78, p<0.05). Conclusion: Imaging temporal drusen in the eye may have benefit for diagnosing and monitoring progression of AD. Our results on CAA severity and temporal intermediate drusen in the AD eye are novel. Future studies are needed to further understand the interactions among CAA and drusen formation.

Download Full-text

Contribution of the marginal peripheral retina to color constancy: Evidence obtained due to contact lens with implanted occluder

Сенсорные системы ◽

10.1134/s0235009219020082 ◽

2019 ◽

Vol 33 (2) ◽

pp. 113-123

Author(s):

G. I. Rozhkova ◽

E. N. Iomdina ◽

O. M. Selina ◽

A. V. Belokopytov ◽

P. P. Nikolayev

Keyword(s):

Contact Lens ◽

Color Constancy ◽

Peripheral Retina

Download Full-text

Lens and Peripheral Retinal Relationships During Vitrectomy: Comparison of 23-, 25-, and 27-Gauge Vitrectomy and Curved Endolaser Probes

Journal of VitreoRetinal Diseases ◽

10.1177/2474126420971979 ◽

2020 ◽

pp. 247412642097197

Author(s):

Jacob S. Duker ◽

Michael J. Venincasa ◽

Pedro F. Monsalve ◽

Armando L. Garcia ◽

Sander R. Dubovy ◽

...

Keyword(s):

Insertion Site ◽

Crystalline Lens ◽

Peripheral Retina ◽

Small Gauge ◽

The Mean ◽

Deceased Donors ◽

23 Gauge ◽

Considerable Range ◽

Safe Access ◽

Phakic Eyes

Purpose: This work aims to compare spatial relationships between the crystalline lens and vitrectomy instruments of different gauges. Methods: Eight phakic eyes recovered from deceased donors were used after fixation. Valved trocars (27-gauge, 25-gauge, and 23-gauge) were sequentially placed in the superotemporal quadrant 4 mm posterior to the limbus in each eye. Intraocular relationships of vitrectomy and curved endolaser probes were measured for each gauge. Results: There were no significant differences in maneuverability between instruments of different gauges. The mean distance from instrument to lens at the geometric center of the globe was 5.5 mm. Vitrectomy probes of all gauges could access the peripheral retina on both sides of the sclerotomy in the 3 to 4 o’clock position adjacent to the sclerotomy without touching the lens. The instruments could be advanced without lens touch to contact the retina within at least 2 mm of the ora serrata 180° away from the insertion site. Conclusions: Vitrectomy and curved endolaser probes achieved similar maneuverability relative to the lens regardless of gauge. This study confirms that small-gauge vitrectomy instruments have a considerable range of safe access to the peripheral retina in phakic eyes from a single sclerotomy.

Download Full-text

Cone opponency in the near peripheral retina

Visual Neuroscience ◽

10.1017/s0952523806233315 ◽

2006 ◽

Vol 23 (3-4) ◽

pp. 503-507 ◽

Cited By ~ 11

Author(s):

I.J. MURRAY ◽

N.R.A. PARRY ◽

D.J. McKEEFRY

Keyword(s):

Color Perception ◽

Peripheral Retina ◽

Test Target ◽

Second Stage ◽

Physiological Differences

Changes of color perception in the peripheral field are measured using an asymmetric simultaneous matching paradigm. The data confirm previous observations in that saturation changes can be neutralized if the test target is increased in size. However, this compensation does not apply to hue shifts. We show that some hues remain unchanged with eccentricity whereas others exhibit substantial changes. Here the color shifts are plotted in terms of a second-stage cone opponent model. The data suggest that the S-L+M channel is more robust to increasing eccentricity than the L-M channel. Observations are interpreted in terms of the known underlying morphological and physiological differences in these channels.

Download Full-text

Ultraviolet polarization vision in fishes: possible mechanisms for coding e–vector

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2000.0664 ◽

2000 ◽

Vol 355 (1401) ◽

pp. 1187-1190 ◽

Cited By ~ 32

Author(s):

Craig W. Hawryshyn

Keyword(s):

Polarized Light ◽

Spatial Arrangement ◽

Short Review ◽

Research Problem ◽

Polarization Sensitivity ◽

Polarization Vision ◽

Selective Reflection ◽

Mosaic Pattern ◽

Cone Mosaic ◽

Biophysical Mechanism

Polarization vision in vertebrates has been marked with significant controversy over recent decades. In the last decade, however, models from two laboratories have indicated that the spatial arrangement of photoreceptors provides the basis for polarization sensitivity.Work in my laboratory, in collaboration with I. Novales Flamarique and F. I. Harosi, has shown that polarization sensitivity depends on a well–defined square cone mosaic pattern and that the biophysical properties of the square cone mosaic probably account for polarization vision in the ultraviolet spectrum. The biophysical mechanism appears to be based on the selective reflection of axial–polarized light by the partitioning membrane, formed along the contact zone between the members of the double cones, onto neighbouring ultraviolet–sensitive cones. In this short review, I discuss the historical development of this research problem.

Download Full-text

Studies on Dark Adaptation IV Pre-Exposure Tolerance of the Dark-Adapted Peripheral Retina*

Journal of the Optical Society of America ◽

10.1364/josa.50.000559 ◽

1960 ◽

Vol 50 (6) ◽

pp. 559 ◽

Cited By ~ 1

Author(s):

John A. Hanson ◽

Joseph W. Wulfeck ◽

Edythe M. S. Anderson

Keyword(s):

Dark Adaptation ◽

Peripheral Retina

Download Full-text

Comparison of fundus fluorescein angiography, optical coherence tomography and optical coherence tomography angiography features of macular changes in Eales disease: a case series

Journal of Ophthalmic Inflammation and Infection ◽

10.1186/s12348-020-00220-4 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Ketaki Rajurkar ◽

Meenakshi Thakar ◽

Priyadarshi Gupta ◽

Anju Rastogi

Keyword(s):

Optical Coherence Tomography ◽

Fluorescein Angiography ◽

Optical Coherence Tomography Angiography ◽

Disease Process ◽

Cystoid Macular Oedema ◽

Peripheral Retina ◽

Optical Coherence ◽

Fundus Fluorescein Angiography ◽

Indirect Ophthalmoscopy ◽

Eales Disease

Abstract Purpose To study the macular features in Eales disease patients observed with fundus fluorescein angiography (FA), optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA). Methods A cross-sectional study was done on treatment naïve 31 eyes (23 patients) with Eales disease. Baseline parameters such as Best-corrected visual acuity (BCVA), slit-lamp bio microscopy (SLB), indirect ophthalmoscopy, FA, spectral-domain OCT {quantitative (central macular thickness [CMT]) and qualitative analysis on SD-OCT} and OCTA were performed. Any media opacity precluding the above investigations was excluded. Results Macular findings comprised of- epiretinal membrane, macular exudation, full thickness macular hole, sub internal limiting membrane bleed, cystoid macular oedema, neurosensory detachment and retinal thickening. Sixteen (51.6%) of our patients had macular changes as seen on all modalities together. SLB and indirect ophthalmoscopy missed macular findings in 50% patients and FA in 18.8% patients. OCT and OCTA diagnosed all macular findings. On comparison of mean BCVA in patients with macular involvement on FA, OCT and OCTA, compared to those without macular involvement, patients with macular involvement had lower BCVA (p 0.000, 0.01 and 0.001 respectively). Thus, FA missed many patients who had significant macular involvement and hence less vision. Conclusion Eales disease though described in literature as classically being peripheral retina disease process, also has macular involvement. OCT and OCTA are useful guides to evaluation of macular involvement in these patients. The latter seems to be superior to FA in detecting macular abnormalities in this ailment. OCTA is non-invasive and shows deep capillary plexus changes which are not shown by any other modality.

Download Full-text