Longitudinal Changes in Ganglion Cell–Inner Plexiform Layer of Fellow Eyes in Unilateral Neovascular Age-Related Macular Degeneration

Background and Hypothesis: Age-related macular degeneration (AMD) is the leading cause of adult blindness in the developed world, and can be classified as one of two types: dry or wet. Abnormalities in retinal and choroidal vasculature may influence dry-to-wet conversion. This study represents a first attempt to use mathematical modeling to characterize the impact of retinal and choroidal blood flow on the oxygenation of retinal layers at various distances from the macula, in healthy individuals and AMD patients. Experimental Design or Project Methods: The macula is modeled as 7 layers: ganglion cell layer (GCL), inner plexiform layer (IPL), inner nuclear layer (INL), outer plexiform layer (OPL), outer nuclear layer (ONL), photoreceptors layer (PH), retinal pigmented epithelium (RPE). Oxygen supply is provided by the vitreous, the choroid, and by three retinal capillary plexi. Oxygen profiles through the macular tissue are calculated by simulating the balance between O2 supply, consumption and diffusion in: physiological baseline conditions; AMD conditions. Results: Choroidal vasculature impairment affects tissue more proximal to the macular center, retinal blood flow impairment affects tissue more proximal to the macular periphery, and oxygenation of the foveal avascular zone is not affected by retinal vasculature impairment. The decrease in oxygenation due to retinal and choroidal blood flow impairment in AMD is more prominent in the RPE, PH and ONL in all three anatomical zones of the macula. Conclusion and Potential Impact: Our mathematical model revealed that reduced choroidal and retinal oxygenation in AMD patients mostly affects the RPE and PH layers, regardless of the distance from the macula. This finding may explain hypoxia inducible factor-1 (HIF-1) production in these layers, which leads to enhanced vascular endothelial growth factor (VEGF) production, causing neovascularization and conversion to wet AMD. Our model suggests that treatment modalities aimed at maintaining stable oxygenation in dry AMD patients may prevent conversion to wet AMD, and reduce vision loss in these patients.

Download Full-text

Macular Pigment Optical Density and Photoreceptor Outer Segment Length as Predisease Biomarkers for Age-Related Macular Degeneration

Journal of Clinical Medicine ◽

10.3390/jcm9051347 ◽

2020 ◽

Vol 9 (5) ◽

pp. 1347 ◽

Cited By ~ 1

Author(s):

Norihiro Nagai ◽

Sakiko Minami ◽

Misa Suzuki ◽

Hajime Shinoda ◽

Toshihide Kurihara ◽

...

Keyword(s):

Macular Degeneration ◽

Optical Density ◽

Outer Segment ◽

Macular Pigment ◽

Age Related Macular Degeneration ◽

Segment Length ◽

Macular Pigment Optical Density ◽

Photoreceptor Outer Segment ◽

Age Related ◽

Fellow Eyes

To explore predisease biomarkers, which may help screen for the risk of age-related macular degeneration (AMD) at very early stages, macular pigment optical density (MPOD) and photoreceptor outer segment (PROS) length were analyzed. Thirty late AMD fellow eyes, which are at high risk and represent the predisease condition of AMD, were evaluated and compared with 30 age-matched control eyes without retinal diseases; there was no early AMD involvement in the AMD fellow eyes. MPOD was measured using MPS2® (M.E. Technica Co. Ltd., Tokyo, Japan), and PROS length was measured based on optical coherence tomography images. MPOD levels and PROS length in the AMD fellow eyes were significantly lower and shorter, respectively, than in control eyes. MPOD and PROS length were positively correlated in control eyes (R = 0.386; p = 0.035) but not in AMD fellow eyes. Twenty (67%) AMD fellow eyes met the criteria of MPOD < 0.65 and/or PROS length < 35 μm, while only five (17%) control eyes did. After adjusting for age and sex, AMD fellow eyes more frequently satisfied the definition (p < 0.001; 95% confidence interval, 3.50–60.4; odds ratio, 14.6). The combination of MPOD and PROS length may be a useful biomarker for screening predisease AMD patients, although further studies are required in this regard.

Download Full-text

The Spectrum of Central Choriocapillaris Abnormalities on Swept-Source Optical Coherence Tomography Angiography in the Fellow Eye of Unilateral Exudative Age-Related Macular Degeneration Patients: From Flow Deficits to Subclinical Non-Exudative Neovascularization

Journal of Clinical Medicine ◽

10.3390/jcm10122658 ◽

2021 ◽

Vol 10 (12) ◽

pp. 2658

Author(s):

Alexis Khorrami Kashi ◽

Eric Souied ◽

Selim Fares ◽

Enrico Borrelli ◽

Vittorio Capuano ◽

...

Keyword(s):

Optical Coherence Tomography ◽

Macular Degeneration ◽

Optical Coherence Tomography Angiography ◽

Clinical Findings ◽

Age Related Macular Degeneration ◽

Optical Coherence ◽

Swept Source ◽

Exudative Amd ◽

Age Related ◽

Fellow Eyes

We evaluated the spectrum of choriocapillaris (CC) abnormalities in the fellow eyes of unilateral exudative age-related macular degeneration (AMD) patients using swept-source optical coherence tomography angiography (SS-OCTA). Fellow eyes of unilateral exudative AMD patients were prospectively included between May 2018 and October 2018. Patients underwent a multimodal imaging including a SS-OCTA. Demographics and clinical findings were analyzed. The estimated prevalence of macular neovascularization (MNV) was computed. Number and size of flow deficits (FDs) and percentage of flow deficits (FD%) were computed on the compensated CC flow images with the Fiji software. We included 97 eyes of 97 patients (mean age was 80 ± 7.66 years, 39 males, 58 females). The prevalence of MNV in the studied eyes was 8.25% (8/97 eyes). In the 89 non-neovascular eyes, FD% averaged 45.84% ± 11.63%, with a corresponding total area of FDs of 4.19 ± 1.12 mm2. There was a higher prevalence of drusenoid pigment epithelial detachment in eyes with subclinical neovascularization (p = 0.021). Fellow eyes with unilateral exudative AMD encompassed a series of CC abnormalities, from FDs of the aging CC to subclinical non-exudative MNV.

Download Full-text

Longitudinal Changes in Retinotopic Rod Function in Intermediate Age-Related Macular Degeneration

Investigative Opthalmology & Visual Science ◽

10.1167/iovs.17-23084 ◽

2018 ◽

Vol 59 (4) ◽

pp. AMD19 ◽

Cited By ~ 11

Author(s):

Chinh T. Nguyen ◽

Rogan G. Fraser ◽

Rose Tan ◽

Emily Caruso ◽

Jia Jia Lek ◽

...

Keyword(s):

Macular Degeneration ◽

Age Related Macular Degeneration ◽

Longitudinal Changes ◽

Age Related ◽

Rod Function

Download Full-text

Drusen Characteristics of Type 2 Macular Neovascularization in Age-related Macular Degeneration

10.21203/rs.2.14559/v2 ◽

2020 ◽

Author(s):

Daniel Ahmed ◽

Martin Stattin ◽

Anna-Maria Haas ◽

Alexandra Graf ◽

Katharina Krepler ◽

...

Keyword(s):

Macular Degeneration ◽

Care Center ◽

Age Related Macular Degeneration ◽

Retrospective Data Analysis ◽

Age Related ◽

The Relationship ◽

Subretinal Drusenoid Deposits ◽

Medical Retina ◽

Fellow Eyes

Abstract Background: To assess the relationship between drusen characteristics and type 2 macular neovascularization (MNV) in age-related macular degeneration (AMD)Methods: Retrospective data analysis of eyes previously diagnosed with neovascular AMD in a tertiary eye care center (Medical Retina Unit, Rudolf Foundation Hospital, Vienna, Austria) between June 2008 and December 2017. Drusen subtypes, fibrosis, atrophy and subfoveal choroidal thickness (SFCT) of both eyes in patients with type 2 MNV lesions were categorized based on multimodal imaging.Results: Type 2 MNV was diagnosed in 27 (3.2%) of 835 eyes (749 patients). Drusen characteristics in type 2 MNV were observed as followed: drusen < 63 mm in 2 eyes (7.4%), drusen ≥ 63 mm in 10 eyes (37%), subretinal drusenoid deposits (SDD) in 8 eyes (29.6%), cuticular drusen in 2 eye (7.4%) and no drusen were evident in 10 eyes (37%). Drusen distribution in 23 fellow eyes was detected as followed: drusen < 63 mm in 2 eyes (8.7%), drusen ≥ 63 mm in 9 eyes (39.1%), SDD in 5 eyes (21.7%), cuticular drusen in 1 eye (4.3%) and no drusen were evident in 9 eyes (39.1%). Mean SFCT was 140 ± 49 mm in affected eyes and 152 ± 41 mm in the fellow eyes. Patients with drusen or SDD were significantly younger (mean 70.88 ± 6.85, p=0.04) than patients without deposits (mean 77.40 ± 5.74). Conclusions: Type 2 MNV remains a rare entity in AMD. It was frequently seen in the absence ofdrusen, a hallmark of AMD. These findings contribute to the heterogeneity of phenotypes related to pure type 2 lesions.

Download Full-text