Novel grid combined with peripheral distortion correction for ultra-widefield image grading of age-related macular degeneration

Age-Related Macular Degeneration and Extramacular Drusen: Genetic Associations in the Coimbra Eye Study

Purpose

To explore the association between the genetics of age-related macular degeneration (AMD) and extramacular drusen (EMD) in patients with and without AMD.

Methods

We included 1753 eyes (912 subjects) with phenotypic characterization regarding AMD and EMD. Genetic sequencing and the genetic risk score (GRS) for AMD were performed according to the EYE-RISK consortium methodology. To test for differences in the GRS from EMD cases, AMD cases, and controls, a clustered Wilcoxon rank-sum test was used. The association of AMD, EMD, and the GRS was evaluated using logistic regression models adjusted for age and sex. Individual associations of common risk variants for AMD with EMD were explored.

Results

EMD were found in 755 eyes: 252 (14.4%) with AMD and 503 (28.7%) without. In total, 122 eyes (7.0%) had only AMD, and 876 (50.0%) were controls. EMD were strongly associated with AMD (odds ratio [OR], 3.333; 95% confidence interval [CI], 2.356-4.623; P < 0.001). The GRS was associated with an increased risk of AMD (OR, 1.416; 95% CI, 1.218-1.646; P < 0.001) but not with EMD. Individually, the common risk variants ARMS2 rs10490924 (P = 0.042), C3 rs2230199 (P = 0.042), and CETP rs5817082 (P = 0.042) were associated with EMD, after adjustment for AMD, sex, and age.

Conclusions

We found a strong association between EMD and AMD, suggesting a common pathogenesis. The GRS for AMD was not associated with EMD, but a partially overlapping genetic basis was suggested when assessing individual risk variants. We propose that EMD per se do not represent an increase in the global genetic risk for AMD.

Prevalence of peripheral retinal findings in retinal patients using ultra-widefield pseudocolor fundus imaging

Ultra-widefield retinal imaging is increasingly used in ophthalmology and optometry practices to image patients identifying peripheral abnormalities. However, the clinical relevance of these peripheral retinal abnormalities is unclear. This cross-sectional study aims to firstly validate a new grading system, secondly, assess the prevalence of peripheral retinal abnormalities in retinal patients, and finally understand how peripheral findings may associate with retinal disease. Ultra-widefield pseudocolor fundus images were taken from the eyes of clinic patients. Demographic data and clinical diagnosis for each patient was noted. The grading system was validated using masked retinal specialists. Logistic regression identified associations between retinal disease and peripheral retinal findings. Using the grading system, inter-observer agreement was 76.1% with Cohen's Kappa coefficient 0.542 (p < 0.0001) and the test-retest agreement was 95.1% with Kappa 0.677(p < 0.0001). 971 images were included, with 625 eyes (64.4%) having peripheral abnormalities. Peripheral drusen was the most common abnormality (n = 221, 22.76%) and correlated with age-related macular degeneration (p < 0.001). Novel correlations were also identified between diabetic retinopathy and retinal pigmentation as well as pigmentary degeneration. This study provides a validated system for identifying peripheral abnormalities and adds to literature highlighting peripheral retinal associations with retinal disease which would benefit from further study.

Peripheral Manifestations in Age Related Macular Degeneration: A Review of Imaging and Findings

Purpose: To review novel findings in research with ultra-widefield imaging for analysis of peripheral manifestations in macular degeneration (AMD). We introduce the evolving widefield imaging modalities while summarizing the analytical techniques used in data collection of peripheral retinal findings thus far. Our review provides a summary of advancements to date and a commentary on future direction for AMD research. Methods: This is a literature review of all significant publications focused on the relationship between AMD and the retinal periphery conducted within the last two decades. Results and Conclusion: Promising research has been undertaken to elucidate peripheral retinal manifestations in macular degeneration using novel methodology. Advancements in ultra-widefield imaging and fundus autofluorescence have allowed us to elucidate peripheral retinal pigmentary changes, drusen deposition, and much more. Novel grid overlay techniques have been introduced to aid in analyzing these changes for pattern recognition and grouping of findings. This review discusses these findings in detail, providing evidence for the pan-retinal manifestations of AMD. Inter-study discordance in analytical approach highlights a need for more systematic future study.

Evaluation of Peripheral Retinal Changes on Ultra-Widefield Fundus Autofluorescence Images of Patients with Age-Related Macular Degeneration

Objectives:

Age-related macular degeneration (AMD) is the most common cause of central vision loss in individuals aged 65 years and older in developed countries. Earlier imaging systems did not enable visualization of the peripheral retina in diseases affecting the macula. With the introduction of new-generation devices, the peripheral retina is easily visualized. In our study, we aimed to evaluate the incidence of peripheral retinal changes in the color and autofluorescence fundus images of patients with AMD.

Materials and Methods:

In the study group, 550 eyes of 277 patients who were diagnosed with AMD and 90 eyes of 45 healthy patients in the control group were evaluated. An ultra-wide-angle imaging device was used to record standard 200° color and autofluorescence fovea-centered fundus images followed by superior and inferior fundus images obtained using the device’s fixation light. The fundus images were examined in 3 sections: zone 1, zone 2, and zone 3.

Results:

Evaluation of color fundus images revealed peripheral retinal changes in 67.8% of the 550 AMD eyes and 47.8% of the healthy eyes. Drusen was the most common peripheral retinal change. Evaluation of autofluorescence images revealed peripheral autofluorescence changes in 39.6% of the AMD eyes and 28.9% of the healthy eyes. Hypoautofluorescence was the most common autofluorescence change.

Conclusion:

Peripheral retinal changes were more common in AMD patients than the control group, indicating that AMD is not only a macular disease, but can affect the entire retina. Future prospective studies will elucidate the relationship between these peripheral retinal changes and patients’ genetic features and their importance in prognosis, diagnosis, and treatment.

Ultra-widefield fundus photography for radiation therapy planning of ocular tumours

PURPOSE

The use of planar ultra-widefield fundus photography (UWF) may result in distortions and inaccurate measurement. The aim of the study was to evaluate the accuracy of UWF instead of the standard narrow field (SF) for the treatment planning phase of ocular tumours.

METHODS

Distortions between conformal SF and UWF were assessed in 43 patients with choroidal melanoma treated with either proton therapy or brachytherapy. imagej software was used to measure distortion.

RESULTS

The median interquartile range ([IQR]) distortion for all cases was 3.7% [1.7-10.8]. For cases with tumours within 6 mm of the optic disc, distortions appeared clinically nonsignificant. For peripheral and/or large tumours, significantly larger distortions were observed on UWF (median 4.4% [2.7-22.6] for tumours ≥6 mm from the optic disc versus 3.3% [1.6-9.9] for those <6 mm, p = 0.04). Images can be subdivided into three groups: minimal distortion (79.1% of eyes), similar level of major distortion for both measured distances (11.6%) and distortion with unequal level of distortion between the measured distances (9.3%).

CONCLUSION

Distortions with UWF appeared minimal in posterior regions of the fundus and increased with the distance from the posterior pole. UWF could therefore be used for treatment planning of ocular tumours as the planned radiation dose to the macula and optic disc are not impacted.

Ultra-wide-field imaging of choroidal melanoma before and after proton beam radiation therapy

Objective:

To evaluate the imaging characteristics of choroidal melanoma before and after proton beam radiotherapy via Optos^® ultra-wide-field scanning laser ophthalmoscopy.

Methods:

Retrospective, descriptive study of choroidal melanoma patients treated with proton beam radiotherapy. All patients underwent full clinical evaluation, including best-corrected visual acuity, ultrasound examination and ultra-wide-field scanning laser ophthalmoscopy imaging in the pseudo-colour (red and green channel) as well as auto-fluorescence mode. Tumours were classified and evaluated according to their location, size, presence of subretinal fluid, drusen, orange pigment and reflectance intensity in ultra-wide-field scanning laser ophthalmoscopy. Tumour sonographic (basal diameter, height) and ultra-wide-field scanning laser ophthalmoscopy imaging dimensions (maximal diameter) were documented.

Results:

A total of 39 eyes (38 patients) were followed for 24 months (range 6–48 months). Mean best-corrected visual acuity dropped from 20/40 to 20/63 after proton beam radiotherapy. There was no change in the imaging tumour characteristics during follow-up. Subretinal fluid changes were better detected in the autofluorescence compared to pseudo-colour mode. Mean tumour diameter did not significantly change in the ultra-wide-field scanning laser ophthalmoscopy although it did so in the ultrasound. No patient showed local tumour recurrence.

Conclusion:

The ultra-wide-field scanning laser ophthalmoscopy imaging characteristics of choroidal melanoma in the Optos^® system do not significantly change after proton beam radiotherapy after a mean follow-up of 2 years.

The clinical relevance of visualising the peripheral retina

Recent developments in imaging technologies now allow the documentation, qualitative and quantitative evaluation of peripheral retinal lesions. As wide field retinal imaging, capturing both the central and peripheral retina up to 200° eccentricity, is becoming readily available the question is: what is it that we gain by imaging the periphery? Based on accumulating evidence it is clear that findings in the periphery do not always associate to those observed in the posterior pole. However, the newly acquired information may provide useful clues to previously unrecognised disease features and may facilitate more accurate disease prognostication. In this review, we explore the anatomy and physiology of the peripheral retina, focusing on how it differs from the posterior pole, recount the history of peripheral retinal imaging, describe various peripheral retinal lesions and evaluate the overall relevance of peripheral retinal findings to different diseases.

Peripheral Changes Associated With Delayed Dark Adaptation in Age-related Macular Degeneration

PURPOSE

To study the association between peripheral changes in age-related macular degeneration (AMD) and dark adaptation (DA).

DESIGN

Prospective, cross-sectional study.

METHODS

We recruited patients with AMD and a control group (>50 years) without any vitreoretinal disease. Ultra-widefield (UWF) pseudocolor and fundus autofluorescence (FAF) were obtained, and were assessed by 2 graders for the presence of several peripheral changes in perimacular, midperipheral, and far-peripheral zones. All participants were also imaged with 7-field color fundus photographs used for AMD staging (Age-Related Eye Disease Study classification system). Both eyes of study participants were tested with a dark adaptation (DA) extended protocol (20 minutes). Multilevel mixed-effect models (accounting for correlated outcomes between 2 eyes) were used for analyses.

RESULTS

We included 128 eyes (n = 72 patients), 75% with AMD and the remainder controls. The presence of reticular pigmentary changes in the midperipheral (ß = 4.3, P = .012) and far-peripheral zones (ß = 8.4, P < .001) was associated with delayed rod-intercept times (RITs), even after adjusting for confounding factors. The presence, number, and extent of peripheral classic drusen did not show a similar association (P ≥ .148). The presence of a mottled decreased FAF pattern in the midperipheral zone was also associated with prolonged RITs (β = 4.4, P = .031).

CONCLUSION

Our results suggest an association between DA and the presence of peripheral reticular pigmentary changes, as well as the presence of a peripheral mottled decreased FAF pattern. This provides new insights on the clinical significance of peripheral changes in AMD, and their contribution to impairments on DA.