Autofluorescence imaging of choroidal neovascularization due to age-related macular degeneration

Multimodal Imaging in the Diagnosis of Exophytic Juxtapapillary Retinal Capillary Hemangioblastoma

PURPOSE

Exophytic juxtapapillary retinal capillary hemangioblastoma (JRCH) can be difficult to diagnose. We explore the value of multimodal imaging to aid in the diagnosis.

DESIGN

Retrospective case series.

METHODS

Medical records and multimodal imaging studies were reviewed on all patients diagnosed with RCH at Bascom Palmer Eye Institute, Miami, Florida, between January 2013 and December 2019. Patients with exophytic lesions within 2 mm of the disc were included. One patient from the Baylor College of Medicine, Houston, Texas was included. Patient demographics, referring diagnosis, history of von Hippel-Lindau syndrome, initial and last visual acuity, and treatments were recorded. Fundus photography, fundus autofluorescence, fluorescein angiography, indocyanine green angiography, optical coherence tomography (OCT), OCT angiography, and B-scan images were reviewed.

RESULTS

Twelve patients were identified with exophytic JRCH. The mean age was 54 years (range 38-73 years). Five patients had von Hippel-Lindau syndrome. The most common referral diagnoses were choroidal neovascularization and neuroretinitis. Imaging features included nodular outer retinal thickening with shadowing and intra-/subretinal fluid on OCT, hypoautofluorescence on fundus autofluorescence, middle to outer retinal hypervascularity on OCT angiography, early hyperfluorescence with late leakage on fluorescein angiography, and lack of choroidal vascular lesion on indocyanine green angiography. Treatments included photodynamic therapy (6 patients), intravitreal anti-vascular endothelial growth factor therapy (6 patients), argon laser photocoagulation (2 patients), intravitreal or sub-Tenon's triamcinolone (3 patients), and observation (4 patients).

CONCLUSIONS

A key to the accurate diagnosis of exophytic JRCH is its intraretinal location, typically involving the outer retinal layers, which results in a clinical appearance that is distinct from the more common and easily recognizable endophytic RCH. Multimodal imaging can aid in ruling out choroidal neovascularization and disc edema by demonstrating an absence of involvement of those structures.

Accuracy of fundus autofluorescence imaging for the diagnosis and monitoring of retinal conditions: a systematic review

BACKGROUND

Natural fluorescence in the eye may be increased or decreased by diseases that affect the retina. Imaging methods based on confocal scanning laser ophthalmoscopy (cSLO) can detect this 'fundus autofluorescence' (FAF) by illuminating the retina using a specific light 'excitation wavelength'. FAF imaging could assist the diagnosis or monitoring of retinal conditions. However, the accuracy of the method for diagnosis or monitoring is unclear.

OBJECTIVE

To conduct a systematic review to determine the accuracy of FAF imaging using cSLO for the diagnosis or monitoring of retinal conditions, including monitoring of response to therapy.

DATA SOURCES

Electronic bibliographic databases; scrutiny of reference lists of included studies and relevant systematic reviews; and searches of internet pages of relevant organisations, meetings and trial registries. Databases included MEDLINE, EMBASE, The Cochrane Library, Web of Science and the Medion database of diagnostic accuracy studies. Searches covered 1990 to November 2014 and were limited to the English language.

REVIEW METHODS

References were screened for relevance using prespecified inclusion criteria to capture a broad range of retinal conditions. Two reviewers assessed titles and abstracts independently. Full-text versions of relevant records were retrieved and screened by one reviewer and checked by a second. Data were extracted and critically appraised using the Quality Assessment of Diagnostic Accuracy Studies criteria (QUADAS) for assessing risk of bias in test accuracy studies by one reviewer and checked by a second. At all stages any reviewer disagreement was resolved through discussion or arbitration by a third reviewer.

RESULTS

Eight primary research studies have investigated the diagnostic accuracy of FAF imaging in retinal conditions: choroidal neovascularisation (one study), reticular pseudodrusen (three studies), cystoid macular oedema (two studies) and diabetic macular oedema (two studies). Sensitivity of FAF imaging using an excitation wavelength of 488 nm was generally high (range 81-100%), but was lower (55% and 32%) in two studies using longer excitation wavelengths (514 nm and 790 nm, respectively). Specificity ranged from 34% to 100%. However, owing to limitations of the data, none of the studies provide conclusive evidence of the diagnostic accuracy of FAF imaging.

LIMITATIONS

No studies on the accuracy of FAF imaging for monitoring the progression of retinal conditions or response to therapy were identified. Owing to study heterogeneity, pooling of diagnostic outcomes in meta-analysis was not conducted. All included studies had high risk of bias. In most studies the patient spectrum was not reflective of those who would present in clinical practice and no studies adequately reported how FAF images were interpreted.

CONCLUSIONS

Although already in use in clinical practice, it is unclear whether or not FAF imaging is accurate, and whether or not it is applied and interpreted consistently for the diagnosis and/or monitoring of retinal conditions. Well-designed prospective primary research studies, which conform to the paradigm of diagnostic test accuracy assessment, are required to investigate the accuracy of FAF imaging in diagnosis and monitoring of inherited retinal dystrophies, early age-related macular degeneration, geographic atrophy and central serous chorioretinopathy.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42014014997.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Advanced imaging for the diagnosis of age-related macular degeneration: a case vignettes study

Background

The aim of this study is to evaluate the diagnosis, staging, imaging and management preferences, and the effect of advanced imaging among practising optometrists in age‐related macular degeneration (AMD).

Methods

Up to 20 case vignettes (computer‐based case simulations) were completed online in a computer laboratory in random order by 81 practising optometrists of Australia. Each case presented findings from a randomly selected patient seen previously at the Centre for Eye Health for a macular assessment in the following order: case history, preliminary tests and colour fundus photography. Participants were prompted to provide their diagnosis, management and imaging preference. One additional imaging result (either modified fundus photographs and infrared images, fundus autofluorescence, or optical coherence tomography [OCT]) was then provided and the questions repeated. Finally, all imaging results were provided and the questions repeated a third time.

Results

A total of 1,436 responses were analysed. The presence of macular pathology in AMD was accurately detected in 94 per cent of instances. The overall diagnostic accuracy of AMD was 61 per cent using colour fundus photography. This improved by one per cent using one additional imaging modality and a further four per cent using all imaging. Across all responses, a greater improvement in the diagnostic accuracy of AMD occurred following the presentation of OCT findings (versus other modalities). OCT was the most preferred imaging modality for AMD, while multimodal imaging was of greatest benefit in cases more often misdiagnosed using colour fundus photography alone. Overall, the cohort also displayed a tendency to underestimate disease severity.

Conclusion

Despite reports that imaging technologies improve the stratification of AMD, our findings suggest that this effect may be small when applied among practising optometrists without additional or specific training.

PATTERNS OF FUNDUS AUTOFLUORESCENCE DEFECTS IN NEOVASCULAR AGE-RELATED MACULAR DEGENERATION SUBTYPES

PURPOSE

To test define characteristic fundus autofluorescence patterns of different exudative age-related macular degeneration subtypes.

METHODS

Cross-sectional study. Fifty-two patients with choroidal neovascularization because of three different neovascular age-related macular degeneration subtypes were included in the study. Macular and peripheral fundus autofluorescence patterns of study subjects were compared in a masked fashion.

RESULTS

Fundus autofluorescence patterns of all three neovascular age-related macular degeneration subtypes revealed similar patterns. However, peripapillary hypo-autofluorescence was more common among patients with polypoidal choroidal vasculopathy (88.2%) compared with patients with retinal angiomatous proliferation (12.5%) and patients without retinal angiomatous proliferation and polypoidal choroidal vasculopathy (21.1%) (P < 0.0001).

CONCLUSION

Presence of peripapillary fundus autofluorescence defects in neovascular age-related macular degeneration maybe suggestive of polypoidal choroidal vasculopathy as a variant of neovascular age-related macular degeneration.

VISUALIZING RETINAL PIGMENT EPITHELIUM PHENOTYPES IN THE TRANSITION TO ATROPHY IN NEOVASCULAR AGE-RELATED MACULAR DEGENERATION

PURPOSE

To enable future studies of retinal pigment epithelium (RPE) fate in the macular atrophy occurring in eyes with neovascular age-related macular degeneration (nvAMD), the authors determined how RPE morphology changes across the transition from health to atrophy in donor eyes with nvAMD.

METHOD

In RPE-Bruch membrane flat mounts of 5 nvAMD eyes, the terminations of organized RPE cytoskeleton and autofluorescent material were compared. In high-resolution histologic sections of 27 nvAMD eyes, RPE phenotypes were assessed at ±500 μm and ±100 μm from the descent of the external limiting membrane (ELM) toward the Bruch membrane. Thicknesses of RPE, basal laminar deposit (BLamD), and RPE + BLamD were determined. Shapes of the ELM descent were recorded.

RESULTS

Approaching the ELM descent, the percentage of different RPE phenotypes and the thickness of RPE, BLamD, and RPE + BLamD each stayed roughly constant. Compared with a separately described cohort of eyes with geographic atrophy, eyes with nvAMD were more likely to have RPE dysmorphia that did not worsen toward the atrophy border, thinner BLamD overall (3.25 ± 3.46 μm vs. 7.99 ± 7.49 μm for geographic atrophy), and a higher proportion of oblique ELM descents (47.9 vs. 31.9%).

CONCLUSION

The distribution of RPE phenotypes at the transition to macular atrophy in eyes with nvAMD differs from that in primary geographic atrophy, likely reflecting greater photoreceptor loss and the effects of exudation in nvAMD. This distribution, the shape of ELM descents, and thickness profiles may be useful metrics in clinical studies of macular atrophy using optical coherence tomography and fundus autofluorescence.

Fundus autofluorescence imaging: systematic review of test accuracy for the diagnosis and monitoring of retinal conditions

We conducted a systematic review of the accuracy of fundus autofluorescence (FAF) imaging for diagnosing and monitoring retinal conditions. Searches in November 2014 identified English language references. Sources included MEDLINE, EMBASE, the Cochrane Library, Web of Science, and MEDION databases; reference lists of retrieved studies; and internet pages of relevant organisations, meetings, and trial registries. For inclusion, studies had to report FAF imaging accuracy quantitatively. Studies were critically appraised using QUADAS risk of bias criteria. Two reviewers conducted all review steps. From 2240 unique references identified, eight primary research studies met the inclusion criteria. These investigated diagnostic accuracy of FAF imaging for choroidal neovascularisation (one study), reticular pseudodrusen (three studies), cystoid macular oedema (two studies), and diabetic macular oedema (two studies). Diagnostic sensitivity of FAF imaging ranged from 32 to 100% and specificity from 34 to 100%. However, owing to methodological limitations, including high and/or unclear risks of bias, none of these studies provides conclusive evidence of the diagnostic accuracy of FAF imaging. Study heterogeneity precluded meta-analysis. In most studies, the patient spectrum was not reflective of those who would present in clinical practice and no studies adequately reported whether FAF images were interpreted consistently. No studies of monitoring accuracy were identified. An update in October 2016, based on MEDLINE and internet searches, identified four new studies but did not alter our conclusions. Robust quantitative evidence on the accuracy of FAF imaging and how FAF images are interpreted is lacking. We provide recommendations to address this.

Evaluation of peripheral fundus autofluorescence in eyes with wet age-related macular degeneration

PURPOSE

We aimed to evaluate the prevalence of abnormal peripheral fundus autofluorescence (FAF) in wet age-related macular degeneration (AMD) using wide-field imaging instrument.

PATIENTS AND METHODS

A retrospective, case-controlled study involving 66 eyes of 46 Japanese wet AMD patients and 32 eyes of 20 control patients was performed. Wide-field FAF images were obtained for typical AMD (37 eyes/28 patients), polypoidal choroidal vasculopathy (PCV) (22 eyes/20 patients), and retinal angiomatous proliferation (RAP) (seven eyes/four patients). Two masked ophthalmologists independently graded the images for mottled, granular, and nummular patterns. Main outcome measures were abnormal peripheral FAF frequencies and relative risks by disease subgroups and treatments.

RESULTS

Abnormal peripheral FAF patterns were found in 51.5% of wet AMD eyes compared with 18.8% of control eyes (P<0.001). Mottled, granular, and nummular patterns were found in 45.5%, 31.8%, and 16.7%, respectively, of wet AMD eyes. Each disease subgroup (typical AMD, 54.1%; PCV, 36.4%; and RAP, 85.7%) showed significantly higher frequencies of peripheral FAF (P<0.001, P=0.03, and P<0.001, respectively) than control eyes (18.8%). There were no significant differences (P=0.76) between the frequencies in untreated and treated eyes.

CONCLUSION

Eyes of Japanese wet AMD patients had a higher abnormal FAF prevalence compared with control eyes. Among the three disease subtypes, abnormal patterns were least prevalent in PCV eyes.

PERIPAPILLARY RETINAL PIGMENT EPITHELIUM CHANGES IN AGE-RELATED MACULAR DEGENERATION

PURPOSE

To describe peripapillary retinal pigment epithelium changes observed in patients with age-related macular degeneration (AMD) and evaluate their prevalence.

METHODS

This study is a prospective, monocentric, comparative case series including 104 consecutive patients with AMD, and 34 patients who are more than 60 years old and consulting for other conditions (control group). Color and fundus autofluorescence images centered on the optic disk were taken and graded by 2 independent readers from 0 to 4: 0, absent; 1, uneven background; 2, focal hyperautofluorescent dots and spots; 3, light reticular pattern; 4, dense reticular pattern. Statistical analysis was performed to correlate the presence of peripapillary retinal pigment epithelium changes with age, sex, and AMD subtype.

RESULTS

Peripapillary retinal pigment epithelium changes were observed in 76/104 AMD eyes (73.0%) and were significantly more frequent than in eyes with other conditions (14/34, 41.1%, P = 0.002), whereas groups did not differ for age (P = 0.14). Grade ≥2 peripapillary retinal pigment epithelium changes were more frequently observed in patients with AMD than in controls (41.3 vs. 17.6%, P = 0.013). No differences were found between patients with AMD having peripapillary retinal pigment epithelium changes and other patients for age distribution (P = 0.14), sex ratio (P = 0.34), or AMD type (P = 0.57).

CONCLUSION

Peripapillary retinal pigment epithelium changes were more frequent in patients with AMD than in controls, and when present, they were of higher grade. Peripapillary retinal pigment epithelium changes significance is not yet understood and needs further evaluation.

Changes in Fundus Autofluorescence after Anti-vascular Endothelial Growth Factor According to the Type of Choroidal Neovascularization in Age-related Macular Degeneration

PURPOSE

To describe the changes of fundus autofluorescence (FAF) in patients with age-related macular degeneration before and after intravitreal injection of anti-vascular endothelial growth factor according to the type of choroidal neovascularization (CNV) and to evaluate the correlation of FAF with spectral domain optical coherence tomography (SD-OCT) parameters and vision.

METHODS

This was a retrospective study. Twenty-one treatment-naïve patients with neovascular age-related macular degeneration were included. Study eyes were divided into two groups according to the type of CNV. Fourteen eyes were type 1 CNV and seven eyes were type 2 CNV. All eyes underwent a complete ophthalmologic examination, including an assessment of best-corrected visual acuity, SD-OCT, fluorescein angiography, and FAF imaging, before and 3 months after intravitreal anti-vascular endothelial growth factor injection. Gray scales of FAF image for CNV areas, delineated as in fluorescein angiography, were analyzed using the ImageJ program, which were adjusted by comparison with normal background areas. Correlation of changes in FAF with changes in SD-OCT parameters, including CNV thickness, photoreceptor inner and outer segment junction disruption length, external limiting membrane disruption length, central macular thickness, subretinal fluid, and intraretinal fluid were analyzed.

RESULTS

Eyes with both type 1 and type 2 CNV showed reduced FAF before treatment. The mean gray scales (%) of type 1 and type 2 CNV were 52.20% and 42.55%, respectively. The background values were 106.72 and 96.86. After treatment, the mean gray scales (%) of type 1 CNV and type 2 CNV were changed to 57.61% (p = 0.005) and 57.93% (p = 0.008), respectively. After treatment, CNV thickness, central macular thickness, and inner and outer segment junction disruption length were decreased while FAF increased.

CONCLUSIONS

FAF was noted to be reduced in eyes with newly diagnosed wet age-related macular degeneration, but increased after anti-vascular endothelial growth factor therapy regardless of CNV lesion type.

Significance of the hyperautofluorescent ring associated with choroidal neovascularisation in eyes undergoing anti-VEGF therapy for wet age-related macular degeneration

AIM

To characterise the presence of a hyperautofluorescent (HAF) ring associated with choroidal neovascularisation (CNV) complex in patients with wet age-related macular degeneration (AMD).

METHODS

Fundus autofluorescence images and spectral-domain optical coherence tomography (OCT) scans from 362 eyes with wet AMD were reviewed. The presence and size of an HAF ring associated with the CNV complex was evaluated. A subgroup of 64 treatment-naive eyes with new-onset CNV was studied to analyse the relationship between pretreatment OCT characteristics and the presence of the HAF ring.

RESULTS

An HAF ring was present in 38% of the entire cohort of eyes and in 39% of treatment-naive eyes. The presence of the HAF ring was significantly correlated with the extent of baseline subretinal fluid (SRF) on OCT (p=0.0113), the number of antivascular endothelial growth factor (VEGF) injections (p=0.0439) and the number of treatment cycles (p=0.0154). Eyes with an HAF ring were more likely to have disruption of the ellipsoid zone line once the SRF was resolved compared with eyes without an HAF ring (p=0.0002). In multivariate analysis, the best predictors for HAF ring were the baseline area of SRF (p=0.0449) and the number of anti-VEGF treatments received (p=0.0568).

CONCLUSIONS

Nearly 40% of wet AMD eyes had an HAF ring. In treatment-naive eyes, the HAF ring had a significant association with SRF and was found as early as the baseline measurement and as long as 18 months after beginning treatment, persisting for up to 6 years after the initial diagnosis. Its association with baseline SRF and disruption of the ellipsoid zone line of the photoreceptors on OCT could indicate continuous stress on the outer retinal structures after exposure to prolonged SRF and/or transmitted autofluorescence from loss of the photoreceptors overlying the retinal pigment epithelium.

Green-light fundus autofluorescence in diabetic macular edema

AIM

To evaluate the role of central green-light fundus autofluorescence (FAF) in diabetic macular edema (DME).

METHODS

A consecutive series of 92 study eyes with diabetic retinopathy were included. Out of those, 51 diabetic eyes had DME and were compared to 41 diabetic eyes without DME. In all subjects, green-light FAF images were obtained, quantified and classified into various FAF patterns. Cross-sectional optical coherence tomography (OCT) scans were obtained for evaluation of Inner/Outer segment (IS/OS) layer integrity, measurements of central RPE-IS/OS layer thickness as well as classification of DME into various subtypes.

RESULTS

Mean central green-light FAF intensity of eyes with DME (1.289±0.140)log did not significantly differ from diabetic patients without DME (1.317±0.137)log. Most classifiable FAF patterns were seen in patients with cystoid DME. Mean central retinal thickness (CRT) of all study eyes with DME was (501.9±112.4)µm compared to (328.2±27.0)µm in diabetic patients without DME. Patients with DME had significantly more disrupted photoreceptor IS/OS layers than diabetic patients without DME (28/51 vs 5/41, P<0.001). Mean RPE-IS/OS thickness of patients with DME (60.7±14.1)µm was significantly (P<0.001) lower than in diabetic eyes without DME (73.5±9.4)µm. Correlation analys1s revealed non-significant correlations of green-light FAF intensity and OCT parameters in all subtypes of DME.

CONCLUSION

Our results indicate a poor correlation of central green-light FAF intensity with CRT, IS/OS layer integrity or RPE-IS/OS layer thickness in diabetic patients with or without DME and its various subtypes. Thus, central green-light FAF is not suitable for detection of retinal thickening in DME.

Fundus autofluorescence not predictive of treatment response to intravitreal bevacizumab in exudative age-related macular degeneration

PURPOSE

Foveal autofluorescence (AF) has been suggested to be a potential predictor of treatment outcome in choroidal neovascularization (CNV) secondary to age-related macular degeneration and could be a useful marker to help prognosticate for patients and for clinical trials. This retrospective study aims to determine if pretreatment foveal AF can predict treatment response to intravitreal bevacizumab monotherapy in CNV secondary to age-related macular degeneration.

METHODS

Ninety-five eyes (85 patients) with naive CNV secondary to age-related macular degeneration, treated with intravitreal bevacizumab monotherapy were included in this study. Lesion size, CNV type on fluorescein angiography, pretreatment best-corrected visual acuity, and foveal AF pattern (intact/nonintact) were used as predictors. Multivariate linear regression and logistic regression were performed using best-corrected visual acuity change and anatomical response at 6 months as the dependent variables separately.

RESULTS

Pretreatment foveal AF (intact or nonintact) did not predict visual outcome (P = 0.17) nor did lesion size (P = 0.2) or CNV type (P = 0.61). Foveal AF did correlate with the visual acuity but it did not predict any treatment response. Pretreatment best-corrected visual acuity was the only predictive factor for the visual outcome (P = 0.043).

CONCLUSION

Pretreatment AF is not a predictor for the treatment response to intravitreal bevacizumab monotherapy in eyes with CNV secondary to age-related macular degeneration.

Determinants of fixation in eyes with neovascular age-related macular degeneration treated with intravitreal ranibizumab

PURPOSE

To correlate the anatomic features of the macula with functional parameters like location and stability of fixation in patients with neovascular age-related macular degeneration treated with intravitreal ranibizumab injections.

DESIGN

Retrospective analysis.

METHODS

The location and stability of fixation were determined in 41 eyes of 41 patients treated with ranibizumab for neovascular age-related macular degeneration for at least 12 months. All patients underwent 3 injections of ranibizumab 1 month apart and were retreated according to predefined criteria. The fixation parameters measured with microperimetry were correlated to visual acuity, qualitative measures on optical coherence tomography, and patterns of autofluorescence.

RESULTS

The location of fixation was predominantly central in 68.29%, poor central in 2.4%, and predominantly eccentric in 29.27%. The fixation was stable in 80.5%, relatively unstable in 7.3%, and unstable in 12.2%. The factors that determined central and stable location of fixation were better visual acuity (P = .004), absence of subretinal thickening (P = .003), intact subfoveal third hyperreflective band (P = .006), and intact external limiting membrane (P = .036). Autofluorescence pattern within the 4-degree circle of fovea did not correlate with fixation characteristics. However, complete absence of autofluorescence in this area was a poor prognostic indicator for central fixation.

CONCLUSIONS

Anatomic characteristics of the macula determine fixation patterns in patients with neovascular age-related macular degeneration treated with intravitreal ranibizumab injections. Further studies focused on eyes with complete absence of autofluorescence in the central 4-degree circle of fovea may help to define the disease characteristics in this group.

Mutations in the USH1C gene associated with sector retinitis pigmentosa and hearing loss

PURPOSE

To determine the molecular cause of sector retinitis pigmentosa and hearing loss in two affected siblings.

METHODS

Direct DNA sequencing of the USH1C gene was performed in two affected siblings. Putative pathogenic sequence changes were assayed in their parent's chromosomes and in control chromosomes. Clinical examination included visual acuity measurement, visual field measurement, electrophysiologic assessment, and fine matrix mapping. Retinal imaging with fundus photography, scanning laser ophthalmoscope (fundus autofluorescence), and optical coherence tomography was performed. Hearing and vestibular function was also assessed.

RESULTS

The siblings were aged 42 years and 40 years, and both were compound heterozygotes for the p.R103H missense change and the novel splice site change c.2227-1G>A in the USH1C gene. Both alleles were found to be in trans. Neither allele was identified in a panel of 866 control chromosomes, and both were considered pathogenic. Both siblings had sector retinitis pigmentosa restricted to the inferior and nasal retina. Fundus autofluorescence imaging showed a clear demarcation between normal and abnormal areas of retina, which corresponded to areas of reduced sensitivity on fine matrix mapping and loss of visual field. Both siblings had severe hearing loss but were able to develop language.

CONCLUSION

We report a novel molecular cause of sector retinitis pigmentosa associated with hearing loss representing a new phenotype associated with mutations in the USH1C gene.

Geographic atrophy in retinal angiomatous proliferation

PURPOSE

To describe the occurrence of geographic atrophy in patients with retinal angiomatous proliferation (RAP).

METHODS

Demographics, visual acuity, color fundus photographs, fluorescein and indocyanine green angiograms, and fundus autofluorescence and near-infrared autofluorescence images were reviewed in 53 patients (66 eyes) with RAP.

RESULTS

Of 53 treatment-naive eyes, 19 (36%) had atrophy at baseline. Of 66 eyes, 57 (86%) developed de novo atrophy or enlargement of preexisting areas of atrophy during the follow-up (median, 17 months; range, 3-53 months) after treatment. Areas of atrophy were observed at the site of the RAP (58 of 66 eyes, 88%) of a previously existing pigment epithelial detachment (18 of 44 eyes; 41%) and elsewhere (43 of 66 eyes, 65%). At presentation, RAP was found to be frequently associated with increased autofluorescence at the fovea because of cystoid macular edema (36 of 53 eyes, 68%) and reduced autofluorescence because of hard exudation (38 of 53 eyes, 72%) and intraretinal hemorrhages (32 of 53 eyes, 60%). Background reticular (39%) and homogeneous (36%) autofluorescence were most commonly observed.

CONCLUSION

Geographic atrophy occurs frequently in patients with RAP after treatment. This information, if confirmed in other cohorts, would be valuable for the counseling of patients with this disease and for the understanding of the pathogenesis of this condition and its progression after treatment.

Fundus autofluorescence patterns in type 2A idiopathic juxtafoveolar retinal telangiectasis

Purpose

To describe fundus autofluorescence (FAF) patterns in patients with type 2A idiopathic juxtafoveolar retinal telangiectasia (IJRT).

Methods

We reviewed FAF images, color photographs, and fluorescein angiography (FA) images of 30 eyes from 16 patients with type 2A IJRT. Eyes with presence of subretinal neovascularization or any other retinal pathology were excluded. All the imaging modalities were obtained with a Heidelberg Retina Angiograph (HRA) confocal laser scanning system.

Results

The mean age of the patients was 50.7 years, 68.5% female. At baseline, the median best-corrected visual acuity was 20/50. Loss of normal foveal hypoautofluorescence was noted in 93.3% of eyes. All the eyes showed hypoautofluorescence corresponding to intraretinal crystals and pigment clumps. Increased FAF around the pigments was noted in 93.3% of eyes. Increased FAF corresponding to the angiographic leakage from telangiectatic and nontelangiectatic areas was noted in 86.6% of eyes and 80% of eyes, respectively.

Conclusions

Loss of foveal hypoautofluorescence and increased FAF corresponding to the nontelangiectatic angiographic leakage areas were predominant features. Fundus autofluorescence patterns corresponding to color photography and FA findings may further add to the understanding of morphologic alterations in type 2A nonproliferative IJRT at early stages.

Retinal pigment epithelial changes in chronic Vogt-Koyanagi-Harada disease: fundus autofluorescence and spectral domain-optical coherence tomography findings

PURPOSE

The purpose of this study was to determine whether fundus autofluorescence (FAF) and spectral domain-optical coherence tomography (SD-OCT) imaging allow better assessment of retinal pigment epithelium and the outer retina in subjects with chronic Vogt-Koyanagi-Harada disease compared with examination and angiography alone.

METHODS

A cross-sectional analysis of a series of seven consecutive patients with chronic Vogt-Koyanagi-Harada disease undergoing FAF and SD-OCT was conducted. Chronic disease was defined as duration of intraocular inflammation >3 months. Color fundus photographs were correlated to FAF and SD-OCT images. The images were later correlated to fluorescein angiography and indocyanine green angiography.

RESULTS

All patients had sunset glow fundus, which resulted in no apparent corresponding abnormality on FAF or SD-OCT. Lesions with decreased autofluorescence signal were observed in 11 eyes (85%), being associated with loss of the retinal pigment epithelium and involvement of the outer retina on SD-OCT. In 5 eyes (38%), some of these lesions were very subtle on clinical examination but easily detected by FAF. Lesions with increased autofluorescence signal were seen in 8 eyes (61.5%), showing variable involvement of the outer retina on SD-OCT and corresponding clinically to areas of retinal pigment epithelium proliferation and cystoid macular edema.

CONCLUSION

Combined use of FAF and SD-OCT imaging allowed noninvasive delineation of retinal pigment epithelium/outer retina changes in patients with chronic Vogt-Koyanagi-Harada disease, which were consistent with previous histopathologic reports. Some of these changes were not apparent on clinical examination.

Fundus autofluorescence in Pseudoxanthoma elasticum

PURPOSE

Pseudoxanthoma elasticum (PXE) is an inherited multisystem disorder of the elastic tissue. Typical ocular manifestations include angioid streaks, peau d'orange, salmon spots, and choroidal neovascularization (CNV). Changes in Bruch membrane lead to progressive atrophy of the retinal pigment epithelium (RPE), secondary CNVs, and visual loss. The RPE-photoreceptor complex was studied in vivo using fundus autofluorescence (FAF) imaging.

METHODS

Forty-six patients (92 eyes) with PXE were investigated using digital fundus photography, fluorescein angiography (FA), and FAF imaging. The diagnosis was confirmed by multisystem clinical examination, mutation analysis of the ABCC6 gene, and skin biopsy.

RESULTS

The mean age of the patient cohort was 50 years (range, 13-74 years), and mean visual acuity was 20/125. Fundus changes typical for PXE were observed in all eyes. Angioid streaks were detected in all but six eyes. Peau d'orange was hardly detectable on FAF, whereas comet tail lesions were apparent. Retinal pigment epithelium atrophy typically was widespread and heterogeneous, located mostly adjacent to angioid streaks or CNVs. Pattern dystrophy-like changes were only found in patients with previous CNV formation in the same or the contralateral eye.

CONCLUSION

Abnormalities of the RPE-photoreceptor complex detected by FAF imaging were more diverse and widespread than expected from conventional fundus imaging. The exhibition of pattern dystrophy-like changes may be a transitional state toward a neovascular event in a subgroup of patients. The extensive alteration of the RPE suggests an important role of pathologic RPE changes in the evolution of visual loss in PXE.

Fundus autofluorescence and progression of age-related macular degeneration

Fundus autofluorescence imaging is an imaging method that provides additional information compared to conventional imaging techniques. It permits to topographically map lipofuscin distribution of the retinal pigment epithelial cell monolayer. Excessive accumulation of lipofuscin granules in the lysosomal compartment of retinal pigment epithelium cells represents a common downstream pathogenetic pathway in various hereditary and complex retinal diseases including age-related macular degeneration (AMD). This comprehensive review contains an introduction in fundus autofluorescence imaging, including basic considerations, the origin of the signal, different imaging methods, and a brief overview of fundus autofluorescence findings in normal subjects. Furthermore, it summarizes cross-sectional and longitudinal fundus autofluorescence findings in patients with AMD, addresses the pathophysiological significance of increased fundus autofluorescence, and characterizes different fundus autofluorescence phenotypes as well as fundus autofluorescence alterations with disease progression.

Fundus autofluorescence after full macular translocation surgery for myopic choroidal neovascularization

BACKGROUND

To investigate fundus autofluorescence (FAF) findings in patients who underwent full macular translocation surgery with 360-degree retinotomy (MT360) for myopic choroidal neovascularization (CNV).

METHODS

Observational case series. Thirty-one eyes of 31 patients who underwent MT360 for myopic CNV from February 1999 through September 2005 were included. We measured the best-corrected visual acuity and obtained color fundus photographs, optical coherence tomography (OCT) images, and fluorescein angiography images. FAF imaging by confocal scanning laser ophthalmoscope was obtained postoperatively in all study eyes and preoperatively in two study participants. FAF features at the new macula were qualitatively evaluated and compared with preoperative lesions associated with CNV. The FAF features at the retinal pigment epithelial (RPE) area with preoperative CNV also were evaluated.

RESULTS

The mean interval between MT360 and the final FAF examination was 58 months (range, 8-94 months). FAF imaging was almost normal in five eyes (16%), the increased FAF was well defined at the new macula area in 23 eyes (74%), and the FAF was decreased in three eyes (10%). Neither newly developed CNV nor subretinal fluid was seen at the new macular region in any eyes on fluorescein angiography or OCT imaging. The configurations of well-defined increased FAF in 23 eyes corresponded with the preoperative CNV in two eyes (9%) and subretinal hemorrhages in five eyes (22%). Well-defined increased FAF larger than the CNV or subretinal hemorrhage was seen in 16 eyes (69%). The RPE area located at the area of the preoperative CNV had a FAF defect or decreased FAF in 30 eyes (97%) on postoperative FAF imaging; there were no increased FAF changes.

CONCLUSIONS

Well-defined increased FAF at the new macula after MT360 suggests that FAF reflects not only fluorophores in the RPE but also in the neurosensory retina. These fluorophores may result from interactions between the retina and CNV/pathologic RPE.

Autofluorescence Imaging in Age-Related Macular Degeneration Complicated by Choroidal Neovascularization

PURPOSE

To determine if integrity of the retinal pigment epithelium (RPE)/photoreceptor complex as assessed by autofluorescence imaging can be predicted on the basis of visual acuity (VA), size, or fluorescein angiographic characteristics of the lesion in the early stage of choroidal neovascularization in age-related macular degeneration (AMD).

DESIGN

Prospective, observational, consecutive case series.

PARTICIPANTS

Seventy-nine eyes of 78 patients with untreated early-stage subfoveal neovascular AMD.

METHODS

Digital color fundus photography and fluorescein angiography were carried out by certified photographers using the same camera throughout the study. Confocal scanning laser ophthalmoscopy images were obtained using a retinal angiograph. Autofluorescence images were compared with digital fluorescein angiography and fundus color photographs using IMAGEnet.

MAIN OUTCOME MEASURES

Autofluorescence at the macula was correlated with VA, angiographic lesion characteristics, lesion size, and length of symptoms.

RESULTS

Of the 79 eyes studied, 40 had classic and predominantly classic choroidal neovascularization, 10 had minimally classic, 29 had occult, 75 were subfoveal, and 4 were juxtafoveal. In 54 eyes, autofluorescence was continuous at the central macula, and this correlated significantly with VA, lesion size, and symptom length but not choroidal neovascularization type. However, there was considerable overlap between the 2 groups such that the integrity of RPE autofluorescence could not be predicted on the basis of these criteria.

CONCLUSION

Intact autofluorescence at the macula in early choroidal neovascularization correlates with VA, lesion size, and symptom length but not lesion type. None predict with any certainty the integrity of the outer retina. Our data suggest that the RPE/photoreceptor complex may be intact at the macula for several months in the presence of choroidal neovascularization, suggesting that VA might be rescued if treatment were effective in suppressing neovascular growth without damaging the RPE/retina complex, although this remains to be tested. It would be sensible to assess autofluorescence in treatment protocols to test this concept because it may be a marker for earlier disease and predict outcomes of treatment.

SOD2 knockdown mouse model of early AMD

PURPOSE

To test the hypothesis that oxidative injury to the retinal pigment epithelium (RPE) may lead to retinal damage similar to that associated with the early stages of age-related macular degeneration (AMD).

METHODS

A ribozyme that targets the protective enzyme manganese superoxide dismutase (MnSOD) was expressed in RPE-J cells, and adeno-associated virus (AAV) expressing the ribozyme gene was injected beneath the retinas of adult C57BL/6 mice. The RPE/choroid complex was examined for SOD2 protein levels and protein markers of oxidative damage using immunoblot analysis and LC MS/MS-identification of proteins and nitration sites. Lipids were extracted from retinal tissue and analyzed for the bis-retinoid compounds A2E and iso-A2E. The mice were analyzed by full-field electroretinography (ERG) for light response. Light and electron microscopy were used to measure cytological changes in the retinas.

RESULTS

The treatment of RPE-J cells with Rz432 resulted in decreased MnSOD mRNA and protein as well as increased levels of superoxide anion and apoptotic cell death. When delivered by AAV, Rz432 reduced MnSOD protein and increased markers of oxidative damage, including nitrated and carboxyethylpyrrole-modified proteins in the RPE-choroid of mice. Ribozyme delivery caused a progressive loss of electroretinograph response, vacuolization, degeneration of the RPE, thickening of Bruch's membrane, and shortening and disorganization of the photoreceptor outer and inner segments. Progressive thinning of the photoreceptor outer nuclear layer resulted from apoptotic cell death. Similar to the eyes of patients with AMD, ribozyme-treated eyes exhibited increased autofluorescence and elevated levels of A2E and iso-A2E, major bis-retinoid pigments of lipofuscin.

CONCLUSIONS

These results support the hypothesis that oxidative damage to the RPE may play a role in some of the key features of AMD.

RPE transplantation and its role in retinal disease

Retinal pigment epithelial (RPE) transplantation aims to restore the subretinal anatomy and re-establish the critical interaction between the RPE and the photoreceptor, which is fundamental to sight. The field has developed over the past 20 years with advances coming from a large body of animal work and more recently a considerable number of human trials. Enormous progress has been made with the potential for at least partial restoration of visual function in both animal and human clinical work. Diseases that have been treated with RPE transplantation demonstrating partial reversal of vision loss include primary RPE dystrophies such as the merTK dystrophy in the Royal College of Surgeons (RCS) rat and in humans, photoreceptor dystrophies as well as complex retinal diseases such as atrophic and neovascular age-related macular degeneration (AMD). Unfortunately, in the human trials the visual recovery has been limited at best and full visual recovery has not been demonstrated. Autologous full-thickness transplants have been used most commonly and effectively in human disease but the search for a cell source to replace autologous RPE such as embryonic stem cells, marrow-derived stem cells, umbilical cord-derived cells as well as immortalised cell lines continues. The combination of cell transplantation with other modalities of treatment such as gene transfer remains an exciting future prospect. RPE transplantation has already been shown to be capable of restoring the subretinal anatomy and improving photoreceptor function in a variety of retinal diseases. In the near future, refinements of current techniques are likely to allow RPE transplantation to enter the mainstream of retinal therapy at a time when the treatment of previously blinding retinal diseases is finally becoming a reality.

Fibrosis and diseases of the eye

Most diseases that cause catastrophic loss of vision do so as a result of abnormal angiogenesis and wound healing, often in response to tissue ischemia or inflammation. Disruption of the highly ordered tissue architecture in the eye caused by vascular leakage, hemorrhage, and concomitant fibrosis can lead to mechanical disruption of the visual axis and/or biological malfunctioning. An increased understanding of inflammation, wound healing, and angiogenesis has led to the development of drugs effective in modulating these biological processes and, in certain circumstances, the preservation of vision. Unfortunately, such pharmacological interventions often are too little, too late, and progression of vision loss frequently occurs. The recent development of progenitor and/or stem cell technologies holds promise for the treatment of currently incurable ocular diseases.

Fundus autofluorescence in exudative age-related macular degeneration

AIM

To evaluate the distribution of fundus autofluorescence in patients with age-related macular degeneration and choroidal neovascularisation (CNV).

METHODS

Colour fundus photographs, fundus fluorescein angiograms (FFA) and fundus autofluorescence images were obtained from a group of 40 patients (43 eyes) with age-related macular degeneration and purely classic or occult CNV. Only patients with newly diagnosed CNV and in whom autofluorescence images were obtained within 2 weeks from FFA were included. The distribution of autofluorescence was qualitatively evaluated, and the findings compared with those from colour fundus photographs and FFA.

RESULTS

29 (67%) eyes had classic CNV and 14 (33%) had occult CNV. In 26 (90%) eyes with classic CNV, a low autofluorescence signal was detected at the site of the CNV; in 7 (50%) eyes with occult CNV, multiple foci of low autofluorescence signal were detected. Outside the area affected by the lesion, homogeneous autofluorescence was observed in most of the cases (n = 33, 77%). Similarly, homogeneous autofluorescence was commonly observed in fellow eyes (62%). A pattern of focal increased autofluorescence was rarely seen in eyes with CNV (n = 4, 9%) or in fellow eyes (n = 4, 15%). In 11 of 43 (25%) eyes, areas of increased autofluorescence, other than a pattern of focal increased autofluorescence, were detected. In four patients, autofluorescence images had been obtained before the development of CNV; in none was any increased autofluorescence detected before the formation of CNV.

CONCLUSIONS

Distinct patterns of autofluorescence were observed in eyes with pure classic and occult CNV. Increased autofluorescence was rarely seen in eyes with CNV and in fellow eyes, suggesting that increased autofluorescence, and thus, retinal pigment epithelium lipofuscin, may not play an essential part in the formation of CNV.