Relation between macular morphology and visual function in patients with choroidal neovascularisation of age related macular degeneration

Strongest Correlation Between Contrast Sensitivity and Morphological Characteristics in Bilateral nAMD

In patients with neovascular age-related macular degeneration (nAMD) there is often an inconsistency between their subjective visual impairment and a still relatively preserved standard Early Treatment of Diabetic Retinopathy Study (ETDRS) best corrected visual acuity. Therefore, in order to better capture the specific functional defects in nAMD, other tests need to be evaluated. In a previous study, we reported contrast sensitivity of the better eye to best correlate with near distance and distance vision related quality of life in patients with bilateral nAMD. Here, we evaluated Pelli-Robson contrast sensitivity, ETDRS visual acuity, low luminance visual acuity and Radner maximum reading speed and correlated them with several morphologic parameters as measured on fundus autofluorescence imaging, optical coherence tomography and optical tomography angiography in 54 patients. A multiple regression analysis was performed which correlated each visual function parameter with the anatomic features. The results showed the strongest correlations between the total area of macular geographic atrophy as well as the percentage of geographic atrophy in the central 1 mm and contrast sensitivity. Further, the regression model selected the total area of macular geographic atrophy, the photoreceptor inner and outer segments interface disruption score, the presence of subretinal fibrosis in the central 1 mm and the central retinal thickness as the variables that explained 71% of the variation in contrast sensitivity when including all eyes. Hence, our results suggest that among the evaluated measures of vision, contrast sensitivity is best correlated with the morphologic impairment in bilateral nAMD. Thus, contrast sensitivity may complement ETDRS visual acuity in clinical trials and serve as a standard diagnostic tool in clinical practice.

Associations of Variation in Retinal Thickness With Visual Acuity and Anatomic Outcomes in Eyes With Neovascular Age-Related Macular Degeneration Lesions Treated With Anti-Vascular Endothelial Growth Factor Agents

Importance

When initiating anti-vascular endothelial growth factor (VEGF) treatment for patients with neovascular age-related macular degeneration (nAMD), knowledge of prognostic factors is important for advising patients and guiding treatment. We hypothesized that eyes with greater fluctuation in retinal thickness over time have worse outcomes than eyes with less variation.

Objective

To investigate whether visual and anatomic outcomes in eyes with nAMD initiating anti-VEGF treatment are associated with fluctuations in retinal thickness.

Design, Setting, and Participants

In this study using data from the Comparison of Age-Related Macular Degeneration Treatments Trials (CATT) and the Inhibition of VEGF in Age-Related Choroidal Neovascularization (IVAN) randomized clinical trial, people with previously untreated nAMD were included. Data were collected from February 2008 to November 2012, and data were analyzed from April 2017 to April 2020.

Main Outcomes and Measures

Foveal center point thicknesses (FCPTs) were extracted from 1165 study eyes from CATT and 566 study eyes from the IVAN trial, excluding those with 3 measurements or less. For each eye, the SD of FCPT was calculated. Eyes were grouped by FCPT SD quartile. Associations of FCPT SD quartile with outcomes were quantified at month 24 or the last available visit by linear or logistic regression, adjusting for baseline best-corrected visual acuity (BCVA) and randomized allocations to drug and treatment regimen, for BCVA, development of fibrosis, and development of macular atrophy.

Results

Of the 1731 included patients, 1058 (61.1%) were female, and the mean (SD) age was 78.6 (7.4) years. The median (interquartile range) FCPT SD was 40.2 (27.1-61.2) in the IVAN cohort and 59.0 (38.3-89.4) in the CATT cohort. After adjustment for baseline BCVA and trial allocations, BCVA worsened significantly across the quartiles of FCPT SD; the difference between the first and fourth quartiles was -6.27 Early Treatment Diabetic Retinopathy Study letters (95% CI, -8.45 to -4.09). The risk of developing fibrosis and macular atrophy also increased across FCPT SD quartiles. Odds ratios ranged from 1.40 (95% CI, 1.03 to 1.91) for quartile 2 to 1.95 (95% CI, 1.42 to 2.68) for quartile 4 for fibrosis and from 1.32 (95% CI, 0.90 to 1.92) for quartile 2 to 2.10 (95% CI, 1.45 to 3.05) for quartile 4 for macular atrophy.

Conclusions and Relevance

Greater variation in retinal thickness in eyes with nAMD during treatment with anti-VEGF was associated with worse BCVA and development of fibrosis and macular atrophy in these post hoc analyses, despite protocol-directed treatment frequency. Practitioners may want to consider variation in retinal thickness when advising patients about their prognosis.

Correlates of Good Vision in Eyes With Subfoveal Scars From Neovascular Age-Related Macular Degeneration

BACKGROUND AND OBJECTIVE

To compare subfoveal disciform scars with good and poor vision in patients with neovascular age-related macular degeneration (nAMD).

PATIENTS AND METHODS

A retrospective case-control study. Twenty-two eyes of 21 consecutively treated patients with nAMD with subfoveal disciform scar and best-corrected visual acuity (BCVA) of 20/63 or better at the final visit were included. Twenty-one eyes of 21 matched patients with disciform scar and final BCVA less than 20/63 served as controls.

RESULTS

Subretinal pigment epithelium scar location was more common in the good vision group than in the poor vision group (P < .001). The mean percent disruption of the ellipsoid and the external limiting membrane layers was significantly greater in poor vision eyes than in good vision eyes from scar formation and throughout follow-up (all P < .01).

CONCLUSION

Preserved photoreceptor layer correlated with good vision in patients with nAMD and subfoveal disciform scar. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:765-774.].

Macular Sensitivity in Eyes with Central Serous Chorioretinopathy

Purpose

To determine macular sensitivity and fixation characteristics in eyes with central serous chorioretinopathy (CSC) using fundus-related microperimetry.

Methods

The authors reviewed 19 eyes with serous elevation within the central 10° due to CSC and 15 normal healthy eyes that had undergone fundus-related microperimetry. The macular sensitivity was measured using the fundus-related microperimeter, MP-1. The best-corrected visual acuity (BCVA), mean retinal sensitivity in the central 10° (central microperimetry, cMP-1) and in the paracentral 10° to 20° (paracentral microperimetry, pMP-1), and fixation stability and location were determined and compared with that of control eyes.

Results

Eyes with CSC showed significantly lower logMAR BCVA (p<0.001), cMP-1, and pMP-1 sensitivity than control eyes (p<0.001, p<0.01, respectively). Eyes with CSC were not significantly different in fixation location (p=1.00) or fixation stability than control eyes (p=0.45). Fixation location was predominantly central in all eyes with CSC; fixation was stable in 17 (89%) and relatively unstable in 2 (11%).

Conclusions

Eyes with CSC showed significantly lower retinal sensitivity not only at the central but also in the paracentral area. Even with decreased BCVA and retinal sensitivity, our patients showed central and stable fixation in their affected eyes.

Quantitative physiological measurements to evaluate the response of antivascular endothelial growth factor treatment in patients with neovascular diseases

Antivascular endothelial growth factor (VEGF) treatment is still used intravitreally worldwide for various neovascular diseases, despite other available, approved treatments. We performed a systematic search of the literature focused on visual physiology studies. We used the online biomedical search engine PubMed and searched key words including “M-chart,” “Preferential Hyperacuity Perimetry,” “microperimetry,” (MP) “electroretinography,” and “contrast sensitivity” to estimate treatment efficacy of anti-VEGF treatments in a quantitative manner. Many studies were identified which used a variety of methodologies, disease entities, injected agents, and patient populations, making it difficult to obtain a direct comparison of their results. However, favorable functional outcomes achieved using current quantitative methods would lend further confidence to the effectiveness of a treat-and-extend protocol using intravitreal anti-VEGF for the management of patients with neovascular diseases. Despite anti-VEGF's wide use, a well-designed longitudinal multicenter study to systematically evaluate and compare different physiological methods or parameters in patients with neovascular diseases is still lacking, though it would benefit therapeutic decisions.

CORRELATION OF VISUAL ACUITY WITH FIBROTIC SCAR LOCATION IN TREATED NEOVASCULAR AGE-RELATED MACULAR DEGENERATION EYES

PURPOSE

To determine whether the optical coherence tomography location of a subfoveal fibrovascular scar is correlated with visual outcome in eyes successfully treated with antivascular endothelial growth factor agents for neovascular age-related macular degeneration.

METHODS

Fifty-six eyes from 56 patients with a subfoveal disciform scar after antivascular endothelial growth factor treatment were included. The initial and final visual acuity, fluorescein angiography, and spectral domain optical coherence tomography scar characteristics were retrospectively reviewed.

RESULTS

Thirty-five of 56 eyes (62.5%) were classified as having entirely subretinal pigment epithelial (sub-RPE) scars, and 21 eyes (37.5%) had subretinal component scars. Mean initial visual acuity was similar between sub-RPE and subretinal scars (20/100 vs. 20/125, P = 0.517); mean final visual acuity was better in the sub-RPE scar group (20/60 vs. 20/200, P = 0.001). Eyes with sub-RPE scar had better preservation of the external limiting membrane, ellipsoid layer, and retinal thickness (P < 0.001, P = 0.017, P = 0.004, respectively) than subretinal component scar eyes. There was no difference between the groups in scar thickness or scar area (P = 0.707, P = 0.186, respectively).

CONCLUSION

Sub-RPE location of subfoveal scarring in eyes treated for neovascular age-related macular degeneration is associated with better preservation of outer retinal structures and better vision, when compared with a subretinal scar.

Microperimetry in age: related macular degeneration

Age-related macular degeneration (AMD) is one of the major causes of visual loss and legal blindness in people over 55. Visual function tests are the cornerstone of visual function investigation and any therapeutic approach to AMD implies, as primary endpoint, the maintenance or improvement of visual function. The progression of visual impairment and the quantification of final residual visual function are currently determined by means of visual acuity quantification. The quantification of high-contrast visual acuity though has many drawbacks and cannot be considered a complete functional examination. Microperimetry is a non-invasive method used to analyse fixation and central visual field defects in a topographic related manner. The introduction of mesopic and more recently scotopic microperimetry, in research and clinical practice of macular disorders, now allows us to better investigate macular function as it strictly relates to macular morphology. We therefore can monitor the functional natural history and quantify the beneficial or detrimental effects of different therapies. The application of microperimetry in clinical studies has provided interesting diagnostic and prognostic information on functional macular changes in AMD patients. The present review brings new updates on the correlation between macular changes, mainly described with optical coherence tomography, and microperimetry changes in patients with AMD.

Visual acuity loss in patients with age-related macular degeneration measured using a novel high-pass letter chart

BACKGROUND/AIMS

Conventional Logarithm of the Minimum Angle of Resolution (logMAR) acuity is the current gold standard for assessing visual function in age-related macular degeneration (AMD). However, visual acuity (VA) often remains 'normal' when measured with these charts, even with advanced retinal changes. We wished to investigate how VA measurements with the Moorfields Acuity Chart (MAC), which employs high-pass filtered letters, compares to conventional letter charts in subjects with AMD.

METHODS

Monocular best-corrected VA measurements and test-retest variability (TRV) were compared for conventional and MAC charts in 38 normal observers (mean age 52.1 years) and 80 patients (mean age 80.6 years) with varying degrees of acuity loss owing to AMD. Methods of Bland-Altman and ordinary least-squares regression were employed for data analysis.

RESULTS

A proportional bias was confirmed between conventional and MAC measurements (r(2)=0.133, p=0.001) such that MAC acuity was -0.45 logMAR 'worse' at the 0.00 logMAR acuity level, but only -0.26 logMAR 'worse' at the 1.00 logMAR level. The mean bias was much smaller in the normal subject group (-0.16 logMAR). Similar TRV (ranging from ±0.09 to ±0.12 logMAR) was found for both charts in both subject groups.

CONCLUSIONS

VA measurements with the MAC chart appear to be more sensitive to functional loss in AMD compared with conventional letter charts, with similar TRV. Simulations indicate this may be because the high-pass filtered letters are more vulnerable to undersampling as a result of retinal cell loss in the disease process.

Macular dysfunction is common in both type 1 and type 2 diabetic patients without macular edema

PURPOSE

To study retinal function in asymptomatic Type 1 and Type 2 diabetic patients with nonproliferative diabetic retinopathy (NPDR) and no clinical signs of diabetic macular edema.

METHODS

Thirty-six consecutive Type 1 and Type 2 diabetic patients with nonproliferative diabetic retinopathy and no diabetic macular edema and 28 healthy controls underwent a complete ophthalmologic examination, including spectral domain optical coherence tomography and microperimetry.

RESULTS

Seventy-one eyes (17 patients with Type 1 and 19 with Type 2 diabetes) were tested, and data from 36 (17 Type 1 and 19 Type 2) eyes were analyzed. Mean best-corrected visual acuity was 0.00 ± 0.01 logMAR and 0.00 ± 0.02 logMAR for Type 1 and Type 2 diabetic patients, respectively (P = 0.075). Mean central foveal thickness was 234.5 ± 13.7 μm and 256.3 ± 12.7 μm for Type 1 and Type 2 diabetic patients, respectively (P = 0.04); the central foveal thickness was statistically different compared with the control groups (P = 0.04 and P = 0.01, respectively). Mean retinal sensitivity was 18.9 ± 0.5 dB and 17.7 ± 0.4 dB for Type 1 and Type 2 diabetic patients, respectively; it was statistically different compared with control groups (P < 0.0001 and P < 0.0001, respectively).

CONCLUSION

We demonstrated a significantly reduced sensitivity in both nonproliferative diabetic retinopathy groups without diabetic macular edema compared with healthy controls; this reduction was greater in Type 2 diabetic patients. Central foveal thickness was increased in all diabetic patients compared with healthy controls, despite the absence of diabetic macular edema.

Correlation of spectral domain optical coherence tomography characteristics with visual acuity in eyes with subfoveal scarring after treatment for wet age-related macular degeneration

PURPOSE

Correlating spectral domain optical coherence tomography characteristics with final best-corrected visual acuity (BCVA) in eyes with subfoveal scarring after treatment for wet age-related macular degeneration.

METHODS

Seventy-nine eyes from 64 subjects, who developed subfoveal scarring after treatment of wet age-related macular degeneration, were retrospectively studied. Spectral domain optical coherence tomography characteristics were analyzed, including percentage disruption of inner segment/outer segment junction and external limiting membrane, central macular thickness, subfoveal scar thickness, subretinal scar area, and proximity of retina with intact outer structures to the fovea. A multivariate stepwise regression analysis was performed with the final BCVA logarithm of minimum angle of resolution as a response and the above-identified spectral domain optical coherence tomography variables as predictors.

RESULTS

There was no correlation between the final BCVA and any of the demographic data, treatment modality received, and central macular thickness. The final BCVA was significantly correlated with the percentage of inner segment/outer segment disruption (P = 0.011), external limiting membrane disruption (P = 0.005), and scar area on spectral domain optical coherence tomography (P = 0.018). Multivariate analysis showed that the baseline BCVA and distance between the fovea and nearest retina with intact outer structures are the most predictive of the final BCVA (R(2) = 0.52).

CONCLUSION

Baseline BCVA and integrity of outer retinal structures are good predictors of the final BCVA of wet age-related macular degeneration patients developing scarring after treatment.

Pharmacogenetic associations with vascular endothelial growth factor inhibition in participants with neovascular age-related macular degeneration in the IVAN Study

PURPOSE

To determine if prespecified genetic polymorphisms influence responsiveness to vascular endothelial growth factor (VEGF) inhibition in neovascular age-related macular degeneration (nAMD). The objectives were to replicate 3 reported pharmacogenetic associations of response in nAMD and to test for novel associations.

DESIGN

Cohort study, combining information about patients' genotypes with information from a randomized controlled trial about responsiveness to anti-VEGF therapy for nAMD.

PARTICIPANTS

Five hundred nine participants with nAMD, enrolled in the Alternative Treatments to Inhibit VEGF in Patients with Age-Related Choroidal Neovascularisation (IVAN) trial.

METHODS

Participants were classified as responders or nonresponders to VEGF inhibition based on the optical coherence tomography (OCT) metric of total retinal thickness (TRT). We computed the change in TRT from baseline to the latest time point for which OCT data were available (3, 6, 9, or 12 months). Eyes with changes in TRT greater than or equal to the 75th percentile or more were classified as responders, and those with changes less than or equal to the 25th percentile or lower were classified as non-responders. Three previously reported associations of response to VEGF inhibition in nAMD involving single nucleotide polymorphisms (SNPs) at the CFH, FZD4, and HTRA1/ARMS2 loci were tested for replication. An additional 482 SNPs also were tested using a candidate gene approach. Associations were estimated as odds ratios (ORs) with confidence intervals (CIs).

MAIN OUTCOME MEASURES

The primary outcome was evidence of a genetic association with response to VEGF inhibition as measured by change in TRT.

RESULTS

One hundred twenty-six participants were classified as responders and 128 were classified as nonresponders. The SNP rs10490924 in HTRA1/ARMS2 showed a borderline association with responsiveness after Bonferroni correction (OR, 1.53; CI, 0.99-2.36; P = 0.055, Bonferroni correction). None of the other 484 additional SNPs tested for association was significant after Bonferroni correction for multiple testing. The smallest corrected P value was 0.84 (P = 0.002, uncorrected) for rs9679290 in the EPAS1 (HIF2A) gene on chromosome 2. Four of the 10 most significant results were in this gene.

CONCLUSIONS

We estimated pharmacogenetic associations using high-quality phenotype data from a randomized controlled clinical trial of nAMD. No significant association or replication of previous associations were observed. Further investigation of the EPAS1 (HIF2A) gene, however, may, be merited.

Repeatability of visual function measures in age-related macular degeneration

PURPOSE

To assess repeatability of visual function measures in patients with early, intermediate or late age-related macular degeneration (AMD) without active neovascular disease in the study eye, but active neovascular AMD in the fellow eye.

METHODS

One hundred subjects from an ongoing trial were screened for this study in which their LogMAR acuity, contrast sensitivity and reading performance were assessed using standardised protocols by trained optometrists. The same measures were repeated one month later and repeatability of the visual functions assessed.

RESULTS

Data from 83 subjects satisfied inclusion criteria for analysis. Coefficient of repeatability was 14.9 letters for LogMAR visual acuity , 7.2 letters for Pelli Robson contrast sensitivity, 0.72 for LogMAR reading acuity, 110.4 words/ min for reading speed and 0.67 for LogMAR critical print size. Intraclass correlation coefficients allowed comparison between measures and were found to be 0.96 for LogMAR visual acuity, 0.93 for contrast sensitivity, 0.75 for LogMAR reading acuity, 0.79 for reading speed and 0.74 for LogMAR critical print size. Coefficients of variation were 9.4 %, 10.7 %, 48.4 %, 28.4 % and 31.8 % respectively.

CONCLUSIONS

We found coefficients of repeatability that concurred with previous studies demonstrating variability of visual functions in patients with AMD. In addition, we found intraclass correlation coefficients to be better with visual acuity and contrast sensitivity than with measures of reading performance.

Predictors of visual outcome in eyes with choroidal neovascularization secondary to age related macular degeneration treated with intravitreal bevacizumab monotherapy

AIM

To evaluate the predictors of visual improvement in eyes with naive choroidal neovascularization secondary to age-related macular degeneration (CNV -AMD) treated with intravitreal bevacizumab (IVB) monotherapy.

METHODS

Fifty eyes with naive CNV- AMD with pretreatment best-corrected visual acuity (BCVA) better than 20/200 and treated with IVB monotherapy were evaluated. Several variables including age, sex, pre-treatment BCVA, CNV type and lesion size on fluorescein angiogram as well as SD-OCT parameters including pre-treatment central macular thickness (CMT), inner-segment/outer-segment (IS/OS) junction integrity, and external limiting membrane (ELM) integrity were analyzed to predict visual outcome.

RESULTS

On univariate regression, pretreatment ELM damage was associated with less visual improvement after treatment (P=0.0145). However, ELM damage predicted only 10% of the visual outcome. On multivariate regression, pretreatment BCVA, IS/OS junction, and ELM integrity on SD-OCT were the significant predictors for the treatment effect and together predicted 37% of visual improvement.

CONCLUSION

Pretreatment BCVA, ELM and IS/OS junction integrity on SD-OCT are of significant value in predicting the visual improvement in naive wet AMD patients treated with IVB monotherapy.

Fixation pattern and macular sensitivity in eyes with subfoveal choroidal neovascularization secondary to age-related macular degeneration. A microperimetry study

PURPOSE

To investigate the effects of subfoveal choroidal neovascularizzation (CNV) secondary to age-related macular degeneration (AMD) on macular functional parameters quantified with an automatic fundus perimeter.

METHODS

118 eyes of 98 consecutive patients with subfoveal CNV secondary to AMD were evaluated. Best corrected visual acuity (ETDRS charts), fundus photography, and fluorescein angiography were performed. Microperimetry (fundus-related perimetry) was used to quantify macular sensitivity and fixation pattern (location and stability).

RESULTS

Of 118 eyes: 26 (21.9%) had central, 18 (15.1%) poor central and 74 (63.0%) eccentric fixation; 31 (26.0%) had stable, 42 (35.6%) relatively unstable and 45 (38.4%) unstable fixation. In 75 eyes (63.4%) a dense central scotoma was found. Angiographic classification of subfoveal CNV (occult versus classic) was not significantly related to fixation pattern (location: P = 0.274; stability: P = 0.385), and presence of dense scotoma (P = 0.41).

CONCLUSION

Microperimetric quantification of macular sensitivity and fixation pattern in eyes with subfoveal CNV secondary to AMD offers new data about the impact of visual impairment in these eyes. Moreover, microperimetry improves the functional evaluation of subfoveal CNV in AMD.

[Adaptation to central scotoma. Part II. Perceptual filling-in phenomenon]

The visual cortex may reorganize after occurrence of a scotoma. Different experimental studies have shown that there is an attempt to minimize the impact of the scotoma, the missing information being filled-in by surrounding information. The clinical consequences of this filling-in phenomenon have been extensively studied by Safran and co-workers. The present review summarizes the current literature on this phenomenon and its clinical consequences. Furthermore, the authors present their own experience with the filling-in phenomenon in patients with age-related macular degeneration. Their study shows that, with few exceptions, the phenomenon only occurs in patients with bilateral central scotoma, in their better eye.

Visual function and dysfunction in early and late age-related maculopathy

Late age-related maculopathy (ARM) is responsible for the majority of blind registrations in the Western world among persons over 50 years of age. It has devastating effects on quality of life and independence and is becoming a major public health concern. Current treatment options are limited and most aim to slow progression rather than restore vision; therefore, early detection to identify those patients most suitable for these interventions is essential. In this work, we review the literature encompassing the investigation of visual function in ARM in order to highlight those visual function parameters which are affected very early in the disease process. We pay particular attention to measures of acuity, contrast sensitivity (CS), cone function, electrophysiology, visual adaptation, central visual field sensitivity and metamorphopsia. We also consider the impact of bilateral late ARM on visual function as well as the relationship between measures of vision function and self-reported visual functioning. Much interest has centred on the identification of functional changes which may predict progression to neovascular disease; therefore, we outline the longitudinal studies, which to date have reported dark-adaptation time, short-wavelength cone sensitivity, colour-match area effect, dark-adapted foveal sensitivity, foveal flicker sensitivity, slow recovery from glare and slower foveal electroretinogram implicit time as functional risk factors for the development of neovascular disease. Despite progress in this area, we emphasise the need for longitudinal studies designed in light of developments in disease classification and retinal imaging, which would ensure the correct classification of cases and controls, and provide increased understanding of the natural course and progression of the disease and further elucidate the structure-function relationships in this devastating disorder.

Contrast sensitivity as an outcome measure in patients with subfoveal choroidal neovascularisation due to age-related macular degeneration

PURPOSE

Although visual acuity is the most frequently used primary outcome measure in clinical trials of treatments for choroidal neovascularisation (CNV) due to age-related macular degeneration (AMD), contrast sensitivity may provide valuable additional information. This paper reviews the evidence for using contrast sensitivity as a measure of visual function and as an outcome measure in clinical trials in patients with subfoveal CNV due to AMD.

METHODS

Medline database searches were performed to retrieve relevant articles on contrast sensitivity. In addition, articles were included from the authors' knowledge of the literature and from the reference lists of retrieved articles.

RESULTS

The published literature demonstrates that contrast sensitivity is an important measure of visual function in patients with subfoveal CNV due to AMD. Most clinical trials of treatments for CNV due to AMD have reported visual acuity as the primary outcome. However, there is evidence that treatment (such as verteporfin therapy) may also provide additional benefits in terms of contrast sensitivity. These benefits may not be completely characterised by measurement of visual acuity alone.

CONCLUSIONS

The inclusion of contrast sensitivity as an outcome measure in studies of patients with CNV due to AMD may provide a more complete understanding of the effects of treatment on visual function and the likely benefits for patients.

Visual acuity and structural findings in old age-related macular degeneration

BACKGROUND

Although exudative age-related macular degeneration (AMD) leads to a substantial visual loss in most patients there is still significant variation in the end- stage visual acuity level. We analysed lesions in eyes with long-standing AMD in order to find contributing factors for this variation.

METHODS

Sixty-one out of 121 patients examined for exudative AMD and still alive 4.8-9.2 (mean 6.8) years after the acute phase were re-examined. The lesion size, area of subretinal fibrosis, geographic atrophy, presence of a persistent exudative process, and shortest distance to normal looking retina were measured from digital fundus photographs taken at the re-examination and correlated with visual acuity.

RESULTS

Lesion size, the presence of a continuing exudative process, or subretinal fibrosis were independent predictors for poor vision. Better vision in the other eye was connected with poor vision in the affected study eye.

CONCLUSIONS

In addition to lesion size, the presence of a continuing exudative process and subretinal fibrosis also have deleterious effects on long-term visual acuity after exudative AMD.

Colour vision testing as an aid to diagnosis and management of age related maculopathy

AIM

To provide a simple test that detects the onset of age related maculopathy (ARM), and can be used to monitor its severity.

METHODS

Colour contrast sensitivity was measured using computer graphics techniques. Colour thresholds were measured along tritan and protan colour confusion axes in the presence of dynamic luminance noise. Thresholds were determined separately for two sizes of optotypes (6.5 degrees and 1.5 degrees). Natural pupils were used. Normal values for the test have been established.

RESULTS

In all patients with unilateral age related macular degeneration, the smaller optotype was invisible in that eye and in almost all, the larger optotype could not be seen. In the symptomless fellow eyes (with ARM) the larger optotype thresholds were raised. The degree of loss was larger for tritan. For the smaller optotype, protan thresholds were elevated in the majority of patients. Tritan losses were greater and disproportionate to the loss seen with the larger optotype. Every person including those with minimal fundal changes had tritan test results for 1.5 degree optotypes >2 SD above the normal mean. Tritan thresholds varied with the severity of the ARM.

CONCLUSIONS

The test is sensitive, simple and quick to administer, and easy for patients. Therefore, it should be useful in detecting and monitoring elderly people with age related changes in their fundi before irreversible loss of vision has occurred.

Verteporfin : a review of its use in the management of subfoveal choroidal neovascularisation

Verteporfin (Visudyne) therapy (photodynamic therapy with intravenous liposomal verteporfin) is the first treatment to effectively prevent the loss of visual acuity in patients with subfoveal choroidal neovascularisation (CNV) secondary to age-related macular degeneration (AMD), pathological myopia or presumed ocular histoplasmosis syndrome (POHS). In adult patients with classic subfoveal CNV or occult with no classic subfoveal CNV secondary to AMD, or subfoveal CNV secondary to pathological myopia or POHS, verteporfin therapy slows or prevents loss of visual acuity. In well designed clinical trials, verteporfin therapy was superior to placebo in patients with subfoveal classic-containing CNV and occult with no classic CNV secondary to AMD at 12 and/or 24 months (Treatment of Age-related macular degeneration with Photodynamic therapy [TAP] Investigation and Verteporfin In Photodynamic therapy [VIP-AMD] trial) and in patients with pathological myopia at 12 months (Verteporfin In Photodynamic therapy [VIP-PM] trial). Limited data suggest that verteporfin therapy also prevents loss of visual acuity in patients with subfoveal CNV secondary to POHS. Verteporfin therapy was generally well tolerated in clinical trials; most adverse events were mild to moderate in intensity and transient. The most frequently reported verteporfin therapy-related adverse events (incidence >2%) were visual disturbance, injection-site reactions, photosensitivity reactions and infusion-related back pain. Approximately 5% of patients with occult with no classic subfoveal CNV secondary to AMD reported severe vision decrease within 7 days of treatment in clinical trials; 3 months later, several patients had recovered some of this loss.

CONCLUSION

Photodynamic therapy with verteporfin, the first photosensitiser approved for the treatment of subfoveal CNV, is a well tolerated treatment that stabilises or slows visual acuity loss in adult patients with predominantly classic or occult with no classic subfoveal CNV secondary to AMD, and subfoveal CNV secondary to pathological myopia or POHS. Thus, verteporfin therapy provides a valuable option for the management of these patients for whom treatment options are few, and should be considered as a first-line therapy in these difficult-to-manage conditions.

Filling-in phenomenon in patients with age-related macular degeneration: differences regarding uni- or bilaterality of central scotoma

PURPOSE

The purpose of this study was to explore the presence of the filling-in phenomenon in patients with uni- or bilateral central scotoma (CS) resulting from natural history or laser photocoagulation of choroidal neovascularization in age-related macular degeneration (AMD).

METHODS

Sixteen consecutive patients with unilateral CS and 14 patients with bilateral CS were assessed (44 eyes) with a scanning laser ophthalmoscope (SLO). Scotoma was delineated by scotometry with a point (1 degree x1 degree) moving radially from the periphery to the center of the lesion. In addition, patients underwent a line test, consisting of a horizontal line moving vertically and a vertical line moving horizontally, from the periphery to the center. The lines were longer than the macular lesion and were projected onto the retina. Patients were asked to indicate when the lines seemed interrupted. The perceptual filling-in phenomenon was considered to be present when limits of the perceived scotoma, determined by the line test, were smaller than those assessed by scotometry. In patients with bilateral CS, the results were analyzed to distinguish the less or more severely affected eye.

RESULTS

In all eyes, the limits of the scotoma obtained with the scotometry test corresponded to the anatomic edges of the macular lesion. In patients with bilateral CS, the filling-in phenomenon was observed in 12 out of 14 (85%) less severely affected eyes, but only in one (7%) of their more severely affected eyes. In patients with unilateral CS, the phenomenon was observed in only one out of 16 (6%) eyes.

CONCLUSION

These results suggest that the filling-in phenomenon mostly occurs in patients with bilateral central scotoma, and almost always in their less affected eye. Thus, it did usually not occur in an eye if the fellow eye was better.

Digital analysis of choroidal neovascularisation in consecutive fluorescein angiograms for use in longitudinal clinical trials

BACKGROUND/AIMS

To document the natural history and to assess the efficacy of interventional therapies in neovascular age related macular degeneration (AMD), an accurate and reproducible method is required for analysis of consecutive fluorescence angiograms. The development and evaluation of an image analysis software for this purpose is described here. It allows for the quantitative analysis of changes in CNV and/or leakage area over time.

METHODS

In digitised angiograms, a mouse driven arrow was used to delineate the CNV border. The ratio of the CNV area to the square of the distance between two vessels was automatically calculated by pixel count to compensate for variation in image sizes at different examination times. These results were directly transferred and stored in a database. To assess reproducibility, CNV areas in 20 patients with occult and 20 patients with classic CNV were determined independently by two readers.

RESULTS

There was only marginal variability between observers with this method: the mean deviation was 0.01 pixels for classic CNV (95% CI -0.17 to +0.15, SD 0.35) and 0.55 pixels for occult CNV (95% CI -1.06 to -0.04, SD 1.14).

CONCLUSIONS

This practical PC based method allows for quantification of angiographic features such as CNV size in early frames and area of leakage in late frames. Limitations include non-readily defined borders in angiograms of poor image quality or indistinct borders of the hyperfluorescent areas of interest. The software is applicable to future clinical trials where the analysis of neovascular complex changes is required, for example, following therapeutic intervention.