Macular Degeneration: Bird AC

Bird AC, Barnes RM. · No affiliation provided · Clin Experiment Ophthalmol. · Pubmed #14641149 No free full text.

This publication has no abstract.

Schmitz-Valckenberg S, Holz FG, Bird AC, Spaide RF. · Department of Ophthalmology, University of Bonn, Bonn, Germany. · Retina. · Pubmed #18327131 No free full text.

Abstract: Fundus autofluorescence (FAF) imaging is a novel imaging method that allows topographic mapping of lipofuscin distribution in the retinal pigment epithelium cell monolayer as well as of other fluorophores that may occur with disease in the outer retina and the subneurosensory space. 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. FAF imaging has been shown to be useful with regard to understanding of pathophysiologic mechanisms, diagnostics, phenotype-genotype correlation, identification of predictive markers for disease progression, and monitoring of novel therapies. FAF imaging gives information above and beyond that obtained by conventional imaging methods, such as fundus photography, fluorescein angiography, and optical coherence tomography. Its clinical value coupled with its simple, efficient, and noninvasive nature is increasingly appreciated. This review summarizes basic principles and FAF findings in various retinal diseases.

Bird AC. · Moorfields Eye Hospital, City Road, London EC1V 2PD, United-Kingdom. · J Fr Ophtalmol. · Pubmed #16395226 links to  free full text

Abstract: To summarize the evidence that exists concerning the pathogenesis of lesions in late age-related macular disease (AMD), we reviewed both experimental evidence and clinical observations that address these problems. There is good evidence that choroidal neovascularization is due to a change in the balance of growth factors derived from the retinal pigment epithelial basolateral plasma membrane domain (RPE). Retinal angiomatous proliferation may also have a similar pathogenesis involving the apical domain. Detachment of the RPE is likely to be a consequence of increased resistance of Bruch's membrane to water flow due to deposition of lipids. Geographic atrophy is preceded by accumulation of autofluorescent material in the RPE and possible causal relationships between the two have been demonstrated. There is increasing understanding concerning the sequence of events that lead to those lesions causing loss of central vision in AMD. Therapeutic approaches that address the underlying mechanisms are more likely to succeed than current treatment options. Such an approach has already been initiated in the management of choroidal neovascularization.

Holz FG, Pauleikhoff D, Klein R, Bird AC. · Department of Ophthalmology (F.G.H.), University of Heidelberg, Heidelberg, Germany. · Am J Ophthalmol. · Pubmed #15013875 No free full text.

Abstract: PURPOSE: To review the evidence that exists concerning the pathogenesis of lesions in late age-related macular disease (AMD). DESIGN: Review of the literature. METHODS: A review of both experimental evidence and clinical observations that address these problems. RESULTS: There is good evidence that choroidal neovascularization (CNV) is due to a change in the balance of growth factors derived from the retinal pigment epithelial basolateral plasma membrane domain (retinal pigment epithelium). Retinal angiomatous proliferation may also have a similar pathogenesis involving the apical domain. Detachment of the retinal pigment epithelium is likely to be a consequence of increased resistance of the Bruch membrane to water flow due to deposition of lipids. Geographic atrophy is preceded by accumulation of autofluorescent material in the retinal pigment epithelium and possible causal relationships between the two have been demonstrated. CONCLUSION: There is increasing understanding concerning the sequence of events that lead to those lesions causing loss of central vision in AMD. Therapeutic approaches that address the underlying mechanisms are more likely to succeed than current treatment options. Such an approach has already been initiated in the management of choroidal neovascularization.

Holder GE, Robson AG, Hogg CR, Kurz-Levin M, Lois N, Bird AC. · Moorfields Eye Hospital, London, UK. · Doc Ophthalmol. · Pubmed #12675481 No free full text.

This publication has no abstract.

Pauleikhoff D, van Kuijk FJ, Bird AC. · Augenabteilung St. Franziskus Hospital Münster. · Ophthalmologe. · Pubmed #11450472 No free full text.

Abstract: The present concepts of the pathogenesis of AMD include cumulative light damage by oxidative processes in the macular photoreceptors as environmental co-factor for the development of AMD. The direct causative connection of this hypothesis has still to be established but wide circumstantial evidence from epidemiological and basic scientific investigations are strongly supportive. Macular pigment consisting of lutein and zeaxanthin through there ability to filter light and by direct antioxidative properties, has been proposed as the most effective protective factor in the central retina ("natural sun glasses") and could be important to reduce light induced oxidative retinal damage. The observation, that with age and especially in eyes with AMD lower concentrations of macular pigment could be found, can be interpreted that low macular pigment concentrations may be associated with higher risk for AMD. Through dietary intake and eventually with supplementation the concentration of macular pigment can be increased, and analysis of the correlation between macular pigment and AMD may be important to characterise a possible influenceable AMD risk factor.

Stevenson MR, Hart PM, Chakravarthy U, Mackenzie G, Bird AC, Owens SL, Chisholm IH, Hall V, Houston RF, McCulloch DW, Plowman N. · Ophthalmology and Vision Science, Royal Hospitals, Belfast BT12 6BA, UK. · Br J Ophthalmol. · Pubmed #16024863 links to  free full text

Abstract: AIMS: To determine whether or not self reported visual functioning and quality of life in patients with choroidal neovascularisation caused by age related macular degeneration (AMD) is better in those treated with 12 Gy external beam radiotherapy in comparison with untreated subjects. METHODS: A multicentre single masked randomised controlled trial of 12 Gy of external beam radiation therapy (EBRT) delivered as 6 x 2 Gy fractions to the macula of an affected eye versus observation. Patients with AMD, aged 60 years or over, in three UK hospital units, who had subfoveal CNV and a visual acuity equal to or better than 6/60 (logMAR 1.0). METHODS: Data from 199 eligible participants who were randomly assigned to 12 Gy teletherapy or observation were available for analysis. Visual function assessment, ophthalmic examination, and fundus fluorescein angiography were undertaken at baseline and at 3, 6, 12, and 24 months after study entry. To assess patient centred outcomes, subjects were asked to complete the Daily Living Tasks Dependent on Vision (DLTV) and the SF-36 questionnaires at baseline, 6, 12, and 24 months after enrolment to the study. Cross sectional and longitudinal analyses were conducted using arm of study as grouping variable. Regression analysis was employed to adjust for the effect of baseline co-variates on outcome at 12 months and 24 months. RESULTS: Both control and treated subjects had significant losses in visual functioning as seen by a progressive decline in mean scores in the four dimensions of the DLTV. There were no statistically significant differences between treatment and control subjects in any of dimensions of the DLTV at 12 months or 24 months after study entry. Regression analysis confirmed that treatment status had no effect on the change in DLTV dimensional scores. CONCLUSIONS: The small benefits noted in clinical measures of vision in treated eyes did not translate into better self reported visual functioning in patients who received treatment when compared with the control arm. These findings have implications for the design of future clinical trials and studies.

Owens SL, Bunce C, Brannon AJ, Wormald R, Bird AC, Anonymous00270. · Medical Retinal Service, Moorfields Eye Hospital, London, UK. · Eye. · Pubmed #12855972 No free full text.

Abstract: PURPOSE: The Drusen Laser Study (DLS) of high-risk age-related maculopathy (ARM) is a randomised, controlled clinical trial designed to answer two questions: (1). Do drusen resolve after macular laser photocoagulation (2). Does macular laser photocoagulation prevent choroidal neovascularisation (CNV) in high-risk eyes? In this report, we present the results of the interim, pooled analysis of CNV prophylaxis for patients in the Unilateral Group of the DLS. METHODS: The DLS is a randomised controlled clinical trial of prophylactic macular photocoagulation for high-risk ARM. Patients in the Unilateral Group had a neovascular complication in the first eye; their fellow eye (Study Eye) had visual acuity of 6/12 or better and drusen. Following informed consent, patients were randomised to the Treatment Group or the No Treatment Group. Patients randomised to treatment received 12 light spots of argon laser photocoagulation to their Study Eye: four burns were placed 750 microm from the centre of the fovea at 12, 3, 6, and 9 o'clock, and the eight remaining burns were placed 1500 microm from the centre of the fovea at 12, 1:30, 3, 4:30, 6, 7:30, 9, and 10:30 o'clock. Drusen were treated directly only if they were present at the protocol treatment locations. All patients were followed in an identical fashion at regular intervals. Best-corrected visual acuity was measured and recorded by a masked observer. Fluorescein angiography was performed at baseline and yearly review, as well as nonprotocol visits if symptoms suggested CNV. Five clinical centres utilised and conformed to a common DLS protocol. Patient care and data collection methodologies were deemed sufficiently similar to permit a pooled data analysis. RESULTS: There were 156 patients included in the interim analysis, and timed information was available on 153. CNV occurred in 21 of 81 (26%) patients in the Treatment Group and in 13 of 75 (17%) patients in the No Treatment Group (P=0.19). Kaplan-Meier survival analysis showed earlier onset of CNV in the Treatment Group compared to patients in the No Treatment Group (statistical significance not calculated). Visual acuity loss at 2 years occurred in nine of 54 (17%) patients in the Treatment Group compared to the two of 48 (4%) patients in the No Treatment Group (P=0.056). CONCLUSIONS: We are only the second group to identify possible laser-induced CNV despite other similar studies in progress. Equipoise of the DLS investigators was lost, and recruitment was halted. We feel ethically bound to notify the ophthalmic community of this finding.

Jonasson F, Arnarsson A, Sasaki H, Peto T, Sasaki K, Bird AC. · Department of Ophthalmology, University Iceland, Reykjavik, Iceland. · Arch Ophthalmol. · Pubmed #12617709 No free full text.

Abstract: OBJECTIVE: To examine the age- and sex-specific prevalence of age-related maculopathy (ARM) and age-related macular degeneration (AMD) in citizens of Reykjavik, Iceland, who were 50 years and older. DESIGN: Random sample, cross sectional. MATERIALS AND METHODS: Response rate was 75.8%. The presence and severity of various characteristics of drusen and pigmentary changes that are typical of ARM and AMD were determined by grading stereoscopic color fundus photographs, using the international classification and grading system for ARM and AMD. RESULTS: We were able to evaluate 1021 right-eye and 1020 left-eye macular photographs. There was no statistically significant difference between right and left eyes. In people aged 50 to 59 years, 4.8% of participants (95% confidence interval [CI], 2.6-7.0) were found to have intermediate soft drusen measuring 63 to 125 micro m in either eye; 1.2% (95% CI, 0.0-2.3) had large soft distinct drusen larger than 125 micro m; and 0.6% (95% CI, 0.0-1.4) had large soft, crystalline, or semisolid drusen. The same figures for those 80 years and older were 18.2% (95% CI, 9.8-26.6), 10.9% (95% CI, 4.0-17.8), and 25.5% (95% CI, 18.4-32.6), respectively. Geographic atrophy was found in either eye in 9.2% of those participants 70 years and older (95% CI, 5.6-12.7), and exudative macular degeneration was found in 2.3% of participants 70 years and older (95% CI, 0.5-4.1). CONCLUSION: Geographic atrophy was found to be more common in our study than in other population-based studies.

Stanga PE, Kychenthal A, Fitzke FW, Halfyard AS, Chan R, Bird AC, Aylward GW. · The Institute of Ophthalmology, University College London, England UK. · Ophthalmology. · Pubmed #12153801 No free full text.

Abstract: PURPOSE: To test the feasibility of a new surgical technique and to assess visual function over the translocated retinal pigment epithelium (RPE) cells in patients operated on for subfoveal choroidal neovascularization (CNV) secondary to age-related macular degeneration (ARMD). DESIGN: Retrospective, noncomparative, interventional case series. PARTICIPANTS: Nine patients with previously untreated exudative ARMD underwent surgical excision of the subfoveal CNV with RPE translocation and were observed for 12 to 32 months. METHODS: The surgery consisted of a standard three-port pars plana vitrectomy, excision of the CNV, and RPE translocation. Pre- and postoperative ocular examination included best-corrected visual acuity measurement, fundus color stereo photography, and fundus fluorescein angiography. Optical coherence tomography and confocal laser scanning ophthalmoscopy (cLSO) were performed after surgery. A crossfixation target and a single-point flashing light were projected on different areas of the posterior pole using a cLSO. Photopic 10 to 2 perimetry, photopic fine matrix mapping, and cLSO microperimetry were also performed after surgery in six patients. MAIN OUTCOME MEASURES: Optical coherence tomography cross-sectional scans and cLSO RPE autofluorescence were recorded to detect the presence of viable translocated RPE. Visual acuity, fixation, photopic 10 to 2 perimetry, photopic fine matrix mapping, and cLSO microperimetry were used to test central visual function. RESULTS: Retinal pigment epithelium was translocated successfully at the time of CNV removal from the edge of the RPE defect to a subfoveal location in seven of nine patients. One patient experienced proliferative vitreoretinopathy, but significant hemorrhage was not a feature. Optical coherence tomography showed the translocated RPE as an area of increased optical reflectivity with optical shadowing external to it. Confocal laser scanning ophthalmoscopy showed autofluorescence of the translocated RPE. The crossfixation target was seen when projected on the translocated RPE. During eccentric fixation, the patients could see a flashing point-target projected on the translocated RPE. Photopic 10 to 2 perimetry, photopic fine-matrix mapping, and cLSO microperimetry showed the presence of central visual function. CONCLUSIONS: The authors propose that translocation of RPE at the time of CNV removal, from the edge of the RPE defect to a subfoveal location, may have a role in the surgical management of ARMD.

Hart PM, Chakravarthy U, Mackenzie G, Chisholm IH, Bird AC, Stevenson MR, Owens SL, Hall V, Houston RF, McCulloch DW, Plowman N. · Department of Ophthalmology, The Royal Victoria Hospital, Queen's University of Belfast, Northern Ireland. · Arch Ophthalmol. · Pubmed #12149056 No free full text.

Abstract: OBJECTIVE: To determine whether teletherapy with 6-mV photons can reduce visual loss in patients with subfoveal choroidal neovascularization in age-related macular degeneration. DESIGN: A multicenter, single-masked, randomized controlled trial of 12 Gy of external beam radiation therapy delivered to the macula of an affected eye vs observation only. SETTING: Three United Kingdom-based hospital units. PARTICIPANTS: Patients with age-related macular degeneration, aged 60 years and older, who had subfoveal choroidal neovascularization and a visual acuity of 20/200 (logMAR 1.0) or better. METHODS: Two hundred three patients were randomly assigned to radiotherapy or observation. Treatment was undertaken at designated radiotherapy centers, and patients assigned to the treatment group received a total dosage of 12 Gy of 6-mV photons in 6 fractions. Follow-up was scheduled at 3, 6, 12, and 24 months. After excluding protocol violators, the data from 199 patients were analyzed. MAIN OUTCOME MEASURES: The primary outcome measure was mean loss of distance visual acuity in the study eye at 12 and 24 months. Other outcome variables analyzed were near visual acuity and contrast sensitivity. The proportions of patients losing 3 or more or 6 or more lines of distance and near acuity and 0.3 or more or 0.6 or more log units of contrast sensitivity at each follow-up were also analyzed. RESULTS: At all time points, mean distance visual acuity was better in the radiotherapy-treated group than in the control group, but the differences did not reach statistical significance. At 24 months, analysis of the proportions of patients with loss of 3 or more (moderate) (P =.08) or 6 or more (severe) (P =.29) lines of distance vision showed that fewer treated patients had severe losses, but there was no statistically significant difference between groups. For near visual acuity, although there was no evidence of treatment benefit at 12 and 24 months, a significant difference in favor of treatment was present at 6 months (P =.048). When analyzed by the proportions of patients losing 3 lines of contrast sensitivity, there was a significant difference in favor of treatment at 24 months (P =.02). No adverse retinal effects were observed during the study, but transient disturbance of the precorneal tear film was noted in treated patients. CONCLUSION: The results of the present trial do not support the routine clinical use of external beam radiation therapy in subjects with subfoveal choroidal neovascularization in age-related macular degeneration.

Stanga PE, Kychenthal A, Fitzke FW, Halfyard AS, Chan R, Bird AC, Aylward GW. · The Institute of Ophthalmology, University College London, UK. · Int Ophthalmol. · Pubmed #11944854 No free full text.

Abstract: PURPOSE: To test the feasibility of a new surgical technique, and to assess visual function over the translocated retinal pigment epithelium (RPE) cells in patients operated upon for subfoveal choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD). MATERIALS AND METHODS: Six patients presenting previously untreated exudative AMD underwent surgical excision of the subfoveal CNV with RPE translocation and were followed from 1 to 10.5 months. The surgery consisted of a standard three port pars plana vitrectomy (TPPPV), excision of the CNV and RPE translocation. Pre and post-operative ocular examination included best-corrected visual acuity measurement, fundus color stereo photography and fundus fluorescein angiography. Optical coherence tomography (OCT) and confocal laser scanning ophthalmoscopy (cLSO) were performed post-operatively. A cross fixation target and a single-point flashing light were projected on different areas of the posterior pole using a cLSO. Photopic 10-2 perimetry, photopic fine matrix mapping, cLSO microperimetry were also performed pre and post-operatively in four patients. OCT cross-sectional scans and cLSO RPE autofluorescence were recorded to detect the presence of viable translocated RPE. Visual acuity, fixation, photopic 10-2 perimetry, photopic fine matrix mapping and cLSO microperimetry were tested for the presence of central visual function. RESULTS: RPE could be effectively translocated at the time of CNV removal from the edge of the RPE defect to a subfoveal location. OCT showed the translocated RPE as an area of increased optical reflectivity with optical shadowing external to it. cLSO showed autofluorescence of the translocated RPE. The cross fixation target was seen when projected on the translocated RPE. During eccentric fixation, the patients could see a flashing point-target projected on the translocated RPE. Photopic 10-2 perimetry, photopic fine matrix mapping and cLSO microperimetry showed presence of central visual function. CONCLUSIONS: The authors propose that translocation of RPE at the time of CNV removal, from the edge of the RPE defect to a subfoveal location, may have a role in the surgical management of AMD.

Lois N, Owens SL, Coco R, Hopkins J, Fitzke FW, Bird AC. · Medical Retinal Service, Moorfields Eye Hospital, London, England. · Am J Ophthalmol. · Pubmed #11860971 No free full text.

Abstract: PURPOSE: To describe fundus autofluorescence (AF) patterns and their change over time in patients with age-related macular degeneration (AMD) and high risk of visual loss participating in the drusen laser study (DLS). DESIGN: Randomized clinical trial. METHODS: The study population consisted of 29 patients (35 eyes) participating in the DLS, which is a prospective, randomized, controlled clinical trial of prophylactic laser therapy in patients with AMD and high risk of neovascular complications. The intervention consisted of 16 eyes having prophylactic laser and 19 receiving no treatment. The main outcome measures were changes in the distribution of drusen and AF. Patients were reviewed for a median follow-up or 24 months (range 12-36 months). RESULTS: At baseline, four patterns of fundus AF were recognized: focal increased AF (n = 18), reticular AF (n = 3), combined focal and reticular AF (n = 2), and homogeneous AF (n = 12). At last follow-up, fundus AF remained unchanged in 15 untreated (78%) and in seven treated (43%) eyes. In only one untreated eye, focal areas of increased AF returned to background levels and were no longer detectable at last follow-up, compared with six treated eyes. This difference was statistically significant (P =.03). Only large foveal soft drusen (drusenoid pigment epithelium detachments) consistently corresponded with focal changes in AF, whereas no obvious correspondence was found between small soft drusen located elsewhere and changes in AF. CONCLUSION: The lack of obvious correspondence between the distribution of drusen and of AF found in this study appears to indicate that drusen and AF represent independent measures of aging in the posterior pole.

Owens SL, Guymer RH, Gross-Jendroska M, Bird AC. · Department of Clinical Ophthalmology, Institute of Ophthalmology, University of London, Moorfields Eye Hospital, United Kingdom. · Am J Ophthalmol. · Pubmed #10372878 No free full text.

Abstract: PURPOSE: Initial studies suggest that drusen associated with age-related maculopathy resolve in response to laser photocoagulation; there are conflicting reports regarding whether this treatment might prevent neovascular complications and blindness. The goal of the Drusen Laser Study is to maintain good visual acuity in eyes at the highest risk for neovascular complications of age-related maculopathy. In this report, we alert the ophthalmic community to possible laser-induced complications in patients treated within the context of this clinical trial. METHODS: A double-masked, randomized, controlled clinical trial of prophylactic macular photocoagulation for high-risk age-related maculopathy is in progress. Patients randomly assigned to treatment received a ring-type distribution of 12 light spots of argon laser photocoagulation. Drusen were treated directly only if they were present at the protocol treatment locations. Fluorescein angiography was performed in all patients at yearly review, and at nonprotocol visits if symptoms or clinical examination were suggestive of choroidal neovascularization. RESULTS: Fluorescein angiographic abnormalities suggestive of choroidal neovascularization have been seen in treated eyes only: one patient in the pilot study and six patients in the Drusen Laser Study. No fluorescein angiographic abnormalities were seen in eyes of control subjects. CONCLUSIONS: Laser photocoagulation in high-risk age-related maculopathy may induce choroidal neovascularization and, therefore, is not recommended outside the context of a randomized, controlled clinical trial.

Sallo FB, Peto T, Leung I, Xing W, Bunce C, Bird AC. · Department of Research and Development, Moorfields Eye Hospital, London, United Kingdom. · Curr Eye Res. · Pubmed #19274532 No free full text.

Abstract: PURPOSE: To determine whether grading based on the International Classification (IC) for age-related macular degeneration (AMD) allows recognition of change during the progression of the disease. METHODS: Stereoscopic color fundus photographs of 50 eyes of 25 patients with AMD and at least 5 years of review were graded in a random and masked fashion for changes over time in the characteristics of drusen, pigmentary changes, and end-stage disease, according to the system defined by the IC for AMD, by two independent graders (F.B.S., I.L.). Fundus images were also analyzed in time sequence for clinical changes by a senior grader (I.L.) and two ophthalmologists (A.C.B., T.P.) without access to the grading forms of the IC grading. Clinical change, as recorded by the IC grading and the individual analysis, were compared. RESULTS: There was 97.8% (kappa = 0.70) concordance in identification of change. In four cases, the clinical classification differed from the IC grading: Two cases of drusen and two of end-stage disease grading. Inter-observer agreement for the IC grading was 89.4% for predominant phenotype (kappa = 0.84), 89.36-91.49% for presence of choroidal neovascularization (CNV) (kappa = 0.79-0.83), 87.23-89.36% for geographic atrophy (GA) (kappa = 0.62-0.74) and 55.32% for area covered by drusen (kappa = 0.31). CONCLUSIONS: Overall, progression from earlier stages of AMD to either of the two forms of advanced AMD were reflected accurately by the IC grading in the vast majority of cases.

Heimes B, Lommatzsch A, Zeimer M, Gutfleisch M, Spital G, Bird AC, Pauleikhoff D. · Department of Ophthalmology, St. Franziskus Hospital, Hohenzollernring 74, 48145 Münster, Germany. · Graefes Arch Clin Exp Ophthalmol. · Pubmed #18509668 No free full text.

Abstract: BACKGROUND: Autofluorescence (AF) of the retinal pigment epithelium (RPE) are thought to reflect metabolic activity of the RPE cells, which in turn is largely driven by photoreceptor outer segment renewal. In exudative AMD, choroidal new vessels (CNV) may be confined to Bruch's membrane, or transgress the RPE, with consequence loss of photoreceptor cells. It has been suggested that they may be distinguished with autofluorescence imaging. The aim of our study was to analyze the prognostic value of RPE autofluorescence in relationship to the therapeutic outcome of anti-VEGF (vascular endothelial growth factor) therapy in exudative AMD. PATIENTS AND METHODS: AF images (Heidelberg Retina Angiograph) were obtained from 95 eyes (95 patients, mean age 77.64 years, 39 male and 56 female) with exudative macular lesions and associated drusen before therapy with intravitreal Bevacizumab (Avastin). Increased, normal, or decreased AF of a central area with diameters of 500 and 1,000 microm around the foveola were distinguished, and compared with the outcome of central vision. As a measure of data reproducibility (inter- and intraobserver variability), the kappa statistics (K > 0.6 "good", K > 0.8 "excellent") and exact agreement in % were calculated. RESULTS: Analysis of AF showed a significant difference in outcome of visual acuity in eyes with changes in AF of the central 500 and 1000 microm (Mann-Whitney test, p500 mum < 0.001, p1,000 microm = 0.02). Comparison of eyes with increased AF to the other eyes also resulted a significant difference in visual acuity at follow-up (p (incr) < 0.001); those with decreased AF had no significant difference to the eyes with normal or increased AF (p (decr) = 0.1733). CONCLUSIONS: The RPE-AF of exudative AMD lesions varies greatly. The AF differences probably represent different kinds of metabolism disorders in the RPE. Furthermore, they apparently have a great influence on the chances of anti- vascular endothelial growth factor (VEGF) therapy success; in particular the development of visual acuity is less favorable in eyes with initially increased central AF.

Lommatzsch A, Hermans P, Müller KD, Bornfeld N, Bird AC, Pauleikhoff D. · Department of Ophthalmology and Ophtha-Lab, St. Franziskus Hospital Münster, Münster, Germany. · Graefes Arch Clin Exp Ophthalmol. · Pubmed #18414889 No free full text.

Abstract: PURPOSE: Basal laminar and linear deposits (BLD) are associated with the development of choroidal neovascularization (CNV). Therefore, analysis of BLD composition may provide further information concerning the pathogenesis of BLD and CNV in age-related macular degeneration (AMD). METHODS: BLD in 25 specimens of surgically removed CNV were examined, using histochemical and immunohistochemical methods, for extracellular matrix proteins and their modulating enzymes, and for cell markers and proteins involved in inflammatory processes. In addition, ultrastructural electron microscopic analysis (EM) was performed. RESULTS: The chemical and structural composition of all the BLD was similar. Only the inner aspect of the BLD contained laminin and collagen IV, which corresponded to a new RPE basal lamina upon EM analysis. The extracellular matrix protein predominantly found in all layers of BLD was vitronectin, which was seen as a homogeneous material within the BLD upon EM analysis. The metalloproteinases MMP-2 and MMP-9 could only be detected in the inner aspect, while MMP-7 and TIMP-3 were observed predominantly in the outer aspect of BLD. In this area, staining for phospholipids and less intensely for neutral lipids was also visible. The labelling of complement complexes C3 and C5b-9 was intensely positive, and vascular endothelial growth factor (VEGF) was detected in all BLDs. CONCLUSIONS: Diffuse deposits such as BLD appear consistently with the development of CNV in AMD. They consist of extracellular matrix components and predominantly vitronectin. However, activated complement and VEGF could also be detected. The results of the current study may support the hypothesis that inflammatory processes are involved in the pathogenesis of BLD and CNV in AMD.

Michaelides M, Jenkins SA, Bamiou DE, Sweeney MG, Davis MB, Luxon L, Bird AC, Rath PP. · Moorfields Eye Hospital, London, England. · Arch Ophthalmol. · Pubmed #18332310 links to  free full text

Abstract: OBJECTIVES: To determine (1) detailed retinal and audiological features of probands harboring the A3243G mitochondrial DNA mutation (m.3243A>G) and their asymptomatic maternal relatives, (2) intrafamilial and interfamilial phenotypic variability, and (3) the presence of other systemic features. METHODS: Seven probands harboring the A3243G mitochondrial DNA mutation and 36 asymptomatic maternal relatives were ascertained. Participants underwent ophthalmologic examination, fundus photography, autofluorescence imaging, and audiological evaluation and completed a questionnaire. Blood samples were taken to test for diabetes, determine renal function, and screen relatives for the A3243G mutation. RESULTS: The A3243G mutation was associated with both intrafamilial and interfamilial variable expressivity regarding retinal appearance, hearing loss, diabetes, and other systemic features. The most common macular appearance in maternal relatives (one-third of those positive for the mutation) was mild abnormalities of the retinal pigment epithelium (more clearly identified using autofluorescence), which may therefore be a useful clinical indicator suggesting positive mutation status. Four probands and 13 mutation-positive relatives were found to have evidence of significant bilateral, cochlear, symmetrical age-adjusted hearing loss, predominantly affecting high frequencies. CONCLUSIONS: Hearing loss and macular disturbance were the most frequent findings in mutation-positive participants, with 95% of mutation-positive relatives having hearing loss. Diabetes was the least frequent finding. Patients with progressive hearing loss may merit ophthalmologic assessment to detect retinal abnormalities consistent with the A3243G mutation. Conversely, patients with macular features in keeping with the A3243G mutation should have audiological testing, even in the absence of diabetes or a positive family history.

Andersen MV, Rosenberg T, la Cour M, Kiilgaard JF, Prause JU, Alsbirk PH, Borch-Johnsen K, Peto T, Carstensen B, Bird AC. · Department of Ophthalmology, Rigshospitalet, University Hospital of Copenhagen and Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark. · Ophthalmology. · Pubmed #18267341 No free full text.

Abstract: PURPOSE: To examine the age- and gender-specific prevalence and describe the common phenotype of early age-related maculopathy (ARM) and late-stage age-related macular degeneration (AMD) among the Inuit in Greenland. DESIGN: Population-based cross-sectional study. PARTICIPANTS: All > or =60-year-olds born in Greenland and living in the communities of Nuuk and Sisimiut, Greenland. METHODS: The presence and form of early (ARM) and late age-related macular disease (AMD) were determined by grading color fundus photographs using the international classification and grading system for ARM and AMD. MAIN OUTCOME MEASURES: Prevalences of ARM and AMD were assessed by masked grading of fundus photographs. RESULTS: Overall, 695 persons were included in the study (response rate, 74.8%). Prevalence of any ARM was 52.3%. Age-related maculopathy was present in the worse eye in 50.0%, 58.8%, and 44.7% of age groups 60 to 69, 70 to 79, and > or =80, respectively. Prevalence of any AMD was 9.5%. Any AMD was present in the worse eye in 3.9%, 14.6%, and 43.2% of age groups 60 to 69, 70 to 79, and > or =80. Prevalences of pure geographic atrophy (GA) in one or both eyes, exudative degeneration in one or both eyes, and GA in one eye and exudative degeneration in the other eye were 2.3%, 6.1%, and 1.1%, respectively. CONCLUSIONS: The prevalence of ARM is higher than in most other populations studied, and the prevalence of AMD in the oldest age group is higher than in most other populations studied. The prevalence of exudative degeneration is higher than the prevalence of GA, in contrast to findings in some of the Nordic countries-particularly Iceland-and earlier observations in Greenland.

Audo I, Vanakker OM, Smith A, Leroy BP, Robson AG, Jenkins SA, Coucke PJ, Bird AC, De Paepe A, Holder GE, Webster AR. · Laboratoire de Physiopathologie Cellulaire Moléculaire et de la Rétine, Institut National de la Santé et de la Recherche Médicale, Université Pierre et Marie Curie, Paris, France. · Invest Ophthalmol Vis Sci. · Pubmed #17724214 links to  free full text

Abstract: PURPOSE: Pseudoxanthoma elasticum (PXE; [MIM 264800]) is an autosomal recessive systemic disorder characterized by progressive degeneration and calcification of elastic fibers in connective tissue. The phenotype is variable, with cutaneous, vascular, and ophthalmic abnormalities. The disorder is a consequence of mutations in the ABCC6 gene. Visual impairment is mainly due to neovascular complications, and retinal function is usually assumed to be normal. The purpose of this study was the objective assessment of macular and generalized retinal function in unrelated patients with clinical and/or genetic features of PXE. METHODS: Four unrelated patients carrying a clinical diagnosis of PXE presented with unexplained visual loss. After ophthalmic examination, retinal and macular function was assessed by full-field electroretinogram (ERG) and pattern ERG, respectively, according to ISCEV (International Society for Clinical Electrophysiology of Vision) recommendations. Molecular analysis of the ABCC6 gene was performed in three patients by dHPLC (denaturing high-performance liquid chromatography) and direct sequencing. RESULTS: Full-field ERG revealed significant reduction of cone and rod responses in all four patients. Funduscopic appearances varied. Three patients were found to carry ABCC6 mutations. In case 1, a novel nonsense mutation (p.L1474X) was detected in exon 31 paired with a splice-site mutation. Mutation analyses in cases 3 and 4 revealed previously reported ABCC6 mutations. CONCLUSIONS: These findings suggest that retinal dysfunction in PXE may not be uncommon. The mechanism underlying retinal dysfunction is unknown but may result from metabolic disturbance leading to retinal toxicity with a possible role of modifying genetic or environmental factors rather than specific ABCC6 mutations.

Yates JR, Sepp T, Matharu BK, Khan JC, Thurlby DA, Shahid H, Clayton DG, Hayward C, Morgan J, Wright AF, Armbrecht AM, Dhillon B, Deary IJ, Redmond E, Bird AC, Moore AT, Anonymous00259. · Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom. · N Engl J Med. · Pubmed #17634448 links to  free full text

Abstract: BACKGROUND: Age-related macular degeneration is the most common cause of blindness in Western populations. Susceptibility is influenced by age and by genetic and environmental factors. Complement activation is implicated in the pathogenesis. METHODS: We tested for an association between age-related macular degeneration and 13 single-nucleotide polymorphisms (SNPs) spanning the complement genes C3 and C5 in case subjects and control subjects from the southeastern region of England. All subjects were examined by an ophthalmologist and had independent grading of fundus photographs to confirm their disease status. To test for replication of the most significant findings, we genotyped a set of Scottish cases and controls. RESULTS: The common functional polymorphism rs2230199 (Arg80Gly) in the C3 gene, corresponding to the electrophoretic variants C3S (slow) and C3F (fast), was strongly associated with age-related macular degeneration in both the English group (603 cases and 350 controls, P=5.9x10(-5)) and the Scottish group (244 cases and 351 controls, P=5.0x10(-5)). The odds ratio for age-related macular degeneration in C3 S/F heterozygotes as compared with S/S homozygotes was 1.7 (95% confidence interval [CI], 1.3 to 2.1); for F/F homozygotes, the odds ratio was 2.6 (95% CI, 1.6 to 4.1). The estimated population attributable risk for C3F was 22%. CONCLUSIONS: Complement C3 is important in the pathogenesis of age-related macular degeneration. This finding further underscores the influence of the complement pathway in the pathogenesis of this disease.

Vaclavik V, Vujosevic S, Dandekar SS, Bunce C, Peto T, Bird AC. · Moorfields Eye Hospital, London, United Kingdom. · Ophthalmology. · Pubmed #17599415 No free full text.

Abstract: 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.

Vujosevic S, Vaclavik V, Bird AC, Leung I, Dandekar S, Peto T. · Fondazione G.B. Bietti per l'Oftalmologia, IRCCS, Via Livenza 3, 00198 Roma, Italy. · Graefes Arch Clin Exp Ophthalmol. · Pubmed #17429674 No free full text.

Abstract: BACKGROUND: Patients with age-related macular degeneration (ARMD) have several imaging techniques carried out regularly. In this study we introduce a new grading model of autofluorescence images (AF), compare it with fluorescein angiography (FFA) and digital colour fundus photos (COL) and test for inter- and intraobserver reliability. METHODS: A total of 71 eyes of 54 patients with bilateral or unilateral CNV had COL, FFA and AF, fulfilling the inclusion criterion of having all 3 types of imaging carried out on the same day or within 14 days. The grading of COL was performed by a trained grader based on the International ARM classification; FFA and AF images were independently graded by two trained retinal specialists in order to assess inter-observer reliability. Overall, 30% of all images were regraded after at least 14 days interval to assess intra-observer variability. RESULTS: The intergrader agreement was exact for classification of CNV (k = 1.00); almost perfect for FFA features (k = 0.83) and correspondence of decreased AF to COL (k = 0.94); substantial for patterns of decreased and increased AF (k = 0.80, k = 0.78), correspondence of patterns of increased AF to FFA and to COL (k = 0.78, k = 0.74) and background AF (k = 0.72); moderate for CNV diameter in FFA (k = 0.45), FFA pattern (k = 0.43), dimension of increased and decreased AF (k = 0.5, k = 0.56); fair for quality of FFA and AF images (k = 0.21, k = 0.26) respectively. The intragrader agreement varied from exact to substantial for all categories. Diffuse and reticular patterns of decreased AF and reticular pattern of increased AF correlated well, with visual acuity worse than 6/24. CONCLUSION: The combined grading system was reliable for evaluating the three imaging techniques, and might be suitable for epidemiological studies and therapeutic trials where such grading is warranted. Certain AF patterns seem to predict VA outcome better than one might have predicted based on FFA. Further studies are needed to evaluate its usefulness in clinical settings for predicting outcomes for patients receiving therapy for end-stage disease.

Trieschmann M, van Kuijk FJ, Alexander R, Hermans P, Luthert P, Bird AC, Pauleikhoff D. · Department of Ophthalmology, St Franziskus Hospital, Münster, Germany. · Eye. · Pubmed #17401321 No free full text.

Abstract: PURPOSE: Clinical investigations have demonstrated variation in both the peak optical density and the spatial distribution of macular pigment. To confirm these impressions histologically, the present study examined the distribution of macular pigment in the human retina. MATERIALS AND METHODS: The macular retina of 11 donor eyes of different ages (28-91 years) were examined histologically on 100 microm vibratome sections directly, without further staining. Measurements were made in two dimensions: (1) adding the number of macular sections with visible macular pigment, and (2) direct measurement of the extension of macular pigment in the foveolar section, which visibly contained the most macular pigment. RESULTS: The measurements with two methods demonstrated good correlation. The macula demonstrated a variation in the spatial extension of the visible macular pigment between 200 and 900 microm diameter around the centre of the fovea, which was also found when direct measurements were taken. There was no correlation with the donor age. The main location of macular pigment was in the layer of the fibres of Henle in the fovea and in the inner nuclear layer at the parafoveal site. CONCLUSIONS: Histologically, a wide variation of the spatial distribution of macular pigment was found that confirms clinical observations. The primary localization of human macular pigment is in the inner retinal layers.

Lengyel I, Flinn JM, Peto T, Linkous DH, Cano K, Bird AC, Lanzirotti A, Frederickson CJ, van Kuijk FJ. · Division of Pathology, Institute of Ophthalmology, 11-43 Bath Street, University College London, and Department of Research and Development, Moorfields Eye Hospital, London EC1V 9EL, UK. · Exp Eye Res. · Pubmed #17313944 No free full text.

Abstract: One of the hallmarks of age-related macular degeneration (AMD), the leading cause of blindness in the elderly in Western societies, is the accumulation of sub-retinal pigment epithelial deposits (sub-RPE deposits), including drusen and basal laminar deposits, in Bruch's membrane (BM). The nature and the underlying mechanisms of this deposit formation are not fully understood. Because we know that zinc contributes to deposit formation in neurodegenerative diseases, we tested the hypothesis that zinc might be involved in deposit formation in AMD. Using zinc specific fluorescent probes and microprobe synchrotron X-ray fluorescence we showed that sub-RPE deposits in post-mortem human tissues contain unexpectedly high concentrations of zinc, including abundant bio-available (ionic and/or loosely protein bound) ions. Zinc accumulation was especially high in the maculae of eyes with AMD. Internal deposit structures are especially enriched in bio-available zinc. Based on the evidence provided here we suggest that zinc plays a role in sub-RPE deposit formation in the aging human eye and possibly also in the development and/or progression of AMD.