Macular Degeneration: Jenkins S

Sivaprasad S, Adewoyin T, Bailey TA, Dandekar SS, Jenkins S, Webster AR, Chong NV. · Laser and Retinal Research Unit, King's College Hospital, King's College London, England. · Arch Ophthalmol. · Pubmed #17420372 links to  free full text

Abstract: OBJECTIVES: To determine the role of systemic complement activation in the pathogenesis of age-related macular degeneration and to examine whether serum C3a des Arg reflects systemic complement activation, independent of individual complement component levels. METHODS: Plasma complement C3a des Arg levels and a single nucleotide polymorphism at position 402 of the complement factor H gene (CFH) were determined in 3 groups of subjects: 42 subjects with early age-related maculopathy, 42 subjects with neovascular (wet) age-related macular degeneration, and a control group of 38 subjects with no clinical evidence of age-related changes at the macula. RESULTS: The median (range) of plasma complement C3a des Arg levels in the age-related maculopathy and neovascular age-related macular degeneration groups were 52.6 (2.8-198.1) ng/mL and 60.9 (3.1-173.1) ng/mL, respectively. The levels were significantly raised compared with the control group (n = 38), which had a median (range) plasma complement C3a des Arg level of 40.3 (6.1-81.7) ng/mL (analysis of variance, P = .02). The concentration of plasma C3a des Arg did not differ significantly between those with different CFH genotypes (P = .07). CONCLUSION: Systemic activation of the complement system may contribute to the pathogenesis of age-related macular degeneration independent of CFH polymorphism. CLINICAL RELEVANCE: The results of this study may be relevant to aiming new treatment strategies toward reducing systemic low-grade inflammation.

Michaelides M, Wilkie SE, Jenkins S, Holder GE, Hunt DM, Moore AT, Webster AR. · Institute of Ophthalmology, University College London, London, United Kingdom. · Ophthalmology. · Pubmed #15953638 No free full text.

Abstract: PURPOSE: To determine the underlying molecular genetic basis of a retinal dystrophy identified in a 4-generation family and to examine the phenotype and the degree of intrafamilial variability. DESIGN: Prospective case series. PARTICIPANTS: Six affected individuals from a nonconsanguineous British family. METHODS: Detailed ophthalmologic examination, color fundus photography, autofluorescence imaging, and electrophysiologic assessment were performed. Blood samples were taken for DNA extraction, and mutation screening of GUCA1A, the gene encoding guanylate cyclase-activating protein 1 (GCAP1), was undertaken. RESULTS: All affected subjects complained of mild photophobia and reduced central and color vision. Onset was between the third and fifth decade, with subsequent gradual deterioration of visual acuity and color vision. Visual acuity ranged between 6/9 and counting fingers. Color vision was either absent or markedly reduced along all 3 color axes. A range of macular appearances was seen, varying from mild retinal pigment epithelial disturbance to extensive atrophy. Electrophysiologic testing revealed a range of electrophysiologic abnormalities: isolated cone electroretinography abnormalities, reduced cone and rod responses (with cone loss greater than rod), and isolated macular dysfunction. The 4 coding exons of GUCA1A were screened for mutations in affected and unaffected family members. A single transition, A319G, causing a nonconservative missense substitution, Tyr99Cys, segregated uniquely in all affected subjects. CONCLUSIONS: The Tyr99Cys GUCA1A mutation has been previously shown to cause autosomal dominant progressive cone dystrophy. This is the first report of this mutation also causing both cone-rod dystrophy and isolated macular dysfunction. The phenotypic variation described here exemplifies the intrafamilial heterogeneity of retinal dysfunction that can be observed in persons harboring the same mutation and chromosomal segment.

Scholl HP, Dandekar SS, Peto T, Bunce C, Xing W, Jenkins S, Bird AC. · Institute of Ophthalmology and Moorfields Eye Hospital, London, United Kingdom. · Ophthalmology. · Pubmed #14711724 No free full text.

Abstract: OBJECTIVE: To compare 35-mm stereoscopic slide transparencies with digitized nonstereoscopic images (resolution 1024x768 pixels) for grading abnormalities in age-related maculopathy (ARM) and age-related macular degeneration (AMD). DESIGN: Comparative observational case series. PARTICIPANTS: Twenty-five patients (50 eyes) with ARM and/or AMD. METHODS: Twenty-five patients with ARM/AMD in at least 1 eye were randomly selected from a large ongoing collection of clinical data and DNA in a tertiary referral United Kingdom population. Retinal photography was performed with mydriasis using the Zeiss FF-series 30 degrees fundus camera on Ektachrome slide transparency film. The images were centered on the macula. The color transparencies were then digitized. The grading process has been set up based on the International ARM Epidemiology Study Group. All images were independently graded by 3 retinal specialists. Both kappa statistics and exact agreement were calculated to assess agreement between and within observers and between the 2 master copies derived from the gradings of the color slides and digitized images. MAIN OUTCOME MEASURE: Agreement between the 2 master copies derived from the gradings obtained from stereoscopic slide transparencies and digitized nonstereoscopic images. RESULTS: For small hard and intermediate soft drusen, agreement ranged between 77% and 91% (kappa, 0.56-0.72) and 83% and 93% (kappa, 0.31-0.64), respectively, for the 3 macular subfields. Agreement for the presence of hyperpigmentation was 12% to 56% (kappa, 0.00-0.27). Agreement was 94% to 96% (kappa, 0.80-0.82) for the presence of geographic atrophy and 93% (kappa, 0.78) for the area covered. For the presence of choroidal neovascularization (CNV), agreement was 94% to 98% (kappa, 0.81-0.88), and it was 95% (kappa, 0.83) for the area covered. For individual features of CNV, exact agreement was 88% to 96% (kappa, 0.22-0.49). In 3 cases of geographic atrophy and 2 cases of CNV, the lesion was missed on digitized images. CONCLUSIONS: Because of the close agreement for most categories between the grading of stereoscopic color slides and digitized images, digitized nonstereoscopic color images prove to be useful for grading ARM and AMD.

Scholl HP, Peto T, Dandekar S, Bunce C, Xing W, Jenkins S, Bird AC. · Institute of Ophthalmology, Moorfields Eye Hospital, 162 City Road, EC1 V2PD, London, UK. · Graefes Arch Clin Exp Ophthalmol. · Pubmed #12545291 No free full text.

Abstract: PURPOSE. To introduce a revised version of the grading system established by the International ARM Epidemiological Study Group for identifying and quantifying abnormalities of age-related maculopathy (ARM) and age-related degeneration (AMD) and to investigate its reliability, specifically the inter- and intra-observer variability. METHODS. Fifty eyes of 25 patients with ARM or AMD in at least one eye were randomly selected from a large ongoing collection of clinical data and DNA in a tertiary referral UK population. Stereoscopic color fundus photographs were taken with a 30 degrees fundus camera and were centered on the macula. Presence and severity of fundus abnormalities in ARM and AMD were graded using a grid to define macular subfields and standard circles to define the size of lesions. Inter-observer variability was assessed by having three retinal specialists evaluate the color slides and intra-observer variability by re-grading the same set. RESULTS. The inter-observer agreement for all subfields was fair to substantial for small hard drusen (70-89%; kappa=0.26-0.63) and intermediate soft drusen (76-94%; kappa=0.27-0.69). Agreement ranged between 87% and 100%, between 50% and 92%, and between 78% and 100% for larger drusen, the presence of hyperpigmentation, and the presence of hypopigmentation, respectively. Agreement was moderate to almost perfect for the presence of geographic atrophy (88-98%; kappa=0.60-0.95) and substantial to almost perfect for the presence of choroidal neovascularization (84-100%; kappa=0.62-1.00). The intra-observer variability for the grading of drusen characteristics and pigmentary changes was similar in magnitude, but slightly greater for features of advanced AMD. CONCLUSION. Reproducibility was achieved using a revised version of the grading system established by the International ARM Epidemiological Study Group. This grading system may therefore be used for phenotyping of ARM and AMD.