Macular Degeneration: Xing W

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.

Patel PJ, Chen FK, Ikeji F, Xing W, Bunce C, Da Cruz L, Tufail A. · Moorfields Eye Hospital, London, United Kingdom. · Invest Ophthalmol Vis Sci. · Pubmed #18326734 links to  free full text

Abstract: PURPOSE: To determine the repeatability of Stratus optical coherence tomography (OCT) measures of retinal thickness and volume in patients with neovascular age-related macular degeneration (nAMD) METHOD: Fifty-one eyes of 51 consecutive patients with nAMD underwent an OCT imaging session in which two fast macular thickness map (FMTM) protocol scans sets were acquired by a single experienced operator certified for clinical trials work. Coefficients of repeatability for each of nine Early Treatment of Diabetic Retinopathy Study (ETDRS)-like regions, foveolar center-point retinal thickness (CPT) and total macular volume (TMV), were calculated. Scans were analyzed retrospectively for errors in retinal boundary placement by two observers, with revised coefficients of repeatability calculated after excluding any scan sets with significant segmentation error. RESULTS: The coefficient of repeatability for the central 1-mm macular subfield was 67 mum (23%) and was less than 75 mum for all macular subfields. There was much larger variability in the center-point thickness measure, with a coefficient of repeatability of 88 mum (32%) for the automated center-point thickness (ACPT). After excluding nine scan set pairs with significant segmentation error, the coefficient of repeatability for the central 1-mm macular subfield was reduced to 50 mum (19%). CONCLUSIONS: OCT-derived retinal thickness measurements are subject to considerable measurement variability in patients with nAMD. Changes in central macular thickness of more than 50 mum may better reflect true clinical change in scan sets without significant segmentation error and may be used to guide the retreatment of patients with nAMD in clinical trials and clinical practice.

Sivaprasad S, Ikeji F, Xing W, Lightman S. · Moorfields Eye Hospital, London, UK. · Clin Experiment Ophthalmol. · Pubmed #17997774 No free full text.

Abstract: PURPOSE: To evaluate the therapeutic effects on the different morphological patterns of uveitic macular oedema and central macular thickness using optical coherence tomography (OCT). METHODS: Retrospective observational case series. Fifty consecutive patients with a clinical diagnosis of new or recurrent macular oedema due to uveitis were examined with serial OCTs for 1 year. The correlation between different patterns of macular oedema (diffuse macular oedema, inner cystoid oedema, outer cystoid oedema, oedema involving both inner and outer layers of retina and serous retinal detachment) and change in logMAR visual acuity and the recorded variables including age, gender, systemic disease associated with uveitis, location and duration of uveitis, and duration of macular oedema were examined. Response to treatment was measured as change in logMAR visual acuity and evolution of patterns of macular oedema. RESULTS: Diffuse macular oedema, external cystoid and serous retinal detachment responded well to treatment. Cysts in the inner retinal layers were more resistant to treatment. The cysts in the outer layers disappeared faster than cysts in the inner layers in patients with cysts in both layers at baseline. Multivariate analysis showed that cystoid macular oedema (all types) (P = 0.03) and inner cystoid oedema (P = 0.031) were the variables significantly associated with final visual acuity. CONCLUSION: Assessment of patterns of uveitic macular oedema by OCT gives useful information on the prognosis. Inner retinal cystoid oedema is more resistant to treatment than any other patterns of oedema.

Owens SL, Bunce C, Brannon AJ, Xing W, Chisholm IH, Gross M, Guymer RH, Holz FG, Bird AC, Anonymous00290. · Moorfields Eye Hospital, London, United Kingdom, and the Universitätsklinikum Benjamin Franklin, Berlin, Germany. · Am J Ophthalmol. · Pubmed #16458680 No free full text.

Abstract: PURPOSE: The Drusen Laser Study evaluated macular laser to prevent choroidal neovascularization (CNV) and vision loss in high-risk age-related maculopathy (ARM). DESIGN: Prospective, interventional, randomized, controlled clinical trial in five hospital centers. METHODS: Patients in the unilateral group had neovascular ARM and drusen in the study eye. Study eyes were randomized to laser-treated or no-laser groups. For patients in the bilateral drusen group, eyes were randomized to right eye, laser or no laser; and left eye, alternative. Laser treatment comprised 12 argon spots. Outcome was best-corrected visual acuity and CNV signs, which were monitored for 3 years. RESULTS: In the unilateral group, vision loss occurred in 21 (28.8%) of 73 patients in laser vs 13 (19.7%) of 66 no-laser patients (P=.214). Incidence of CNV was 27 (29.7%) of 91 in laser vs 15 (17.65%) of 85 no-laser patients (P=.061). CNV onset was approximately 6 months earlier in laser-treated compared with no-laser patients (P=.05). In the bilateral group, vision loss occurred in six (8.3%) of 72 laser-treated vs 10 (13.9%) of 72 fellow eyes (P=.3877). CNV incidence was 12 (11.6%) of 103 in laser-treated vs seven (6.8%) of 103 fellow eyes (P=.225). There was no difference in onset of CNV. CONCLUSIONS: Results do not support prophylactic laser of the fellow eye of patients with neovascular ARM. Its role in patients with bilateral drusen remains unclear.

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.