journal article
Download Only Collection
Home
Desai, Parul; Reidy, Angela; Minassian, Darwin C
doi: 10.1136/bjo.83.8.893pmid: 10413688
AIMS/METHODS A national data collection exercise was carried out in more than 100 hospital eye service units within the UK to provide clinical and administrative information on patients undergoing cataract surgery. This included patient clinical data such as visual acuity at the time of wait listing and at the time of admission for surgery, presence of other eye disorders, other serious medical disorders, and data on waiting time and type of admission. RESULTS The profiles of the 18 454 patients aged 50 years or older are reported. Findings of particular note were as follows. At the time of wait listing for cataract surgery 31% had visual acuity of 6/12 or better, 54% had visual acuity between 6/18 and 6/60, and 15% had less than 6/60 vision. Considering those who had visual acuity of 6/12 or better at the time of wait listing, by the time of admission for surgery, the vision deteriorated to 6/18–6/60 in 33% and in a further 3% the vision deteriorated to below 6/60. In patients with moderately poor visual acuity (<6/12–6/60) at the time of wait listing, 13% had less than 6/60 vision by the time of admission for surgery. CONCLUSION This type of data collection and reporting exercise provides new material that can be used in the planning and provision of cataract surgery services in the UK.
doi: 10.1136/bjo.83.8.897pmid: 10413689
AIMS To evaluate the outcome of extracapsular cataract extraction (ECCE) and posterior chamber intraocular lens implantation (PC-IOL) in an African eye clinic during the transition from intracapsular cataract extraction to ECCE and PC-IOL. METHODS A retrospective survey of 461 consecutive operations for age related cataract with a mean follow up of 52.9 weeks (range 0–275) and a minimum follow up of 4 weeks in 87.9% of eyes. RESULTS A best corrected vision of 6/18 or better was obtained in 94.3% of eyes, and an uncorrected vision of 6/18 or better in 78.2% of eyes. Six eyes (1.5%) had a best corrected vision of less than 6/60. The visual acuity at 2 months was strongly predictive of the vision at 1 year or more after surgery. Preoperative biometry and IOL power calculation increased the proportion of eyes obtaining an uncorrected vision of 6/18 or better from 73.8% to 81.3%. Four eyes developed visually significant posterior capsule opacity. CONCLUSION ECCE and PC-IOL can give very good results in an African setting. A better visual outcome should lead to increased demand for cataract surgery, which will eventually reduce the number of cataract blind people in Africa.
Sinthanayothin, Chanjira; Boyce, James F; Cook, Helen L; Williamson, Thomas H
doi: 10.1136/bjo.83.8.902pmid: 10413690
AIM To recognise automatically the main components of the fundus on digital colour images. METHODS The main features of a fundus retinal image were defined as the optic disc, fovea, and blood vessels. Methods are described for their automatic recognition and location. 112 retinal images were preprocessed via adaptive, local, contrast enhancement. The optic discs were located by identifying the area with the highest variation in intensity of adjacent pixels. Blood vessels were identified by means of a multilayer perceptron neural net, for which the inputs were derived from a principal component analysis (PCA) of the image and edge detection of the first component of PCA. The foveas were identified using matching correlation together with characteristics typical of a fovea—for example, darkest area in the neighbourhood of the optic disc. The main components of the image were identified by an experienced ophthalmologist for comparison with computerised methods. RESULTS The sensitivity and specificity of the recognition of each retinal main component was as follows: 99.1% and 99.1% for the optic disc; 83.3% and 91.0% for blood vessels; 80.4% and 99.1% for the fovea. CONCLUSIONS In this study the optic disc, blood vessels, and fovea were accurately detected. The identification of the normal components of the retinal image will aid the future detection of diseases in these regions. In diabetic retinopathy, for example, an image could be analysed for retinopathy with reference to sight threatening complications such as disc neovascularisation, vascular changes, or foveal exudation.
George, L D; Lusty, J; Owens, D R; Ollerton, R L
doi: 10.1136/bjo.83.8.911pmid: 10413691
AIMS To determine whether software processing of digitised retinal images using a “sharpen” filter improves the ability to grade diabetic retinopathy. METHODS 150 macula centred retinal images were taken as 35 mm colour transparencies representing a spectrum of diabetic retinopathy, digitised, and graded in random order before and after the application of a sharpen filter (Adobe Photoshop). Digital enhancement of contrast and brightness was performed and a X2 digital zoom was utilised. The grades from the unenhanced and enhanced digitised images were compared with the same retinal fields viewed as slides. RESULTS Overall agreement in retinopathy grade from the digitised images improved from 83.3% (125/150) to 94.0% (141/150) with sight threatening diabetic retinopathy (STDR) correctly identified in 95.5% (84/88) and 98.9% (87/88) of cases when using unenhanced and enhanced images respectively. In total, five images were overgraded and four undergraded from the enhanced images compared with 17 and eight images respectively when using unenhanced images. CONCLUSION This study demonstrates that the already good agreement in grading performance can be further improved by software manipulation or processing of digitised retinal images.
Klevering, B Jeroen; van Driel, Marc; van de Pol, Dorien J R; Pinckers, Alfred J L G; Cremers, Frans P M; Hoyng, Carel B
doi: 10.1136/bjo.83.8.914pmid: 10413692
AIMS To describe two phenotypic variations of autosomal recessive retinal dystrophy occurring in a consanguineous family in a pseudodominant pattern, resulting from mutations in the ATP binding cassette transporter (ABCR) gene. METHODS Patients of this family underwent an extensive ophthalmic evaluation, including fundus photography, fluorescein angiography, and electroretinography (ERG). Genetic analysis comprised sequence analysis of the retina specific ABCR gene. RESULTS Five patients presented with decreased visual acuity in the second decade, central chorioretinal atrophy associated with a central scotoma, and severely decreased photopic and scotopic ERG responses. This clinical picture, which in our opinion resembles a cone-rod dystrophy (CRD), was associated with compound heterozygosity for IVS30+ 1g →t and IVS40+5g→a mutations in the ABCR gene. The four remaining patients presented with night blindness in the first decade because of a retinitis pigmentosa-like (RP-like) dystrophy. In addition to a pale “waxy” optic disc, attenuated retinal vessels and bone spicule deposits, a widespread chorioretinal atrophy was observed. The scotopic ERG was extinguished and the photopic ERG was severely diminished. Genetic analysis revealed a homozygous 5′ splice mutation IVS30+1g →t in the ABCRgene. CONCLUSION Mutations in the ABCR gene can cause clinical pictures resembling autosomal recessive RP and autosomal recessive CRD.
Bessant, David A R; Anwar, Khalid; Khaliq, Shagufta; Hameed, Abdul; Ismail, M; Payne, Annette M; Mehdi, S Qasim; Bhattacharya, Shomi S
doi: 10.1136/bjo.83.8.919pmid: 10413693
BACKGROUND Congenital microphthalmia (OMIM: 309700) may occur in isolation or in association with a variety of systemic malformations. Isolated microphthalmia may be inherited as an autosomal dominant, an autosomal recessive, or an X linked trait. METHODS Based on a whole genome linkage analysis, in a six generation consanguineous family with autosomal recessive inheritance, the first locus for isolated microphthalmia was mapped to chromosome 14q32. Eight members of this family underwent clinical examination to determine the nature of the microphthalmia phenotype associated with this locus. RESULTS All affected individuals in this family suffered from bilateral microphthalmia in association with anterior segment abnormalities, and the best visual acuity achieved was “perception of light”. Corneal changes included partial or complete congenital sclerocornea, and the later development of corneal vascularisation and anterior staphyloma. Intraocular pressure, as measured by Schiotz tonometry, was greatly elevated in many cases. CONCLUSIONS This combination of ocular defects suggests an embryological disorder involving tissues derived from both the neuroectoderm and neural crest. Other families with defects in the microphthalmia gene located on 14q32 may have a similar ocular phenotype aiding their identification.
Mauget-Faÿsse, Martine; Chiquet, Christophe; Milea, Dan; Romestaing, Pascale; Gérard, Jean-Pierre; Martin, Philippe; Koenig, Françoise
doi: 10.1136/bjo.83.8.923pmid: 10413694
BACKGROUND/AIMS Radiotherapy has been proposed as an alternative treatment for patients with subfoveal choroidal neovascularisation (CNV) that is untreatable according to macular photocoagulation study guidelines. This prospective study was designed to evaluate whether radiotherapy may affect the functional and anatomical outcome in a large cohort of patients affected by subfoveal CNV, with a follow up period up to 24 months. METHODS 212 patients (231 eyes) with newly diagnosed subfoveal CNV not amenable to laser therapy were included in this study. Two radiotherapy methods, the lateral beam technique (6 MV, 20 Gy in five fractions) and lateral arc therapy (25 MV, 16 to 20 Gy, in four or five fractions), were used. Comparisons of best corrected visual acuity (VA), fluorescein (FA) and indocyanine green (ICG) angiography, at inclusion and 6, 12, 18, and 24 months after radiotherapy were performed using univariate analysis. RESULTS A VA improvement of two or more lines was observed in 34% at 12 months, 31% at 18 months, and 32% of the eyes at 24 months. Paired comparisons of CNV areas in FA and ICG showed no significant change between baseline and each visit. However, 12 and 18 months after treatment, 47% of the eyes showed a decrease of 10% or more in CNV size both in ICG and FA. Radiation side effects included radiation retinopathy (eight eyes), optic neuropathy (four eyes), choroidal vasculopathy (five eyes), and branch retinal vein occlusion (three eyes). CONCLUSION Compared with the natural course of subfoveal CNV, the results of this prospective study suggest that radiotherapy could stabilise visual and anatomical outcome in selected cases.
Showing 1 to 10 of 36 Articles