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Query: UMLS:C0086543 (cataract)
 29,165 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The Lens Opacities Classification System II (LOCS II) utilizes photographic standards (two retroilluminated Neitz-CTR and one standard slit lamp Zeiss photographs) for the classification of cortical and posterior subcapsular cataracts, nuclear color and nuclear opalescence. However, dedicated photographic devices, particularly retroillumination cameras, are not always available and this study was aimed at evaluating the suitability of a retroillumination photographic technique with a standard slit lamp camera for cortical and posterior subcapsular cataract classification according to LOCS II. Two observers examined 273 eyes. Kappa statistics demonstrated that agreement between the standard slit lamp, clinical grading (according to published LOCS II methodology) and photographic grading (according to our photographic technique), as well as inter- and intraobserver reproducibility, were excellent (Kappa > 0.74) for the classification of all lenticular regions. The results indicate that a standard slit lamp camera can be as useful as a dedicated retroillumination camera when LOCS II standards are used for cataract classification.
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PMID:Suitability of slit lamp retroillumination photographs for classifying cataracts according to 'Lens Opacities Classification System II (LOCS II)'. 145 28

Inter-observer agreement on cataract diagnosis performed by two examiners was evaluated. The classification systems employed were the Japanese Cataract Cooperative Epidemiology Study Group System (Jap-CCESGS) and Lens Opacity Classification System (LOCS II). Examiner A was a highly trained specialist who has been involved in the development of Jap-CCESGS, but had no experience in the application of LOCS II. Examiner B had no experience in either system and was given explanations about both classification systems a few days before the first application. During the first examination, the inter-observer agreement using the Jap-CCESGS ranged from 37.5% to 83.3%, and the kappa values from 0.22 to 0.58. Regarding LOCS II, they ranged from 39.6% to 68.8% and from 0.18 to 0.29, respectively. Before the second examination, there was a training session utilizing both slit and retroillumination images of the previous subjects. Inter-observer agreement and the kappa value obtained from the second examination ranged from 70.1% to 93.4% and from 0.42 to 0.50 in the Jap-CCESGS and those in the LOCS II ranged from 61.3% to 94.2% and from 0.49 to 0.55, respectively. To obtain high grade results in cataract investigations that apply a unified classification system, training sessions are required.
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PMID:[Inter-observer agreement tests in cataract epidemiology surveys]. 179 70

In the field work of population-based research, 3 groups of eyes were graded by 2 observers in LOCS II. The reproducibility of LOCS II was evaluated by agreements (85%-100%) and k values (0.661-1) obtained in our study. The satisfying results show that LOCS II is not only easy to be learned and to be applied consistently by different observers, but also good reproducibility in the field work. The longitudinal cataract study is going to be performed in our plan.
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PMID:Evaluation of a lens opacities classification system II (LOCS II) in the survey population-based sample. 184 67

Data collected from 3646 eyes in the Italian-American Natural History Study of Age-Related Cataract were used to investigate whether the reliability of the Lens Opacities Classification System II (LOCS II) by the severity of the opacity that is being graded or is influenced by the presence and severity of coexisting opacities. Reliability was assessed by comparing the slit-lamp gradings of two clinical examiners (346 eyes) and the gradings performed at the slit lamp with gradings of photographs (3646 eyes). The severity of cortical and nuclear opacities did not affect the reproducibility of slit-lamp gradings, but clinical grading of posterior subcapsular opacities became more reliable as the severity of the posterior subcapsular opacities increased. More advanced coexisting opacities decreased the agreement in the slit-lamp diagnosis of nuclear, but not cortical or posterior subcapsular, opacities. Comparisons of clinical and photographic gradings showed very good to excellent agreement for nuclear and cortical opacities, regardless of the severity of the specific opacity or the severity of the coexisting opacities. Agreement in diagnosing posterior subcapsular opacities was decreased in eyes with milder posterior subcapsular opacities and in eyes with more severe coexisting nuclear and/or cortical opacities. The effect of the severity of the opacity being graded and the severity of coexisting opacities on the reliability of the LOCS II must be considered in studies that use the system to classify and grade cataracts.
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PMID:The effect of cataract severity and morphology on the reliability of the Lens Opacities Classification System II (LOCS II). 207 51

The Lens Opacities Classification System I (LOCS I) was used to classify lens opacities in the clinic-based Italian-American Case-Control Study of Age-Related Cataract. Data on the distribution of cataract types among the 1008 patients (age range, 45-79 years) are presented. A single type of cataract was found in 65% of all cases in whom both lenses could be graded. Among all patients and among patients with only one type of cataract, cortical opacities occurred most frequently and posterior subcapsular opacities least frequently. In patients with bilateral cataracts there was a high degree of concordance of cataract type and severity. The high degree of concordance of cataract type between eyes and the decreasing prevalence of unilateral cataract with increasing age suggest that patients with unilateral cataract are at high risk of developing the same opacity in the fellow eye. Cortical cataracts were found more frequently in women, and in patients with unilateral cataract, the left eye was more frequently affected. Clinic-based data on the distribution of cataract may be of assistance in planning future clinical studies of cataract.
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PMID:Distribution of lens opacities in the Italian-American Case-Control Study of Age-Related Cataract. The Italian-American Study Group. 237 79

The Lens Opacities Classification System (LOCS II) has been tested as a method for detecting and grading longitudinal changes in cataract severity. The LOCS I and II systems have already been tested and validated for cross-sectional classification of human cataracts in vivo. 130 eyes (of 68 patients) were photographed at baseline and follow-up visits with Neitz CTR and Zeiss slit photography. The mean length of follow-up was 14.7 +/- 4.4 months. The severity of nuclear opalescence (NO), cortical (C) and posterior subcapular cataract (P) was graded in a masked fashion using the LOCS II standards. Side-by-side comparisons of baseline and follow-up photos were also done in a masked fashion to detect more subtle changes than might be evident in the LOCS II gradings. The annual percent progression in cataracts graded by LOCS II standards are: (NO): 12.4%, (C): 17.9%, and (P): 6.5%. The LOCS II standards are offered as a promising subjective method for longitudinal grading of human cataractous change in vivo.
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PMID:Strategies for measuring the rate of age-related cataract formation in vivo. 248 69

The Lens Opacities Classification System II (LOCS II) has been offered for use in clinical studies of cataract. The system uses slit lamp and retroillumination photographic standards to grade lens opacities into classes of increasing severity. The authors evaluated the reproducibility and validity of LOCS II before its possible use in a natural history study of age-related cataract. The authors found excellent inter- and intraobserver reproducibility when the LOCS II standard photographs were used for clinical or photographic gradings of cataract. There was a tendency to underestimate posterior subcapsular cataracts on photographic gradings compared with slit-lamp gradings. The accuracy of the photographic gradings of posterior subcapsular opacities tended to decrease as the severity of coexisting opacities increased.
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PMID:An independent evaluation of the Lens Opacities Classification System II (LOCS II). The Italian-American Cataract Study Group. 274 17

The Lens Opacities Classification System, version II (LOCS II), uses a set of colored slit-lamp and retroillumination transparencies to grade different degrees of nuclear, cortical, and subcapsular cataract. The system uses four nuclear standards for grading nuclear opalescence and color, five cortical standards, and four subcapsular standards. The LOCS II can be used to grade patients' cataracts at the slit lamp or to grade slit-lamp and retroillumination photographs; it is easy to learn and can be applied consistently by different observers. We obtained very good interobserver reproducibility of the clinical gradings at the slit lamp, excellent intraobserver reproducibility, very good to excellent interobserver reproducibility of photographic gradings, and good agreement between clinical and photographic gradings. The LOCS II is potentially useful for both cross-sectional and longitudinal studies of cataract.
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PMID:Lens opacities classification system II (LOCS II) 240 Mar 38

The Roche European-American Anticataract Trial (REACT) will assess the effect of antioxidants on progression of cataract in humans. This report evaluates the methods used in REACT. Seventy three subjects (139 eyes) with cortical (C), posterior subcapsular (P), nuclear (N) or mixed cataract were seen twice within two weeks for eye examinations, assessments of visual function, lens photographs and CCD images. The degree of cataract and nuclear color (NC) were assessed with subjective (LOCS III) and objective (computerized, CASE 2000 CCD) methods. Repeat visit values were used to calculate intraclass correlation coefficients (r1) and 95% tolerance limits (TL). A clinically significant change (CSC) was defined as one step in LOCS III. The relative power of each method to detect cataract change and sample sizes needed to achieve statistically significant results were calculated. The r1 values for visual function tests ranged from 0.76 to 0.88; if these tests of visual function were used to detect a clinically significant change in cataract severity, sample sizes of 840 to 2707 per group would be needed. The r1 values for LOCS III were 0.88 to 0.97, and sample sizes ranged from 50 to 135 per group. The r1 values for the CCD were 0.93 to 0.98, and sample sizes ranged from 1 to 42 with poorer values relating to measurement of P. We conclude that the methods used in REACT are reproducible. The analytical algorithms in the image analysis programs did not permit differentiation between C and P opacification; therefore, P cataract is best measured with LOCS III. REACT sample sizes are adequate to detect a difference of 0.2 LOCS III units/year between the mean rates of cataract progression in two groups.
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PMID:Validation of methods for the assessment of cataract progression in the Roche European-American Anticataract Trial (REACT) 884 Oct 56

Subjective and objective systems are used to quantify cataract at The Center for Clinical Cataract Research. We have described each system and its use, presented data on reproducibility and validity, and for objective systems, demonstrated the correlation to the subjective grade of the cataract as defined by the Lens Opacities Classification Systems, Versions II and III (LOCS II and III). The subjective systems are used to classify nuclear color, nuclear opalescence, cortical cataract, and posterior subcapsular cataract. Reported kappa scores for LOCS II range from 0.85 to 1.0. Intraclass correlation coefficients for LOCS III (r1) range from 0.67 to 0.94. The computerized objective system are: (1) fast spectral scanning colorimetry (FSSC) for assessment of nuclear color (r1 = 0.96 to 0.98); (2) nuclear mean density (NMD) for assessment of nuclear opalescence (r1 = 0.97); and (3) percent area opacity (anterior = a; posterior = p) (OPAC-a and OPAC-p) for assessment of cortical and posterior subcapsular cataract (r1 = 0.92 to 0.96).
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PMID:Quantitating cataract and nuclear brunescence, the Harvard and LOCS systems. 830 24


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