Abstract
Abstract: :
Purpose: There is much interest in including cataract in genetic studies of other diseases of aging, though adequate resources may not exist to support direct examination of the lens, forcing reliance on historical information. We sought to explore the accuracy of a history of cataract and cataract surgery (self-report and for a sibling), and to determine which demographic, cognitive and medical factors are predictive of accurate medical history. Methods: The SEECAT study of the genetics of age-related cataract has to date obtained bloods and lens photographs on 132 probands (mean age 69.8 years, 59.8% female, 22.7% black) and 236 siblings (mean age 71.7, 60.6% female). All probands are questioned about a history of cataract or cataract surgery in themselves and their siblings, and siblings are also asked about their own history. Digital slit lamp and retro-illumination photographs are graded by two trained observers using the Wilmer system, with nuclear cataract ≷= grade 2 (out of 4), cortical cataract ≷= 2/16 of the lens, any PSC and/or pseudophakia/aphakia in either eye being considered a positive history for cataract. A history of systemic co-morbidities, and cognitive and physical testing are also obtained for all probands. Results: Sensitivity of a history of cataract provided for a sibling was 0.32, specificity 0.98, positive predictive value (PPV) 0.95, negative predictive value (NPV) 0.53. The performance was better for a history of cataract surgery: sensitivity 0.90, specificity 0.89, PPV 0.97, NPV 0.73. For self-report of cataract: sensitivity 0.55, specificity 0.77, PPV 0.76, NPV 0.57. Self-report of cataract surgery: sensitivity 0.94, specificity 1.0, PPV 1.0, NPV 0.98. The impact of various cutoffs for the definition of cataract will be discussed, as will the predictive value of various demographic, health and cognitive factors for an accurate medical history. Conclusion: While accurate self and family history for cataract surgery may be obtainable, it may be difficult to gather information on cataract status with acceptable sensitivity and specificity from history alone.
Keywords: 338 cataract • 420 genetics • 309 aging