Analysis of Internal Optical Aberrations in Eyes with Different Types of Cataract

PURPOSE: The present study investigates the patterns of internal optical aberrations in eyes with different types of cataract. METHODS: Eighty eyes of 70 cataract patients were included in the present study. Internal optical aberrations were measured with a KR-1W wavefront aberrometer before cataract operation. Types of cataract were classified into three groups; cortical, nuclear and posterior subcapsular cataracts. The differences in the results of the wavefront data of 6-mm pupil diameter zones were compared among three groups. The Kruskal-Wallis test and Mann-Whitney U test were used for comparing data. RESULTS: A total of 80 eyes consisting of 30 cortical cataracts, 30 nuclear cataracts and 20 posterior subcapsular cataracts were found. In the 6-mm pupil diameter zone, the average internal spherical aberrations by original value were 0.042 microm of cortical cataracts, -0.092 microm of nuclear cataracts and -0.109 microm of posterior subcapsular cataracts. The average internal spherical aberrations by absolute value were 0.122 microm of cortical cataracts, 0.533 microm of nuclear cataracts and 0.202 microm of posterior subcapsular cataracts. The internal spherical aberrations by original value were not statistically significantly different, but by absolute value were statistically significantly different (p = 0.003, Kruskal-Wallis test). Nuclear cataracts have a much higher positive or negative value than other cataract groups in the distribution of internal spherical aberrations by original value for each type of cataract. Other than this difference, the internal astigmatism and internal high order aberrations were not statistically significantly different. CONCLUSIONS: The change in internal spherical aberrations of nuclear cataract from the original value was larger than cortical and posterior subcapsular cataract. Therefore, nuclear cataracts have much higher positive or negative values than other cataract groups.

Epidemiology of Risk Factors for Cataract at Chang-Nyung District, Kyung-Nam Province

The epidemiologic study to evaluate the risk factors and types of cataract had been performed in 210 cataract patients and in 103 normal controls at Chang-Nyung District, Kyung-Nam Province, from September 1995 to April 1996, using the slitlamp biomicroscopy and Scheimpflug camera(EAS-1000, Nidek, Japan). All the patients were asked to fill out a questionnaire. The results obtained are as follows: 1. The most common type of cataract in Chang-Nyung District was nucleosclerotic opacity. 2. The dominant jobs were farmer and housewife. 3. The more sunlight exposure and heavy drinker were related to nucleosclerotic opacity and smoking habit also related to peripheral cortical opacity of lens. 4. The patients with diabetes mellitus were related with posterior subcapsular opacity ; those with arthritis related with nucleosclerotic opacity. 5. The patients with long-term use of herb medicine were related with peripheral cortical and nucleosclerotic opacity ; those with corticosteroid related with posterior subcapsular opacity. 6. There was no relationship between cataractogenesis and family history of cataract and parity in female. 7. The patients with nucleosclerotic opacity preferred grain and vegetables and those with posterior subcapsular opacity, fruit, meats and coffee. In conclusion, multi-factors are involved in the cataractogenesis including age, occupation, outdoor working hours, smoking, drinking habits, systemic disease, long-term used drug, family history, parity, favorite food, etc. Each factor is considered to be related to specific type of lens opacity.