[Changes in the lens epithelium of diabetic and non-diabetic patients with various forms of opacities in senile cataract].

BACKGROUND

The crucial role of the lens epithelium with respect to cataractogenesis has to be further evaluated. In this prospective clinical study, morphological characteristics of human lens epithelium in type-II diabetics and nondiabetics were examined and compared.

MATERIALS AND METHODS

30 (16 female, 14 male, mean age 73.0 years) of the overall 59 patients with age-related cataract suffering from type-II diabetes were assigned to group I and 29 nondiabetics (16 female, 13 male, mean age 68.2 years) to group II. Age, gender, type of cataract and the blood parameters fasting blood sugar and glycolized hemoglobin were further parameters. The different types of opacities (LOCS II) were summarized into 4 groups. After surgery the collected hematoxylin-eosin stained anterior central lens capsules with attached lens epithelial cells were analyzed by light microscope for the cell parameters cell density (morphometry), nucleus area (A0), nucleus volume (V), cell area (A) and nucleus-plasma-ratio.

RESULTS

The mean cell density in type-II diabetics (group I) is 3691 +/- 346 cells/mm2 and in nondiabetics (group II) 4162 +/- 504 cells/mm2, respectively (p = 0.001). The total female mean cell density (4036 +/- 525 cells/mm2) was not significantly higher than the male (3788 +/- 412 cells/mm2). A decrease of the mean cell density could be attributed to age only in the nondiabetic group. With regard to the type of cataract the posterior subcapsular cataract shows the lowest mean cell density (3620 +/- 333 cells/mm2) and the nuclear cataract (4250 +/- 513 cells/mm2) the highest, respectively. The medium nucleus area and -volume and cell area are in the type-II diabetic group significantly larger than in nondiabetics. With regard to the type of cataract the posterior subcapsular opacity has the significantly largest values. The medium nucleus-plasma-ratio in type-II diabetics is lower than in nondiabetics and decreased with age.

CONCLUSIONS

The significantly lower mean cell density in type-II diabetics compared with nondiabetic eyes and in posterior subcapsular cataracts in comparison with nuclear and cortical cataracts seem together with the other morphological cell characteristics to be due to the cataractogenic influence of diabetic metabolic disorder on the lens epithelium, especially in cases of posterior subcapsular opacity. These may be some clues for the primary cataractogenic importance of the lens epithelium in type-II diabetes.