Retina-Vitreous
2007 , Vol 15 , Num 2
Evaluation of Visual Function in Cases with Diabetic Retinopathy by Neutral Density Filter and Tests of Binocularity
1S.B. Hınıs Devlet Hastanesi, Erzurum, Uzm. Dr.2S.B. Ankara Atatürk Eğit. ve Araşt. Hast. 1.Göz Kliniği, Ankara, Uzm. Dr.
3S.B. Ankara Atatürk Eğit. ve Araşt. Hast. 1.Göz Kliniği, Ankara, Asist. Dr.
4S.B. Ankara Atatürk Eğit. ve Araşt. Hast. 1.Göz Kliniği, Ankara, Şef Yard., Doç. Dr.
5S.B. Ankara Atatürk Eğit. ve Araşt. Hast. 1.Göz Kliniği, Ankara, Şefi, Prof. Dr. Purpose: To evaluate the role of neutral density filter and test of binocularity to detect visual function changes in early diabetic retinopathy and to study the prospect of these tests in diabetic retinopathy follow-up.
Materials and Methods: A total of 131 cases (262 eyes) were included in this study. Control group (Group I) was consisting of 45 healthy cases. There were 86 cases with diabetic mellitus. Diabetic cases were separated into 3 groups. Cases in Group II were cases with diabetes mellitus but without any diabetic retinopathy. Cases in Group III were cases with diabetes mellitus and non-proliferative diabetic retinopathy. Cases in Group IV were cases with diabetes mellitus and proliferative diabetic retinopathy. Visual acuity testing at different levels of luminance were performed by neutral density filters (NDF). Binocularity of cases were tested by near stereopsis, stereopsis at far, Worth 4 dot test (W4DT), and Bagolini. NDF values decreasing visual acuity less than 0.9 log unit were accepted as positive.
Results: Difference with regard to sex, laterality and type of diabetes mellitus between groups was not statistically significant (p=0.388, p=0.380, p=0.377). Difference between groups in NDF values decreasing visual acuity was statistically significant (p=0.001). Although difference of NDF values decreasing visual acuity between Group I and II was statistically insignificant (p=0.131), difference between Group I and III (p=0.001) and between Group I and IV (p=0.001) were statistically significant. Also the differences between Group II and III (p=0.002) and between Group II and IV (p=0.002) were statistically significant. There was no statistically significant difference between Group III and IV (p=0.470). There was no statistically significant difference between group I and II with regard to near and far stereopsis (p=0.023, p=0.029). Responses to far W4DT was positive in all cases both in group I and II. However 5 cases in group III (13%) and 11 cases (50%) in group IV have negative far W4DT. The difference between group III and IV was significant (p=0.01). All cases in group I, II and III have positive near W4DT responses. But 3 cases in group IV have negative responses. Bagolini test responses were all positive in all of the cases.
Conclusion: It might be concluded that NDF and binocularity tests may not be accurate in diagnosis of early functionally changes in diabetic patients, however this test could be helpful in follow up diabetic cases. Keywords : Neutral density filter, diabetic retinopathy, binocularity