|Year : 1979 | Volume
| Issue : 3 | Page : 6-8
Colour vision in diabetes mellitus
AK Sinha1, RPS Bhatia2
1 Nehru Institute of Ophthalmology, and Research, Sitapur Eye Hospital, Sitapur (U.P.), India
2 Lecturer in Ophthalmology, I.M.S., Banaras Hindu University, Varanasi (U.P.), India
A K Sinha
Nehru Institute of Ophthalmology and Research, Sitapur Eye Hospital, Sitapur (U.P.)
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Sinha A K, Bhatia R. Colour vision in diabetes mellitus. Indian J Ophthalmol 1979;27:6-8
Diabetes, a complex metabolic disorder is frequently encountered in ophthalmic practice. Well documented reports on colour vision defects in diabetes mellitus are very few. An analysis of such defects has recently been done by Kinnear et al, who found colour discrimination among diabetics was poorer than comparable non-diabetic population.
We examined the state of colour vision in seventy three diabetics and the following material compares the performance of those without retinopathy v/s those with retinopathic changes.
| Material and Methods|| |
In the present study, forty non-diabetics, forty diabetics without retinopathic changes (80 eyes) and thirty three with retinopathic changes (66 eyes) were examined. A detailed history regarding duration of diabetes, state of control, familial incidence of diabetes and colour defects were taken. Patients giving mildest indications about colour defects in family and/or with gross impairment of vision were excluded from this study. The state of colour vision in each eye was recorded with the help of Ishiahara test charts for colour vision and Tokyo Medical College Colour vision charts, Umazume.
The same was also examined in forty normal subjects, well matched for age and sex to diabetic group. The examinations were done with normal pupil and in strict accordance with instructions manual supplied with the tests. Each eye was tested on two occassions and the results averaged. A detailed ocular examination was done in each case, including assessment of visual acuity, intra-ocular tension and biomicroscopy. The fundus examination was done after dilating the pupil by 10% Drosyn. On the basis of fundus findings the diabetics were further divided into Group-A (Diabetics without retinopathy) and Group-B (Diabetics with retinopathy).
| Observations|| |
None among the normal non-diabetic subjects (40) were found to have defective colour vision. However, diabetic subjects showed some defects and the data on colour vision from the diabetics without retinopathy (Group-A) and those with retinopathy (Group-B) is summarised in [Table - 1],[Table - 2].
In Group-A (Diabetics without retinopathy) thirty nine patients i.e. 78/80 eyes (97.5%) had normal colour vision while only one case i.e. 2/80 eyes (2.5%) revealed a Tritan type of defect.
In Group-B (Diabetics with retinopathy) twenty nine patients i.e. 58/66 eyes (87.9%) had normal colour vision while four patients i.e. 8/66 eyes (12.1%) showed a Tritan type of defect. Definite Deutan or Protan defects were not revealed by any of the subjects included in this study, although two diabetic subjects showed slight hesitation with a few plates. It was further observed that no patient had any complaint about colour defect.
| Discussion|| |
Colour vision defects were not studied in diabetics for a long time. Various workers analysed colour vision in diabetics and reported an abrasion towards blue-spectrum Cox; Francois, Verriest; Linksz; Rubin; and Kinnear et al.
The mechanism and causation of defective colour perception in diabetics is a matter of conjuncture. In fact the complexities of diabetic retinopathy as well as the associated defects of colour perception are little understood and theoretically a discolouration of lens, Ruddock pre-mature senility, Varriest; Kinnear; disturbances of cone pigments, Krill and Fishman; faulty perception or transmission owing to the pathological changes in neurones Bloodworth; may individually or collectively contribute to loss of brightness or colour perception. The colour vision defects in diabetics have recently been well documented by Kinnear et a1 who reported a very high incidence of yellow-blue losses among diabetics even without retinopathy. However, they found the mean red green losses within normal limits in diabetics even with retinopathic changes. In our present study we found only one patient with Tritan defect in Group-A, i.e. diabetics without retinopathic changes. However an appreciable number of Tritan defect was noted in diabetics with retinopathic changes i.e. Group-B. Protan and Deutan defects were not revealed by any diabetic patient.
Our observations, thus, were in partial agreement with that of Kinnear et al probably due to different technique of colour vision recording employed in the two studies. The study, however is incomplete in true sense but it is apparent that Tritan defects are more common in diabetics with retinal involvement and colour vision testing should be utilised as an adjunct in evaluating patients with diabetes.
| Summary|| |
In the present study seventy three diabetics were examined for their state of colour perception. Forty normal non-diabetic individuals well matched for age and sex with diabetics, were also examined for the same. A significant Tritan defect was noted in diabetics with retinopathic changes. No significant colour perception defect was noted in diabetics without retinopathy.
| References|| |
Bloodworth, J.M.B., 1962, Jr. Diabetics, 11, 1.
Cox, J., 1961, Brit. Jour. Physiol. Ophthal., 8,
Francois, J., Verriest, G. 1961, Vision. Res., 1,
Francois, J., 1963, Bull. Soc. Belg. Ophthal., 134,
Ishihara, S., Tests for Colour Blindness; Kanchara Shuppan Co. Ltd. Japan. 1970.
Kinnear, P.R., Aspinall, P.A. and Lakowaski, R., 1972, Trans. Ophthal. Soc. U.K., 92,
Krill, A.E. and Fishman, F.A., 1971, Trans. Amer. Acad. Ophthal., 75,
Lakowski, R., Aspinall, P.A. and Kinnear, P.R., 1972, Ophthal. Research., 4,
Linksz, A., 1971, Trans. Amer. Acad. of Ophthal., 75,
Ruddock K., 1965, Vision. Res., 5, 37.
Ramsay, J.W., Ramsay C.R., Purple, L.R. and Knobloch, H.W., 1977, Amer. J. Ophthal., 84,
Rubin, M.L., 1971, Trans. Amer. Acad. Ophthal., 75,
Umazume, K., Tokyo Medical College Colour Vision Test, Murakame Colour Research Lab. Tokyo (1957).
Verriest, G., 1964, Bull. Acad. Roy. Med. Belg., 45,
[Table - 1], [Table - 2]