RESUMEN
Background: Diabetic retinopathy is the most common cause of blindness in industrialised nations and the incidence of diabetes is expected to rise over the next 10 years. Early treatment of proliferative diabetic retinopathy and diabetic maculopathy improves visual outcome and with effective screening, blindness could be reduced. Patients suffering from diabetes mellitus show alterations in their colour perception. Colour vision testing provides a sensitive, non-invasive method to assess macular damage in diabetic retinopathy and any deterioration in colour vision often precedes changes in other clinical measures such as visual acuity and morphological changes. Optical coherence tomography (OCT) provides cross-sectional images of the retina, information concerning internal retinal structure as well as reproducible measurements of retinal thickness. Aims & Objective: This study was intended to examine the relationship between macular thickness on OCT (Optical coherence tomography) and colour vision deficiency patterns in diabetics. Material and Methods: A total of 100 patients with established diabetic retinopathy visiting hospital were examined and a detailed history of diabetes, duration and inability to differentiate colours was taken. Retinal examination for evidence of diabetic retinopathy and colour vision patterns on Ishihara colour vision chart were noted. OCT was performed on these patients. Results: 21% (21 out of 100) of patients under study showed a gross deficiency of red green pattern of colour blindness. The colour vision deficiency increased with increasing macular thickness. Macula thickness on OCT in subjects varied from 188 to 462 microns. The average macular thickness of patients with total colour vision deficiency was 290 microns that with red green was 274 micron and those without any colour vision deficiency was 228. Prevalence of colour vision deficiency increased with duration of diabetes and severity of retinopathy. Conclusion: Higher prevalence of red green colour blindness was observed in patients of diabetes with macular oedema. Impaired colour vision was more in patients with macular thickness above 228 micron.
RESUMEN
Background: There were 31.7 million diabetics in India in year 2000 with a projection to reach 79.4 million by year 2030. We must identify and treat high-risk persons before severe loss of vision occurs. We doctors of all specialities have to strive together to create awareness of the importance of routine eye evaluation for all diabetics as this blindness is largely irreversible once set in. Visual impairment as a result of Diabetic Retinopathy (DR) has a significant impact on patients’ quality of life. In communities in which intensive retinopathy screening programmes have been implemented, rates of vision loss have decreased. There is a need to increase the awareness among doctors of all specialities on the importance of retinal examination by ophthalmologists even in well controlled diabetics. Aims & Objective: A survey to assess the practice patterns among doctors about diabetic retinopathy referral, its complications, treatment modalities and the knowledge about timing of referral to ophthalmologists. Material and Methods: Questionnaires consisting of 16 questions pertaining to general awareness, clinical manifestations, complications and treatment was given to doctors in two sections A and B. Answers were analysed and tabulated. Results: 36 doctors of various specialities participated in the survey. 19.4% of doctors felt there was no need to refer all diabetics routinely for fundus examination. 80.6% (29 of 36) of doctors were regularly referring all diabetics to ophthalmologist, where as 19% did not. 86.1% of the participants felt there was no need to worry about retinopathy if blood sugar levels were controlled. Amongst the participants 75% were well aware of DR, its presentation, complications and 88.9% about its treatment. Conclusion: Diabetic retinopathy still is not well understood among general doctors and non-ophthalmologists. It is therefore advisable to educate consultants about the severity of the problem and need for early referral to prevent complications. General Practitioners can be educated about the timing to seek expert opinion for treatment.
RESUMEN
Background: Diabetic retinopathy causes vascular complications of retina causing blindness. Macular edema is the crucial cause of visual impairment and may occur at any stage of diabetic retinopathy. Patients suffering from diabetes mellitus can show alterations in their colour perception. Colour vision testing provides a sensitive method to assess macular damage. Deterioration in colour vision often precedes changes in other clinical measures such as visual acuity and morphological changes. Elevated homocysteine levels play a causative role in inducing vascular endothelial cell damage and causing retinopathy in diabetics. Aims & Objective: This observational study was intended to examine if serum homocysteine is a risk factor for developing colour vision defects in diabetes and worsening of retinopathy. Material and Methods: A total of 92 patients with established diabetic retinopathy and having colour vision defects visiting hospital were examined and a detailed history of duration of diabetes was taken. Retinal examination for evidence of diabetic retinopathy and colour vision patterns on Ishihara colour vision chart were noted. OCT was performed on these patients. Results: 92 of patients with diabetic retinopathy under study had a gross colour vision deficiency. The average macular thickness on OCT of patients with total colour vision deficiency was 279 microns. Prevalence of colour vision deficiency increased with duration of diabetes and severity of retinopathy. The average serum homocysteine level in these patients was 21.98 μM/L which was above the normal range. Serum homocysteine levels ranged from 11.0 μM/L to 30.2 among males and 11.1to 41.0 in females. Conclusion: Higher prevalence of colour blindness was observed in patients of diabetes with macular oedema and high circulating serum homocysteine levels. Impaired colour vision was more in patients with average macular thickness of 228 micron and raised homocysteine levels thus suggesting it could be a possible risk factor.