165. Ans. a. Immediately (Ref. Harrison 19/e p2408, 18/e p3000; Kanski's 5/e p439, 455, Parsons 20/e p294-299)If a person is diagnosed to be a diabetic on his 45th birthday, dilatedfundoscopic examination should be recommended immediately.'Ophthalmoscopic examination should be done in patients of non-insulin dependent DM (Formerly Type II DM) at the time of diagnosis. "FeatureInsulin Dependent DM (Formerly Type 1 DM)Non-Insulin Dependent DM (Formerly Type II DM)Usual Age at Diagnosis10-20 yearsQ50-70 yearsQPeriod of Latent diseaseLessQMoreQIncidence of diabetic retinopathyMore (40%)QLess (20%)QIncidence of proliferative diabetic retinopathyMoreQLessQOnsetDiabetic retinopathy rarely develops within 5 years of the onset of diabetes or before pubertyQ All most all patients with Type I diabetes (IDDM) develop retinopathy in about 15 years.About 5% of type 2 (NIDDM) diabetics have diabetic retinopathy at presentationRisk factorDuration of diabetes is most important risk factorQRisk of retinopathy increase with the duration of diabetes, accompanying hypertension and smokingQInitial examinationOphthalmoscopic examination within 5 years of diagnosisQOphthalmoscopic examination at the time of diagnosisQFollow-upThen recommendations for periodic fundus examination are as follows:* Every yearly, till there is no diabetic retinopathy or there is mild non proliferative DR (NPDR)* Every 6 monthly, in moderate NPDR* Every 3 monthly, in severe NPDR* Every 2 monthly, in PDR with no high risk characteristic* Involvement of fovea by edema and hard exudates or ischemia (diabetic maculopathy) is the MC cause of visual impairment in diabetic patientsQ particularly those with type 2 diabetes (NIDDM). Ocular Involvement in Diabetes MellitusComplications of Diabetic retinopathyOthers* Exudative maculopathy and macular edema- MC cause of visual loss in diabetic patients (specially in NPDR)Q- Manifest as metamorphopsia* Vitreous hemorrhage- Manifest as floatersQ- MC cause of visual loss in patients with PDRQ* Tractional Retinal detachmentQ- Usually asymptomatic (no photopsia and floaters) unless macula is involved* Neovascular glaucoma - rubeosis iridisQ* Early onset of senile cataract* True diabetic cataract/snowflake/snow storm cataractQ* Nerve palsy MC 3rd nerveQ* MyopiaQ because of fluid imbibitions and swelling of lens induced by hyperglycemia* Index hypermetropiaQ' (in undertreated)Management of Diabetic RetinopathyGeneral MeasuresStrict control of blood glucose may delay the onsetControl of hypertension when associated is essentialAntioxidants are also useful for diabeticsScreeningYearlyTill there is no diabetic retinopathy (DR) or there is mild NPDR (non proliferative diabetic retinopathy)Q 6 monthlyIn moderate NPDRQ3 monthlyIn severe NPDRQ2 monthlyIn PDR with no high risk characteristicsQPhotocoagulationIt is the main stay of treatmentQDouble frequency YAG (532) laser, Argon laser or diode laser is usedMacula is treated by laser only if there is clinically significant macular edemaLaser is contraindicated in ischemic diabetic maculopathyQPan retinal or Scatter laser photocoagu laiionFocal argon laser bumGrid pattern laser burns* It consists of 1200-1600 spots, each 500 pm and 0.1 sec duration* It is applied 2-3 disc areas from the centre of macula extending peripherally to equator* It Is indicated in PDR (proliferative diabetic retinopathy) with one of the high risk characteristicsQ* It is applied to individual mtcrovascular formations in the centre of hard exudates ring in focal exudative maculopathyQ* It is applied in macular area for diffuse macular edemaQPars plana vitrectomy is indicated for dense persistent vitreous hemorrhage, fractional retinal detachment and epiretinal membranes.