Chronic Kidney Disease has become oneof the big burdens to the world and its major causes are increasing incidenceof diabetes, hypertension, obesity and the sedentary life style. CKD accordingto K/DOGI is defined as abnormalities of kidney structure or function, presentfor more than 3 months, with implications for health and is classified intovarious stages on the basis of cause, GFR, and albuminuria. The worldwideprevalence of CKD is estimated to be 8-16% 1.
Leading cause of CKD isdiabetic kidney diseases approximately 40% and others are non-diabetic renal disease (NDRD) causeswhich includes mainly immunoglobulin A (IgA) nephropathy in Asian populationand focal segmental glomerulosclerosis (FSGS) in western countries 2.CKD being an inflammatory disease hasimpact on all the aspects of the body. It has effect on the vessels especiallythe microvasculature 3.The Patients with chronic kidneydisease experience co-morbid illnesses, includingcardiovascular disease (CVD) and retinopathy 4. Our findings may provide evidence thatpresence of retinopathy reflect early subclinical damage in the renalmicrovasculature that is subsequently associated with development of renaldisease. So it becomesvery important to early recognize the condition and take measures to avoid theprogression and complications of the disease.Retinopathy is defined as presence of retinalmicro vascular abnormalities (micro aneurysms, hemorrhages, hard and softexudates or arteriovenous nipping, focal arteriolar narrowing, or lowestquartile arteriole-venue ratio). The retinal micro vascular examination iseasiest way to visualize the micro vascular changes in human body and retinalvasculature may reflect similar changes in renal vasculature.
Micro vascular abnormalitieshave been suggested to represent early pathological abnormalities in thekidney.5 However, such microvascular changes occurring in the glomerular vascular bed cannot be visualizeddirectly and non-invasively 6. Retinal and renal circulations share similar anatomic andphysiologic characteristics, 7, 8, and 9. The retinal microvasculatureprovides an opportunity to study the renal microvasculature Many renal diseasesalso have characteristic retinal features. This is particularly true ofinherited renal disease because the inner retina and glomerular filtrationbarrier share developmental pathways 10 and structural features 11,including ciliated epithelial cells 12, basement membranes comprising ?3?4?5 collagen IV, and theextensive capillary beds seen in the choriocapillaris and glomerulus 13.
Retinal abnormalities in inherited renal disease include drusen (Alportsyndrome, dense deposit disease), coloboma (reflux nephropathy), retinitispigmentosa (nephronophthisis; Myopathy, Encephalopathy, Lactic Acidosis,Stroke-like episodes MELAS syndrome), crystal deposits (oxalosis,cystinosis), and vascular anomalies (Hereditary Angiopathy, Nephropathy, andmuscle Cramps syndrome; Fabry disease) 14, 15. Retinal effects inacquired renal disease include vasculitis and infarcts in systemic lupuserythematous, Wegener granulomatosis and microscopic polyangitis 16, 17,and possibly central serous retinopathy in Goodpasture syndrome, in whichantibodies bind to the internal limiting and Bruch membranes 18. Non-invasively Ocularphotography may provide a noninvasive method to assess the vascular conditionof the kidneys 19. There isincreased prevalence of retinopathy in patients with CKD 20.
Variousstudies have been done to show the co-relation between retinopathy and CKD. Astudy conducted by SabanayagamC et al in adults of Malay ethnicity aged 40-80 yearsliving in Singapore showed that retinopathy was found to be positivelyassociated with both estimated glomerular filtration rate (eGFR) andmicro/macro albuminuria and that retinal arteriolar narrowing is associatedwith chronic kidney disease, independent of diabetes and Hypertension 21.Juan E.
Grunewald et al inchronic renal insufficiency study showed that 11% of non-diabetic and 49percentage of diabetic CKD patients has retinopathy 22. Anotherstudy conducted by Wang TJ et al in Taiwan showed that patientswith CKD had significantly higher prevalence of retinal disorders and other eyeproblems i.e. 16.62% 23. Moreover, it has already been suggestedfor regular retinal examination in the patients of CKD because CKD isassociated with progression of retinal micro vascular changes 24.
Withthe age there is degeneration of macula but with CKD, there is early maculardegeneration occurs25. Cardiovascular events are the major causes of mortality inCKD patients. Ana C. Ricardo et al conducted a study in USA for knowing majorcauses of mortality and compared normal with those having CKD and retinopathy andfound that cardiovascular or other causes of mortality were 1.02% withretinopathy, 1.
52% with CKD, and 2.39% with both CKD and retinopathy 26. So retinopathy can bepredictor for defining the prognosis of cardiovascular events in CKD patients. Presence of retinopathy reflect earlysubclinical damage in the renal microvasculature which may lead to thesubsequent development of renal disease so Retinalmicrovscular changes may precede the development of overt proteinuria and renalfailure and.
Intervention at this level may retard theprogression of CKD and associated complications. This study will help us to get ideaabout the correlation of retinopathy with various stages of CKD and itsmanagement to be done.