Organ transplantation has evolved over many years. Renal transplantation has become a very successful and routine procedure in now a days. With near optimal rates of transplant patient and allograft survivals, the focus has shifted to the alleviation of complications that can improve outcomes. Advances in surgical technique and development of more effective immunosuppressive agents have rendered kidney transplantation an effective renal replacement therapy. Pharmacologic immunosuppressant like steroids, cyclosporine and tacrolimus has played a major role in the advancement of these transplantation procedures. However, immunosuppressant has been shown to carry the risk of many complications.
Ocular complications following renal transplantation are mainly secondary to age, immunosuppressive therapy(Steroids) and the cause of the underlying renal disease (Diabetes(DM),Hypertension(HPN)) and accumulation of noxious materials(1).There are many studies mentioning that most of the ocular complications following renal transplantation are recognized as secondary to immunosuppressive drugs, especially to the use of corticosteroids (2-5). Steroid induced cataract is a common ocular complication that occurs in post renal transplant patients. It can be seen in as high as 62.5% of cases(2).There were studies on the relationship between the occurrence of posterior sub-capsular cataract (PSC) and total doses of steroids(4,6,7). The magnitude of PSC cataract and the amount of steroids was statistically significant( 55.3% with high-dose steroids, 28.2% in the low-dose steroid group and 6.2% in those who received no steroids). Grading the severity of PSC showed a significant correlation between the degree of PSC and the steroid therapy(6). Increased intraocular pressure was found in 12.5%(2) and 20% (8) of all the renal transplant cases. Dialysis time before transplantation was shown to have a significant influence on ophthalmic complications that happen to occur after transplantation, and the longer the dialysis time before transplantation is the higher rate of glaucoma(1). Anterior segment problems seen in post renal transplant patients were conjunctival degeneration 36.6%, posterior sub-capsular cataracts 24%, pinguecula 17.3%(9).There are also interesting posterior segment findings with different descriptions found in different studies. Pigmentary changes in the choroid and retinal pigment epithelium was seen in transplant cases (4,8,9) as high as 14%(9). This may result in loss of vision caused by serous retinal detachment .
Retinal vein occlusions seen in 3.3%(9), 1.4%(2). Arteriovenous crossing changes in 8.6%, proliferative diabetic retinopathy(PDR) in 6%, central serous chorioretinopathy in 3.3%, and non-proliferative diabetic retinopathy(NPDR), optic nerve atrophy and diabetic macular edema each in 2.7%(9). In another study with different description micro aneurysms, preretinal wrinkling, serous detachments of the retina, hemorrhages and exudates-were observed(8). Renal transplantation stabilized Diabetic retinopathy status in the majority of diabetic patients(60%) though other co-morbid factors such as hypertension, lipid profile, and pre-existing retinopathy status have a significant contribution for the final outcome(10).There are reports that the systemic small vessel disease such as diabetes seen in end-stage renal failure does not normalize after renal transplantation(11).
Cyclosporine is one of the commonly used immunosuppressive drugs used for renal transplant patients. Occipital white matter appears to be uniquely susceptible to the neurotoxic effects of cyclosporine(12). It is also implicated in the development of optic nerve head oedema and in some cases associated with pseudotumour cerebri (13). Bilateral or unilateral sixth nerve palsies and bilateral ptosis were also seen in patients who were on cyclosporine after transplant(14). Some experience visual loss after renal transplantation and cyclosporine therapy(15). Cortical blindness is also mentioned as a cause of visual loss for bone marrow transplant patients who were on cyclosporine (16). Tacrolimus is a relatively new immunosuppressive agent that is particularly indicated in liver transplantation and bone marrow transplantation. It is also used in renal transplant patients these days. It is mentioned as a cause of cataract due to an accumulation of sorbitol in the lens secondary to the diabetogenic effect of the drug. It is supposed that cataract would not develop with tacrolimus if diabetic parameters are under control(17). The other new immunosuppressive agent used and show a promise in graft survival is MMF(mycophenolate mofetil).
Opportunistic infections like cytomegalovirus ocular infection and herpes simplex ocular infections are the other problems detected in these group of patients(18). CMV infections were seen in 2.8% (2), 5% (5),8%(8) of renal transplant cases and it was attributable to the immunosuppressive drug therapy(5). Blindness and deafness are also reported secondary to other opportunistic infections like meningocerebral cryptococcosis after kidney transplantation.(19) Mucormycosis is an extremely rare complication following kidney transplantation. Augmented immunosuppression, especially with corticosteroids, anti-rejection therapy, older age and PTDM are found to be the main predisposing factors for the infection( 20).Saint Paul’s Hospital Millennium Medical College is a pioneer in providing major organ transplant like kidney transplant in Ethiopia. Very few patients had the opportunity to receive the service. Even if this is a life changing and exiting addition to the countries health service coverage, its long term outcomes including various complications is not yet assessed. Though visually significant ocular complications such as cataract or increased intraocular pressure observed frequently after renal transplantations, attention to eye check up is uncommon in post transplant patients. Therefore, the aims of this study is to describe ocular findings in renal transplant recipients at St .Paul's Hospital Millennium Medical college.