When should children and young adults with sickle cell disease be referred for eye assessment?

Children and young adults who suffer from sickle cell disease (SCD) are at risk of blindness from retinopathy and other complications. The incidence of proliferative retinopathy in SCD patients varies from 5 to 10% depending on the genotype, being commoner in SC than SS and S-thal. 'Sudden' blinding sequelae such as vitreous haemmorrhage and tractional retinal detachment can eventuate from vasculo-proliferative retinal lesions, known as sea fans, in otherwise 'quiet' eyes. This risk can be minimised considerably if the lesions are detected in a timely fashion and treated, usually with laser photocoagulation and possibly with cryotherapy. This communication aims, by a review of relevant literature and through our original data, to highlight a time frame for the development of proliferative sickle retinopathy to enable paediatricians decide on an appropriate time of referral for ophthalmic assessment. Ninety patients with SCD (88 SS, 2 SC) aged 5-36 years were examined for anterior and posterior ocular signs of SCD using dilated binocular indirect ophthalmoscopy. Other relevant literature was reviewed. Twenty-four percent of these patients had some form of SCD related posterior pathology, 5.6% of which was pre-proliferative or proliferative. This included a 14-year-old SS patient with arterio-venous anastomosis. The literature reveals that patients begin to exhibit evidence of proliferative retinopathy from about the age of 10 and the frequency tends to increase with age. However, though rare, vitreous haemmorhage has been known to occur below the age of 20. Children with SCD should, from about the age of ten, be referred for at least biennial dilated binocular indirect ophthalmoscopy preferably with fluorescein angiography if such facilities are available, so that neovascular lesions can be treated before blinding sequelae occur. From the age of 20, the frequency of eye examination should increase to yearly. Antisickling remedies, such as NIPRISAN may be beneficial in prophylaxis.