artery occlusion, vitreous hemorrhage or retinal detachment. Intravascular occlusions may be seen in optic disc vessels. Cause Normal adult hemoglobin A molecule comprises two α and two β globin chains associated with a heme ring. Mutation at the 6th position of the beta chain is the cause of sickle cell disease. Due to sickle cell disease, vascular occlusion may occur in the conjunctiva, iris, retina, or choroid. Retinal changes occur due to blockage of retinal blood vessels by abnormal RBCs. Diagnosis Diagnostic Techniques Diagnosis is conducted in a multidisciplinary manner. The diagnosis of sickle cell disease can be confirmed by cation high performance liquid chromatography, haemoglobin electrophoresis in adolescents and adults and molecular genetic diagnosis in prenatal and neonatal populations. Anterior segment signs including the conjunctival sign and iris atrophy are ocular manifestations that are strongly indicative of sickle cell disease. Early stages of sickle cell retinopathy are asymptomatic. However, retinal changes that are diagnostic of sickle cell retinopathy can be visualized using fundoscopic examinations, retinography, fluorescein angiography and coherence tomography. Ultra Widefield Fluorescein Angiography is the gold standard for diagnosis of proliferative sickle cell retinopathy. It is an invasive method that assesses both anterior and posterior segment structures. Spectral Domain Optical Coherence Tomography and Coherence Tomography Angiography are non invasive methods of diagnosing proliferative retinopathy. Visual acuity and intraocular pressure assessments can also yield results that are diagnostic of sickle cell retinopathy. Differential diagnosis Sickle cell retinopathy should be differentiated from other retinal conditions that arise due to similar pathologies. The following differentials are classified by those pathologies. Additional causes of macular ischemia Diabetic retinopathy Retinal embolization (talc retinopathy, internal carotid artery embolism) Retinal vascular occlusion Infectious retinopathy Inflammatory diseases leading to ischemia Sarcoidosis Retinal vasculitis Intermediate uveitis Acute retinal necrosis Alternative causes of ischemic vascular disease Proliferative diabetic retinopathy Central retinal vein occlusion Branch retinal vein occlusion Ocular ischemic syndromE Radiation retinopathy Retinopathy of prematurity Unclassified causes Incontinentia pigmenti Autosomal dominant vitreoretinochoroidopathy Chronic rhegmatogenous retinal detachment Scleral buckle Retinitis pigmentosa Prevention Screening Screening is an important pillar of prevention of sickle cell retinopathy as it provides the benefit of early detection and treatment thus reducing complications. Screening also provides an opportunity for education of families predisposed to retinopathy as a result of a family history of sickle cell disease. Screening can take the form of DNA screening at birth and Ophthalmology-related examinations later in life. DNA screening in