Sickle cell retinopathy

Last updated
Sickle cell retinopathy
Specialty Ophthalmology, optometry
Complications Blindness
CausesSickle cell disease
Risk factors Heredity
Diagnostic method Eye examination
TreatmentMedical, laser and surgery

Sickle cell retinopathy can be defined as retinal changes due to blood vessel damage in the eye of a person with a background of sickle cell disease. It can likely progress to loss of vision in late stages due to vitreous hemorrhage or retinal detachment. [1] Sickle cell disease is a structural red blood cell disorder leading to consequences in multiple systems. It is characterized by chronic red blood cell destruction, vascular injury, and tissue ischemia causing damage to the brain, eyes, heart, lungs, kidneys, spleen, and musculoskeletal system. [1] [2]

Contents

People affected by sickle cell disease are commonly of African or Asian descent. [3] Emigration patterns towards the Western Hemisphere have led to increased numbers of persons affected by sickle cell disease in regions where it was previously uncommon. Knowledge and understanding of sickle cell disease and its management are now increasingly relevant in areas such as the European Union. [3] At a young age, a great proportion of people living with sickle cell disease can develop retinal changes. Sickle cell disease consists of several subtypes; however, the Haemoglobin type C (HbSC) subtype carries the gravest prognosis for sickle cell retinopathy and vision changes. [2]

Regular retinal examinations can aid in early detection and treatment, thus reducing the impact of the condition and the risk of vision loss. Development and progression of sickle cell retinopathy can be favorably modified through management of the underling sickle cell disease. Treatment of the general disease can ameliorate its systemic effects. [3] [4]

Classification

Sickle cell retinopathy can be classified based on retinal changes into non-proliferative and proliferative subtypes. [5]

Non-proliferative sickle cell retinopathy (NPSCR)

Non-proliferative sickle cell retinopathy (NPSCR) can feature the following retinal manifestations:

Proliferative sickle cell retinopathy (PSCR)

Proliferative sickle retinopathy is the most severe ocular complication of sickle cell disease. Even though PSCR begins in the first decade of life, the condition remains asymptomatic and unnoticed until visual symptoms occur due to vitreous hemorrhage or retinal detachment. [8]

Goldberg classification [10]

Goldberg classified PSR into following 5 different self-explanatory stages:

  1. Stage of peripheral arterial occlusion and ischemia: It is the earliest abnormality that can be visualized by fundus examination. The occluded arterioles can be seen as dark red lines. They eventually turn into white silver-wire vessels. [11]
  2. Stage of peripheral arteriolar-venular anastomoses: Arteriolar-venular anastomoses develop as blood is diverted from blocked arteries to nearby venules.
  3. Stage of neovascularization and fibrous proliferation: Neovascularization starts from the arteriolar-venular anastomoses, and grow into the ischemic retina. Characteristic fan-shaped appearance due to neovasularization is known as sea fan neovascularization. [11]
  4. Stage of vitreous hemorrhage. Peripheral neovascular tufts bleed and cause vitreous hemorrhage.
  5. Stage of vitreoretinal traction bands and tractional retinal detachment: Traction on the sea fan and adjacent retina causes traction retinal detachment.

Signs and Symptoms

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. [10] 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. [12]

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. [3] Anterior segment signs including the conjunctival sign and iris atrophy are ocular manifestations that are strongly indicative of sickle cell disease. [5] Early stages of sickle cell retinopathy are asymptomatic. [2] However, retinal changes that are diagnostic of sickle cell retinopathy can be visualized using fundoscopic examinations, retinography, fluorescein angiography and coherence tomography. [2] Ultra Widefield Fluorescein Angiography is the gold standard for diagnosis of proliferative sickle cell retinopathy. [2] It is an invasive method that assesses both anterior and posterior segment structures. [2] [5] Spectral Domain Optical Coherence Tomography and Coherence Tomography Angiography are non invasive methods of diagnosing proliferative retinopathy. [1] Visual acuity and intraocular pressure assessments can also yield results that are diagnostic of sickle cell retinopathy. [2]

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.

  1. Diabetic retinopathy
  2. Retinal embolization (talc retinopathy, internal carotid artery embolism)
  3. Retinal vascular occlusion
  4. Infectious retinopathy
  1. Sarcoidosis
  2. Retinal vasculitis
  3. Intermediate uveitis
  4. Acute retinal necrosis
  1. Proliferative diabetic retinopathy
  2. Central retinal vein occlusion
  3. Branch retinal vein occlusion
  4. Ocular ischemic syndromE
  5. Radiation retinopathy
  6. Retinopathy of prematurity
  1. Incontinentia pigmenti
  2. Autosomal dominant vitreoretinochoroidopathy
  3. Chronic rhegmatogenous retinal detachment
  4. Scleral buckle
  5. 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. [1] Screening also provides an opportunity for education of families predisposed to retinopathy as a result of a family history of sickle cell disease. [4] Screening can take the form of DNA screening at birth and Ophthalmology-related examinations later in life.[ citation needed ]

  1. DNA screening in newborns at risk of having sickle cell disease allows the early diagnosis of the disease. [3] Families can then be educated on the possible effects of sickle cell disease at each stage of life. [4]
  2. Ophthalmology-related examinations - dilated fundoscopic examination is recommended from the age of 10 and biannually thereafter in patients with no abnormal retinal findings. [1] [3] [4] Fluorescein angiography and angioscopy is recommended for patients with abnormal findings that may be indicative of proliferative sickle cell retinopathy. The frequency of follow up appointments is determined by the ophthalmologist based on the severity of the findings. [4]

Care of systemic disease

Sickle cell disease is a systemic disease that affects several organs in the body. Management of the underlying disease can therefore prevent the development of retinopathy and slow its progression. [3]

  1. Fetal haemoglobin transfusion - Fetal haemoglobin (HbF) is a form of haemoglobin that is found in children up to 6 months after birth. This type of haemoglobin is beneficial in sickle cell patients as it resists modification to the sickled shape. As a result, transfusion of HbF in younger populations can prevent and slow the progression of sickle cell retinopathy. [3]
  2. Hydroxyurea administration - Hydroxyurea is a drug that can be used as an alternative method of increasing fetal haemoglobin levels in the blood of a patient with sickle cell disease. [2] Hydroxyurea also provides the benefit of reducing inflammation. [4]
  3. Haematopoetic stem cell transplantation - This process is more commonly known as a bone marrow transplant. It is useful in the management of sickle cell disease. However, access to this method is limited due to cost and the need for a donor that is biologically compatible with the person requiring the transplant. [2] [4]
  4. Anti-inflammatory and anti-adhesive drugs reduce the likelihood of occlusions in the small blood vessels of the retina therefore preventing the development of sickle cell retinopathy. There drugs include anti adhesive antibodies, anti-integrin antibodies, anti-Willebrand factor, sulfasalazine and statins. [2]
  5. Gene therapy has also been proven beneficial in the prevention of sickle cell retinopathy. [3]

Treatment

Medical

Vascular endothelial growth factor (VEGF) is known to be associated with sea fan lesions which are types of neovascularization. [4] Bevacizumab is an anti-VEGF drug used in intravitreal injection that is known to cause reversal of sea fan lesions and reduce the duration of vitreous hemorrhage. [3] [4] Intravitreal injection of anti-VEGF drugs can also be used prior to surgery to aid separation of tissues involved in the sea fan lesion and to reduce intraoperative and postoperative hemorrhage. [3] [4] It is useful in combination with photocoagulation. [5]

Laser

Indications for laser photocoagulation include [13]

There are two methods of photocoagulation mainly used; feeder vessel coagulation and scatter laser coagulation. [13] The first method closes the vessels that supply the neovascularized areas using laser burns. Both the xenon arc and argon laser can be used however, the argon laser carries a reduced risk of complications. [13] In comparison, scatter laser coagulation has an indirect effect. Ischemic retina produces vascular endothelial growth factor (VEGF) which promotes neovascularization. Scatter laser coagulation destroys this ischemic retina using laser burns thus preventing vitreous hemorrhage, retinal detachment and vision loss. [13] [3]

Surgery

Surgical intervention is indicated for severely advanced disease that poses a threat to visual acuity. [5] Indications include longstanding vitreous haemorrhage, vitreous haemorrhage in both eyes, vitreous haemorrhage in patients with only one eye, epiretinal membranes, macular holes and the various forms of retinal detachment. [3] [4] Scleral buckle was a previously popular surgical intervention however, its complications include anterior segment ischemia as a result of vascular occlusion. [5] [4] The vascular occlusion can in turn lead to phthisis bulbi. [5] Pars plans vitrectomy is useful for the management of vitreous haemorrhage. [3] Its complications include cataracts, hyphema, glaucoma and unresolved vitreous haemorrhage. [5] [4]

Related Research Articles

<span class="mw-page-title-main">Retinopathy</span> Medical condition

Retinopathy is any damage to the retina of the eyes, which may cause vision impairment. Retinopathy often refers to retinal vascular disease, or damage to the retina caused by abnormal blood flow. Age-related macular degeneration is technically included under the umbrella term retinopathy but is often discussed as a separate entity. Retinopathy, or retinal vascular disease, can be broadly categorized into proliferative and non-proliferative types. Frequently, retinopathy is an ocular manifestation of systemic disease as seen in diabetes or hypertension. Diabetes is the most common cause of retinopathy in the U.S. as of 2008. Diabetic retinopathy is the leading cause of blindness in working-aged people. It accounts for about 5% of blindness worldwide and is designated a priority eye disease by the World Health Organization.

<span class="mw-page-title-main">Diabetic retinopathy</span> Medical condition

Diabetic retinopathy, is a medical condition in which damage occurs to the retina due to diabetes mellitus. It is a leading cause of blindness in developed countries.

Retinopathy of prematurity (ROP), also called retrolental fibroplasia (RLF) and Terry syndrome, is a disease of the eye affecting prematurely born babies generally having received neonatal intensive care, in which oxygen therapy is used due to the premature development of their lungs. It is thought to be caused by disorganized growth of retinal blood vessels which may result in scarring and retinal detachment. ROP can be mild and may resolve spontaneously, but it may lead to blindness in serious cases. Thus, all preterm babies are at risk for ROP, and very low birth-weight is an additional risk factor. Both oxygen toxicity and relative hypoxia can contribute to the development of ROP.

<span class="mw-page-title-main">Retinal detachment</span> Medical condition of the eye

Retinal detachment is a disorder of the eye in which the retina peels away from its underlying layer of support tissue. Initial detachment may be localized, but without rapid treatment the entire retina may detach, leading to vision loss and blindness. It is a surgical emergency.

<span class="mw-page-title-main">Fluorescein angiography</span> Technique for examining the circulation of the retina and choroid of the eye

Fluorescein angiography (FA), fluorescent angiography (FAG), or fundus fluorescein angiography (FFA) is a technique for examining the circulation of the retina and choroid using a fluorescent dye and a specialized camera. Sodium fluorescein is added into the systemic circulation, the retina is illuminated with blue light at a wavelength of 490 nanometers, and an angiogram is obtained by photographing the fluorescent green light that is emitted by the dye. The fluorescein is administered intravenously in intravenous fluorescein angiography (IVFA) and orally in oral fluorescein angiography (OFA). The test is a dye tracing method.

Retinal hemorrhage is a disorder of the eye in which bleeding occurs in the retina, the light sensitive tissue, located on the back wall of the eye. There are photoreceptor cells in the retina called rods and cones, which transduce light energy into nerve signals that can be processed by the brain to form visual images. Retinal hemorrhage is strongly associated with child abuse in infants and young children and often leaves such abused infants permanently blind. In older children and adults, retinal hemorrhage can be caused by several medical conditions such as hypertension, retinal vein occlusion, anemia, leukemia or diabetes.

Neovascularization is the natural formation of new blood vessels, usually in the form of functional microvascular networks, capable of perfusion by red blood cells, that form to serve as collateral circulation in response to local poor perfusion or ischemia.

Eales disease is a type of obliterative vasculopathy, also known as angiopathia retinae juvenilis, periphlebitis retinae or primary perivasculitis of the retina. It was first described by the British ophthalmologist Henry Eales (1852–1913) in 1880 and is a rare ocular disease characterized by inflammation and possible blockage of retinal blood vessels, abnormal growth of new blood vessels (neovascularization), and recurrent retinal and vitreal hemorrhages.

Rubeosis iridis is a medical condition of the iris of the eye in which new abnormal blood vessels are found on the surface of the iris.

Ocular ischemic syndrome is the constellation of ocular signs and symptoms secondary to severe, chronic arterial hypoperfusion to the eye. Amaurosis fugax is a form of acute vision loss caused by reduced blood flow to the eye; it may be a warning sign of an impending stroke, as both stroke and retinal artery occlusion can be caused by thromboembolism due to atherosclerosis elsewhere in the body. Consequently, those with transient blurring of vision are advised to urgently seek medical attention for a thorough evaluation of the carotid artery. Anterior segment ischemic syndrome is a similar ischemic condition of anterior segment usually seen in post-surgical cases. Retinal artery occlusion leads to rapid death of retinal cells, thereby resulting in severe loss of vision.

<span class="mw-page-title-main">Angioid streaks</span> Medical condition

Angioid streaks, also called Knapp streaks or Knapp striae, are small breaks in Bruch's membrane, an elastic tissue containing membrane of the retina that may become calcified and crack. Up to 50% of angioid streak cases are idiopathic. It may occur secondary to blunt trauma, or it may be associated with many systemic diseases. The condition is usually asymptomatic, but decrease in vision may occur due to choroidal neovascularization.

<span class="mw-page-title-main">Intraocular hemorrhage</span> Medical condition

Intraocular hemorrhage is bleeding inside the eye. Bleeding can occur from any structure of the eye where there is vasculature or blood flow, including the anterior chamber, vitreous cavity, retina, choroid, suprachoroidal space, or optic disc.

<span class="mw-page-title-main">Macular telangiectasia</span> Disease of the retina affecting central vision

Macular telangiectasia is a condition of the retina, the light-sensing tissue at the back of the eye that causes gradual deterioration of central vision, interfering with tasks such as reading and driving.

<span class="mw-page-title-main">Laser coagulation</span> Procedure widely used in eye surgery

Laser coagulation or laser photocoagulation surgery is used to treat a number of eye diseases and has become widely used in recent decades. During the procedure, a laser is used to finely cauterize ocular blood vessels to attempt to bring about various therapeutic benefits.

<span class="mw-page-title-main">Familial exudative vitreoretinopathy</span> Retinal vascular disease

Familial exudative vitreoretinopathy is a genetic disorder affecting the growth and development of blood vessels in the retina of the eye. This disease can lead to visual impairment and sometimes complete blindness in one or both eyes. FEVR is characterized by incomplete vascularization of the peripheral retina. This can lead to the growth of new blood vessels which are prone to leakage and hemorrhage and can cause retinal folds, tears, and detachments. Treatment involves laser photocoagulation of the avascular portions of the retina to reduce new blood vessel growth and risk of complications including leakage of retinal blood vessels and retinal detachments.

<span class="mw-page-title-main">Vitreous hemorrhage</span> Medical condition

Vitreous hemorrhage is the extravasation, or leakage, of blood into the areas in and around the vitreous humor of the eye. The vitreous humor is the clear gel that fills the space between the lens and the retina of the eye. A variety of conditions can result in blood leaking into the vitreous humor, which can cause impaired vision, floaters, and photopsia.

<span class="mw-page-title-main">Branch retinal vein occlusion</span> Medical condition

Branch retinal vein occlusion is a common retinal vascular disease of the elderly. It is caused by the occlusion of one of the branches of central retinal vein.

<span class="mw-page-title-main">Radiation retinopathy</span> Medical condition

Radiation retinopathy is damage to retina due to exposure to ionizing radiation. Radiation retinopathy has a delayed onset, typically after months or years of radiation, and is slowly progressive. In general, radiation retinopathy is seen around 18 months after treatment with external-beam radiation and with brachytherapy. The time of onset of radiation retinopathy is between 6 months to 3 years.

Polypoidal choroidal vasculopathy (PCV) is an eye disease primarily affecting the choroid. It may cause sudden blurring of vision or a scotoma in the central field of vision. Since Indocyanine green angiography gives better imaging of choroidal structures, it is more preferred in diagnosing PCV. Treatment options of PCV include careful observation, photodynamic therapy, thermal laser, intravitreal injection of anti-VEGF therapy, or combination therapy.

Drug abuse retinopathy is damage to the retina of the eyes caused by chronic drug abuse. Types of retinopathy caused by drug abuse include maculopathy, Saturday night retinopathy, and talc retinopathy. Common symptoms include temporary and permanent vision loss, blurred vision, and night blindness. Substances commonly associated with this condition include poppers, heroin, cocaine, methamphetamine, tobacco, and alcohol.

References

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  2. 1 2 3 4 5 6 7 8 9 10 11 12 13 Ribeiro MV, Jucá JV, Alves AL, Ferreira CV, Barbosa FT, Ribeiro ÊA (December 2017). "Sickle cell retinopathy: A literature review". Revista da Associação Médica Brasileira. 63 (12): 1100–1103. doi: 10.1590/1806-9282.63.12.1100 . PMID   29489976.
  3. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 Abdalla Elsayed ME, Mura M, Al Dhibi H, Schellini S, Malik R, Kozak I, Schatz P (July 2019). "Sickle cell retinopathy. A focused review". Graefe's Archive for Clinical and Experimental Ophthalmology = Albrecht von Graefes Archiv für Klinische und Experimentelle Ophthalmologie. 257 (7): 1353–1364. doi: 10.1007/s00417-019-04294-2 . hdl: 11392/2481989 . PMID   30895451. S2CID   84186180.
  4. 1 2 3 4 5 6 7 8 9 10 11 12 13 Amissah-Arthur KN, Mensah E (August 2018). "The past, present and future management of sickle cell retinopathy within an African context". Eye. 32 (8): 1304–1314. doi:10.1038/s41433-018-0162-8. PMC   6085343 . PMID   29991740.
  5. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 Bonanomi MT, Lavezzo MM (October 2013). "Sickle cell retinopathy: diagnosis and treatment". Arquivos Brasileiros de Oftalmologia. 76 (5): 320–7. doi: 10.1590/s0004-27492013000500016 . PMID   24232951.
  6. 1 2 "Ophthalmologic Manifestations of Sickle Cell Disease (SCD): Overview, Posterior Segment Abnormalities, Anterior Segment Abnormalities". 2021-06-03.{{cite journal}}: Cite journal requires |journal= (help)
  7. ↑ Stewart EE, Valsecchi M, Schütz AC (November 2020). "A review of interactions between peripheral and foveal vision". Journal of Vision. 20 (12): 2. doi:10.1167/jov.20.12.2. PMC   7645222 . PMID   33141171.
  8. 1 2 Bonanomi MT, Lavezzo MM (October 2013). "Sickle cell retinopathy: diagnosis and treatment". Arquivos Brasileiros de Oftalmologia. 76 (5): 320–7. doi: 10.1590/S0004-27492013000500016 . PMID   24232951.
  9. ↑ Salmon JF (13 December 2019). "Retinal vascular disease". Kanski's clinical ophthalmology : a systematic approach (9th ed.). p. 533. ISBN   978-0-7020-7711-1.
  10. 1 2 3 4 "Sickle Cell Retinopathy". eyewiki.aao.org.
  11. 1 2 3 "Sickle-Cell Retinopathy". Albert & Jakobiec's principles and practice of ophthalmology (3rd ed.). Saunders Elsevier. ISBN   9781416000167.
  12. ↑ Khurana AK (2015). "Diseases of Retina". Comprehensive ophthalmology (6th ed.). Jaypee, The Health Sciences Publisher. ISBN   978-93-86056-59-7.
  13. 1 2 3 4 Myint, Kay Thi; Sahoo, Soumendra; Moe, Soe; Ni, Han (2013-10-17), The Cochrane Collaboration (ed.), "Laser therapy for retinopathy in sickle cell disease", Cochrane Database of Systematic Reviews, Chichester, UK: John Wiley & Sons, Ltd, pp. CD010790, doi:10.1002/14651858.cd010790 , retrieved 2021-07-10
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