Introduction
Choroid rupture (CR) is a physical affliction of the posterior segment of the eyes. It is characterized by a break of the choroidal and retinal structures. It can lead to chorioretinitis sclopetaria or traumatic chorioretinal rupture if a rupture of the entire retina and choroid from the sclera occurs.
What Is the Main Cause for CR?
The leading cause for CR remains any physical injury or blunt trauma to the eye and its surrounding structures.
What Are the Risk Factors Associated With CR?
The significant risk factors analogous to CR are:
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Sports activities like hockey, tennis, basketball, golf, etc.
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Car accidents.
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Forcep delivery.
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Sometimes diseases like Ehlers-Danlos syndrome (is a group of connective tissue disorders) and pseudoxanthomonas (a condition characterized by calcium deposition in connective tissue) are linked with CR.
How Does the CR Develop?
Sclera and retina are spared in closed globe injury by blunt trauma due to their tensile strength and elasticity, respectively. The Bruch's membrane gets ruptured as it is inelastic. There is the formation of the choriocapillaris complex, which leads to subretinal hemorrhage and bleeding. With time, the blood is replaced by a yellowish-white streak in the optic disc region called CR.
What are the Signs and Symptoms of CR?
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Patients with CR always present a history of blunt trauma to the orbit or globe. It is more common in young males and infants.
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Clinical features of CR mainly depend on the location of the rupture. Patients with fractures away from the fovea are asymptomatic, whereas if the crack is present near the fovea, it leads to impaired vision. The maximum number of CRs occurs temporally or inferiorly to the disc.
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Multiple CRs, intraocular, subretinal, and intra-choroidal bleeding, and retinal disruptions worsen the vision.
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CR appears as white crescent-shaped streaks with pigmented margins in the posterior pole region. The lesions widen in case of multiple ruptures.
What are the Different Forms of CR?
CR are of different types:
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Based on the coverage of involvement of choroid, it is of two types -
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Partial-thickness CR covers only part of the choroid or retina.
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Full-thickness CR involves the whole retina and choroid.
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Based on the mechanism of rupture -
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Direct choroidal ruptures are less common. They are seen in the fundus and oro serrata region.
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Indirect choroidal ruptures are more common. They are present in the posterior pole area.
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What Comorbidities Occur With CR?
Blunt trauma affects many parts of the eye and the choroid. The comorbidities associated with CR are broadly divided into -
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Anterior segment comorbidities - involve the iris, filtration angles, cornea, and lens. It leads to corneal injuries, lens subluxation, and hyphema (blood collection in the anterior chamber).
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Posterior segment comorbidities - affect the macula, retina, and optic nerve. It causes macular holes, optic nerve neuropathy or avulsion, and retinal tear or detachment.
What Are the Diagnostic Tests Performed for CR?
Diagnosis of CR involves clinical evaluation, diagnostic tests, and lab procedures.
Clinical Examination - CR is evaluated clinically with the help of an ophthalmoscope.
Diagnostic Tests - Diagnostic procedures performed for diagnosing CR comprise functional and non-functional tests.
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Non-functional Tests:
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Fluorescein angiography detects the location of small CR and suspected cases of neovascularization after remission of subretinal hemorrhage.
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Indocyanine green angiography is used to detect the location of CR and choroidal perfusion and its potential complications even in the presence of bleeding.
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Fundus autofluorescence helps in evaluating RPE. It uses the fluorescent properties of retinal fluorophores and lipofuscin.
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Functional Tests:
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Defects in the visual field occurring along with CR like the central scotomas (blind spots affecting the vision), nasal steps, and enlargement of blind spots are best observed using functional tests.
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Biomicroscopy and microperimetry are the two standard functional tests investigating the functional impairment caused by the trauma.
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Imaging - Several imaging techniques are helpful in the diagnosis of CR.
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Multicolor imaging is a confocal laser ophthalmoscopy technique that distinguishes the lesions based on their depth using monochromatic wavelengths.
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Spectral-domain optical coherence tomography (SD-OCT) helps diagnose CR and subretinal bleeding immediately after the injury.
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OCT angiography is a new technique that assesses the choroidal and retinal perfusion changes without injecting a dye.
Which Diseases Mimic CR?
Despite having specific features, CR shares similarities with other retinal and choroidal disorders.
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Lacquer cracks appear in the eyes of patients with a history of high myopia. They appear as yellowish cracks in the macula of the eyes. They represent the healing of ruptured Bruch’s membrane.
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Angioid streaks are dehiscence of the Bruch’s membrane clinically seen as reddish-brown bands with radial distribution in the peripheral retina. It is often associated with other systemic conditions like Ehlers-Danlos syndrome, Paget's disease, etc.
How Can CR Be Managed?
CR by itself does not require any treatment.
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Treatment modalities include injections of tissue plasminogen and anti-vascular endothelial growth factors (VEGF), photodynamic therapy, lasers, and surgery. They intercept worsening comorbidities related to CR like glaucoma, subretinal hemorrhage, and choroidal neovascularization.
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Patients with CR are kept under the long-term follow-up to ward off further complications, especially in the first year after rupture.
Can CR Be Prevented?
CR can best be prevented by avoiding heavy activities and wearing protective eyewear to avert closed globe injury (an injury that does not involve the entire thickness of the ocular wall).
What Are the Complications of CR?
CR is linked to a few significant complications -
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Choroidal Neovascularization (CNV): CNV in the initial stages is involved in healing the rupture and regresses spontaneously. However, persistent and hostile CNV leads to severe vision impairment due to the bleeding of the new blood vessels followed by fibrosis.
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Optic Nerve Atrophy: The optic nerve that plays a vital role in the formation of CR is damaged by indirect trauma, thus severing the vision.
Other complications include subretinal hemorrhage.
What Is the Prognosis of CR?
CR does not affect the vision directly. The prognosis of CR depends on the location and extent of the rupture. The presence of CNV in the subfoveal area leading to hemorrhage, subretinal edema, macular hole, and optic nerve neuropathy escalates the risk of vision loss.
Conclusion:
CR is a severe complication of a physical trauma involving the globe. It leads to deteriorating visual acuity. It is mainly caused by direct physical injury. Timely diagnosis and aggressive follow-up help in staving off serious complications.
