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A lens injury can result in subluxation or dislocation of the lens in the eye. This can cause decreased vision, double vision, astigmatism, cataract, and glaucoma. Trauma is the most common cause, but conditions like Marfan syndrome and Homocystinuria can also contribute. Treatment may involve observation, surgical removal of the lens, or other interventions depending on the severity of the injury.
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LENS INJURY Blowout fracture
Lens posterior to the pupil and iris , within the cavity of the eyebal, is the lens proteins called crystallins . arranged like the layers of an onion , make up the lens , which normally is perfectly transparent and lacks blood vessels . it is enclosed by a clear connective tissue capsule held in position by encircling zonular fibers , which attach to the ciliary processes. the lens focus images on the retina to facilitates clear vision
LENS INJURY SUBLUXATION/DISLOCATION Definition: Subluxation: Partial disruption of the zonular fibers; the lens is decentered but remains partially in the pupillary aperture Dislocation: Complete disruption of the zonular fibers; the lens is displaced out of the papillary aperture The dislocated lens can be positioned either in the posterior segment or the anterior chamber.
Symptoms: Decreased vision, double vision that persists when covering one eye (monocular diplopia). Signs: Decentered or displaced lens,. Marked astigmatism, Cataract, Angle-closure glaucoma as a result of pupillary block, acquired high myopia, viterous in the ant. Chamber, asymmetry of the ant. Chamber depth.
Causes : 1. Trauma most common cause (In sports and other physical activities, lens dislocation is usually provoked by direct trauma to the globe of the eye , are more common in contact sports such as rugby or football or sports involving fast moving projectiles like tennis or cricket balls. ) 2. Marfan Syndrome 3. Homocystinuria 4. Ehlers-Danlos syndrome 5. Sulfite oxidase deficiency 6.syphilia
Marfan syndrome is a genetic disorder of the connective tissue. Marfan syndrome can also seriously affect the eyes and vision. and astigmatism is the most common, Subluxation (dislocation) of the crystalline lens in one or both eyes (ectopia lentis) (in 80% of patients) also occurs and may be detected by an ophthalmologist or optometrist using a slit-lamp biomicroscope. In Marfan's the dislocation is typically superotemporal. Sometimes eye problems appear only after the weakening of connective tissue has caused detachment of the retina. Early onset glaucoma can be another related problem. Supertemporal dislocation of a lens in the right eye of a patient with Marfan syndrome
Treatment 1. Subluxation: Asymptomatic; Observe High uncorrectable astigmatism; Surgical removal of them lens Symptomatic cataract: Surgical removal, Mydriasis (Scopolamine), and aphakic correction, pupillary constriction (Pilocarpine), and phakic correction. 2. Pupillary block 3. In dislocation; surgical intervenetion Complications Cataract ,glaucoma , uveitis
Cataract - Any opacity of lens - Most common cause of reversible blindness - Types : Nuclear sclerosis , cortical , posterior sub capsular - Etiology Acquired ( age related . Systemic disease , traumatic , intraocular inflammation , radiation ) Congenital
Traumatic cataracts occur secondary to blunt or penetrating ocular trauma. Infrared energy , and ionizing radiation are other rare causes of traumatic cataracts. Cataracts caused by blunt trauma classically form stellate- or rosette-shaped. penetrating trauma with disruption of lens capsule forms cortical changes
Clinical features : • gradual , painless , progressive decrease in visual acuity • Second sight phenomena pateint is more myopic than previously noted due to increase refractive power of the lense<nuclear sclerosis> • Diagnosed by slit lamp exam,and by noting change changes in red reflexe using ophthalmoscpe • May impair view of retina during fundoscope
History • Mechanism of injury - Sharp versus blunt • Past ocular history - Previous eye surgery, glaucoma, retinal detachment, diabetic eye disease • Past medical history - Diabetes, sickle cell, Marfan syndrome, homocystinuria, hyperlysinemia, sulfate oxidase deficiency • Visual complaints • Decreased vision - Cataract, lens subluxation, lens dislocation, ruptured globe, traumatic optic neuropathy, vitreous hemorrhage, retinal detachment • Monocular diplopia - Lens subluxation with partial phakic and aphakic vision • Binocular diplopia - Traumatic nerve palsy, orbital fracture • Pain - Glaucoma , or lens particles; retrobulbar hemorrhage;
Physical • Complete ophthalmic examination (defer in case of globe compromise) • Vision and pupils - Presence of afferent pupillary defect (APD) indicative of traumatic optic neuropathy • Extraocular motility - Orbital fractures or traumatic nerve palsy • Intraocular pressure - Secondary glaucoma, retrobulbar hemorrhage • Anterior chamber - Hyphema, iritis, shallow chamber, iridodonesis, angle recession • Lens - Subluxation, dislocation, capsular integrity (anterior and posterior), cataract (extent and type), swelling, phacodonesis • Vitreous - Presence or absence of hemorrhage, posterior vitreous detachment • Fundus - Retinal detachment, choroidal rupture, commotio retinae, preretinal hemorrhage, intraretinal hemorrhage, subretinal hemorrhage, optic nerve pallor, optic nerve avulsion
Blowout fracture is a fracture of the walls or floor of the orbit. Intraorbital material may be pushed out into one of the paranasal sinuses , orbits rim remains intact Common medical causes of orbital fracture may include: Direct orbital blunt injury Sports' injury Motor vehicle accidents
Symptoms: Pain (especially on attempted vertical eye movement) Local tenderness Binocular double vision Eyelid swelling And creptius after nasal blowing • Sign: Critical: -Restricted eye movement -Subcutaneous and conjunctival emphysema -Hypesthesia in the distribution of the infreaorbital nerve -Point tenderness -Enophthalmos other: nose bleed, eyelid edema and ecchymosis Investigation 1- Plain films waters view and lateral 2- CT: anteroposterior and coronal view of orbits
Treatment(most adult orbital fractures can initially be followed conservatively) *Broad spectrum oral antibiotic (may be use but not mandatory) *Instruct the patient not to blow his nose *Apply ice packs to the orbit for the first 24 to 48 hours The aim of treatment is prevention of permanent diplopia and cosmetically unacceptable enophthalmos. The factors that determine the risk of late complications are -Fracture size -Herniation of orbital content into the maxillary sinus -Muscle entrapment *Surgical repair -Immediate repair (usually within 24hr.) -Repair in 1 to 2 weeks *Neurosurgical consultation is recommended