CONTUTIONAL INJURIES

Blunt close globe injury without corneal or scleral wall wound. It may vary in severity

from a simple corneal abrasion to an extensive intra ocular damage.

Etiology:

• Ocular contusions resulting from blunt trauma• such as a fist, tennis ball, champagne cork,

stone, falling on the eye, or a cow’s horn are very common.

• Significant deformation of the globe can result where the diameter of the blunt object is less than that of the bony structures of the orbit.

Lesions seen in contusional closed-globe injuries are briefly enumerated here structurewise.

I. Cornea• Corneal epithelium damage: Simple abrasions: Etio:Corneal abrasions are generally a result of trauma to the surface of the eye. Common

causes include jabbing a finger into an eye, walking into a tree branch, getting grit in the eye and then rubbing the eye or being hit with a piece of projectile metal. A foreign body in the eye may also cause a scratch if the eye is rubbed. Injuries can also be incurred by "hard" contact lenses that have been left in too long. Damage may result when the lenses are removed, rather than when the lens is still in contact with the eye. In addition, if the cornea becomes excessively dry, it may become more brittle and easily damaged by movement across the surface.

Symps & signs: Symptoms of corneal abrasion include pain, photophobia foreign-body sensation, excessive squinting, and a reflex production of tears. Signs include epithelial defects and edema and often conjunctival injection, swollen eyelids, large pupils and a mild anterior-chamber reaction. The vision may be blurred, both from any swelling of the cornea and the excess tears. Crusty build up from excess tears may also be present.

Diag: Fluorescein staining is used to diagnose Treat. Usually heal with in 24 hrs with pad bandage after instilling antibiotic ointment.

sometimes a topical cycloplegic to reduce pain and improve comfort. Topical anesthetics are not to be used for continued pain control as they can reduce healing and cause secondary keratitis

cont.Fig:A corneal abrasion after staining with Fluorescein

cont.

Recurrent erosions: Etio: This occurs due to abnormally loose attachment of epithelium to the underlying

Bowman’s membrane. Symps &signs: Recurrent attacks of pain, photophobia(i.e. sensitivity to bright lights),

and tearing often at the time of awakening or during sleep when the eyelids are rubbed or opened. Signs of the condition include corneal abrasion or localized roughening of the corneal epithelium, sometimes with map-like lines, epithelial dots or microcyts, or fingerprint patterns.

Diag : opthalmoscope although usually Fluorescein stain must be applied first and a blue-light used.

Treat. Loosely attached epithelium should be removed by debridement & ‘pad & bandage’ applied for 48 hrs, so that firm healing is established Where episodes frequently occur, or there is an underlying disorder, three types of surgical curative procedures may be attempted: use of therapeutic contact lens, controlled puncturing of the surface layer of the eye (Anterior Stromal Puncture) and laser phototherapeutic keratectomy(PTK). These all essentially try to allow the surface epithelium to reestablish with normal binding to the underlying basement membrane, the method chosen depends upon the location & size of the erosion.

Fig: The epithelial defect in the cornea is readily visible when the eye is examined through a blue light after administration of Fluorescein sodium dye.

cont.

• Blood Staining of the Cornea: Corneal blood staining is defined as deposition of hemoglobin and its

breakdown products in the cornea. Etiology: A combination of hyphema and resultant elevated intraocular pressure

are believed to be important in the pathogenesis of blood stained corneas. A patient with hyphema and intraocular pressure greater than 25 mm Hg for 6 days is associated with greatest risk of corneal blood staining. Other predisposing factors are injury to Descemet’s membrane or endothelial damage.

Symps & signs: The clinical signs in the progression of corneal blood staining include fine yellow granules in the posterior stroma, yellow discoloration of the stroma, red to brown stromal color followed by shades of green, black, and grey.

Treatment: Prevention is contingent on removal of the hyphema. Clot removal via an anterior chamber wash-out procedure is usually performed before 6 days of raised intraocular pressure (25 mm Hg or greater) and certainly with the first sign of blood staining.

Fig: a traumatic hyphema (number 1). The cornea peripheral to arrow 2 is white and that located more centrally is yellow to brown (blood staining). The lens is cataractous (number 3). Corneal blood staining may extend to Bowman's layer and even the epithelium in severe cases. Clearance of the blood staining begins peripherally and progresses centrally, and can take up to 3 years

II.Anterior chamber• Traumatic Hyphaema: Etio: Hyphema describes the condition of the aqueous humor

when red blood cells form a suspension in it. The choroid and the iris contain a rich complex of vessels. The pupil is outlined and controlled by a complex set of iridial muscles, sphincters, and dilators. These muscles can be ruptured by sharp and/or blunt trauma. This is a frequent source of intraocular hemorrhage (hyphema). In addition, the iris root and/or the ciliary spur is a common location of bleeding from blunt trauma.

Treatment :The customary treatment of patients with traumatic hyphema has included hospitalization, bed rest, bilateral patching, and sedation. analgesics are required for pain relief. The injured globe requires adequate protection with a patch and shield.

Fig:The clinical grading system for traumatic hyphemas

III.Iris, pupil and ciliary body

• Traumatic mydriasis & miosis: In cases of blunt orbital trauma the iris

sphincter (the muscle responsible for closing the pupil) or the nerves controlling it can be damaged, reducing or eliminating consensual reactivity to light.

cont• Radiating tears in the iris stroma:  sometimes reaching up to ciliary body,

may occur occasionally.

Fig:Tear in theora serrata

cont• Iridodialysis  Detachment of iris from its root at the ciliary body occurs frequently. It results

in a D-shaped pupil and a black biconvex area seen at the periphery. Symptoms and signs: Those with small iridodialyses may be asymptomatic and

require no treatment, but those with larger dialyses may have corectopia orpolycoria and experience monocular diplopia, glare, orphotophobia

Treat: Iridodialysis causing an associated hyphema has to be carefully managed, and recurrent bleeds should be prevented by strict avoidance of all sporting activities. Management typically involves observation and bed rest. Red blood cells may decrease the outflow of aqueous humor, therefore the eye should be kept soft by giving oral acetazolamide. Later, surgical repair may be considered for larger avulsions causing significant double vision, cosmesis or glare symptoms.Surgical repair is usually done by 10-0 prolene suture taking the base of iris avulsion and suturing it to the scleral spur and ciliary body junction.

Complication: Those with traumatic iridodialyses (particularly by blunt trauma) are at high risk for angle recession, thereby causing increased intraocular pressure(IOP).

fig: Iridodialysis caused by blunt trauma to the eye

cont• Traumatic aniridia or iridremia: In this condition, the completely torn iris (from ciliary body)

sinks to the bottom of anterior chamber in the form of a minute ball.

Treat.: The medical treatment is directed toward control of intraocular pressure, which includes the topical use of the following: Miotics,Beta-blockers

Treatment of photophobia and nystagmus: Tinted or iris contact lenses, Tinted spectacle lenses

Treatment of refractive errors - Careful refraction and complete correction

Surgical separation of the iris from the trabecular meshwork in selected cases

Aniridia. 3-D image showing absence of the inferior half of the iris and absence of most of the anterior leaf of the iris in the upper half. In the less affected area, the iris is represented mostly by the posterior pigment epithelium. No choroidal coloboma was present.

cont

• Angle recession: Refers to the tear between longitudinal and circular muscle

fibres of the ciliary body. It is characterized by deepening of the anterior chamber and widening of the ciliary body band on gonioscopy. Later on it is complicated by glaucoma.

Clinical Findings: On gonioscopy, the ciliary body band is increased in size and irregularly widened. OCT has been recommended to give a 3D image of the recessed angle and more accurately determine the extent without putting pressure on the anterior segment

Treatment: The glaucoma is treated as open angle glaucoma. Some have indicated that trabeculectomy with antimetabolite therapy is more effective than other surgical treatment in these patients

a diagnostic method in sections of the eye that involves drawing a line through the optic axis (pink arrowed line in diagram) and then drawing a second line (yellow arrowed lines in picture) parallel to the first but which includes the scleral spur. If the angle recess is located posteriorly to the line (as the white arrow indicates) then there is angle recession.