Signs and Symptoms
The patient with a corneal laceration has experienced significant ocular trauma, typically from a metallic object such as a hand tool. (Fingernail scratches, for example, do not usually have enough force to lacerate a cornea.) There is intense pain initially which may diminish slightly due to corneal desensitization. Patients are photophobic and lacrimate profusely. There is a significant attendant uveitis and the anterior chamber is shallow or even flat in a full thickness laceration. Intraocular pressure generally ranges from 2 to 6 mmHg. Bubbles within the anterior chamber are a key finding. There is significantly reduced visual acuity. Other associated findings may include lens dislocation, iridodialysis, and hyphema.
A corneal laceration results from direct trauma to the cornea, typically from a metallic object impacting with sufficient force. There may be either a full thickness laceration or a partial thickness laceration. A full thickness laceration is termed a penetrating injury. In full thickness lacerations, there will be a flat chamber. Seidel’s sign will be present: as fluorescein is added, you will see the aqueous oozing out from the wound amidst the fluorescein. There may also be bubbles in the anterior chamber. Damage to the iris may result in an irregularly shaped, unreactive iris. Additional pressure on the globe may result in extrusion of uveal tissue through the wound.
The diagnosis of corneal laceration must be made as quickly as possible with as little intervention as possible. Additionally, a partial thickness laceration must be differentiated from a full thickness laceration with the use of Seidel’s test. Intraocular pressure measurement should be avoided in any cases suspected to be full thickness lacerations, as any pressure applied to the globe may cause uveal tissue to extrude through the wound. Visual acuity must be taken, if possible. Judicious use of a topical anesthetic will alleviate patient discomfort and allow the clinician to make an appropriate diagnosis. Open a fresh bottle to avoid intraocular contamination.
Do not unnecessarily manipulate the eye with a full thickness laceration. A topical antibiotic solution may be judiciously applied. Absolutely avoid pressure patch or bandage contact lens. Use an eye shield to protect the eye. Again, exert no pressure upon the eye. Arrange for the corneal laceration to be surgically repaired by a corneal specialist immediately. Instruct the patient to neither eat nor drink prior to the surgical consultation.
With full thickness corneal lacerations, the less done in the office the better. Assess the injury, arrange for the appropriate referral, and shield the eye gently for protection while the patient is in transit to the surgeon.
With a corneal laceration, the patient frequently is lacrimating too heavily for the Seidel test to be performed with any degree of accuracy. In these cases, a shallow or flat anterior chamber or the presence of bubbles within the anterior chamber indicates a breach in the corneal integrity.
Advise the patient that the initial entering acuity may represent the best vision that the patient can expect to achieve after surgical repair. Of course, vision may improve after surgical repair; however, it is best not to elevate a patient’s expectations.