How Do Ophthalmic Diagnostics Work?

Ophthalmic diagnostics are fluorescent substances known as disclosing agents, which help diagnose and treat certain eye conditions. A fluorescent orange dye is applied on the surface of the eye to visualize damage to the cornea, or foreign bodies in the eye. The fluorescent dye stains the problem area in the eye and appears a bright green when seen using a blue light.

The fluorescent dye is usually used in combination with ophthalmic anesthetic medications to numb the eye and prevent pain during diagnostic and treatment procedures. ophthalmic local anesthetics block the nerves in the eye from sending pain signals to the brain.

Ophthalmic diagnostic agents are used in different forms:

• Solutions that are topically administered on the eye, which is the most common method.
• Strips which are gently brushed over the eye to stain it.
• Intravenous injection into a vein in the upper arm, in which the dye reaches the eye through blood circulation.

Uses of ophthalmic diagnostic agents, mostly in combination with ophthalmic anesthetics, include the following:

• Diagnostic eye examinations
• Minor surgical procedures on the superficial parts of the eye such as the cornea or conjunctiva (the membrane that covers the eye and the inner surface of the eyelids)
• Removal of foreign bodies
• Removal of sutures
• Tonometry, a diagnostic procedure to test the pressure inside the eye (intraocular pressure)
• Ophthalmic angiography with intravenous injection and a special camera to examine the condition of the blood vessels in the eye and examine eye’s posterior parts such as the retina and macula
• Ophthalmic anesthesia for the deeper parts of the eye

Side effects of ophthalmic diagnostics may include the following:

Ocular side effects:

• Transient local stinging and burning
• Inflammation in the top layer of the cornea (epithelial keratitis)
• Conjunctival redness
• Gray ground glass appearance of the cornea
• Sloughing of the corneal epithelium
• Inflammation of the iris and the posterior membrane (Descemet's membrane) of the cornea (iritis with descemetitis)

Rare ocular side effects

• Severe immediate allergic reaction in the cornea
• Conjunctival congestion
• Conjunctival hemorrhage

Systemic side effects:

• Fissuring of fingertips
• Allergic contact dermatitis
• Hives
• Skin discoloration (yellow)
• Seizure
• Dizziness
• Headache
• Shock
• Drop in blood pressure (hypotension)
• Fainting (syncope)
• Itching (pruritus)
• Gastrointestinal distress
• Vomiting
• Taste disturbance
• Urine discoloration
• Leakage of fluid from blood vessels (extravasation)
• Blood clots in the veins (thrombophlebitis)
• Bronchospasm
• Pulmonary edema
• Respiratory arrest
• Sickle cell crisis in people with sickle cell disease
• Localized paralysis (nerve palsy)
• Loss of red blood cells (hemolytic anemia)
• Cardiac arrest (rare)
• Block in blood flow to brainstem and parts of the brain (basilar artery ischemia), rare

Information contained herein is not intended to cover all possible side effects, precautions, warnings, drug interactions, allergic reactions, or adverse effects. Check with your doctor or pharmacist to make sure these drugs do not cause any harm when you take them along with other medicines. Never stop taking your medication and never change your dose or frequency without consulting your doctor.

Generic and brand names of some ophthalmic diagnostic drugs include:

• Ophthalmic benoxinate hydrochloride/fluorescein sodium
• Fluorescein sodium (Fluorescite)
• Fluorescein sodium/proparacaine hydrochloride, ophthalmic