Definition
Ocular herpes is a common infection of the eye, mainly supported by the herpes simplex virus. Although a single episode of ocular herpes tends to resolve without any complication, in some cases the infection can cause scarring at the corneal level or, worse still, irreversibly compromise the sight.
Causes and mode of transmission
Ocular herpes is mainly caused by an infection caused by the Herpes simplex virus type 1. The virus can be transmitted in several ways:
- Through contact with a person affected by cold, ocular or, less often, genital herpes
- Autocontamination: the spread of the virus can occur simply by touching the eyes with the hands after having scratched or rubbed a herpetic lesion (eg of the lips) during the contagious phase
- Reactivation of the virus: Ocular herpes tends to recur more often in the same patient. As we know, once the infection is contracted, the herpes viruses tend to hide along the nerve endings: here, they can remain silent for life - thus not causing any symptoms - or recur on certain occasions. It has been observed that herpetic lesions tend to reappear in the presence of strong psychological and / or physical stress, or as a consequence of excessive exposure to sunlight or a marked hormonal alteration (eg pregnancy).
In 40-50% of cases, patients suffering from ocular herpes again experience the same symptoms as the infection.
Types of ocular herpes
Based on the depth of infection at the eye level, more forms of ocular herpes can be distinguished:
- Herpes keratitis : this is probably the most common corneal infection that affects the surface layer of the cornea. Generally, this type of eye infection heals without leaving scar tissue at the corneal level.
- Stromal keratitis: The infection supported by the Herpes simplex goes deeper reaching the stroma (the central layer of the corneal membrane). This infection is rather dangerous: in fact, when not adequately treated, it can cause scarring of the cornea, therefore a progressive alteration of vision up to blindness.
- Iridocyclitis: the eye infection sustained by the Herpes Simplex reaches the iris and the ciliary bodies. These internal ocular structures become inflamed, causing hypersensitivity to light (photophobia), blurred vision, eye pain and redness of the eyes. Iridocyclitis is a particular type of viral uveitis.
- Retinitis: when the infection affects the retina or the innermost lining of the eye, Ocular Herpes is called herpetic retinitis.
Symptoms
To learn more: Symptoms Herpes Zoster Ophthalmic
The symptoms with which simple ocular herpes begins are comparable to those of infectious viral conjunctivitis, ie pain, photophobia, blurred vision, abundant tearing and red eyes.
Rarely, common eye herpes (superficial keratitis) causes irreversible damage or corneal lacerations.
Relapsing forms are generally more aggressive: Herpes, in fact, can cause deep corneal ulcers, permanent scars and reduction / loss of vision. The presence of corneal ulcers almost always reveals a suspicion of ocular herpes .
Differential diagnosis
Since the typical symptoms of an ocular herpes are almost the same as those of viral conjunctivitis, the differential diagnosis is essential to choose the most appropriate therapy.
A diagnostic error exponentially increases the risk of recurrence of ocular herpes
The diagnosis begins with the anamnesis: here, the doctor will carefully evaluate the symptoms reported by the patient and his clinical history, focusing in particular on the search for past herpetic infections.
The patient's eye is usually analyzed with an instrument called the ophthalmoscope, which is useful for examining the deepest part of the eye, the optic nerve and the blood vessels. The slit lamp is instead an instrument consisting of a light source and a magnifying glass that displays the internal ocular structures in detail: the slit lamp is therefore very useful to evaluate possible corneal abrasions / ulcerations.
In case of suspected glaucoma, the optician will carefully evaluate the internal ocular pressure through a special instrument called a tonometer.
To ascertain the infectious agent in the hypothesis of an ocular herpes, the doctor can take a sample from the conjunctiva or ocular secretion for a subsequent cytological (cellular) laboratory investigation.
Care
Treatment for ocular herpes depends on the severity of the infection, or on the ocular structure involved (superficial cornea, deep cornea, retina, iris etc.).
A superficial ocular herpes, even when associated with minor corneal ulcers, is easily eradicated with the application of eye drops or ophthalmic ointments with antiviral action. The most indicated drug for the treatment of ophthalmic Herpes is Ganciclovir: the dosage (dosage) involves instilling the drug in the form of eye drops in the eye 5 times a day, until the corneal ulcer regresses.
Contact lenses should be avoided during ophthalmic infection therapy.
When necessary, your doctor may also recommend simultaneous oral administration (in tablet form) of antiviral drugs.
The use of cortisone-based eye drops is reserved exclusively for severe cases of ophthalmic Herpes (involvement of the corneal stroma): in similar circumstances, patients must strictly follow the instructions given by the doctor. Inordinate or inadequate use of these drugs can paradoxically aggravate the symptoms.
If the doctor deems it appropriate, the patient can instill in the eye affected by Herpes Simplex a drop of antibiotic for exclusively prophylactic purposes (to prevent a possible bacterial infection).
Surgery is necessary when corneal scars do not respond to pharmacological treatment; in the presence of a permanent corneal scar induced by a profound ocular herpetic infection, corneal transplantation is the only lifeline to preserve sight.
Read also: Remedies for Ocular Herpes ยป
