The herpes virus that every year annoys millions of people with cold sore blisters can also develop into sinister eye diseases – diseases that can lead to blindness.

Fortunately the occasions on which this happens are quite rare, but nevertheless it does happen, and it’s good to know what to look for by way of symptoms and what to do by way of seeking medical help.

Herpetic retinitis is a particularly serious variant of eye herpes.

The virus

The basic herpes virus called “Herpes Simplex Virus” (HSV) type 1 is responsible for millions of people worldwide waking up one morning and out of the blue having a tingling feeling on the top lip – it’s the beginning of a cold sore!

By the way there are over the counter proprietary medications that can stop the cold sore developing further, but you have to be quick! An easier home remedy is to hold an ice cube on the spot where the tingling sensation is for as long as you can stand the pain – it works!

The type 1 herpes virus lies dormant in a big proportion of the population, almost certainly acquired as children from being kissed on the lips by a loving family member who has the virus.

Now it’s no big deal to have a cold sore once a year as it goes away fairly quickly, and no-one seems all that perturbed looking at you – but if the virus spreads to the eyes then that’s another matter.

About 0.2% of those people who have the type 1 virus contract ocular (eye) herpes, by chance perhaps but probably by transfer through touch.

The type 2 virus is a degree worse since it affects the genital area, and fortunately it’s quite rare for transfer to the eyes.

The range of eye herpes diseases

The herpes virus can attack and inflame various parts of the eye, starting at the front surface and moving to the very back with the seriousness of the disease increasing:

•    At the very front – herpes keratitis affects the top layer (the epithelium) and is readily treated. An optometrist is sometimes able to clear up the affected area using initially only a cotton swab. It is better though to treat it with Zovirax ointment that has been made specifically for the eye.

•    Deeper into the eye, the stroma is the middle layer, and the inflammation is appropriately called “stromal keratitis”. Without treatment scarring of the cornea can be the result.

•    Even deeper into the eye “herpetic uveitis” affects the area from the iris to the choroid further to the rear. Treatment involves the prescription of corticosteroids and the problems that can arise from that medication regime.

•    To the very rear of the eye is the retina images are formed and sent to the brain – this is an extremely vulnerable area obviously so that any inflammation or infection can have serious consequences. Without effective treatment there is the possibility of retinal detachment leading to blindness.

Symptoms

Particular and unusual symptoms are “floaters” appearing to be seen by the patient – these are imaginary cobweb-like structures that are generated by changes in the internal gel of the eye.

Gradual loss of visual accuracy in one eye.

Treatment

Initially treatment is similar to those for stromal keratitis and herpetic uveitis, with acyclovir prescribed, but with higher dosage and at times even applied intravenously.

If retinal breaks do appear then laser surgery is preferred before conventional surgery, and finally a vitrectomy procedure can be carried out, which involves a lengthy process of replacing the gel inside the eye with fluid under pressure to maintain integrity of the retina.