What Is Herpes Zoster Ophthalmicus (HZO)?
Because of the effects of aging in the body, an individual tends to have a weakened immune system; becoming more at risk to the development of illnesses, emotional or psychological stress, and side effects of certain medical treatments. This vulnerability to certain factors results into a decreased response of the virus-specific, cell-mediated immune system. In these specific circumstances, the inactive VZV residing in the dorsal roots become reactivated and develops in the form of localized skin rashes coming out in a dermatome. This development is called herpes zoster (HZ) or shingles. In the event that the virus resided in the ophthalmic branches and trigeminal nerve and becomes reactivated, the disease is now termed as herpes zoster ophthalmicus (HZO).
History of Herpes Zoster Ophthalmicus
Several centuries ago, herpes zoster ophthalmicus (HZO) was already described by the famous Greek philosopher Hippocrates. But, it was not that long ago, during the actualization of modern medical tools when HZO was related to VZV; such as the utilization of immuno-histochemical assays.
When released from the trigeminal nerve, the reactivated Varicella zoster virus (VZV) moves down the ophthalmic division of the trigeminal nerve toward the naso-ciliary nerve. This system of nerve connection then divides to supply nerves to the surface of the eye orbit and the skin of the nose up to its tip. This movement of the viral particles usually takes three to four days to get to the nerve endings. As the viral particles make their movements, they influences the development of intra-neural (within the nerve) and perineural (near a nerve or nerves) leading to damaging effects of the eye and/or its surrounding structures.