Signs of Dry Eye Syndrome
The main signs are found in the cornea and conjunctiva. Different techniques such as special fluorescein and lissamine green staining of the ocular surface are used to observe these lesions. Fluorescein staining evaluated with the cobalt light of the slit lamp reveals superficial punctate keratitis (yellow dots revealing de-epithelialized areas of the cornea) which can be evaluated according to severity from 0 to 4 (0= not at all, 4= very much) with the Oxford scale. Lissamine green staining evaluated with the white light of the slit lamp reveals green staining over the nasal or temporal conjunctival zone and over the cornea (areas without the mucin layer of the tear film) which can be evaluated according to severity from 0 to 3 (0= none, 3= very much) in nasal conjunctival zone, corneal zone, and temporal conjunctival zone with the Van Bijsterveld scale (maximum score 9).
In very advanced cases there is a whitish discharge that forms filaments that stick to the cornea (filamentous keratitis).
In evaporative dry eye it is common to find signs of blepharitis or Meibomian gland dysfunction, with irregularities in the free palpebral margin with redness, telangiectasias (dilation of blood vessels), keratinization, chalazion (swollen protuberance on the eyelid), collars, scales, notches, infiltrates, etc.