Pterygium, from the Greek pterygos meaning “wing”, is awing-like degenerative change (duplication) of the conjunctiva, visible on the surfacewithin the palpebral fissure of the eye. Whitish fibrovascular conjunctival growth, within the palpebral fissure extending onto the corneal surface, occurs more frequently at the nasal limbus than the temporal.It usually occurs in people who are exposed to ultraviolet radiation andlive in warmer regions, or due to exposition to various kinds of chronic irritations from the outside environment, dust, wind.
If the pterygium progresses centrally, towards the projection of the pupil, it can significantly reduce visual acuity, even after its removal because of the obscuration of the visual axis, as well as by inducing regular or irregular astigmatism. Therefore, if signs of progression are observed, this change should be surgically removed in time. Using modern treatmenti.e., appropriate surgical technique, its recurrence is minimized.
It should be distinguished from pseudopterygium (a scar formation).
Chalazion is mostly a painless lumpor nodulein the upper or lower eyelid (i.e., in the area of tarsus – fibrous plate). It is a localized, chronic inflammation, caused by obstruction of the meibomian glandsin the eyelids.As the gland orifices on the eyelid margin become plugged, the glands are releasing their contents (sebum) to the surrounding eyelid tissuewhich elicits an inflammatory response.
Surgical incision and curettage or intrachalazion corticosteroid therapy may be indicated if chronic chalazia are large, malformed, and persist despite conservativetherapy.It is very important for other eyelid diseases to be ruled out (especially malignant neoplasm).
Abnormalities of eyelid position: ectropion and entropion
Ectropionis a condition in which the eyelid margin is turned outward (everted) so that its edge does not touch the eyeball. The most common symptoms arethe eye irritation, excessive tearing, discomfort, due to impaired function of the “lacrimal pump” (tears do not drain properly into the puncta) and due to exposure of the eyelid inner surface to external factors and drying, as well as owing to disturbed protective function of eyelids when blinking and closing the eyes.
Treatment is often surgical and the appropriate choice of techniquedepends on the cause of mentioned changes (senile ectropion,paralytic,cicatritial, spastic, mechanical, allergic, congenital).
Entropion is a condition in which the eyelid margin is turned inward (inverted), causing the eyelashes and the eyelid skin part to rub against the eyeball. Lower eyelid entropion is much more common. Such condition causesconstant irritation of the eye with possible severecomplications and changes on the transparent eye surface (the cornea – epithelial defects, ulcerationand perforation). It can be a consequence of various causes: senile (consequence of aging), cicatritial (consequence of scarring in other diseases), spastic, mechanical, congenital.
Treatment depends on the cause of the change and often it is neededthe specific surgical correction.