CONJUNCTIVAL DISORDERS 8 BY Prof Ahmad Mostafa Conjunctival
CONJUNCTIVAL DISORDERS 8 BY Prof. Ahmad Mostafa
Conjunctival Degenerations n. Pinguecula n. Pterygium
(1) Pinguecula n A piguecula is an extremely common lesion which consists of a yellow-white deposit on the bulbar conjunctiva adjacent to the nasal or temporal aspect of the limbus.
n Histological examination shows degeneration of the collagen fibres of the conjunctival stroma, thinning of the overlying epithelium, and occasionally calcification. n Treatment: surgical excision is seldom required if it is enlarged.
(2) Pterygium Definition n Aetiology n Pathology n Clinical picture n Course n Complications n Differential diagnosis n Treatment n
n Definition: It is a triangular encroachment of the conjunctiva on to the cornea. It is very common in Egypt. n Aetiology: Is unknown and may be related to: - Chronic irritation by dust, wind, fumes…etc - UVR of the sun is probably the most important factor. It is common in dry sunny climates. N. B. It is not known if pinguecula is a precursor for pterygium or not.
n Pathology: it consists of: 1. A single layer of conj. epithelium Fibrovascular tissue (F. T. + B. Vs. ) Bowman’s membrane is destroyed Superficial layer of corneal stroma. 2. 3. 4.
■ Clinical picture: n Symptoms: 1. Irritation & F. B. sensation 2. If reaches the central cornea diminution of vision
n (a) (b) Signs Site: On the nasal side, less commonly temporal, it is always bilateral. Shape: it is triangular and consists of: 1. Apex: lies over the cornea 2. Neck: overlies the limbus 3. Body: lies over the sclera
n Course (1) Progressive: - Thick & fleshy - Vascular (2) Stationary - Thin, membranous - less vascular N. B. A pterygium never disappears alone
Differential diagnosis of Pterygium n From pseudo-pterygium Pterygium Nature Site Hook Course pseudo-pterygium Degenerative condition A fold of conj. attached to the base of healed corneal ulcer Unilateral, anywhere Bilateral, on nasal side Can be passed under Cannot be passed under the neck Always stationary Progressive or stationary
n Complications: 1. If reaches the central corneal opacity & diminution of vision High incidence of recurrence after excision Recurrent pterygium limitation of ocular motility and may diplopia due to marked fibrosis and symblepharon 2. 3.
n Treatment: by surgical excision which is indicated: 1. For cosmetic reasons or 2. If the pterygium encroaches onto the cornea and progresses towards the visual axis.
n There is a high incidence of recurrence of pterygium after its excision. n The use of conjunctival grafting, topical mitomycin C may be effective in reducing rate of recurrencece of recurrence of pterygium after its excision.
Differential Diagnosis of A Red Eye n n n Acute Conjunctivitis Acute Keratitis & corneal ulcer Acute iridocyclitis Acute congestive glaucoma Subconjunctival hemorrhage
- Slides: 16