Pterygium is a wing-shaped growth of conjunctiva that encroaches on the cornea. It is more common in people living in hot, dusty climates who are exposed to sun and ultraviolet rays. Pterygium is a degenerative condition where subconjunctival tissue proliferates as vascularised granulation tissue under the epithelium, destroying the corneal epithelium, Bowman's layer and superficial stroma. It presents as a triangular fold of conjunctiva on the cornea, usually on the nasal side. Surgical excision is required if it encroaches the pupil or causes diplopia. Recurrence after excision is common, ranging from 30-50%, but use of

1. PTERYGIUM
Dr Mayuri Borgohain

2. Pterygium (L. Pterygion = a wing) is a wing-shaped fold of
conjunctiva encroaching upon the cornea from either side
within the inter-palpebral fissure.
Etiology. The disease is more common in people living in hot
climates such as exposure to sun (ultraviolet rays), dry heat,
high wind and abundance of dust.

3. Pathology
Pterygium is a degenerative and hyperplastic condition of
conjunctiva.
The subconjunctival tissue undergoes elastotic degeneration and
proliferates as vascularised granulation tissue under the
epithelium, which ultimately encroaches the cornea.
The corneal epithelium, Bowman's layer and superficial stroma
are destroyed.

4. Clinical features
Pterygium is more common in elderly males doing outdoor
work.
It may be unilateral or bilateral.

5. It presents as a triangular fold of conjunctiva encroaching the
cornea in the area of palpebral aperture, usually on the nasal
side, but may also occur on the temporal side.

6. Deposition of iron seen sometimes in corneal epithelium
anterior to advancing head of pterygium is called stocker's line.

8. Types.
Depending upon the progression
1. Progressive pterygium is thick, fleshy and vascular with a
few infiltrates in the cornea, in front of the head of the
pterygium (called cap of pterygium).
2. Regressive pterygium is thin, atrophic, attenuated with very
little vascularity. There is no cap. Ultimately it becomes
membranous but never disappears.

9. Symptoms.
Pterygium is an asymptomatic
Visual disturbances occur when it encroaches the pupillary area
or due to corneal astigmatism
Occasionally diplopia
Complications .
Cystic degeneration and infection
Rarely, neoplastic change

10. Differential diagnosis.
Pterygium must be differentiated from pseudopterygium.
Pseudopterygium is a fold of bulbar conjunctiva attached to
the cornea. It is formed due to adhesions of chemosed bulbar
conjunctiva to the marginal corneal ulcer. It usually occurs
following chemical burns of the eye.

12. Treatment.
Surgical excision for:
(1) Cosmetic reasons,
(2) Once the pterygium has encroached pupillary area,
(3) diplopia due to interference in ocular movements.
Complication.
Recurrence (30-50%).

13. Reduction of recurrence.
1. Use of mitomycin-C
2. Surgical excision with bare sclera.
3. Surgical excision with free conjunctival auto-graft
4. In recurrent recalcitrant pterygium, surgical excision coupled
with lamellar keratectomy and lamellar keratoplasty.

14. Surgical techniqueof pterygiumexcision
1. After topical anaesthesia, eye is cleansed, draped and
exposed using universal eye speculum.
2. Head of the pterygium is lifted and dissected off the cornea
very meticulously

15. 3. The main mass of pterygium is
then separated from the sclera
underneath and the conjunctiva
superficially.
4. Pterygium tissue is then
excised taking care not to
damage the underlying medial
rectus muscle
5. Haemostasis is achieved and
the episcleral tissue exposed is
cauterised thoroughly.

16. 6.
i. In simple excision the conjunctiva is
Sutured back to cover the sclera
ii. In bare sclera technique, some part of
conjunctiva is excised and its edges are
sutured to the underlying episcleral tissue
leaving some bare part of sclera near the
limbus
iii. Limbal conjunctival autograft transplantation
(LLAT) to cover the defet after pterygium
excision is the latest and most effective
technique in the management of pterygium.