Pterygium - Clinicals, Diagnosis, and Management

Opthalmology

Clinicals - History

Fact Explanation
Visible growth Pterygium is a benign epithelial and fibrovascular outgrowth of the of the ocular surface that has proliferative, invasive, and highly vascularized microscopic appearance and invades the cornea and pupillary field. Visible growth
Pterygium is a benign epithelial and fibrovascular outgrowth of the of the ocular surface that has proliferative, invasive, and highly vascularized microscopic appearance and invades the cornea and pupillary field.
Foreign body sensation The fibrovascular elevation in pterygium causes a foreign body sensation in the eye prior, to it being visible to naked eye examination. Foreign body sensation
The fibrovascular elevation in pterygium causes a foreign body sensation in the eye prior, to it being visible to naked eye examination.
Blurring of vision The as the lesion grows into the visual axis, the alteration of corneal contour, causes irregular astigmatism and breakup of the precorneal tear film, this results in a reduction in visual acuity. Blurring of vision
The as the lesion grows into the visual axis, the alteration of corneal contour, causes irregular astigmatism and breakup of the precorneal tear film, this results in a reduction in visual acuity.
Previous history of pterygium Pterygium has a high recurrence rate even after surgical treatment. Recurrence following the bare sclera technique can be as high as 40%. Previous history of pterygium
Pterygium has a high recurrence rate even after surgical treatment. Recurrence following the bare sclera technique can be as high as 40%.
Dryness, itchiness and redness Often seen in advanced pterygia, occurs as the pterygium grows larger. They cause ocular surface irritation, which is experienced as dryness and itchiness. Redness is due to inflammation of the pterygium. Dryness, itchiness and redness
Often seen in advanced pterygia, occurs as the pterygium grows larger. They cause ocular surface irritation, which is experienced as dryness and itchiness. Redness is due to inflammation of the pterygium.
Risk factors: increased exposure to UV radiation Incidence is increased in the lower lattitudes, in the male gender, the elderly and occupations that involve sun exposure such as competitive surfing, farmers and welders. Risk factors: increased exposure to UV radiation
Incidence is increased in the lower lattitudes, in the male gender, the elderly and occupations that involve sun exposure such as competitive surfing, farmers and welders.

Clinicals - Examination

Fact Explanation
Growth towards the medial side of the eye This is a benign growth that causes a wedge-like fibrovascular growth of actinically damaged conjunctiva encroaching across the limbus and invading the cornea. Growth towards the medial side of the eye
This is a benign growth that causes a wedge-like fibrovascular growth of actinically damaged conjunctiva encroaching across the limbus and invading the cornea.

Investigations - Diagnosis

Fact Explanation
Slit lamp examination Pterygium can be graded according to its slit lamp appearance.
Grade I - between limbus and a point midway between limbus and pupillary margin

Grade II - head of the pterygium present between a point midway between limbus and pupillary margin and pupillary margin (nasal papillary margin in case of nasal pterygium and temporal margin in case of temporal pterygium)

Grade III - crossing pupillary margin
Slit lamp examination
Pterygium can be graded according to its slit lamp appearance.
Grade I - between limbus and a point midway between limbus and pupillary margin

Grade II - head of the pterygium present between a point midway between limbus and pupillary margin and pupillary margin (nasal papillary margin in case of nasal pterygium and temporal margin in case of temporal pterygium)

Grade III - crossing pupillary margin
Corneal topography A pterygium-induced refractive changes often leads to visual impairment. The distortion of the cornea can be documented by corneal topographic measurements. Corneal topography
A pterygium-induced refractive changes often leads to visual impairment. The distortion of the cornea can be documented by corneal topographic measurements.

Investigations - Management

Fact Explanation
Testing of visual acuity Screening test, to evaluate visual acuity. Pterygium can cause irregular astigmatism that reduces visual acuity. Testing of visual acuity
Screening test, to evaluate visual acuity. Pterygium can cause irregular astigmatism that reduces visual acuity.
Slit lamp examination of the anterior and ocular adnexa Done to rule out other ocular surface disorders. Slit lamp examination of the anterior and ocular adnexa
Done to rule out other ocular surface disorders.

Management - Supportive

Fact Explanation
Protective eyewear Useful in primary prevention and to slow progression. An increased incidence of pterygium has been reported in the lower latitudes and in individuals with more UV exposure. Protective eyewear
Useful in primary prevention and to slow progression. An increased incidence of pterygium has been reported in the lower latitudes and in individuals with more UV exposure.
Lubricating eye drops Provides lubrication to the ocular surface. Ocular surface irregularities are common in pterygium and this can be associated with an irregular tear film. Lubricating eye drops
Provides lubrication to the ocular surface. Ocular surface irregularities are common in pterygium and this can be associated with an irregular tear film.
Corticosteroid eye drops Prednisolone eye drops are prescribed in order to reduce inflammation in an inflamed pterygium. It is also prescribed in the post operative period. Corticosteroid eye drops
Prednisolone eye drops are prescribed in order to reduce inflammation in an inflamed pterygium. It is also prescribed in the post operative period.
Follow up Close follow up is needed in the immediate post operative period for complications such as corneal scarring, infection etc. Follow up
Close follow up is needed in the immediate post operative period for complications such as corneal scarring, infection etc.

Management - Specific

Fact Explanation
Surgery: bare sclera technique Indications for surgery are: visual impairment; recurrent inflammation; motility restriction and cosmetic disfigurement.This technique involves the removal of the pterygium, and allows the the sclera to re-epithlialize. Is associated with a high percentage of recurrence (upto 40% in some studies). Surgery: bare sclera technique
Indications for surgery are: visual impairment; recurrent inflammation; motility restriction and cosmetic disfigurement.This technique involves the removal of the pterygium, and allows the the sclera to re-epithlialize. Is associated with a high percentage of recurrence (upto 40% in some studies).
Surgery: conjunctival auto graft technique This has the lowest recurrence rates (less than 2% in some but can increase up to 30%). Involves harvesting a conjunctival autograft from a different part of the conjunctiva and subsequently grafting over the exposed scleral bed, where the pterygium was excised. Surgery: conjunctival auto graft technique
This has the lowest recurrence rates (less than 2% in some but can increase up to 30%). Involves harvesting a conjunctival autograft from a different part of the conjunctiva and subsequently grafting over the exposed scleral bed, where the pterygium was excised.
Surgery: Amniotic membrane grafting The amniotic membrane is thought to naturally contain proteins which promote the adherence, migration and differentiation of epithelial cells and prevent their apoptosis. The amniotic membrane graft reduces recurrence of pterygium by promotion of conjunctival epithelial wound healing, suppression of fibroblasts and reduced extracellular matrix production. Surgery: Amniotic membrane grafting
The amniotic membrane is thought to naturally contain proteins which promote the adherence, migration and differentiation of epithelial cells and prevent their apoptosis. The amniotic membrane graft reduces recurrence of pterygium by promotion of conjunctival epithelial wound healing, suppression of fibroblasts and reduced extracellular matrix production.
Mitomycin C eyedrops Used as an adjunct to surgical management to reduce recurrence rates. Mitomycin C (MMC) is used for its property of inhibiting fibroblast cells. Currently ophthalmologists use MMC intra operatively on the exposed scleral bed after pterygium excision; while some prescribe MMC eyedrops post operatively. Mitomycin C eyedrops
Used as an adjunct to surgical management to reduce recurrence rates. Mitomycin C (MMC) is used for its property of inhibiting fibroblast cells. Currently ophthalmologists use MMC intra operatively on the exposed scleral bed after pterygium excision; while some prescribe MMC eyedrops post operatively.
Beta irradiation An adjunctive method employed intra operatively and post operatively in addition to primary surgery. Beta irradiation reduces mitosis of the rapidly dividing cells of the sclera to reduce recurrence. Possible side effects are: scleral necrosis, endophthalmitis and sectorial cataract formation. Beta irradiation
An adjunctive method employed intra operatively and post operatively in addition to primary surgery. Beta irradiation reduces mitosis of the rapidly dividing cells of the sclera to reduce recurrence. Possible side effects are: scleral necrosis, endophthalmitis and sectorial cataract formation.

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