Terrien’s marginal degeneration is an uncommon but distinct variety of marginal thinning of the cornea. It causes a slowly progressive non-inflammatory, unilateral or asymmetrically bilateral peripheral corneal thinning and is associated with corneal neovascularization, opacification and lipid deposition.

It is a slowly progressive, bilateral, peripheral corneal thinning disorder associated with corneal neovascularisation, opacification and lipid deposition. The disease is usually bilateral but may initially present in one eye.

Terrien (1900) first described this disorder. The condition is usually bilateral and starts in the superonasal quadrant as a fine, yellow- white punctate stromal opacity that may progress along the circumference of the cornea.

Two types of Terrien’s marginal degeneration have been documented. One type occurs primarily in the older population. It is usually asymptomatic and slowly progressive. The other, more inflammatory type characteristically occurs in younger patients and may be associated with episcleritis or scleritis. It has also been reported in patients with posterior polymorphous dystrophy, anterior basement membrane dystrophy, and erythema elevatum diutinum (rare chronic dermatosis).

SYMPTOMS:

• Painless progressive blurred vision.
• Progressive change of glasses.
• Recurrent attacks of ocular irritation.
• Pseudo-pterygium.

CAUSE:

• Classic form:The classic form most commonly affects patients older than 40 years of age without rheumatoid arthritis and progression is extremely slow.
• Inflammatory type:Inflammatory variant of Terrien’s marginal degeneration affects younger subjects and it is characterised by recurrent and disabling attacks of acute pain and inflammation.

May be associated with:

• Episcleritis.
• Scleritis.
• Posterior polymorphous dystrophy.
• Keratoconus.
• Anterior basement membrane dystrophy.
• Erythema elevatum diutinum 

DIAGNOSIS - clinical, based on history, slit lamp (bio-microscopy) examination of the eye, and corneal topography.

COMPLICATIONS:

• Corneal hydrops
•  Corneal perforation
•  Pseudo-pterygium

HOMOEOPATHIC MANAGEMENT:

Gelsemium  - person has dim or blurred vision. Mostly distant objects seem blurred. Along with this discomfort in eyes is felt. Next double vision may be present. It occurs mostly when looking sideways. Lastly squinting may be there.

Physostigma - dimness is for distant objects that seem blurred and mixed. It can be       followed by dull pain over and between the eyes. Vision may also be dim when reading.  It is also indicated for dim vision at night time. Sometimes double vision is also there.

Ruta  - eyes have weary pain while reading. Other than this there occurs blurred vision attended with burning aching in the eyes. Blurring of vision mostly is felt from reading too much. Persons needing it feel dimness of vision with a sensation as if shadow is moving before the eyes.

Onsomodium - vision blurred; optic disc hyperćmic, and retinal vessels enlarged. Strained feeling in eyes; worse, using eyes. Eyes heavy and dull, muscular asthenopia; ocular muscles tense. Internal eye muscles paretic. Pain in eyeballs between orbit and ball, extending to left temple.

Lilium Tigrinum-  Hyperæsthesia of retina. Pain, extending back into head; lachrymation; and impaired vision. Myopic astigmia. Useful in restoring power to the weakened ciliary muscle

Heloderma Suspectum- the eyeball becomes more prominent and the cornea opacities. The exophthalmus is due to the pressure of the blood behind the eyeball