Staphylomas

Definition

Staphyloma is the bluish or black discoloration of the eye because of thinning of the sclera (the outer, white coat of the eye). The thinned sclera causes the underlying pigmented tissue to add its color to eye giving an appearance of bluish to almost black color.

It is an abnormal protrusion of the eyeball that is not harmful or fatal but can affect vision of the person. Many staphyloma cases go unnoticed until the patient complains of vision loss or an eye examination exposes the condition.

Clinical types of Staphyloma:

Depending upon the location of the protrusion on the eyeball, staphyloma can be of following types:

• Posterior staphyloma or staphyloma on back side of the eyeball that is typically diagnosed at the region of the macula.
  • Causes:
    • Congenital
    • Manifestation of extreme myopia

• Anterior staphyloma or staphyloma in the front of the eye that involves the cornea and sclera. It occurs due to disturbed scleral architecture and stretching of eye leading to raised internal pressure from a weak point and eventually causing the protrusion and typical appearance of staphyloma.
  • Causes:
    • TraumaInfection
    • Surgical weakening of the sclera

• Intercalary staphyloma is a staphyloma that appears as a localised bulge in the limbal area of the eye.
  • Causes:
    • Weak scar tissue formed due to an injury or corneal ulcer
    • Secondary angle closure glaucoma

• Ciliary staphyloma is a bulge of weak sclera that is lined by ciliary body and occurs about 2–3 mm away from the limbus.
  • Causes:
    • Perforating injury
    • Scleritis
    • Absolute glaucoma

• Equatorial staphyloma occurs on the equator of the eye.
  • Causes:
    • Myopia
    • Scleritis

Causes of Staphyloma

It is basically an acquired defect that occurs due to weakness and thinning of the scleral-uveal coat because of any of the following reasons:

• Severe & progressive myopia
• Trauma
• Necrotizing infection
• Scleritis
• Glaucoma
• Inflammation
• Surgical weakening of the sclera
• Radiotherapy

Symptoms of Staphyloma

• Severe axial myopia
• Decreased vision
• Eye fatigue
• Insomnia
• Eye pain
• Diminished vision
• Black or purplish-blue protrusion in front of the eye (anterior staphyloma)

Diagnosis of Staphyloma

• An elaborated eye exam along with dilated fundal eye examination and ophthalmoscopy may expose the presence of staphyloma.

Treatment of Staphyloma

Although there is no specific treatment for staphyloma, but attempt to resolve the condition are made by an ophthalmologist. It may include:

• Application of banked sclera to reinforce anterior staphylomas that appear threatening to erode into the eye.
• Laser treatment to resolve retinal detachment
• Localised staphylectomy under heavy doses of oral steroids
• Corrective lenses for myopia