What Is Bullous Keratopathy?

Medically Reviewed by Poonam Sachdev on August 25, 2022
Written by Sarah Vallie
5 min read

Our eyes are delicate muscles, and many things can cause them to not work properly. If you’ve recently had eye surgery, your doctor may have warned you about bullous keratopathy.

Bullous keratopathy is an eye condition in which the cornea has become permanently swollen as a result of damage to the inner-most layer of the cornea.

The cornea is the clear dome at the front of your eye that covers your iris and pupil. The cornea filters and focuses light into your eye while also providing a protective barrier. The cornea is made up of several layers:

  • Epithelium, the outer-most layer that acts as a barrier for chemicals, microbes, and water that also creates a smooth surface of the eye and houses Langerhans cells, which are important for immune functions
  • Bowman’s layer, the second layer that helps maintain the proper corneal shape
  • Stroma, the third layer that acts as the cornea’s main refracting lens, contributes to the transparency of the cornea, and gives strength to the cornea
  • Descemet’s membrane, the resting layer for the endothelial cells
  • Endothelium, the fourth and inner-most layer of the eye that removes excess fluid from the cornea

The most common cause of damage to the endothelium layer of the cornea is eye surgery. Any kind of trauma, glaucoma, or inflammation from eye surgery can result in bullous keratopathy. 

Bullous keratopathies are much less common than they used to be as surgery techniques and implants have improved. Complications from cataract surgery used to be the most common cause of bullous keratopathy. Currently, the most common cause of bullous keratopathy is complications due to glaucoma surgery. 

Occasionally, bullous keratopathy may be caused by a corneal dystrophy. Corneal dystrophies are a group of genetic conditions that result in abnormal material accumulating within the cornea. Rarely, a few other eye conditions or blunt-force trauma to the eye can cause bullous keratopathy.

Patients with bullous keratopathy may initially not have any symptoms at all. However, the following symptoms may eventually emerge:

  • Decreased vision
  • Eye pain and discomfort
  • Light sensitivity
  • Blurred vision
  • The feeling of a foreign object in the eye
  • Loss of corneal sensation
  • A swollen cornea

Many eye conditions can cause these symptoms. If you are experiencing these symptoms, especially after an eye surgery, meet with your ophthalmologist right away.

Your ophthalmologist will diagnose you with bullous keratopathy based on your medical history and an eye exam. Diagnostic exams and procedures may include:

  • A slit-lamp exam: an exam using a slit lamp, a microscope with a bright light
  • Corneal pachymetry: a test to determine the thickness of the cornea
  • Specular microscopy: an imaging technique that produces highly magnified images of the cornea

Your doctor will look for signs such as:

  • Small blisters or cysts on the cornea
  • The formation of a bulla, a large, fluid-filled blister
  • Corneal edema, or swelling of the cornea
  • Scarring from corneal edema 
  • Folds in the endothelial layer
  • Corneal neovascularization, or the formation of new capillaries in the cornea
  • Increased thickness of the cornea

Bullous keratopathy has many treatment options, both medicinal and surgical. 

Medical management options for bullous keratopathy include:

  • Contact lenses to help protect the eye, improve vision, and alleviate pain
  • Lubricants to prevent irritation and dryness
  • Steroids to reduce inflammation or prevent postoperative complications after cataract surgery
  • Hyperosmotic agents in the form of sodium chloride drops and ointment to form a tear film and reduce fluid accumulation overnight
  • Antiglaucoma drugs to reduce pressure when glaucoma or glaucoma surgery is the culprit
  • Antibiotics to fight infected bullous keratopathy

The ultimate method of curing bullous keratopathy is a corneal transplant. A corneal transplant replaces the affected cornea with a donor. This may include transplant techniques such as a penetrating keratoplasty to replace the entire cornea, or a Descemet Stripping Endothelial Keratoplasty (DSEK), Descemet Stripping Automated Endothelial Keratoplasty (DSAEK), or Descemet Membrane Endothelial Keratoplasty (DMEK) to replace the just the Descemet membrane.

Other surgical management options for bullous keratopathy include:

  • Amniotic Membrane Grafting (AMG), a procedure in which donor amniotic membrane is grafted over the cornea
  • Annular Keratotomy, a procedure in which a small hole is performed on the cornea to relieve pain
  • Anterior Stromal Puncture, a procedure in which multiple holes are punched into the stroma
  • Basement Membrane Polishing, a procedure in which a diamond tool is used to remove damaged tissue and polish the epithelial basement membrane, the membrane at the bottom of the epithelial layer that separates it from the stroma
  • Bowman’s Membrane Cautery, a procedure in which the barrier between the epithelium and stroma is tightened, reducing pain and preventing fluid buildup
  • Corneal Collagen Crosslinking with Riboflavin (C3R), a new procedure to temporarily reduce corneal edema. In this procedure, UVA light activates riboflavin, or vitamin B2, which strengthens bonds in the stroma
  • Gunderson Conjunctival Flap, a procedure in which a thin flap of the conjunctiva, a clear membrane covering the surface of the eye and inner eyelids, is placed over the cornea
  • Phototherapeutic Keratectomy (PTK), a laser treatment to reduce pain, bullae, and stromal edema

Medical management generally can’t cure bullous keratopathy — only surgery can. Prognosis is poor for those who only use medical management. Timely surgical intervention often has a good prognosis. Without proper treatment, bullous keratopathy could lead to blindness.

The treatment options for bullous keratopathy may have their own side effects and complications. Complications of medical management for bullous keratopathy include:

  • Dry eyes
  • Drug toxicity or reactions
  • Irreversible corneal edema

Complications of surgical interventions for bullous keratopathy may include:

  • Cystoid macular edema, a condition in which blood vessels of the retina, the tissue lining the back of the eye, leak fluid into the macula, a small part of the retina that helps us see clear details
  • Expulsive choroidal hemorrhage, an accumulation of blood between the sclera, the whites of the eyes, and the choroid, the layer separating the sclera from the retina
  • Graft failure or graft rejection, in which the graft fails or the body rejects the graft
  • Iatrogenic trauma, in which tissue is damaged due to medical treatment
  • Secondary glaucoma, in which glaucoma may develop due to medical treatment
  • Vitreous prolapse, in which the gel that fills the space between the lens and back of the eye spills into the front portion of the eye

If you suspect you may have a bullous keratopathy, especially if you’ve recently undergone eye surgery, speak with your ophthalmologist right away.