Investigations

Corneal topography (Pentacam)

Corneal topography is a technology that creates 3D maps of the surface curvature of the cornea. Corneal topography produces a detailed, visual description of the shape and power of the cornea. This analysis provides your doctor with very fine details of the cornea used to diagnose, monitor, and treat various eye conditions. They are also used in fitting contact lenses and for planning surgery, including laser vision correction like PRK and LASIK.

Specular microscopy

It is a technology used to assess the morphology, density and function of corneal endothelial cells. Endothelium is the innermost of the 5 layers of cornea.

Common ocular conditions, such as glaucoma, uveitis and Fuchs endothelial dystrophy, may produce changes in the structure and function of the corneal endothelium that result in corneal edema and visual impairment. Additionally, clinical circumstances, such as contact lens wear and intraocular surgery, may compromise the endothelium and cause corneal edema. An accurate diagnosis of endothelial disease may be the key in not only determining cause of corneal edema, but also developing a treatment plan. 

Corneal surgical procedures

Pterygium surgery:

Pterygium surgery is a procedure performed to remove the conjunctival growth on the cornea. A pterygium is a growth of scar-like tissue of the conjunctiva onto the edge of the cornea. It typically occurs on the nose side of the eye but can also occur on the ear side. Small pterygia are common and often don’t cause significant symptoms. They can cause redness and irritation. If they get large, they can also affect the vision. If they cause decreased vision or severe discomfort, they can be surgically removed.

The pterygium is excised and some conjunctival tissue from the upper part of the eye is removed and placed in the area from which the pterygium was removed, to decrease the chance of recurrence of the pterygium. However, the pterygium can occasionally recur. Pterygium surgery is performed using local or topical anesthesia.

Corneal Collagen cross linking:

Corneal collagen cross-linking or C3R is a treatment for an eye problem called Keratoconus In this condition, the front part of your eye, called the cornea, thins out and gets weaker over time. This makes it bulge into a cone shape, which can distort your vision and make it hard to see. If the symptoms of keratoconus get severe, you will need a corneal transplant. In corneal cross-linking, doctors use eyedrop medication and ultraviolet (UV) light from a special machine to make the tissues in your cornea stronger. The goal is to keep the cornea from bulging more. It’s called “cross-linking” because it adds bonds between the collagen fibers in your eye. They work like support beams to help the cornea stay stable. Corneal cross-linking is the only treatment that can stop progressive keratoconus from getting worse. And it may help you avoid a corneal transplant, which is major surgery.

You’re more likely to get it if you:

• Are over 40 years old
• Have a family history of glaucoma
• Are nearsighted or farsighted
• Have poor vision
• Have diabetes
• Take certain steroid medications such as prednisolone
• Have had an injury to your eye or eyes
• Have corneas that are thinner than usual
• Have high blood pressure, heart disease, diabetes, or sickle cell anemia
• Have high eye pressure

Types of glaucoma

There are two main kinds:

Open-angle glaucoma: This is the most common type. Your doctor may also call it wide-angle glaucoma. The drain structure in your eye (called the trabecular meshwork) looks fine, but fluid doesn’t flow out like it should.

Angle-closure glaucoma: This is more common in Asia. You may also hear it called acute or chronic angle-closure or narrow-angle glaucoma. Your eye doesn’t drain like it should because the drain space between your iris and cornea becomes too narrow. This can cause a sudden increase of pressure in your eye. It’s also linked to farsightedness and cataracts.  

Less common types of glaucoma include:

Secondary glaucoma: This is when another condition, like cataracts or diabetes, causes added pressure in your eye.

Normal-tension glaucoma: This is when you have blind spots in your vision or your optic nerve is damaged even though your eye pressure is within the average range. Some experts say it’s a form of open-angle glaucoma.

Pigmentary glaucoma: With this form, tiny bits of pigment from your iris, the coloured part of your eye, get into the fluid inside your eye and clog the drainage canals.

Symptoms

Most people with open-angle glaucoma don’t have symptoms. If symptoms do develop, it’s usually late in the disease. That’s why glaucoma is often called the "silent thief of vision." The main sign is usually a loss of side, or peripheral, vision.

Symptoms of angle-closure glaucoma usually come on faster and are more obvious. Damage can happen quickly. If you have any of these symptoms, get medical care right away:

• Seeing halos around lights
• Vision loss
• Redness in your eye
• Eye that looks hazy (particularly in infants)
• Upset stomach or vomiting
• Eye pain

Diagnosis

Glaucoma tests are painless and don’t take long. Your eye doctor will test your vision. They’ll use drops to widen (dilate) your pupils and examine your eyes. They’ll check your optic nerve for signs of glaucoma. They may take photographs so they can spot changes at your next visit. They’ll do a test called tonometry to check your eye pressure. They may also do a visual field test to see if you've lost peripheral vision. If your doctor suspects glaucoma, they may order special imaging tests of your optic nerve.

Treatment:

Your doctor may use prescription eye drops, oral medications, laser surgery, or microsurgery to lower pressure in your eye.

Eye drops: These either lower the creation of fluid in your eye or increase its flow out, lowering eye pressure. Side effects can include allergies, redness, stinging, blurred vision, and irritated eyes. Some glaucoma drugs may affect your heart and lungs. Because of potential drug interactions be sure to tell your doctor about any other medical problems you have or other medications you take. Also let them know if it’s hard for you to follow a regimen involving two or three different eye drops or if they have side effects. They may be able to change your treatment.

Oral medication: Your doctor might also prescribe medication for you to take by mouth, such as a beta-blocker or a carbonic anhydrase inhibitor. These drugs can improve drainage or slow the creation of fluid in your eye.

• IridotomyThis makes a tiny hole in your iris to let fluid flow more freely.

Microsurgery: In a procedure called a trabeculectomy, your doctor creates a new channel to drain the fluid and ease eye pressure. Sometimes an a valve or an implant may be required in addition to trabeculectomy.

Open-angle glaucoma is most often treated with combinations of eye drops, laser trabeculoplasty, and microsurgery. Doctors tend to start with medications, but early laser surgery or microsurgery could work better for some people.

Acute angle-closure glaucoma is usually treated with a laser procedure.