What Is Pigmentary Glaucoma?
Glaucoma is a broad category of eye disorders related to an elevated eye pressure. The optic nerve fibers, which carry images from the retina to the brain, can be damaged from the increased pressure. Pigmentary glaucoma, according to the Mayo Clinic, is a type of glaucoma associated with a scattering of the pigment granules within the eye. These granules mix with the fluid inside the eye and interfere with eye drainage. By collecting in the meshwork that allows the fluid to maintain a proper level, eye pressure becomes elevated.
Medications to control the fluctuations of pressure in the eye are the first option considered. Pigmentary glaucoma treatment often requires a combination of medications to get the elevated eye pressure under control.
Medications used for eye pressure treatment, as reported by the Merck Manuals, include:
- Eye drops to decrease aqueous humor production in the eye, which may include Beta-blockers such as timolol, betaxolol, levobetaxalol or metipranolol and carbonic anhydrase inhibitors such as methazolamide, acetazolamide or dorzolamide.
- Medications used to increase the aqueous humor outflow, which may include prostaglandin-like compounds such as travoprost, bimatoprost, unoprostone or latanoprost and cholinergic drugs such as pilocarpine, neostigmine, carbachol, isoflurophate and physostigmine.
- Combination drugs, such as epinephrine, dipivefrin, apraclonidine and brimonidine that work by decreasing aqueous humor production while increasing the outflow.
The American Academy of Ophthalmology defines three types of surgery as options for pigmentary glaucoma, if medications are not sufficient to control the eye pressure. Laser trabeculoplasty, which creates tiny holes in the filtration angle of the eye, treats cells of the trabecular meshwork to reduce the intraocular pressure.
Laser iridotomy creates a tiny hole in the iris, which allows equalization of pressure between the posterior and anterior chambers and moves the iris away from the lens. With a flattened iris, loss of pigment does not occur.
Trabeculectomy, also known as filtering surgery, is a slightly more invasive technique requiring a local anesthetic. Your ophthalmologist makes a small flap in the sclera (the white of the eye) and creates a reservoir to collect the aqueous humor. Surrounding blood vessels absorb the excess fluid from the reservoir.
Prognosis for Pigmentary Glaucoma
With early and proper diagnosis and treatment, the prognosis for pigmentary glaucoma is good. Glaucoma can develop with no recognizable signs, so regular checkups to monitor eye pressures are vital to preventing future damage to the optic nerve.
Tests used in evaluating glaucoma include tonometry, which measures the intraocular pressure of each eye and ophthalmoscopy, in which an ophthalmologist looks at the inside of your eye using a special instrument with a light. Other tests may include a visual field test to check peripheral vision or for blind spots and a gonioscopy to examine the angle of the iris.
Mayo Clinic: Glaucoma https://www.mayoclinic.com/health/glaucoma/DS00283/DSECTION=causes
Merck Manuals Online Medical Library: Glaucoma https://www.merckmanuals.com/home/sec20/ch233/ch233a.html#dtb233_1
American Academy of Ophthalmology: Ophthalmic Pearls: Glaucoma https://www.aao.org/publications/eyenet/200901/pearls.cfm?RenderForPrint=1&