It is not surprising that, as two relatively common diseases in the aging population, a combination of glaucoma and cataract can appear in the same person.
Cataract, a clouding of the natural lens of the eye, is quite common in the elderly population. When the cataract becomes dense enough to interfere with the patient’s lifestyle, it may be time for the cataract to be removed. An Intraocular Lens Implant (IOL) is used to restore the vision to near normal levels.
Glaucoma, a disease of the optic nerve, is usually associated with elevated intraocular pressure. Medications are used in the eye to reduce the pressure and stop the disease process. Unfortunately, the glaucoma cannot be “removed” from the eye in the same way a cataract is permanently removed. Laser surgery and traditional surgery can both be utilized to assist in the control of the disease.
When a patient has glaucoma and needs cataract surgery, the situation may be very different from another patient who does not have glaucoma. Cataract surgery in the glaucoma patient can be more difficult to perform. The pupil often dilates poorly, making access to the cataract more limited. In certain types of cataracts, the supporting structures of the cataract can be weak, influencing the way the cataract must be removed, and the risk is slightly greater. Eye surgeons not frequently performing surgery on glaucoma patients may modify the surgery, not utilizing more advanced techniques.
THE DECISION AS HOW TO PROCEED DEPENDS ON MANY FACTORS:
How severe is the glaucoma?
If the glaucoma is relatively advanced, with a lot of visual field loss, the eye can be very sensitive to a post-cataract surgery rise in intraocular pressure. This could cause further loss of visual field.
How well controlled is the glaucoma?
Is the intraocular pressure controlled as low as the disease requires? This is determined by the doctor for each patient depending on many risk factors. The goal is lifetime preservation remaining vision for the patient.
How much medication does the patient take and what medication intolerances (or allergies, etc.) are there, or have there been?
Has previous glaucoma surgery been successful?
The presence of other eye disease – Macular Degeneration, etc.?
The health of the other eye?
Combined Cataract and Glaucoma Surgery
If the glaucoma is significant or the pressure uncontrolled on many medications or if the medications are poorly tolerated (or not used), this is the likely alternative. The reason for this choice is the frequent occurrence of a rise in pressure to dangerously high levels during the first few weeks after cataract surgery. The optic nerve can be very sensitive to this rise in pressure which could quickly damage the vision. This rise in pressure can be avoided in most cases by combined cataract and glaucoma surgery. The glaucoma operation also may make the glaucoma much easier to control after surgery, requiring less medication.
Cataract Surgery Alone
If the glaucoma is not significant (amount of visual field loss), and the intraocular pressure is easily controlled on few well-tolerated or no medications, this is the likely alternative. This can be done with a “no-stitch” technique. It is often, however, more difficult to perform cataract surgery in glaucoma patients as the pupil may not dilate well requiring special surgical maneuvers. Laser trabeculoplasty has been recommended by some eye surgeons to be used before cataract surgery, to avoid the need for combined cataract and glaucoma surgery. This does not, however, avoid the potential postoperative rise of pressure in the first few weeks after cataract surgery.
No Cataract Surgery
There are some glaucoma patients in whom cataract surgery should be delayed. When a patient is in the advanced stages of glaucoma, perhaps with only one sighted eye, and the glaucoma is well controlled, it may be best to wait until the vision is more affected by the cataract. Also, certain glaucoma medications make the pupil smaller. This would give the impression that the cataract is worse than it really is. As an alternative, a laser procedure could be performed to widen the pupil while the patient is on these medications allowing better vision until the cataract progresses. If the glaucoma is uncontrolled and itself requires surgery,
glaucoma surgery alone could be performed as another alternative for these patients, as often the medications making the pupil small can be deleted, allowing better vision. The cataract can then later be removed when needed.
MEDICATIONS WHICH AFFECT WOUND HEALING
Certain medications can increase the success of the glaucoma part of the operation. At the time of this writing, anticancer drugs as 5 fluorouracil and mitomycin-c have been used. Other drugs will likely be utilized in the future. These medications decrease scar tissue formation that causes glaucoma operations to fail. These drugs can increase the risk of the procedure, but may improve success in the hands of an experienced surgeon.
The decision as to which alternative should be used is made on an individual basis. The experience and skills of the surgeon influence the choice that is made. Dr. Hurvitz and Dr. Wahl are surgeons experienced in the removal of cataracts from glaucoma patients. They enjoy discussing your case with you and assisting you in making the proper decision for your particular case. Our ongoing commitment is to safely bring together the most advanced techniques from glaucoma surgery and cataract surgery for the benefit of their patients.