Glaucoma Following Cataract Surgery
Chat Highlights – December 19, 2012
Guest Speaker – Dr. Anand Mantravadi
Lorraine Miller, Editor, Chat Topic Researcher
Moderator: Good evening. Tonight’s chat is entitled, “Glaucoma Following Cataract Surgery.” Dr. Anand Mantravadi is our medical expert this evening.
P: What is a secondary glaucoma and why can it occur after cataract surgery?
Dr. Mantravadi: Secondary glaucoma is any form of glaucoma that is “secondary” to a known or identifiable cause. This can happen early after cataract surgery due to a number of causes such as inflammation, bleeding, the retainment of a “viscoelastic device” used in surgery, or the retainment of lens fragments. It can also happen after cataract surgery if outflow is compromised for any reason. For example, if there is a pre-existing pseudoexfoliation syndrome.
P: What types of glaucoma can be considered secondary after cataract surgery?
Dr. Mantravadi: A broad variety of glaucomas can be secondary to cataract surgery and are usually due to a complicated surgery. Both open-angle and angle-closure glaucomas can result.
P: When and how is this form of glaucoma discovered?
Dr. Mantravadi: It is usually discovered during post-operative evaluations or, if symptoms develop in the interim, when the patient re-presents to their physician.
P: How is secondary glaucoma after cataract surgery initially treated?
Dr. Mantravadi: It is usually based on a causative factor. Initially, medical therapy is instituted. Surgical therapy is used if medical therapy fails, or if the causative factor is particularly well-tailored to surgical treatment. For example, if retained lens material is the problem, then further surgery to remove it is required. If blood is the causative factor, then removal can possibly proceed with or without glaucoma surgery. If retained viscoelastic is the factor, sometimes a small “release” of fluid from the cataract incision may be indicated and sufficient. All treatments are tailored to the individual case at hand.
P: If the initial treatment does not generate a positive response, what other treatment options are available?
Dr. Mantravadi: If the optic nerve is at risk for damage and glaucoma surgery is needed, filtration surgery as a trabeculectomy or the installation of a tube shunt may be required. There is a possibility that other surgery may be required such as the removal of a lens fragment or a vitrectomy. It all depends on the cause, the severity and the progression of damage.
P: Is the cause of the secondary glaucoma reflected in the method of treatment?
Dr. Mantravadi: Yes, often it is.
P: Do any of the risk factors for glaucoma apply to secondary glaucoma following cataract surgery?
Dr. Mantravadi: Yes, particularly pseudoexfoliation syndrome.
P: Does the secondary glaucoma affect the outcome of the cataract surgery?
Dr. Mantravadi: If secondary glaucoma develops, prompt treatment may lead to an excellent outcome.
P: Can secondary glaucoma following cataract surgery be temporary with treatment?
Dr. Mantravadi: Yes. Inflammation can resolve, and retained viscoelastic material can either be absorbed or resolved.
P: Is medical treatment always required with this secondary glaucoma or will IOP return to normal levels over time?
Dr. Mantravadi: Medical treatment during the immediate post-operative window is temporary and may be discontinued after stabilization occurs. Thus, medication use may be temporary.
P: Is secondary glaucoma due to congenital, infantile, or pediatric cataract surgery different than adult secondary glaucoma?
Dr. Mantravadi: Usually yes, due to different mechanistic issues. Congenital, infantile, and pediatric glaucomas have a pre-existing outflow problem. In contrast, adult secondary glaucomas, developed after cataract surgery, may involve a normal outflow system that is temporarily overwhelmed but will resume normal functionality as time passes and the eye stabilizes. It can be very different.
P: Is the transient normal post-operative pressure rise due to the cataract surgery considered secondary glaucoma?
Dr. Mantravadi: No, and many procedures do not cause a pressure rise.
P: Does the surgical technique performed affect the number of secondary glaucoma cases that occur?
Dr. Mantravadi: Meticulous surgical technique can minimize but not eliminate secondary glaucomas. There are some eyes that are pre-disposed and will develop secondary glaucoma regardless of the most precise and flawless techniques.
P: Does LASIK surgery change the probability of secondary glaucoma following cataract surgery?
Dr. Mantravadi: LASIK results in a thinner cornea but should not lead to a greater risk of post-cataract surgery secondary glaucomas.
P: Does the type of intraocular lens (IOL) implanted in the eye affect the risk of secondary glaucoma?
Dr. Mantravadi: Older anterior chamber lens implants had a higher incidence of secondary glaucomas. Newer lens implants do not cause different incidence rates of secondary glaucomas.
P: If those without glaucoma can develop glaucoma after cataract surgery, is it possible that a patient with glaucoma develops an additional type of glaucoma due to the surgery?
Dr. Mantravadi: Open-angle glaucomas can be exacerbated, and in rare instances, open-angle glaucomas can become closed-angle.
P: After successful cataract surgery with lens implantation, what is the best vision if a diagnosis of glaucoma exists?
Dr. Mantravadi: Early to moderate glaucomas can have very good vision and even advanced cases may have good central acuity. If the glaucoma is the limitation, even despite successful cataract surgery, the best possible vision may be limited to varying degrees.
Moderator: Doctor, one thing we haven’t mentioned is that IOP can often decrease after cataract surgery. I was off drops for at least a couple of years after cataract surgery in my affected eye.
Dr. Mantravadi: Great point! There is a growing body of evidence to suggest that lens removal can result in a long term pressure reduction in select populations.
P: Can controlled glaucoma worsen with cataract surgery?
Dr. Mantravadi: Sometimes, but this can be impossible to predict ahead of time. Controlled glaucomas can often remain controlled after cataract surgery and these patients may derive a modest, long term benefit of lower IOP following cataract removal.
P: Could the type of cataract, (PSC, nuclear, or sclerotic) manifest and influence the type of angle disposition and impending glaucoma?
Dr. Mantravadi: Large lenses, that become larger with nuclear sclerosis-type cataract formation, can narrow the angle and lead to angle-closure glaucomas. This is termed, phacomorphic glaucoma. Other cataracts in average or larger eyes may not significantly affect the angle configuration.
P: What is the difference in the central and peripheral vision of someone recently diagnosed with secondary glaucoma following cataract surgery compared to an individual newly diagnosed with glaucoma that has been treated and detected early?
Dr. Mantravadi: The more advanced the glaucoma, the more of a visual threat to both central and peripheral vision.
Moderator: Thank you, Dr. Mantravadi.
Dr. Mantravadi: Happy Holidays and all the best in 2013!