Cataract Surgery Risks – James S. Lewis, MD
Also Serving Philadelphia, Bucks County, King of Prussia, Delaware Valley, Warminster, Conshohocken and Phoenixville
Virtually all surgeries have some degree of risk. You and your surgeon must balance the risks against the benefits. The surgeon should describe the risks from surgery in general as well as the special risks you might have following a complete and detailed ocular examination.
Prior to making this decision you should consider what problems you are experiencing visually and how they impact your life. The onset of cataract development is not a reason to have surgery. In fact, most patients over 60 have some degree of cataract development and in many of these cases the signs and symptoms are sub-clinical. Your surgeon should dissuade you from surgery if your cataract is not effecting your activities of daily living. Similarly your surgeon should make sure you are not simply rationalizing your symptoms and avoiding surgery because you are scared, you don’t want to complain, or you think you are too old.
Cataract surgery is one of the most successful procedures in modern medicine. Well over 99% of patients are very happy with the results or can at least recognize significant visual functional improvement. Approximately .5% have problems after surgery that will be described below. Most of this small group will recover through additional therapy and sometimes additional surgery. Most of the common and uncommon risks are listed below.
Rarely the retina, the neuro-ocular tissue that lines the inside back of the eye, can become separated from its blood supply at the time of surgery or soon thereafter. Retinal detachment also occurs without surgery particularly in those with significant myopia (nearsightedness), trauma, or a family history. When patients are at a high risk of retinal detachment Dr. Lewis asks a retinal specialist to evaluate your risks and perform any prophylactic treatment to minimize the chances of a detachment. Because postoperative patients are followed immediately after surgery and for a few months thereafter these detachments are caught early. The signs and symptoms of retinal detachment are described to all surgical patients to facilitate their recognition and prompt a quick response. Over 90% of patients who alert their doctor to symptoms of flashes, floaters, and a curtain crossing the vision will recover all or almost all of their vision.
Cystoid macular edema is usually a self-limited phenomenon that can go unrecognized in many patients. The use of topical non-steroidal anti-inflammatory medications routinely is theorized to reduce this complication. In some patients with diabetes, uveitis, or pre-existing macular disorders (epi-retinal membrane, partial lamellar hole) cystoid macular edema is anticipated and treated aggressively with topical medications. If this is exacerbated after cataract surgery, more aggressive and effective drug treatment has become available recently. If this condition does not resolve promptly or if you are recalcitrant to standard therapy, Dr. Lewis will refer you to a retinal specialist who will administer these newer agents.
Stable macular degeneration is rarely exacerbated by cataract surgery. If a patient has active hemorrhagic macular degeneration (wet), Dr. Lewis will ask a retinal specialist to treat this condition and to clear you for subsequent cataract surgery when your ocular health has stabilized.
Other Retinal Problems
Rarely other retinal problems can occur. While most are not caused or do not appear to be caused by cataract and related surgeries, it is worthwhile mentioning them here. Retinal vascular occlusion, epi-retinal membrane development, initiation or progression of a macular hole, retinal hemorrhage, vitreous hemorrhage, and other extremely rare retinal anomalies.
Almost all patients experience a change in the amount and frequency of “floaters” . This is the result of additional movement of the partially liquified vitreous humor that composes the vast majority of the ocular volume. Shadows are cast by the more condensed portions of the vitreous and they are interpreted as flies or clouds that move. Because this is a virtual image (existing entirely within the eye) there are really no flies or clouds. In almost all cases these floaters resolve over days, weeks, or months. Very rarely, additional laser treatment and sometimes a pars plana vitrectomy is required.
Infection of the intraocular contents is an extremely rare phenomenon. It occurs in as few as 1 out of every 5000 to 10,000 surgeries. It is almost always recognized during the early post-operative visits and if treated resolves with recovery of all or almost all vision in 95% of cases. Cataract surgeons worldwide have endeavored to reduce the occurrence of endopthalmitis through the use of topical betadine (iodine-like antiseptic) applied to both the lids and the surface of the eye as well as advanced topical antibiotics both before surgery, during surgery, and following surgery. Care must be taken to maintain excellent incision construction. This has become a simpler tasks now that Dr. Lewis’s incision size has been reduced to 2.2 millimeters. Dropless therapy has been shown to reduce the risk of endophthalmitis dramatically. Some report the incidence to be below 1 in 50,000. We continue to use Dropless on all appropriate cases.
Very rarely the support structure of the natural crystalline lens do not survive surgery. This is slightly more common in those patients with severe pre-existing trauma (including surgical trauma), unusual ocular developmental issues, or systemic metabolic disorders. In most of these cases the advances in capsular support technologies (endocapsular rings, scleral sutured rings, capsular retraction devices) allow the surgery to progress without incident. If the capsule can not be retained the implant can be sutured to the iris or more physiologically to the scleral using the Lewis Suture Technique. The new Yamane technique has now supplanted most other methods of scleral fixation. In the rare instance in which some lens material can not be removed at the time of surgery a pars plana vitrectomy is scheduled with a retinal surgeon. In the extremely rare case the intraocular lens implantation is simply scheduled for another day.
IOL Power Surprise
The accuracy of intraocular lens power calculations have helped make cataract surgery on par with LASIK surgery. In fact, most postoperative cataract patients can pass the Pennsylvania driver’s test without glasses (95% in Dr Lewis’s Study). In patients with unusual corneal topography as is present in corneal ectasia (Keratoconus, Pellucid Marginal Degeneration, Keratoglobus), irregular astigmatism (trauma, previous surgery, Peripheral Marginal Degeneration, resolved microbial keratitis, Salzmann’s Nodules, Severe Dry Eye), or previous LASIK, Epi-LASIK, Penetrating Keratoplasty, Lamellar Keratoplasty, RK, AK, Intacs, or ALTK the formulas are less effective. The formulas are also less successful in patient who have had retinal detachment surgery, posterior staphaloma, silicone oil treatment, and coloboma. While the implant power determination can be accomplished using advanced techniques sometimes the results are not perfect. In these cases patients elect to wear glasses, or to have an intraocular lens exchange, intraocular lens piggyback, or corneal refractive correction (LASIK). Dr. Lewis does this at no cost to the patient. Our practice has developed a number of special techniques to minimize these IOL Power issues.
Floppy iris syndrome is usually the results from the use of Flomax (or other newer medications) for urinary retention. Thanks to innovative surgical appliances these cases have gone from extremely difficult to routine. Iris damage is extremely rare because of the improvements in viscoelastics, iris retractors (Graether Pupillary Ring, Malyugin Ring) and improved fluidics. Iris repair techniques are used to ameliorate these pupillary issues.
Retained Lens Material
On occasion a small portion of cataract can escape detection and be found at some time postoperatively. If it is small enough this resolves naturally, when it is larger or primarily composed of lens nucleus a 2 minute return trip to the operating room is required. This is a rare event and usually results in complete recovery.
When larger incisions were prevalent the corneal shape was changed during cataract surgery and vision did not recover completely until the sutures were removed. Because incisions today have been reduced to 2.2 millimeters and are self-sealing excessive residual astigmatism is extremely rare. Sometimes limbal relaxing incisions (LRI, RLI) are performed to correct pre-existing corneal astigmatism. Sometimes it does not completely eliminate the patient’s astigmatism, only rarely is the astigmatism made worse. This can be resolved by suturing or removing sutures from the cornea. Sometimes procedures like LASIK are required. With the improvement in phacoemulsification instrumentation corneal burns, an unfortunate complication of cataract surgery which can induce corneal damage and irregular astigmatism, has been minimized in our practice.
Following surgery for a very dense cataract, or in an eye with a small anterior chamber (as in some cases of hyperopia), the cornea can remain less than crystal clear for a few days and sometimes even weeks. This can also occur when patients have a reduced number of endothelial cells either from previous surgery, trauma, or a condition knowns as Endothelial Dystrophy (Fuchs). In the rare instance the cornea does not recover, these cells are replaced using procedure known as DSEK or a related technique DMEK. Sometimes, Dr. Lewis will recommend performing the DSEK (endothelial corneal transplantation) at the same time as the cataract and intraocular lens procedure. This “triple procedure” results in rapid and dramatic visual rehabilitation.