Premium IOL technology has improved considerably over the past 2 decades. The current generation presbyopia-correcting and astigmatism-correcting lenses provide excellent visual results and have enabled the great majority of patients selecting these IOLs to reduce or eliminate their dependence on glasses. However, achieving successful outcomes with premium IOLs is dependent upon many factors. Here are some strategies for success with these lenses:
1. Patient selection
Patients have increased expectations and often assume perfect vision, rapid recovery, and no complications after surgery. Therefore, selecting appropriate candidates is critical for achieving “20/happy” outcomes. Patients must be motivated to reduce their dependence on glasses or contact lenses, understand the limitations and risks of surgery, have realistic expectations about the results of surgery, and have no contraindications to the use of the chosen lens. For premium IOLs, it is essential to match the right lens to patient needs. This is accomplished by listening to the patient and asking about visual needs (i.e., daily activities, occupation, and hobbies).
2. Make a specific recommendation
Avoid giving the patient too much information. The patient is relying on the surgeon for his or her expert opinion, so rather than explaining all the different lens technologies in detail, it is best to keep it simple and recommend the lens you feel is best based on the patient’s needs and ocular health.
Toric IOL: The Alcon Acrysof toric IOL does a superb job of correcting up to 4 D of corneal astigmatism. It requires minimal additional physician time for testing or counseling, and patients are extremely satisfied with the results. It should be offered to any patient with 1 D or more of astigmatism who desires monofocal implants for bilateral distance correction, near correction, or monovision.
Multifocal IOLs: I have had excellent success with both the Alcon ReSTOR +3 and the Tecnis multifocal IOLs. A multifocal is my lens of choice because it provides the best range of uncorrected vision. Patients should be able to tolerate mild glare/halos at night and must not have any eye condition that could compromise the function of the IOL. I prefer the Tecnis lens because it is pupil size independent, providing the best near vision in all lighting conditions. For optimal functioning, multifocal IOLs must be perfectly centered in the capsular bag and corneal astigmatism must be corrected.
Accommodating (Crystalens) IOL: This lens is better for patients who spend more time on the computer and want to do so without glasses but don’t mind wearing glasses for reading up close. It is also the best alternative for patients who have a contraindication for a multifocal lens and who are glare/halo sensitive. In particular, I find that younger patients (< 45 years old) have more trouble with glare/halo from multifocal lenses. For optimal results, this lens must be rocked and rotated at least 90 degrees at the conclusion of surgery to position it correctly in the capsular bag. In addition, the incision must be watertight (a suture is recommended) and a drop of atropine used for cycloplegia in order to prevent the lens from moving out of position in the immediate postoperative period.
3. Hit the refractive target
Delivering the best refractive results depends on precise preoperative measurements and meticulous surgical technique. This is a multifactorial process that includes obtaining accurate keratometry and axial length values (use of optical biometry devices such as the IOLMaster and Lenstar 900 in conjunction with optimized 4th generation IOL formulas is recommended), detecting and treating tear film and corneal irregularities (i.e, ocular surface disease and anterior basement membrane dystrophy which can have a significant impact on keratometry measurements), being cognizant of surgically induced astigmatism, and standardizing surgical technique for wound and capsulorhexis construction. It is also important to detect any other abnormalities of the cornea, retina, and optic nerve that could contribute to reduced vision or could increase the risk of a complication. Similarly, specialized testing is often necessary for surgical planning. Corneal topography must be performed to detect pathology and identify astigmatism. Furthermore, this test along with corneal pachymetry is used to determine whether the patient can safely undergo laser vision correction for a residual refractive error. I also believe it is necessary to obtain a macular OCT in all patients desiring a multifocal IOL because OCT can detect subtle macular pathology that may not be visible on direct exam and that could preclude the use of such a lens.
4. Reduce postoperative complications
This starts with a postoperative topical medication regimen of a potent, broad-spectrum antibiotic to prevent infection, and a steroid and NSAID to treat inflammation and prevent cystoid macular edema (CME). I administer a topical steroid and NSAID for 4-8 weeks after surgery depending on the patient’s risk of developing CME (i.e., increased risk with diabetes, uveitis, retinal vein occlusion, epiretinal membrane). For patients with no increased risk of CME who select a presbyopia-correcting IOL, I use these drops for 6 weeks to minimize CME since even subtle edema can interfere with the performance of these IOLs.
5. Manage outcomes
Proper postoperative counseling is also important, so any issues that arise should be addressed and treated promptly. This process should be initiated prior to surgery by adequately preparing patients as to what to expect after surgery. Doing so will reduce the amount of postoperative chair time. Often patients just want their concerns validated, and simple reassurance is sometimes all that is needed.
Blurry vision: The treatment of reduced vision depends on the etiology. The most common cause of postoperative blurred vision is a residual refractive error. I treat this with laser vision correction once the refraction has stabilized (I like to wait at least 3 months). Dry eye is also a frequent cause of blurry vision, and therefore I carefully evaluate all surgical patients preoperatively for dry eye and treat it aggressively before and after surgery. CME must be considered when patients develop deterioration in vision 2-6 weeks after surgery. Unless the patient is at increased risk for CME, I find this complication very rare (<1%) with the use of postoperative topical NSAIDs in addition to steroids. Finally, posterior capsular opacification can cause reduced vision in the early or late postoperative period. Subtle PCO changes can have a significant impact on patients with multifocal and accommodating lenses, so I tend to perform laser posterior capsulotomy earlier for these patients.
Halos: Halos around lights at night are a form of dysphotopsia that is common with multifocal IOLs. Therefore, I warn patients that this occurs and is normal. The halos improve with time and usually resolve within 6-12 months. When patients are having difficulty with halos, constricting the pupil with Alphagan-P or pilocarpine can be quite helpful. Vision training may be beneficial as well. Ultimately, an IOL exchange can be considered but is rarely needed.
Poor near vision: Variable near vision is also a limitation of presbyopia-correcting IOLs. I therefore warn all patients of this possibility prior to surgery and emphasize that these lenses will reduce dependence on glasses but do not always eliminate the need for glasses, particularly for reading. After surgery, near vision tends to continue to improve over weeks to months as patients adapt to their new vision and learn how to see with the lens. I also explain to patients that these lenses work best binocularly so the near vision will improve after surgery on their second eye. In addition, it is helpful to show patients what their near vision would have been had they not had a presbyopia-correcting IOL, and this can be easily demonstrated by having them read at near through -2.50 or -3.00 D lenses.