CASE PRESENTATION
A 60-year old white male with high myopia and astigmatism presented for a refractive surgery consultation. The patient reported needing stronger contact lenses every 6 months for approximately 3 years. He had recently been told that he had developed cataracts. The patient stated his business partner had recently undergone successful clear lens extraction with multifocal implantation, and the patient expressed his strong desire to undergo surgery with the Array multifocal implant.
The patient's UCVA was 2/200 in both eyes. Visual acuity with his current spectacles was 20/50 in the right eye and 20/60 in the left eye, His manifest refractions achieved 20/30+2 vision with a -15.50 +1.00 x 090 in the right eye and 20/30-1 with -15.75 +4.00 x 083 in the left eye. Upon slit-lamp examination, there was 3-4+ nuclear sclerosis in both eyes. The corneas were clear, anterior chambers were quiet, and I did not observe any other anterior segment pathology. Fundus examination revealed typical myopic discs with no macular pathology. No tears or breaks in the peripheral retina were detected after a subsequent consultation with a retinal specialist.
HOW WOULD YOU PROCEED?1. Would you routinely recommend an Array multifocal implant for a patient with extreme myopia or for myopia in general?
2. Would you offer this patient corneal astigmatism correction surgery? If yes, intraoperative or postoperative?
3. If you offered the patient astigmatic correction surgery, would it be with limbal relaxing incisions (LRI) or astigmatic keratotomy (AK)?
SURGICAL COURSE
After the initial consultation, I advised the patient that he was not an ideal candidate for the Array multifocal implant, and he elected not to have surgery at that time. The patient returned 1 year later; his vision with his newer spectacles had declined to 20/50-2 in the right eye and 20/70 in the left eye. The patient reported a precise history of achieving 20/20 vision with spectacles prior to developing cataracts. He repeated his strong desire to receive the Array multifocal implant at the time of his cataract surgery. He understood that he would require correction of his corneal astigmatism to achieve uncorrected visual acuities consistent with obtaining a near benefit postoperatively with the Array multifocal implant. The patient's pupils in very dim light measured 6 mm using infrared pupillometry. A subsequent discussion regarding the risks and benefits of the Array multifocal implant, including the possibility of significant glare and halos with night driving, did not dissuade this patient's desire to receive the multifocal implant.
Two weeks following the surgery, the patient's distance UCVA was 20/30+1 in the right eye, with Jaeger 1- near visual acuity. He underwent similar surgery in the left eye, and received a 9.00 D SA40 foldable silicone Array multifocal implant. One week following surgery on his left eye, the patient's UCVA at distance was 20/20-2 in the right eye and 20/50+1 in the left eye. His near visual acuities were Jaeger 2 in the right eye and Jaeger 6 in the left eye. His manifest refractions were -2.00 +2.50 x 090 in the right eye yielding a vision of 20/20-1, and -4.75 +4.75 x 085 yielding a vision of 20/25-1 in the left eye. Corneal topography revealed extensive with-the-rule astigmatism in both eyes (Figures 1 and 2). His spherical equivalents were -0.75 D in the right eye and -2.37 D in the left eye. Corneal topography revealed 2.90 D of corneal astigmatism in the right eye and 3.60 D of corneal astigmatism in the left eye (Figures 1 and 2).
Approximately 3 weeks following cataract surgery in the second eye, I performed AK on the right eye and AK/mini-RK on the left eye. The right eye received two 45º arcuate keratotomy incisions with an optical zone of 9.00 mm at an axis of 90º. The left eye received two 60º arcuate keratotomy incisions with an optical zone of 9.00 mm at axis 85º. In addition, the left eye received a pair of on-axis mini-RK incisions with an optical zone of 4.50 at axis 85º. The mini-radial incisions started at the 4.50 optical zone mark and ended just short of the arcuate incisions at the 9.00 mm optical zone. The radial incisions did not cross or jump over the arcuate incisions.
OUTCOME
Two weeks following these incisional keratotomy procedures, the patient's UCVA at distance was 20/20-1 in the right eye and 20/25-2 in the left eye. His near vision was Jaeger 1 in the right eye and Jaeger 1- in the left eye. The patient's manifest refraction at the 2-week postoperative visit was plano +0.25 X 140 in the right eye yielding a vision of 20/20, and -0.50 +1.00 X 040 in the left eye yielding a vision of 20/20-1. The patient was overwhelmed with his visual improvement and extremely pleased with the result.
DISCUSSION
The most interesting aspect of this case is that it does not represent the typical patient who is likely to have an excellent result with the Array multifocal implant. In general, high degrees of patient satisfaction are more likely to be achieved with hyperopes than myopes. If surgeons are not comfortable with correcting corneal astigmatism, either intraoperatively or postoperatively, this can be a barrier to patient satisfaction with the Array multifocal implant. Corneal astigmatism of 1.00 D represents a UCVA of 20/30. It has been shown that the efficiency of the near visual acuity with the Array multifocal implant drops off precipitously when UCVAs are less than 20/30. Visual acuities in high myopes are frequently less than 20/20, and this would, again, put candidates at risk for not achieving an optimum result postoperatively with the multifocal implant.
I prefer performing incisional keratotomies postoperatively, as I believe they are more accurate than intraoperative LRIs or AKs. The higher levels of astigmatism in this patient and the presence of Array multifocal implants demanded greater degrees of precision when correcting this patient's astigmatism. The magnitude of the low level of myopia in the left eye can only be confirmed by allowing the implant to settle in the bag and evaluating the patient a number of weeks following the procedure. LRI nomograms vary widely because the distance of the limbus from the center of the cornea varies widely. A reliable nomogram can only be created when measuring the distance from the center of the cornea outward, and not from the limbus inward.
Mini-RK incisions with optical zones of greater than 4.25 mm are an effective tool for correcting low degrees of myopia, and will not create diurnal fluctuations or progressive hyperopia. I believe the overall risk/benefit ratio for correcting small refractive errors following implant surgery is much lower with RK/AK incisions versus the use of LASIK.
In summary, this case represents an atypical use of the Array multifocal lens, and stresses the need for discussing the potential for glare and halos postoperatively before proceeding with a multifocal implant. The psychodynamics associated with the patient's perception of glare, halos, or other visual phenomena following implantation of the Array multifocal implant is a topic in need of further study. I have implanted more than 800 Array multifocal implants in both cataract and refractive patients, and have consistently observed that a high level of patient satisfaction is associated with a strong subjective desire to function without reading glasses or bifocals.
Frank. A. Bucci, Jr., MD, is in private practice at the Bucci Cataract & Laser Institute in Wilkes Barre, Pennsylvania. He does not hold a financial interest in any product mentioned herein. Dr. Bucci may be reached at (570) 825-5949; buccivision@aol.com
