Microincisional Cataract Surgery
BY ROBERT M. KERSHNER, MD, FACS
Techniques
for optimizing refractive results are within our grasp.
Bigger is not always better, at least not where cataract surgery is concerned. The popularity of refractive procedures to eliminate or reduce the need for glasses has led patients to expect—even demand—faster and smaller incisions, quicker recovery, and better visual outcomes from their cataract procedure. With the explosion of new technologies and techniques, microincisions and high-tech IOLs provide the simplest and most reproducible route to full visual correction with cataract surgery. This approach also holds promise for the correction of presbyopia.
Because
today's cataract procedure uses small (less than 2.5-mm) incisions, it is more
safe, consistent, and more predictable than ever. Due to the development of
laser phaco, phakonit, and other advanced technologies, the size of cataract
incisions is rapidly approaching 1 mm or smaller. These microincisions are
positioned on the clear cornea, which precludes the need for conjunctival
dissection, cautery, sutures, the injection of anesthetics, bandaging, and the
postoperative restriction of patients’ activities. In addition, microincisional
cataract surgery has all but eliminated the complications of wound leak, uveal
prolapse, and surgically induced astigmatism.
These
advances have paved the way for faster, more efficient surgery with less
instrumentation, less intervention, and better uncorrected visual recovery for
the patient. In turn, the superior visual results patients have achieved
through IOL correction of their preexisting myopia, hyperopia, and astigmatism
(with or without arcuate keratotomy incisions) has translated into fewer
complications and less worry for the surgeon.
I
have developed and adhered to a single-incision, single-instrument approach to
cataract surgery that involves: (1) the smallest possible clear corneal
microincision; (2) the simultaneous correction of spherical and astigmatic
errors with refractive keratotomy and toric IOLs; (3) in-the-bag
phacoemulsification with a mini-phaco-flip maneuver; and (4) the injection of
the IOL through the unenlarged microincision. Patients’ visual results and
immediate, unrestricted recovery have been made possible by improved tools for
incision construction, newer high-tech viscoelastics, and advanced-technology
IOLs that reduce spherical aberration, improve UCVA, and can be implanted
through increasingly smaller incisions. The refractive outcomes achieved by
following these techniques are the best we have ever achieved, and, with
incision sizes approaching 1 mm, this technology holds promise for even greater
advances in the near future.
All
my cataract surgery patients undergo a comprehensive, preoperative ophthalmic
evaluation. When devising a surgical plan, I take into consideration the
patient’s cycloplegic refraction, combined with corneal topography and
ultrasonic biometry, in order to select the best surgical approach and the
ideal IOL for complete refractive correction.
I
use topical anesthesia with self-fixation to stabilize the eye as I place the
incision. I position the Kershner Reversible Eyelid Speculum (Rhein Medical,
Tampa, FL) under the eyelid margins, away from the incision site. I then locate
the steep meridian and make the incision with the Becton Dickinson Clear Cornea
Incision System (BD Ophthalmic Surgery, Waltham, Mass) using an accurate depth
blade or 600 microns and a 2.5-mm keratome. It is important to keep the cornea
dry when creating the incisions. Rather than irrigate with BSS, I apply a
single drop of 2.5% hydroxypropylmethylcellulose to the corneal surface after
creating the incisions to protect the cornea, keep it clear and moist, and
provide 1.5 X magnification.
Capsulorrhexis,
Hydrodissection, and Phacoemulsification of the Lens
I
inject a hyaluronate viscoelastic (Healon and Healon 5; Pharmacia, Peapack, NJ)
into the anterior chamber to flatten the capsule and reduce zonular stress
during capsulorrhexis.
The
Kershner One-Step Micro Capsulorrhexis Forceps (Rhein Medical) creates a 5-mm,
round, central capsulotomy through a 125 micron incision. I perform
hydrodissection with a Binkhorst cannula and BSS irrigation (Alcon
Laboratories, Ft. Worth, TX) to loosen the subincisional cortex prior to
phacoemulsification. I execute in-the-bag, three-step, single-incision,
single-instrument phacoemulsification with a 30º tip, phaco power at 20%,
maximum vacuum at 500 mm Hg, and an aspiration rate of 25cc/min. Before
rotating the lens, I perform central sculpting deeply and widely.
Next,
I press the phaco tip on the superior pole of the nucleus, flipping it inside
the capsular bag while I remove the remainder of the lens. I remove residual
cortex with the Kershner Clear Corneal I/A Tip (Rhein Medical, Tampa, FL) and
irrigate all lens epithelial remnants out of the capsular bag. I then inflate
the capsular bag with Healon to open
the capsular rim without overinflating the anterior chamber of the eye. I place
a single bolus of Healon5 at the center of the capsule to facilitate unloading
of the lens.
Injecting the IOL
I
prefer the three-piece, silicone CeeOn Edge 911A lens (Pharmacia, Peapack, NJ),
the aspheric Tecnis Z 9000 IOL (Pharmacia), or the silicone Toric IOL (STAAR
Surgical, Monrovia, CA) for full refractive correction. I load the IOL into the
injector shuttle, pass the lens through the incision into the capsular bag at
the proper meridian, and insert the IOL without additional manipulation.
Surgeons
have within their grasp the techniques for optimizing the refractive results of
their cataract procedure. Today, we can fully correct refractive error with
cataract removal and IOL implantation, and do so with minimal intervention and
virtually no interruption in the patient’s normal routine. Microincisional
cataract surgery has made the procedure faster, with quicker recovery and
better UCVA than previously possible. Patients are seeing that smaller is
better and expect nothing less from their surgeons.
Robert M. Kershner, MD, FACS, is Director
of the Eye Laser Center, Suite 303, 1925 West Orange Grove Road in Tucson,
Arizona. Dr. Kershner holds no financial or proprietary interest in any of the
techniques or instruments mentioned herein. He may be reached at (520)
797-2020; kershner@eyelasercenter.com.
REFERENCES
1.
Kershner RM, ed. Refractive Keratotomy
for Cataract Surgery and the Correction of Astigmatism. Thorofare, NJ:
Slack; 1994.
2.
Kershner RM. Keratolenticuloplasty: Arcuate keratotomy for cataract surgery and
astigmatism. J Cataract Refract Surg.
1995;21:274-277.
3. Kershner RM. One-step forceps for capsulorhexis. J Cataract Refract Surg. 1990;16:762-765.
4.
Kershner RM. Embryology, anatomy and needle capsulotomy. In: Koch PS, Davison
JA, eds. Textbook of Advanced Phacoemulsification Techniques.
Thorofare, NJ: Slack; 1991:35-48.
5.
Kershner RM. Sutureless one-handed intercapsular phacoemulsification: The
keyhole technique. J Cataract Refract
Surg. 1991;17(suppl):719-25.
6.
Kershner RM. Topical Anesthesia for Small Incision Self-Sealing Cataract
Surgery—A Prospective Study of the First 100 Patients. J
Cataract Refract Surg. 1993;
19(3):290-292.
7.
Kershner RM. Capsular Rupture at Hydrodissection. J Cataract Refract Surg.
1992;18:201.
8.
Kershner RM. Antibacterial Prophylaxis Before, During and After Routine
Cataract Surgery. In: Masket S, ed. Consultative Section. J Cataract Refract Surg. 1993; 19(1):110.
9.
Kershner RM. Topical Anesthesia Cataract Surgery. Ophthalmic Practice.
1993;11(4):160-165.
10.
Kershner RM. Clinical Consultation—Single Instrument Phaco and Continuous
Curvilinear Capsulorhexis. Ophthalmic
Practice. 1994;12(1):39.
11.
Kershner RM. How to be a Hero to Your Patients: Refractive Cataract Surgery. Review of Ophthalmology. 1996;3(6):50-4.
12.
Kershner RM. Clear Corneal Cataract Surgery and the Correction of Myopia,
Hyperopia and Astigmatism. Ophthalmology.
1997;104(3):381-389.
13.
Kershner RM. Patient's Adaptation to Cataract Surgery. Ophthalmology 1998;105(1):6-7.
14.
Kershner RM. Refractive Cataract Surgery. In: Lindstrom R, ed. Current Opinion in Ophthalmology.
Pennsylvania: Thompson Science 9(1):46-54, February 1998. [Au: Is this a book? Please explain the volume and issue numbers.]
15.
Kershner RM. The case for one-handed clear corneal cataract surgery. Review of Ophthalmology.
1998;5(3):68-73.
16.
Kershner RM. Six Tips to Clear Cornea Cataract Surgery. Review of Ophthalmology. 1999;6(4):120-124.
17.
Kershner RM. Toric Lenses for Correcting Astigmatism in 130 Eyes. Ophthalmology.
2000;107(Discussion):1776-82.
FIGURES.
Figure 1. The disposable Becton Dickinson Clear
Cornea Incision System (BD Ophthalmic Surgery) may be used to create the proper
corneal incisions for cataract surgery.
(See CD-ROM QuickTime Movie: 1KershnerIncision.mov)
Figure 2. The author facilitates creation of the
capsulorhexis with Healon5 (Pharmacia) and the Kershner One-Step Micro
Capsulorrhexis Forceps (Rhein Medical). (See CD-ROM QuickTime Movie: 2KershnerInjectH5.mov and
3KershnerCapsulorhexis.mov)
Figure 3. The author performs phacoemulsification
with a single-incision, single instrument approach.
(See CD-ROM QuickTime Movie: 4KershnerHydrodissection.mov,
5KershnerPhaco.mov)
Figure 4. The IOL is aligned with the steep
meridian and injected into the capsular bag.
(See CD-ROM QuickTime Movie: 6KershnerFillBag.mov,
7IOLInjection.mov)
Figure 5. The remaining viscoelastic is removed
with I/A.
(See CD-ROM QuickTime Movie: 8KershnerIA.mov)