Minimally Invasive Surgery: Femtosecond Lasers and Other Innovative Microsurgical Techniques Julio Narváez MD Associate Professor of Ophthalmology Loma Linda University
Non-Refractive Applications of Femtosecond Lasers
Femtosecond Laser Corneal Surgery Penetrating Keratoplasty Lamellar and Endothelial Keratoplasty Intracorneal Ring Channel Creation
Traditional Penetrating Keratoplasty (PKP) Used less as it is being replaced by modern, minimally invasive corneal surgery» Full thickness procedures have unstable vertical wounds. DSAEK now used by many corneal surgeons for >40% of corneal transplants (endothelial failure) DALK used now for some cases of stromal disease
Traditional PKP vs. DSAEK Large vertical incision Delayed recovery ~ 1 year Vulnerable to trauma Small beveled incision Rapid recovery ~ 3 months No concern about trauma
IntraLase Enabled Keratoplasty Less invasive surgery for patients still in need of a full thickness procedure Early data suggests:» Less astigmatism» Much stronger wound healing» More rapid recovery of vision» Long-term research needed, but no significant disadvantages known
Zig-Zag Shaped Keratoplasty Hermetic wound seal Angled edges provide more precise tissue alignment Smooth transition between host and donor
IntraLase Advanced Keratoplasty The Zig-Zag shaped incision is more prominent at 3 months, suggesting early fibrosis. Surface area of wound larger and stronger than traditional PKP
Alignment Marks Allow for More Precise Placement of Sutures Alignment marks are created at the same time as the laser trephination Allow perfectly spaced sutures every time
Infinite Possibilities for Shapes Traditional Zigzag Top Hat Christmas Tree LAMELLAR Zig Square
Lamellar Keratoplasty Early studies have shown that femtosecond laser-created partial thickness corneal transplants are safe and effective. Patients with anterior corneal scars can benefit from anterior partial thickness corneal transplants precisely cut with the laser.
Intacs Channel Creation with IntraLase More accurate depth of placement than manual dissection Decreased complications More flexibility on dimensions of channels More precise centration of channels
Loma Linda University IntraLase The IntraLase in our facility is upgraded to be able to perform refractive and corneal procedures Loma Linda Ophthalmology is equipped to offer the least invasive and advanced corneal and refractive procedures for your patients
Refractive Applications of Femtosecond Lasers
Femtosecond Laser Lenticule Extraction First efficacy and safety study of femtosecond lenticule extraction for the correction of myopia: six-month results. J Cataract Refract Surg. 2008 Sep;34(9):1513-20. Sekundo W, Kunert K, Russmann C, Gutenberg University RESULTS: Ninety percent of eyes were within +/-1.00 D and 40% were within +/-0.50 D of the intended correction. On a standardized questionnaire, all patients said they were very satisfied with the results. CONCLUSIONS: Preliminary results indicate that FLE is a promising new corneal refractive procedure to correct myopia.
IntraLase Laser Flap Configuration IntraLase creates»consistent flap thickness and a predictable stromal bed»programmable diameter, depth, width, hinge placement, and centration»uniformly dry stromal bed
IntraLase Flaps vs. Mechanical Microkeratome Meniscus Flaps Mechanical microkeratomes create meniscus flaps»steeper corneas yield thinner central cornea»potential for irregular flap morphology & buttonholes»may induce astigmatism and high order aberrations
Precise Thin Uniform Flap Attempted = 90 um Achieved = 89 90 um
Microkeratome Flap Meniscus Shaped 179 172 155 159 170 187» Target = 160 um» Variability in central thickness across different flaps (standard deviation)» Also significant variability regionally within a flap Image provided by Jon Dishler, MD
LASIK Using the IntraLase LASIK Using the IntraLase Computer-Controlled Laser
IntraLase FS Laser Benefits Increased precision, preserves corneal stroma Stronger biomechanical properties postoperatively in cornea Less risk of ectasia and other complications Less dry eye after surgery Provides less induced astigmatism
Loma Linda University Refractive Surgery University offers your patients the most advanced technology available» Iris registration, Intralase, custom treatment» Expert surgeons We welcome comanagement of your patients Contact our staff for comanagement packets or other information regarding vision correction
IntraLase Demonstration Today After our last lecture today IntraLase corneal surgery will be demonstrated in porcine eyes Across the street at our offices Maps will be provided at the back by our staff Interested doctors are welcome to come and observe live surgery during work week. Contact our staff for details
Microincision Cataract Surgery
Case Presentation 75 y/o lady presents with loss of vision OS, and difficulty driving. Unprompted she requests a multifocal IOL, RESTOR to eliminate her dependence on glasses. Exam:» BCVA OD20/40 +2, OS 20/40-1» Rx +2.00-0.50 X 150 OD, +1.75-0.50 X 156 OS» Nuclear, cortical, and posterior subcapsular cataract OU consistent with vision.
Topography With the rule asymmetric astigmatism and inferior steepening, Normal Orbscan, and pachymetry >600 microns.
What is the best approach to this case? A superior incision would reduce ATR astigmatism, but would worsen asymmetric astigmatism and would increase final coma and result in worse UCVA and loss of quality of vision.
What is the best approach to this case? A standard 3.0 mm clear corneal temporal cataract surgery would induce more ATR astigmatism of up to 0.50 D. More induced astigmatism would increase the size of the limbal relaxing incision needed to reduce postoperative astigmatism
Solution: Microincision Cataract Surgery 2.2 to 2.4 mm incision is used Only 0.15 D of astigmatism induced with clear corneal temporal incision Smaller limbal relaxing incision needed inferiorly to reduce both astigmatism and asymmetry Results in less invasive surgery
Incision Comparison Standard Incision» 3.0 mm Microincision» 2.4 to 2.2 mm
Why Microincision Cataract Surgery Less invasive: demonstrated to use less ultrasound energy used to remove cataract (Less CDE: cumulative dissipated energy) Less endothelial loss demonstrated in study at Duke University at 6 months. No additional complications. Almost no induced astigmatism ~ 0.15D
Why Microincision Cataract Surgery Seen Clinically» Clear corneas» More rapid visual recovery» Less postoperative inflammation postoperatively
Additional Advantages of Microincision Cataract Surgery Very useful in patients with small eyes and shallow anterior chambers as smaller tip is more distant from delicate ocular structures Helpful in cases of Flomax (IFIS), and small pupils for greater intraoperative stability of anterior chamber and iris
IOLs Compatible With Microincision Cataract Surgery Standard IOLs RESTOR and Toric IOLs Have used Crystalens, but requires some enlargement of incision to 3.0 mm Toric IOL Crystalens
Case Presentation Outcome Patient very pleased with outcome. UCVA first day after surgery 20/25 distance, and J2 at near We welcome your referrals for this beneficial technology
Other Minimally Invasive Surgical Solutions
Case Presentation 2 65 y/o CF presents with severe bilateral glare. Started after bilateral attack of angle closure glaucoma which resulted in dilated fixed pupils. Has undergone cataract surgery OU
Case Presentation 2 BCVA 20/30 OD, 20/25 OS Exam:» Fixed, dilated, nonreactive pupils OU» Posterior chamber IOLs
Preoperative Appearance
Traditional Solutions Sunglasses Painted Contact Lenses Suture pupil into a square with four interrupted McCannel sutures Live with glare disability
Postoperative Result Marked reduction in glare, and increased patient functionality
Case Presentation 3 41 y/o truck driver presents with monocular diplopia OD and loss of vision BCVA 20/60- OD, 20/30 OS SLE: inferiorly dislocated IOL
Traditional Solution Remove IOL through large (6 mm) incision Replace with scleral sutured IOL Create scleral flaps by cutting conjunctiva, cauterizing sclera, & cutting flap
Video Clips of Minimally Invasive IOL Repositioning
Case Presentation 3 Postoperative» BCVA 20/30-1 OD, 20/30-1 OS» Monocular diplopia eliminated» Patient back to work, and driving safely