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Surgical Correction of Presbyopia Rosa Braga-Mele, MD, Med, FRCSC, Kendall Donaldson, MD, MS, for the Meaning Elder

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Surgical Correction of Presbyopia Rosa Braga-Mele, MD, Med, FRCSC, Kendall Donaldson, MD, MS, for the Meaning Elder REVIEW/UPDATE Surgical correction of presbyopia Richard S. Davidson, MD, Deepinder Dhaliwal, MD, D. Rex Hamilton, MD, Mitchell Jackson, MD, Larry Patterson, MD, Karl Stonecipher, MD, Sonia H. Yoo, MD, 07/05/2020 on zn1b0nypLWme4NZDgqbkliW3RTrlKZBf5lir6IjP75TV4g5JBcqV8dedQV65yo+i40i6Hxc83lOtdpTaAz3cso4xInfg4/IP4dVZhd0QqWWamtUVPyxlA2kiRsrwHe0Whdvy6XCc9o6yzpi0gmcLHCKARzEk0lpR4C4TIAgeZuA= by https://journals.lww.com/jcrs from Downloaded Rosa Braga-Mele, MD, Med, FRCSC, Kendall Donaldson, MD, MS, for the Downloaded ASCRS Refractive Cataract Surgery Subcommittee from https://journals.lww.com/jcrs Presbyopia is the most common refractive disorder for people older than 40 years. It is charac- terized by a gradual and progressive decrease in accommodative amplitude. Many surgical procedures for the correction of presbyopia exist, with additional procedures on the horizon. by This review describes the prevalent theories of presbyopia and discusses the available surgical zn1b0nypLWme4NZDgqbkliW3RTrlKZBf5lir6IjP75TV4g5JBcqV8dedQV65yo+i40i6Hxc83lOtdpTaAz3cso4xInfg4/IP4dVZhd0QqWWamtUVPyxlA2kiRsrwHe0Whdvy6XCc9o6yzpi0gmcLHCKARzEk0lpR4C4TIAgeZuA= options for correction. Financial Disclosure: Proprietary or commercial disclosures are listed after the references. J Cataract Refract Surg 2016; 42:920–930 Q 2016 ASCRS and ESCRS The term presbyopia originates from the Greek word The amplitude of accommodation is greatest in early “presbyteros,” meaning elder. It is the most common childhood, with 15 diopters (D) or more of accommo- refractive disorder in people older than 40 years and dation attainable. This ability declines with age in a manifestsasagradualandprogressivedecreasein linear fashion universally and predictably. A change accommodative amplitude. The underlying cause in the shape of the crystalline lens is responsible for remains unclear and is likely multifactorial. Three main the change in the optical power during accommoda- etiologic categories exist1: lens- and capsule-based the- tion. Ciliary muscle contraction alters zonular tension ories, which focus on the decreasing capsule elasticity to effect this change. However, there is no consensus and increasing stiffness/sclerosis of the aging lens; extra- on the precise mechanism. Two prevailing theories lenticular theories, which consider a decrease in ciliary exist: Helmholtz (described by Michaels2 and Fin- body contractility to be the main cause of presbyopia; cham3) and Schachar.4 Others have expanded and and the geometric theory, in which presbyopia is thought elaborated these theories with debate over the exact to be due to a decrease in the distance between the mechanism5,6; many agree on some movement of the equatorial edge of the lens and the ciliary body, which lens and ciliary body complex toward or away from in turn causes a decrease in zonular tension. Some the sclera during accommodation. overlap exists between the first and third categories. The lens grows continuously throughout life, This review describes the prevalent theories of and the equatorial diameter increases approximately presbyopia and discusses currently available surgical 20 mm a year.1 Schachar4 believes the effective force options for correction. that the ciliary muscle can apply to the lens equator decreases in a linear fashion with age and is the pri- PHYSIOLOGY OF ACCOMMODATION AND PRESBYOPIA mary etiology of presbyopia. This is the genesis of his concept of scleral expansion surgery to treat Accommodation is the ability of the eye to change its presbyopia. optical power to focus from distant to near objects. on 07/05/2020 Submitted: September 26, 2015. SURGICAL OPTIONS FOR PRESBYOPIA CORRECTION Final revision submitted: January 23, 2016. Corneal Options Accepted: January 26, 2016. Monovision Monovision is a concept familiar to many University of Colorado Health Eye Center, University of Colorado in the eye-care field who treat patients complaining of School of Medicine, Aurora, Colorado, USA. presbyopia. With monovision, 1 eye (usually domi- Corresponding author: Richard S. Davidson, MD, University of nant) is corrected for distance vision and the other Colorado Health Eye Center, 1675 North Aurora Court, Aurora, eye is corrected for near vision. Whether fitting a Colorado 80045, USA. E-mail: [email protected]. patient with contact lenses, determining the best target 920 Q 2016 ASCRS and ESCRS http://dx.doi.org/10.1016/j.jcrs.2016.05.003 Published by Elsevier Inc. 0886-3350 REVIEW/UPDATE: PRESBYOPIA SURGERY 921 for laser in situ keratomileusis (LASIK) surgery, or sign a special consent confirming their refractive target counseling patients about their options for cataract preoperatively so both patient and surgeon are in surgery, discussion and consideration of monovision agreement with the surgical plan. is integral to the decision-making process.7 The selec- Conductive Keratoplasty Conductive keratoplasty (CK) tion of monovision surgical correction through laser (Viewpoint CK System, Refractec, Inc.) was U.S. Food vision correction or monofocal intraocular lens (IOL) and Drug Administration (FDA) approved in 2004 as a implantation during cataract surgery is critical to noninvasive treatment for mild to moderate hyperopia achieving patient satisfaction. (C0.75 to C3.00 D).8,9 It uses radio waves to adjust the Evaluation for monovision correction must include contour of the cornea by shrinking the corneal collagen a thorough patient history, comprising the patient's around a radioactive probe. Basically, the procedure prior experience with contact lens use; specifically, is designed to steepen the central cornea, creating a any experience with monovision or multifocal contact hyperprolate contour and thus increasing refractive lenses. Because some patients may not tolerate the power. anisometropia induced by monovision, a contact lens Treatment with CK is based on the effect of heat on trial can be undertaken to simulate the proposed the biomechanical properties of the cornea. At 55 Cto refractive target prior to surgery. Evaluation is opti- 65 C, collagen dehydrates and retracts but returns to mally performed in a real-life situation instead of an its original configuration on cooling. At temperatures artificial simulation such as the examination room. above 70 C to 100 C, collagen completely denatures, Both multifocal and monovision contact lens users resulting in permanent changes. Circular applications tend to be more tolerant of blur and are more of 8 spots are created by repeated insertion of the amenable to permanent surgical monovision correc- probe at optical zones of 6.0 mm, 7.0 mm, or 8.0 mm tion. Additionally, it is helpful to use a questionnaire circumference, determined by a preset nomogram, or alternative interview process designed to ascertain for a total of 8, 16, 24, or 32 spots. Shrinking the periph- a patient's daily visual needs, both professional and eral collagen has a tightening effect on the midperiph- extracurricular. A patient's leisure activities, such as eral cornea. golf, tennis, recreational or commercial piloting, The efficacy of CK was validated in a prospective or other activities involving extremely acute depth consecutive case series by Stahl,10 which showed perception and stereopsis, may preclude the ability safe, effective results at 1 year in a series of 10 emme- to tolerate monovision.7 tropic presbyopic patients who had CK in their Blended vision or mini-monovision is an excellent nondominant eye. Patients had a mean preoperative option for many presbyopic patients. This approach near acuity of Jaeger (J) 10. Postoperatively, 90% of aims for À1.00 to À1.25 D in the nondominant eye patients achieved a mean uncorrected near visual and plano in the dominant eye. Patients generally acuity (UNVA) of J1 and 100% achieved a UNVA of adjust to this degree of anisometropia with little diffi- J3 or better. No eye lost corrected visual acuity at dis- culty. In addition, blended vision maintains distance tance or near. Treated eyes lost a mean 2.2 lines G 2.0 (SD) vision of approximately 20/40; thus, patients experi- of uncorrected distance visual acuity (UDVA) but ence little effect on distance acuity and minimal induc- gained a mean 8.7 G 2.0 lines of UNVA. Effects were tion of photic phenomena (eg, glare and halos at – sustained at the 1-year follow-up.8 10 Although pa- night). Patients can also retain some useful stereopsis. tients reported glare and halos during the early post- Ideally, the surgical outcome in patients having operative period, high levels of satisfaction and monovision correction provides a high degree of spec- spectacle independence for near were reported tacle independence with minimal neuroadaptation to – 1 year postoperatively.8 10 Despite these encouraging induced anisometropia. In cases in which the patient results, patients having CK tend to experience signifi- is not satisfied with the visual outcome or is unable cant regression over time, with some patients revert- to adapt to the anisometropia, laser vision correction ing to their preoperative refractive state.11 Currently, provides a minimally invasive option for conversion CK is not commonly performed because of the to bilateral distance correction or enhancement of the lack of long-term stability; however, some surgeons distance eye. Patients with monovision appear to be perform it in select patients to enhance near vision. more sensitive to changes in their distance eye, making them more likely to request enhancement for small Corneal Inlays The concept of the
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