April 2019


Innovations in Lenses
Challenging EDOF
Extended depth of focus IOLs in non-routine cases

by Chiles Aedam R. Samaniego EyeWorld Contributing Writer

Symfony IOL in an eye with 12 cut RK
Source: Shannon Wong, MD

Slit lamp photo of a Tecnis Symfony EDOF IOL
Source: Daniel Chang, MD


As an increasingly popular option for presbyopia correction, extended depth of focus (EDOF) IOLs must contend with the challenges facing all premium IOLs. To date, premium IOLs have tended to be less than ideal options for non-routine cases. Given that the target population consists significantly of aging and elderly eyes, it is not uncommon for these eyes to be complicated by comorbid conditions such as glaucoma or by previous refractive surgery.
EyeWorld corresponded with Daniel Chang, MD, James Loden, MD, Shannon Wong, MD, and Elizabeth Yeu, MD, to find out how the lenses have fared against such conditions in their respective practices.

EDOF in complicated eyes

Despite their superior light transmission and visual quality, surgeons should still exercise caution when considering EDOF IOLs for complicated eyes. “It is still important to have an overall healthy eye, and I do not place either the Tecnis Symfony [Johnson & Johnson Vision] or multifocal IOLs in an eye that has macular drusen or ERMs,” Dr. Yeu said.
She still considers both EDOF and multifocal IOLs for glaucomatous eyes that have no visual field loss and a healthy ocular surface, but only an EDOF IOL—possibly combined with a concomitant MIGS procedure—if there is some OSD as is common in stable early to moderate primary open angle glaucoma. “I do think that the Symfony IOL is more resilient to visual fluctuations associated with OSD,” she said.
Dr. Chang considers EDOF IOLs a potential benefit to two kinds of “complicated” eye. First are eyes with refractive complications such as OSD, anterior basement membrane dystrophy, corneal scarring, and post-refractive corneas. “Since EDOF IOLs provide a broader focal range than monofocal IOLs, they can be advantageous when refractive targeting and stability are difficult,” he said. “With the Symfony IOL, I frequently aim slightly (~0.5 D) plus to left-shift the defocus curve, thus utilizing the depth of focus for refractive stability (of distance vision) instead of range of vision.”
Second are eyes with sensory complications such as epiretinal membranes, macular degeneration, and glaucoma. “For an EDOF IOL that provides image quality and contrast comparable to a monofocal, like the Symfony, I still offer it to these patients,” he said. He offers a surgical option since other solutions for presbyopia such as bifocal glasses can increase the elderly’s risk of trips and falls. “I do make it clear to these patients that if their pathology progresses, their visual quality could likely decrease regardless of the IOL they receive.”
“Because the EDOF lens performs similarly to a monofocal lens in eyes with coexisting corneal, retinal or optic nerve pathology, we use EDOF lenses in these patients but counsel them extensively preop about what to expect,” Dr. Wong said. “Usually patients with an EDOF lens and coexisting macular pathology do not read up close as well as EDOF patients with normal maculas. The far vision seems to be equivalent to a monofocal lens in patients with macular pathology.”
Dr. Loden, however, avoids complicated eyes altogether. Once the patient has paid for the upgrade, he said, their expectations are set for the superior vision they thought they “bought.” “It seems that no amount of preop discussion can alleviate this tendency,” he said.

EDOF and refractive lens exchange

Drs. Chang, Wong, and Yeu use EDOF IOLs for refractive lens exchange (RLE). “I see lens pathology to be a continuum of progression from a young healthy lens to a dysfunctional lens to a cataractous lens,” Dr. Chang said. “Regardless of the condition of the phakic lens prior to removal, the patient will have the same potential vision postoperatively. Therefore, as long as I expect that the patient will be happy with the relative functional gains in their uncorrected vision acuity after surgery, I do not hesitate to offer EDOF IOLs as an option.”
Dr. Yeu, however, only performs RLE in hyperopic patients over the age of 45; she will not perform RLE in myopic patients until at least the age of 58.
Dr. Loden is more cautious. “Although refractive lensectomy works, it comes with trade-offs,” he said. “In my opinion there is currently no product that can fully satisfy the patient who has preop BCVA of 20/15 with spectacles or contact lenses. Glare, halos, starbursts, spider webs, loss of contrast, and range of vision all remain issues. Take great care in interviewing your patient and setting expectations preop.”

Unhappy patients

No procedure is perfect, and as in all cases, preparation is everything. “It is exceedingly difficult to handle an unhappy EDOF IOL patient who was not properly counseled preoperatively,” Dr. Chang said. “The two primary areas of dissatisfaction with EDOF IOLs are (1) not enough uncorrected near visual acuity and (2) unsatisfactory dysphotopsias or night vision symptoms.”
He tells all patients being offered an EDOF IOL, but especially low myopes, that they may still need readers for small print, particularly in dim light. “Additionally, I not only tell them that they will likely have night vision symptoms, I also describe to them the specific symptoms that they will be having—in the case of the Symfony, fine starbursts with multiple fine halos,” he said. He asks about their satisfaction with regard to uncorrected distance and night vision at 1 day and at 1 week after receiving the IOL in the first eye. “If they are unhappy with either, I will address the issue before working on the contralateral eye.
“Before surgery and continuing postoperatively, it is important to evaluate and treat the ocular surface and macula,” he continued. “Postoperatively, uncorrected refractive error and posterior capsular opacification can be sources of unhappiness. I check for these aggressively and emphasize having a good postoperative refraction, being careful not to over-minus EDOF IOL patients. When stable, I offer laser vision correction and/or YAG laser capsulotomy as needed.”
“Preoperative counseling is key,” Dr. Wong agreed. “We advise EDOF patients that they will see a night halo/spider web with 100% certainty and that they will need glasses some of the time for some activities. …We do not promise perfection and get the patient’s buy-in on realistic expectations before they choose to have surgery. Preoperative counseling—medical and psychological—is mandatory for all patients.”
For unhappy patients, Dr. Wong offers keratorefractive surgery for refractive misses, lens exchanges, and the full spectrum of refractive surgery.
“An unhappy EDOF patient is like any other unhappy refractive cataract surgery patient and should be handled as such—with extra special care,” Dr. Yeu said. “Specifically, manage the ocular surface carefully, reserve performing any posterior capsulotomy if there is any concern that the IOL would need to be exchanged, address residual refractive errors, and see them more frequently than not until the issue can be resolved. I do not move on to the second eye surgery until some resolution is reached with the first eye. Besides greater near vision being achieved with binocular summation, the quality of vision of this IOL is so good that if there is a concern with the IOL itself, it is generally not a quality of visual acuity issue in the long term from any permanent waxiness, but from night vision-related concerns or the need for some reading glasses for near vision. Preoperative chair time to set these expectations is essential in the process.”
In Dr. Loden’s experience, residual refractive error is the main source of postop unhappiness. Residual sphere and cylinder as low as 0.25 D, he said, can affect patients. “I have seen patients with refractions of +0.25–0.50 @180 with dramatic resolution of symptoms when trial framed,” he said. “This patient then needs PRK/LASIK or to accept spectacles on a part-time basis. Cylinder of 0.75 D or greater is a near 100% need for PRK/LASIK in my practice. Sphere of +0.50 or greater is a deal killer. The real goal is plano unless a mini-monovision effect is desired. Of course, mild PCO must be evaluated and managed as well. 
“For the truly unhappy patient there may be no alternative other than explantation for a monofocal IOL,” he concluded.
“While no IOL is perfect, EDOF IOLs represent a major step forward in our efforts to treat presbyopia,” Dr. Chang said. “They have given me the confidence to offer a surgical solution for presbyopia in a majority of my patients. When used wisely and in conjunction with high-quality multifocal IOLs that minimize optical aberrations, EDOF IOLs make many of my patients very happy.”

At a glance

• EDOF IOLs still require caution when being considered for complicated eyes, although the broader focal range confers a number of advantages, particularly
in cases where refractive targeting and stability are issues.
• EDOF IOLs can be used successfully for refractive lens exchange, but it must be made clear to patients that even these lenses may not be able to replicate the full visual acuity and quality of their crystalline lenses.
• As always, preoperative counseling is essential in managing patients receiving EDOF IOLs.

Contact information
: dchang@empireeyeandlaser.com
Loden: lodenmd@lodenvision.com
Wong: shannon@austineye.com
Yeu: eyeulin@gmail.com

About the doctors
Daniel Chang, MD

Cataract and refractive surgeon
Empire Eye & Laser Center
Bakersfield, California

James Loden, MD
Founder and president
Loden iVision Centers
Nashville, Tennessee

Shannon Wong, MD
CEO of Austin Eye
Clinical assistant professor of ophthalmology
The University of Texas at Austin Dell Medical School
Austin, Texas

Elizabeth Yeu, MD
Assistant professor of ophthalmology
Eastern Virginia Medical School
Norfolk, Virginia

Financial interests
Chang: AcuFocus, Johnson & Johnson Vision
Loden: Johnson & Johnson Vision
Wong: Johnson & Johnson Vision
Yeu: Alcon, Johnson & Johnson Vision, Carl Zeiss Meditec

Challenging EDOF Extended depth of focus IOLs in non-routine cases Challenging EDOF Extended depth of focus IOLs in non-routine cases
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