November 2017

COVER FEATURE

Dry eye disease update
Identifying and treating ocular surface disease before cataract surgery


by Rich Daly EyeWorld Contributing Writer


Meibum being expressed from the inferior MG
Source: Elizabeth Yeu, MD


Elizabeth Yeu, MD, shows meibum being expressed
from the inferior MG

Surgeons identify key approaches

Unstable ocular surface disease can produce both objective and subjective disappointments if not managed preoperatively.
“Objectively, cataract surgery diagnostics will provide inaccurate corneal power and astigmatism measurements,” said Elizabeth Yeu, MD, assistant professor, Eastern Virginia Medical School, and partner, Virginia Eye Consultants, Norfolk, Virginia. “Subjectively, patients’ dry eye disease can worsen after cataract surgery, often resulting in irritation or suboptimal quality of vision.”
Dry eye disease impacts cataract surgery patients by reducing preop visual acuity due to an irregular tear film or an irregular corneal surface, said David Glasser, MD, assistant professor of ophthalmology, Johns Hopkins University School of Medicine, Baltimore.
“This can interfere with the assessment of the contribution of the cataract to the visual disability,” Dr. Glasser said. 
Additionally, an irregular tear film or cornea surface will render keratometry and corneal topography measurements inaccurate, which will in turn reduce the accuracy of IOL calculations.
Postop visual acuity can be reduced, especially since the use of topical medications in the periop period may contribute to further surface irregularity, Dr. Glasser noted.

Exam critical

Richard Davidson, MD, professor, UCHealth Eye Center, University of Colorado School of Medicine, Aurora, Colorado, said it is important to thoroughly evaluate the patient for dry eye disease (DED) and meibomian glad dysfunction (MGD) prior to cataract surgery.
“I practice in Colorado so most patients already have some element of DED and MGD,” Dr. Davidson said.
Dr. Davidson recommended performing a detailed slit lamp examination, paying attention to lid position, presence of conjunctivochalasis, and tear meniscus. Additionally, he urged meibomian gland imaging and tear film lipid layer analysis. 
Expensive equipment is not necessary to diagnose DED, Dr. Glasser said about the use of a good clinical history or a dry eye questionnaire, a slit lamp, and fluorescein and lissamine green or rose bengal dye.
“Clinical evaluation of the meibomian gland orifices and quality of the meibum by gentle pressure on the lids, and assessment of the tear meniscus and tear film breakup time can all be performed without the need for adjunctive testing,” Dr. Glasser said. “Evaluation of lid position and function are critical components of the exam. Evaluation of the corneal mires for shifting irregularity with a simple keratometer is an unheralded but sensitive test for the presence of an unstable tear film.”

Medical therapies

Acute normalization of the ocular surface can readily occur by using frequent lubrication and a short course of topical steroids, as needed, Dr. Yeu said.
“I’m a huge advocate of hypochlorous acid spray in preparation for surgery, particularly in the presence of anterior blepharitis,” Dr. Yeu said.
Dr. Yeu recommends oral omegas, and if MGD is present, she routinely recommends thermal pulsation therapy, particularly if the patient has symptomatic disease or if he or she is leaning toward a refractive cataract surgery option.
Although Dr. Davidson views artificial tears as a reasonable first line therapy, in patients with anything worse than mild dry eye he recommends topical lifitegrast or cyclosporine.
To establish a stable ocular surface in the cataract patient, Dr. Glasser uses a combination of artificial tears, hot compresses, oral omega-3 supplements, and environmental modifications. Dr. Glasser agreed topical cyclosporine and lifitegrast may be helpful in those who respond poorly to initial therapy but noted those medications take a substantial amount of time to work.
“Topical steroids rapidly address any inflammatory component but are generally not good long-term solutions for most patients,” Dr. Glasser said. “Punctal plugs are often helpful in those with a significant component of aqueous deficiency and minimal or no inflammatory component.”
For patients with a significant blepharitis component that fails to respond to conservative therapy, Dr. Glasser considers trials of topical antibiotic ointment to the lid margins, pulsed topical azithromycin and topical tacrolimus, in that order. 

Preop MGD

Hot compresses, lid hygiene, and oral omega-3 supplements may be sufficient preop cataract surgery treatments for some patients with MGD, Dr. Davidson said.
Those with rosacea respond well to oral doxycycline or minocycline. Other treatments, such as LipiFlow (TearScience, Morrisville, North Carolina) can be beneficial to “reset” the meibomian glands and stabilize the tear film prior to surgery. Meibomian gland probing has been of limited use and usually only lasts a few weeks, in Dr. Davidson’s experience.
“Intense pulsed light has received attention recently, and while there is some published evidence of its efficacy, the literature is sparse, and I would like to see a prospective randomized controlled study,” said Dr. Davidson, who has not tried the therapy.

Implant concerns

For patients with ocular surface disease who want premium lens implants, Dr. Yeu said it is important to step back and take the entire presentation into consideration.
“What comorbidities exist? What DED treatments have been utilized? Is the patient willing to maintain chronic DED treatment in order to optimize the vision after the surgery? These questions are important to consider because while I can often improve the ocular surface enough for cataract surgery, the patient may not want to keep up with the maintenance necessary to keep the vision optimized for a presbyopia-correcting IOL, for example,” Dr. Yeu said.
Equally as important, Dr. Yeu said, is how well the patient responds to treatment with acute therapies, like topical steroids.
“If the DED is recalcitrant to aggressive therapy, this is a patient in whom certain ATIOLs would be contraindicated,” Dr. Yeu said. “Also, this information helps to guide the conversation on outcomes and expectations with surgery.”
Dr. Davidson’s key consideration for premium lens implants in such patients is getting the best possible IOL measurements and having patients comfortable postop and thrilled with their vision.
“Therefore, putting the time in to optimize the ocular surface prior to surgery is well worth the effort,” Dr. Davidson said.
Key considerations for premium lens implants in patients with ocular surface disease include the need for the tear film and ocular surface to be smooth and stable both preop and postop, according to Dr. Glasser.
“Simply achieving a stable surface preop is insufficient if the patient will be unable or unwilling to continue the treatment program necessary to maintain stability long term after surgery,” Dr. Glasser said.

DED postop

Dr. Davidson’s DED treatment regimen post-cataract surgery includes artificial tears, cyclosporine, and lifitegrast drops. However, he does not default to a single specific regimen. “I customize based on signs and symptoms of DED,” Dr. Davidson said.
For Dr. Glasser, gentle treatment of the ocular surface for MGD patients in the periop period is paramount. That should include short surgical times and aggressive intraop lubrication. Additionally, a viscoelastic placed on the ocular surface during surgery can help.
“The number of topical medications should be limited, with particular attention given to the use of non-steroidal anti-inflammatory medications,” Dr. Glasser said. “Use of a ‘less drops’ regimen with once-daily steroids and NSAIDs can preserve the integrity of the ocular surface without the necessity of intravitreal injections for those who prefer not to go that route. I eliminate topical NSAIDs entirely for those patients with significant dry eye disease and no risk factors for cystoid macular edema.”

Editors’ note: Dr. Yeu has financial interests with Alcon (Fort Worth, Texas), Johnson & Johnson Vision (Santa Ana, California), TearScience, Allergan (Dublin, Ireland), Shire (Lexington, Massachusetts), TearLab (San Diego), ScienceBased Health (Oak Ridge North, Texas), OCuSOFT (Richmond, Texas), and Ocular Science (Manhattan Beach, California). Dr. Davidson has financial interests with Shire. Dr. Glasser has no financial interests related to his comments.

Contact information

Glasser: dbg@comcast.net
Davidson: richard.davidson@ucdenver.edu
Yeu: eyey@vec2020.com

Identifying and treating ocular surface disease before cataract surgery Identifying and treating ocular surface disease before cataract surgery
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