Before cataract surgery, take care of ocular surface
An unstable tear film is misleading, even for the best biometers.
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Optimal performance of premium IOL technologies requires precise biometry, which in turn requires a healthy ocular surface. Every premium cataract surgeon should first take care of “preparing the ground” by treating or preventing ocular surface disease, meibomian gland dysfunction and blepharitis, according to Matteo Piovella, MD, and Barbara Kusa, MD.
“In our country, only 1% of IOLs are premium technologies. There is still a lot of skepticism and a lot of fear of not meeting patients’ expectations. But we do have the technology and the methods to make the outcomes of presbyopic and toric IOLs predictable, obtaining postoperative results within half a diopter in 97% of the cases. What I wish is that more ophthalmologists become aware of this, feel reassured and finally embrace premium IOL solutions,” Piovella said.
A latest-generation biometer is mandatorily required in a modern cataract surgery facility to provide accurate IOL power calculation including the toric component. The identification and total correction of corneal astigmatism are the most complex and significant steps in achieving a postoperative visual quality that satisfies all patients. However, even the best biometers might be misled in their measurements by an unstable tear film.
“The low quality of the tear film has a considerable influence in determining imprecise and unreliable biometric measurements,” Piovella said.
The key concept of biofilm
In 90% of patients who are about to undergo cataract surgery, tear film quality could be improved with appropriate preoperative treatment, according to Piovella and Kusa. They personally developed a protocol that is now applied in their practice to all patients who are candidates for premium IOLs. The aim is to reestablish correct functioning of the meibomian glands or to prevent postoperative failures.
“The malfunctioning of meibomian glands is an extremely common condition. More than half the population have different forms of blepharitis and dry eye disease, and the likelihood increases with age,” Kusa said.
A diseased ocular surface is the result of a cascade of events, all correlated to one another and with a single etiology and a single starting point.
“The starting point relates to the key concept of biofilm. Since billions of years before the appearance of man on Earth, bacteria have learned to live in colonies, protected by a self-produced polymeric matrix that adheres to living surfaces,” Kusa said.
Quoting from the website of the Center for Biofilm Engineering, Montana State University, a leader in biofilm research: “Biofilms grow virtually everywhere, in almost all environments where there is a combination of moisture, nutrients and a surface,” she said. The eyelid margins make no exception, and within this favorable environment bacteria thrive, well protected from common disinfectants such as povidone-iodine and most drugs.
“Biofilms are a survival strategy developed over billions of years and therefore are quite impenetrable, much like a fortress on a hill,” Kusa said.
Like an armature, the biofilm on the eyelids and lashes protects bacteria and provides nourishment to mites such as Demodex, which is the cause of specific forms of blepharitis. As the mites penetrate into the meibomian glands, the biofilm causes progressive occlusion of the excretory ducts, leading to meibomian gland dysfunction, with consequent ocular surface alterations, inflammation and dry eye.
Cleaning and unclogging
BlephEx (BlephEx LLC) and LipiFlow (Johnson & Johnson Vision) are two sequential treatments aimed at removing the excess deposits at the free eyelid border, as well as unclogging the meibomian gland excretory ducts. BlephEx is essentially an eyelid hygiene method, consisting of an exfoliating, nontraumatic action aimed at removing the biofilm from the eyelids.
“A rotating micro-sponge soaked with a specific cleansing shampoo is spun along the eyelid margins, both lower and upper, for 1 minute. It generally starts from the lower eyelid, moving it downwards, while the patient looks up so that you don’t accidentally touch the cornea. After 30 seconds, the direction of rotation is reversed. Once the two eyelids of the same eye are treated, the sponge is changed. At the end of the procedure, the eye is cleansed with [balanced salt solution],” Kusa said.
While BlephEx cleans up the surface, LipiFlow acts in the meibomian glands. First, by applying a constant temperature of 42.5°C, it liquefies the solidified meibum deposits. Then, by massaging the eyelids, it conveys and expresses the material out of the ducts.
“The LipiFlow treatment is aimed at unclogging the meibomian glands that, because of the sediments deposited there over many years, have become practically inactive, with a production below 10%,” Kusa said.
At the end of the treatment, lubricants and low-penetration corticosteroids drops are prescribed for a period of 4 to 6 weeks.
“At the end of this period, you can properly carry out your biometry for the implantation of an advanced technology IOL,” Piovella said. “Over the past 3 years, we have applied this protocol in 89% of patients waiting to be implanted with premium lenses, and for a year now we have extended it to all our cataract patients.”
Postponing surgery by more than a month might not sound desirable to patients, unless they understand that this delay is to their advantage.
“Talk to your patients. Inform them well. Eventually, they will be grateful for this accurate preparation of the eye in view of the best outcomes of surgery,” Piovella said. – by Michela Cimberle
- For more information:
- Matteo Piovella, MD, and Barbara Kusa, MD, can be reached at CMA, Centro Microchirurgia Ambulatoriale, Via Donizetti 24, 20052 Monza, Italy; email: piovella@piovella.com.
Disclosures: Piovella reports he is a consultant for Johnson & Johnson and Carl Zeiss Meditec. Kusa reports no relevant financial disclosures.
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