BLOG: Would you operate without keratometry?
In our cover story of this issue of Ocular Surgery News, we explore the ASCRS Cornea Clinical Committee’s protocol for treating dry eye. I was part of this committee during the early days of Chris Starr formulating the protocol. What he and the committee eventually produced was an incredibly cohesive approach to ocular surface disease using today’s most modern tools.
To some of our colleagues, this protocol is a welcome road map to treating a challenging, ubiquitous problem. To others who have little interest in treating dry eye, it is certainly less exciting. However, to all who are involved in the care of cataract patients, understanding and treating dry eye effectively are essential. Getting accurate readings of the curvature at the air-tear film interface — the eye’s most powerful refracting surface — is incredibly important yet impossible in the presence of meaningful ocular surface disease. Indeed, operating without managing dry eye is like choosing a lens implant without keratometry.
Eric Donnenfeld, Alice Epitropoulos and I conducted a study of about 100 cataract patients with dry eye, defined as those with corneal staining and a reduced tear breakup time, and examined the effect on surgical accuracy of treating the ocular surface with Xiidra (lifitegrast 5%, Novartis). Examining two time points — before and after lifitegrast treatment — we saw highly significant improvements in higher-order aberrations, corneal staining, tear breakup time, SPEED questionnaire scores and conjunctival redness. Moreover, more than twice as many patients after lifitegrast treatment were candidates for a multifocal implant as before lifitegrast treatment, when candidacy was defined as corneal higher-order aberrations being less than 0.5 µm.
Maybe most importantly, we looked at the refractive surgical outcome based on the keratometry reading measured before and after lifitegrast, and we found that the predicted implant power based on pretreatment keratometries was significantly less accurate than that measured after treatments; about 70% of patients were within a half diopter of treatment vs. 80% after treatment. Furthermore, in our study we put patients back on lifitegrast about a month after surgery to determine if the benefit to the ocular surface was sustained, and we found that tear breakup time, conjunctival redness and SPEED scores continued to improve further as disease continued under treatment. This study has been submitted for peer-reviewed publication and presented at the American Academy of Ophthalmology meeting.
Naturally, lifitegrast is just one treatment for dry eye, and many others can be employed, either separately or in combination. But to our knowledge, this was the first study that demonstrated an improvement in refractive accuracy with treatment of dry eye. It certainly stands to reason that a comprehensive treatment approach to dry eye, as suggested by the clinical committee’s white paper, would achieve even better results than the single form of therapy that was the focus of our study.
In other words, you can’t be a results-focused cataract surgeon without paying attention to and pretreating dry eye. For patients who are choosing elective refractive implants, it’s a well-known element of success. For those who choose more basic surgery, it is still the right thing to do.
Disclosure: Hovanesian reports he is a consultant to Novartis, and the study described was conducted with a grant from Novartis.