Cataract and Refractive Surgery New Technology for Optimizing Outcomes

JANUARY 2012 CATARACT & REFRACTIVE SURGERY TODAY 19 N early one in five individuals in North America has dry eye disease (DED); it may be one of the most common yet frequently undiagnosed and untreated problems seen every day by ophthalmologists.1 Less appreciated, perhaps, are the profound visual impact of DED and the progressive nature of the disease if left undiagnosed and untreated. A hallmark of DED is the eye’s decreased ability to regulate tear osmolarity in response to adverse environmental challenges. As a result, the patient becomes susceptible to having a new, more hyperosmolar set point, further variation in tear osmolarity, and greater tear film instability. An increase in both the temporal and interocular variation and the absolute value of tear osmolarity is not only a component of all forms of DED, it is central to its pathogenesis2,3 (Figure 1). DED has a profound impact on both highand lowcontrast visual acuity and contrast sensitivity,4-7 because tears represent the most anterior refractive surface of the eye. It is essential to assess the osmolarity of tears in patients undergoing cataract and refractive surgery. The surgical trauma of these procedures along with the severing of nerves and associated inflammation presents a challenge to the ocular surface. Patients with DED lose the ability to respond to these challenges. Surgeons therefore must identify ahead of time patients who require treatment to optimize the tear film and ocular surface. Whether a patient is considering cataract surgery with a conventional or premium IOL or LASIK, preexisting DED is a risk factor for a suboptimal visual outcome, fluctuating vision, and reduced contrast sensitivity. To avoid a poor result, accurate diagnosis, distinct staging of disease severity, and appropriate preemptive treatment are required. New technology can help.