Increasing age changes the quality of the tears. Older patients require careful attention to treating dry eye before LASIK laser eye surgery.
A 54 year old patient from Santa Barbara recently asked my why her eyes were getting drier as she got older and wondered if she still could be a candidate for LASIK.
A recent British study about the role aging plays in tear quality helps answer this question. It is well understood by ophthalmologists that the tears have three layers: the bottom layer is a protein layer, the middle layer is a water layer, and the top layer is an oil, or “lipid” layer. The job of the lipid layer is to prevent the underlying tears from evaporating off of the eye. Deficiency in the lipid layer is perhaps the most common cause of dry eye.
The British study looked at the role of aging on the lipid layer of the tears, and therefore, on dry eye itself. In this study 160 patients younger than age 45 were studied in one group and 58 patients older than age 45 formed the other group. Results showed that the lipid layer was significantly thinner in the older patients and that the effect was more predominant in women in this group than in men. In fact, the lipid layer of older women was thinner than that of both younger women and older men. A thinner lipid layer would mean less tendency for the tears to stay on the cornea and protect it from dryness.
These results mirror what we clinically see on a daily basis in my LASIK and PRK practice. Older patients, particularly older women, have drier eyes than younger patients. Often, they report evaporative symptoms (tears evaporating too quickly due to a poor lipid layer) such as fatigue with computer use. However, it should be noted that young patients can have extremely dry eyes before LASIK and older patients often have no significant dry eye symptoms before their LASIK. There still is quite a bit of individual variation regardless of age. Clearly, though, on average, older people tend to have drier eyes and menopause does seem to be strongly associated with drier eyes in women.
Regardless of age, it is important to pre-treat dry eye before patients have laser vision correction eye surgery, whether it be LASIK or PRK. Optimizing the surface of the eye makes for quicker and better healing after surgery. There are treatments which can be targeted at the lipid layer, such as oral omega-three supplementation. Restasis and topical azithromycin (Azasite) also can help the lipid layer of the tears. Clinically, however, the British study does correlate with the fact that older patients often require a bit more aggressive treatment of their pre-existing dry eye before LASIK. Once dry eye successfull is controlled, however, most of these patients are still good candidates for either LASIK or PRK laser vision correction!
See Also
Tear Film Dynamics and Lipid Layer Characteristics — Effects of Age and Gender
A study showing that increasing age decreases the quality of the lipid layer of the tears that coat the cornea.
Functional Aspects of the Tear Film Lipid Layer
A discussion of the role of the oil, or lipid, layer of the tears.
The Ocular Surface and Tear Film
The University of Rochester Eye Institute’s discussion of the role of tear quality in treatment of dry eye syndrome.
Dry Eyes and LASIK
All About Vision’s discussion of dry eye and LASIK laser eye surgery.
Post-LASIK Dry Eye
A Review of Ophthalmology medical journal’s discussion of dry eye after LASIK.
Your Questions on LASIK Eye Surgery: NPR
National Public Radio’s discussion of LASIK issues, including dry eye.