Should LRIs or additional procedures that may harm the corneal surface be avoided in cataract patients with pre-existing dry eye?

Plausible, but experience says no

Louis D. Nichamin

It would seem plausible that a limbal relaxing incision (LRI) might exacerbate pre-existing dry eye or cause symptoms in a patient who was previously asymptomatic. However, in my experience with tens of thousands LRIs, the incidence and/or worsening of dry eye has been extraordinarily low. I think it is an important concern; there are not a lot of studies to analyze, but in my lengthy personal clinical experience it continues not to surface, and especially nothing like that which we see after LASIK.

When I perform LRIs, I never exceed 90º and rarely go beyond 60º of arc, and so that may be part of the explanation if the incidence of dry eye is a function of the extent of the incision. But at this point in time, I do not feel that dry eye is a contraindication for LRIs. Far more important is that the ocular surface be optimized before surgery, and I think if we add an LRI to the refractive procedure, it gives us extra impetus to be aware of and focus on the assessment and treatment of the precorneal tear film.

There are situations in which a toric implant is preferable to an LRI in general, including post-refractive surgery patients, especially after radial keratotomy and astigmatic keratotomy, and in patients with dry eye in association with advanced rheumatoid disease or other advanced corneal thinning disorders. I might include severe or poorly compensated dry eye as being an indication for a toric implant over an LRI.

Part of this conversation should involve bioptics or the use of excimer laser after cataract surgery, which may be of greater impact on dry eye than LRIs. In patients with severe dry eye, I certainly would lean toward PRK instead of LASIK, explaining that their enhancement procedure could worsen their dry eye symptoms. I think that is something that is perhaps overlooked in the patient assessment, and frankly, I give that more weight than I do the use of an LRI with regard to potential significance to dry eye.

Louis D. “Skip” Nichamin, MD, is an OSN Cataract Surgery Board Member.

Dry eye with staining a relative contraindication

Eric D. Donnenfeld

Very little is known about the effect of LRIs and dry eye, and in fact, there has never been a study that looks at this very important issue. LRIs are done on tens of thousands of patients annually, and we know anecdotally that there are patients who do have worsening of their dry eye. I have seen several patients who have focal dry eye immediately adjacent to or central to the LRIs. Corneal neural architecture is formed by large nerve trunks entering in the anterior stroma in the periphery, and cutting these large trunks should cause a more significant anesthesia than treatment in the center of the eye.

Dry eye with corneal staining is a relative contraindication to any elective surgery, and I would include LRIs in that grouping. Before performing LRIs, I would suggest that the patient undergo a dry eye evaluation, including evaluation of the tear film, super vital staining of the conjunctiva with lissamine green or rose bengal, and fluorescein staining of the cornea. If there is significant staining, I would defer LRIs until the patient has responded to therapy.

Toric lenses are a good option for patients having cataract surgery who want to have a monofocal improvement in their quality of vision, as it gives better results and should induce no more dry eye than cataract surgery. For patients who have multifocal lenses or accommodating lenses, or patients in which toric lenses are a cross factor, LRIs become more important.

Clearly, a prospective trial that evaluates the effect of LRIs on dry eye is needed, and we are actually right now beginning such a multicenter study with six sites. We should have some answers to this question in about 6 months. PRK and LASIK are much more precise than LRIs. If we find that they also produce less dry eye, it would again be another reason to lean toward ablative procedures rather than incisional procedures in managing astigmatism in patients after cataract surgery.

Eric D. Donnenfeld, MD, is an OSN Cornea/External Disease Board Member.