Managing Photophobia From Refractive Surgery
By William L. Miller, OD, PhD, FAAO
The numbers from the 2010 International Society of Cataract and Refractive Surgeons survey would indicate that refractive surgery procedures rebounded in 2010 from the year prior. As the numbers increase, our likelihood of seeing complications in the postoperative management period increases. It is true, by and large, that complications after the two most prominent refractive surgeries—photorefractive keratoplasty (PRK) and Laser-Assisted in Situ Keratomileusis (LASIK)—are low, yet they remain a possible clinical entity.
A More Rare Complication
One complication, Transient Light Sensitivity Syndrome (TLSS), although rare, can be encountered in your practice. TLSS primarily occurs in LASIK when the flap is prepared with a femtosecond laser. This enhanced laser technology has to some extent improved the safety and efficacy of flap generation; however additional new complications have arisen. The early days of the femtosecond laser resulted in greater levels of TLSS due to the increased energy levels when making the flap. Today's lasers typically show rates of TLSS that are less than 1 percent.
TLSS, as the name implies, centers on the symptom of photosensitivity, which can range from a mild aversion to light to more severe forms of extreme light discomfort. A patient who has a severe form of TLSS may present to your office with darkly tinted sunglass and a brimmed hat. Although there are certainly many other causes for light sensitivity in an ophthalmic practice, this predominant symptom is associated with femtosecond laser LASIK and usually develops two to six weeks after a routine, uneventful LASIK procedure.
Although other LASIK complications such as diffuse lamellar keratitis and epithelial ingrowth may result in light sensitivity, it is the lack of corneal or anterior chamber signs along with the more extreme levels of light sensitivity that point to your diagnosis of TLSS. No obvious signs of inflammation are observed in TLSS, nor is the patient's visual acuity affected.
Several theories exist on what causes the condition, most of which focus primarily on the level of infrared energy delivered to the ocular surface. One popular theory involves the evacuation of gases instituted by the laser in the intrastromal space. These cavitation bubbles may spread to the peripheral cornea and episclera, secondarily irritating the ciliary body. The surgeon will typically use the lowest energy setting possible to aim at prevention.
Although TLSS may spontaneously resolve after a few months, the level of patient symptoms will dictate the need for therapeutic intervention. You should first calm the inflammation as quickly as possible. Once TLSS is definitively diagnosed, prescribe prednisolone acetate 1% every one to six hours depending on the severity and subsequently taper over the next week to month depending on light sensitivity symptoms.
Still others have advocated the use of cyclosporine b.i.d. or q.i.d. in conjunction with topical steroid application (Stonecipher et al, 2006). Some mention of the benefits of nonsteroidal anti-inflammatories is also necessary. Some surgical practices also focus on the immediate postoperative period (one to three days) as a window for aggressive steroid treatment to prophylactically prevent the genesis of TLSS in certain patients. CLS
For references, please visit www.clspectrum.com/references.asp and click on document #185.
Dr. Miller is the director, Cornea and Contact Lens Service at the University of Houston College of Optometry. He is a member of the American Optometric Association and serves on its Journal Review Board. You can reach him at firstname.lastname@example.org.