Bilateral Monocular Light Streaks After Lasik

To describe the symptomatology, etiology, and management of a patient who complained of seeing a novel type of dysphotopsia coming from both eyes 10 years after LASIK.

St. Luke’s Medical Center, Quezon City, Philippines

A 32-year-old male noticed seeing vertical light streaks from each eye since 1 yr ago. Past medical history includes an uneventful femto-LASIK of both eyes 10 yrs ago and a limited superficial keratectomy (SK) of the left eye 5 yrs ago.

The patient described the streaks as long, thick, vertical light rays coming from any pinpoint source of light. The lines leaned to the same side as his head tilt. These disappear as he opened his eyes wider. He had failed treatment with brimonidine, pilocarpine, a rigid gas permeable contact lens, and pinhole CLs. 

On eye examination, UDVA was 6/6 on the right eye, and 6/9.5 on the left. Manifest refraction on the right eye was plano -1.00 x 65 (6/6) and plano -1.50 x 75 (20/20) on the left. On slit-lamp biomicroscopy, the corneas were unremarkable except for the outline of the previous LASIK flaps. Corneal tomography was unremarkable.

The light streaks may be related to the patient’s eyelid position. In fact, past literature have documented the effect of eyelid position on the anterior corneal shape. This creates an arch line called the "Handmann Line” visible via OCT. The epithelial thickness disparity gave a difference of 17um on each eye.

The patient was prescribed scleral lenses to prevent pressure from the upper eyelids. After a few weeks of use, the patient reported significant lessening of the light streaks. Repeat epithelial mapping showed a decreased epithelial thickness gradient on both eyes (10um on the OD, and 11 um on the OS) 

Light streaks is a newly described visual phenomena that is brought about by the Handmann Line, evident though corneal epithelial mapping. Methods to minimize the pressure of the upper eyelid on the corneal surface may be a good management option for these cases.