Delayed-Onset Interface Fluid Syndrome After Laser In Situ Keratomileusis (Lasik) Secondary To Descemet Stripping Only (Dso)

To report a case of Interface Fluid Syndrome (IFS) occurring in the immediate postoperative period following Descemet Stripping Only (DSO) in a patient with Fuchs Endothelial Dystrophy, years after prior Laser In Situ Keratomileusis (LASIK).

IFS is described as a LASIK related complication in which a pocket of fluid develops at the flap-cornea interface. Typical cases of IFS are associated with steroid-induced ocular hypertension and low endothelial density or Fuchs Endothelial Dystrophy (FED). DSO has become one of the preferred surgical treatments for patients with FED without evidence of peripheral guttae. Although corneal edema may worsen immediately after surgery, the advantage of DSO is that no donor endothelium is required.

A 56-years-old female was referred due to decreased visual acuity. She had undergone LASIK for the correction of myopia twenty-five years ago. Her best-corrected visual acuity (BCVA) was 0.1 LogMAR (20/25) in both eyes. The slit lamp examination (SLE) showed FED with centrally disposed guttae and nuclear cataracts in both eyes. Intraocular pressure (IOP) was 15 mmHg. An optical coherence tomography (OCT) was also performed, showing a central corneal thickness (CCT) of 563 mm and a thin line of fluid at the flap interface. We elected to perform a triple procedure at the same surgery in the left eye. First, phacoemulsification of the cataract and implantation of a monofocal intraocular lens was carried out. Then, a 5mm diameter circular descematorhexis was done, without subsequent donor endothelium transplantation. Day after surgery, the patient had visual blurring. IOP was 16 mmHg and SLE revealed a diffuse cloudy interface, flap and endothelial edema. The OCT showed a CCT of 883 mm and increased fluid at the flap-cornea interface, confirming the diagnosis of IFS. Corticosteroids eyedrops were discontinued and two weeks later, fluid collection and edema had resolved. Four months later, IOP was 10 mmHg and BCVA was 0.2 LogMAR (20/32) in left eye. Endothelial cell density was 1177 cells/mm² and CCT has been reduced to 508 mm. One year after DSO, BCVA was 0.1 LogMAR (20/25), cornea was clear and endothelial cell density was 1253 cells/mm^2.

Ophthalmologists should carefully assess post-LASIK corneas in patients with compromised endothelium as well as consider the possibility of IFS after DSO in a patient who has undergone LASIK previously. Also, IFS can disappear only with endothelial cell repopulation, without requiring an endothelial transplant.