Noninflammatory flap edema after laser in situ keratomileusis associated with asymmetrical preoperative corneal pachymetry

Late-onset interface fluid syndrome: A case report and literature review

PURPOSE

To present a case of late-onset interface fluid syndrome (IFS) and a literature review on this rare clinical entity.

INTRODUCTION

IFS is an uncommon complication of laser in situ keratomileusis (LASIK). Although generally appearing in the early postoperative period, IFS has been reported even years after LASIK.

METHODS

A case report of IFS manifesting 19 years after uneventful LASIK, which prompted a literature search for similar, late-onset cases in MEDLINE PubMed. This article reports on a case of IFS appearing 19 years after LASIK surgery, including extensive patient history and analytical presentation of clinical findings, ancillary testing, and short-term follow-up. Furthermore, a literature search for similar cases was performed on MEDLINE, focusing on the etiology and management of late-onset IFS.

RESULTS

Through thorough ancillary testing, the interface fluid was attributed to elevated intraocular pressure (IOP) arising from primary open-angle glaucoma. Antiglaucoma drops resulted in complete fluid regression. A narrative review was conducted based on the 29 case reports that were recovered from the literature search.

CONCLUSION

IFS represents an uncommon complication that could appear years after LASIK. Careful clinical examination and anterior segment optical coherence tomography promote early diagnosis. Similar cases may manifest due to elevated IOP of variable etiology or as a result of endothelial dysfunction. Depending on the etiology, IOP control or keratoplasty may resolve the condition.

Evaluation of corneal thickness alterations during menstrual cycle in productive age women

PURPOSE

To determine the change in corneal thickness through different phases of menstrual cycle in women who are in their productive age.

MATERIALS AND METHODS

Fifty healthy women with normal past medical history were enrolled in this prospective study. Central corneal thickness was measured with ultrasound pachymeter three times during a menstrual cycle: Beginning of the cycle (days 1-3), ovulation time, and at the end of cycle (days 27-32). We confirmed ovulation time with determining a peak in luteinizing hormone in urine. To avoid the diurnal variation of the corneal thickness which is well recognized, we checked all our subjects at 10 in the morning.

RESULTS

In days 1 to 3 of menstruation, mean corneal thickness was 541.40 ± 11.36 and 540.82 ± 11.70 microns for left and right eyes respectively. At ovulation time the mean thickness changed to 556.50 ± 7.11 and 555.98 ± 7.26 microns for left and right eyes respectively, and at the end of the cycle, the corneal thickness turned in to 536.38 ± 12.83 and 535.48 ± 13.08 microns for left and right eyes respectively. The difference of corneal thickness was statistically significant relating to the different stages of menstrual cycle.

CONCLUSION

The thickest cornea during the menstruation cycle is achieved at the ovulation time and the thinnest at the end of the cycle and this should be taken in to account whilst plan to do a corneal refractive surgery.

Interface Fluid Syndrome in Human Eye Bank Corneas after LASIK

PURPOSE

To evaluate the effects of corneal edema on human donor corneas that had previous LASIK using a laboratory model with histologic and ultrastructural correlations.

DESIGN

Experimental study.

PARTICIPANTS

Thirty human eye bank corneas from 15 donors (mean age +/- standard deviation, 49.9+/-8.9 years) who had had previous LASIK surgery (2-8 years before death).

METHODS

The corneas were mounted in an artificial anterior chamber and the corneal endothelium was perfused for up to 5.0 hours with 0.9% saline solution (endothelial cell damage group) or BSS Plus at a pressure of 15 mmHg (control group), or BSS Plus at a pressure of 55 mmHg (high-pressure group). The corneas were evaluated by confocal and specular microscopy before, during, and at the end of the experimental period. Subsequently, the specimens were evaluated by light and electron microscopy.

MAIN OUTCOME MEASURES

Corneal thickness, reflectivity, histology, and ultrastructure.

RESULTS

Endothelial cell damage resulted in an increased (141.5+/-38.8 microm) total corneal thickness relative to controls (52.3+/-33.7 microm), whereas high pressure resulted in a decreased thickness (24.8+/-14.1 microm) relative to controls. This ultimately was due to swelling of the LASIK interface in both groups and swelling of the residual stromal bed (RSB) in the endothelial cell damage group or compression of the RSB and, possibly, the flap in the high-pressure group. A significant increase in corneal reflectivity at the LASIK interface occurred in both groups, primarily due to varying degrees of fluid accumulation and associated hydropic keratocyte degeneration, as well as increased corneal reflectivity in the RSB only in the endothelial cell damage group.

CONCLUSIONS

After LASIK surgery, edematous corneas preferentially hydrate and swell in the paracentral and central interface wound, commonly resulting in a hazy corneal appearance primarily due to keratocyte hydropic degeneration. More severe corneal edema is characterized by the formation of an optically empty space corresponding to an interface fluid pocket. The spectrum of interface fluid syndrome can be described in 3 stages.

Early Transient Visual Acuity Loss After LASIK Due to Steroid-induced Elevation of Intraocular Pressure

PURPOSE

To report the clinical course of early transient reduction of uncorrected visual acuity (UCVA) after LASIK surgery resulting from steroid-induced elevation of intraocular pressure (IOP).

METHODS

Twenty-nine eyes of 15 patients who received topical corticosteroids after uneventful myopic LASIK surgery and had a decrease in UCVA within the first 3 weeks were evaluated retrospectively.

RESULTS

Intraocular pressure increased by 4 to 30 mmHg from preoperative to postoperative days 4 to 20. Twenty-seven of 29 eyes had a decrease in UCVA and/or best spectacle-corrected visual acuity (BSCVA). All eyes, except one, had edema without evidence of inflammation in the interface or the remainder of the cornea. Discontinuation of topical corticosteroids and application of anti-glaucoma medications resulted in a decrease of IOP to normal levels, reduction or disappearance of the edema, and recovery of BSCVA.

CONCLUSIONS

Early onset steroid-induced elevation of IOP after LASIK may cause corneal edema and a sudden decrease in UCVA. Rapid diagnosis and treatment can control IOP and recover the visual loss.