Spontaneous Resolution of Acute Corneal Hydrops in a Patient With Post-LASIK Ectasia

Ectasia After Corneal Refractive Surgery: A Systematic Review

INTRODUCTION

The incidence of ectasia following refractive surgery is unclear. This review sought to determine the worldwide rates of ectasia after photorefractive keratectomy (PRK), laser-assisted in situ keratomileusis (LASIK), and small incision lenticule extraction (SMILE) based on reports in the literature.

METHODS

A systematic review was conducted according to modified Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Publications were identified by a search of eight electronic databases for relevant terms between 1984 and 2021. Patient characteristics and preoperative values including manifest refractive spherical refractive equivalent (MRSE), central corneal thickness (CCT), anterior keratometry, postoperative residual stromal bed (RSB), and percent tissue altered (PTA) were summarized. In addition, annual rates of each refractive surgery were determined, and incidence of post-refractive ectasia for each type was calculated using the number of ectatic eyes identified in the literature.

RESULTS

In total, 57 eyes (70 eyes including those with preoperative risk factors for ectasia) were identified to have post-PRK ectasia, while 1453 eyes (1681 eyes including risk factors) had post-LASIK ectasia, and 11 eyes (19 eyes including risk factors) had post-SMILE ectasia. Cases of refractive surgery performed annually were estimated as 283,920 for PRK, 1,608,880 for LASIK, and 96,750 for SMILE. Reported post-refractive ectasia in eyes without preoperative identifiable risk factors occurred with the following incidences: 20 per 100,000 eyes in PRK, 90 per 100,000 eyes in LASIK, and 11 per 100,000 eyes in SMILE. The rate of ectasia in LASIK was found to be 4.5 times higher than that of PRK.

CONCLUSION

Post-refractive ectasia occurs at lower rates in eyes undergoing PRK than LASIK. Although SMILE appears to have the lowest rate of ectasia, the number of cases already reported since its recent approval suggests that post-SMILE ectasia may become a concern. Considering that keratoconus is a spectrum of disease, pre-existing keratoconus may play a larger role in postoperative ectasia than previously accounted for in the literature.

Scleral Lens Visual Rehabilitation of Sequential Bilateral Corneal Hydrops With Post-LASIK Ectasia

ABSTRACT

This case report describes a unique presentation of bilateral sequential acute corneal hydrops that manifested several years after laser in situ keratomileusis. Initial management included anterior chamber perfluoropropane gas injection and corneal suturing. Longer-term visual rehabilitation involved the use of scleral lenses which significantly reduced lower- and higher-order ocular aberrations.

Management of acute corneal hydrops with intracameral gas injection

Purpose

To report two cases of severe acute corneal hydrops that were resolved by intracameral gas injection alone.

Observations

Case 1 is a 27-year-old woman with bilateral severe keratoconus who developed sequential acute corneal hydrops in the right eye followed by the left eye that were each successfully treated using intracameral 20% sulfur hexafluoride gas injection. Case 2 is a 62-year-old man that developed a large fluid cleft beneath a pre-existing LASIK flap, which resolved with intracameral 20% sulfur hexafluoride gas injection without the need for corneal transplantation.

Conclusions and importance

In acute corneal hydrops, intracameral gas injection to tamponade Descemet's membrane tears with decompression of stromal fluid can be an effective intervention to delay or avoid keratoplasty in individuals whose corneal hydrops does not improve with conventional medical management.

Management of acute corneal hydrops after laser in situ keratomileusis

A 43-year-old man developed acute corneal hydrops after laser in situ keratomileusis (LASIK). A persistently fluid-filled interface between the corneal flap and stroma (without flap dehiscence or wound leakage) did not respond to the conservative treatment. To avoid keratoplasty, the subflap fluid was drained by an air injection into the anterior chamber; the surgery also included suturing of the corneal flap and stroma. The corrected distance visual acuity improved rapidly after resolution of the fluid-filled interface and corneal stromal edema, and no leakage was observed. Thus, a minimally invasive surgery to drain the subflap fluid by an air injection was effective for treating a persistently fluid-filled interface in a case of acute corneal hydrops after LASIK.