Corneal Hydrops Secondary to Intrastromal Corneal Ring Intrusion into the Anterior Chamber 7 Years after Implantation: A Case Report

Abstract

IntroductionThis report describes the first known case of late-onset intrusion of an intrastromal ring segment into the anterior chamber due to posterior migration of a ring segment. To our knowledge, intrastromal ring segment penetration has only been shown to occur in the intraoperative or immediate postoperative period. We postulate that the perforation in this case is due to progressive thinning of the cornea, possibly in combination with habitual eye rubbing.Case ReportA 44-year-old man presented with acute corneal hydrops related to penetration of Descemet’s membrane and endothelium by an intrastromal ring segment implanted 7 years prior. Removal of the ring segment resulted in an anterior chamber fistula that directed fluid through the ring segment tunnel to the ocular surface. Leakage of aqueous humor was successfully controlled, and corneal edema gradually resolved.ConclusionThis case indicates the need for long term monitoring of ring segment proximity to the posterior corneal surface, especially in patients with ectatic ocular conditions and/or habitual eye rubbing behavior.

Delayed Perforation of an Intrastromal Corneal Ring Segment into the Anterior Chamber: A Case Report and Review of the Literature

“…Due to the significant time between implantation and perforation (7 years) as well as the traumatic cause (eye rubbing), we suggest that the case presented by Moshirfar et al [ 7 ] be classified as a late perforation, instead of delayed. All 3 cases of delayed perforation likely were caused by a microperforation intraoperatively that was not clinically apparent until one to 3 weeks after surgery.…”

“…Before our case presentation, ICRS perforation through the endothelium into the AC had only been reported in 30 eyes [ 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 ]. A summary of each publication can be found in Table 1 .…”

“…Currently, there are 2 options for tunnel creation: mechanical/manual tunneling or through the use of the femtosecond laser [ 20 ]. Perforations into the AC have been reported in both manual (60%) and femtosecond laser tunneling techniques (33%), while 7 percent of cases reported in the literature did not specify the tunneling method [ 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 ]. The manual technique involves making an initial incision at a predetermined corneal depth, usually 70%.…”

“…The third case of perforation through the endothelium into the AC occurred 7 years after insertion and was attributed to aggressive eye rubbing. Interestingly, the segment had also extruded through the corneal epithelium creating a fistula requiring emergent surgical intervention [7]. [18] reported time to explantation but did not record when the perforation had occurred.…”

“…Usually, perforation occurs intraoperatively and is believed to be due to excessive force or inaccurate depth estimation [ 5 ]. Delayed or late perforation is much less common, with only 3 reported cases in the literature [ 6 , 7 , 8 ]. We report a delayed intrusion of an inferior corneal ring segment into the AC within 1 week after surgery in a patient with keratoconus.…”