Traumatic In-The-Bag Intraocular Lens Subluxation
Before the 1990s dislocation of a posterior chamber intraocular lens usually occurred outside of the capsular bag, resulting in pupillary capture, a sunrise or sunset syndrome, or a lens implant lost into the vitreous cavity. These cases most often occurred within 3 months of cataract surgery and were predominantly due to asymmetric fixation of the intraocular lens or to complicated cataract surgery.8,9
In-the-bag intraocular lens dislocation was first reported by Davison in 1993. He described 6 cases of spontaneous in-the-bag intraocular lens dislocation due to capsular contraction syndrome after uncomplicated phacoemulsification cataract extraction using continuous curvilinear capsulorhexis. He suggested that “the collective effort of weakened or absent zonules” due to age or pseudoexfoliation “may be unable to oppose the relatively increased strength of the centrally directed contractile forces generated by capsular fibrosis.”10
As the continuous curvilinear capsulorhexis, phacoemulsification, and in-the-bag placement of an intraocular lens became standard of care by the start of the 21st century,11 several authors noted that although the incidence of early postoperative intraocular lens dislocation due to surgical complications or incorrect haptic placement had decreased, that late-in-the-bag intraocular lens dislocation, occurring ≥3 months after cataract was being reported with increased frequency.12–15 In a letter to Ophthalmology in 2002, Chang16 wrote that “the incidence of this delayed complication appears to have skyrocketed after universal adoption of the capsulorhexis technique, which may be a key factor in causation.