Reply: Management of Descemet Membrane Detachment After Forceps Birth Injury
There is a well-documented set of similarities between keratoconic eyes and eyes having sustained forceps-related birth injuries: both tend toward axial myopia, corneal steepening, thinning, scarring, and large amounts of corneal astigmatism.1–3 In adults, the two entities can easily be confused, and often the distinction is made according to whether the observed changes are unilateral (forceps injury) or bilateral (true keratoconus) and whether the involved eye is amblyopic (suggesting a birth injury).
The etiology of these similarities remains somewhat of a mystery: presently, it is unclear whether birth-time forceps trauma induces these associated ocular abnormalities or whether it is structural weaknesses in the infant's eye that both predispose to these characteristics and also make the cornea vulnerable to rupture during forceps delivery.
We are grateful to the authors of “Management of Descemet Membrane Detachment After Forceps Delivery” for exposing another similarity between these two categories of eyes.4 In keratoconics, corneal hydrops is associated with both breaks in Descemet membrane and also intrastromal fluid clefts that can be located and selectively drained with the assistance of anterior segment optical coherence tomography. Draining these fluid clefts is not only possible but also apparently necessary for prompt resolution of corneal edema, such that rebubbling efforts alone are often insufficient.5 In this article, Kancherla et al demonstrate that fluid clefts are also present within the corneas of infants with forceps injuries and likewise must be drained for rapid corneal deturgescence to occur. In so doing, this article not only suggests a new first line of care for these patients but also further hints at structural/pathological similarities between corneas with forceps injuries and corneas with keratoconus.
Rapid resolution of hydrops with minimal risk of pupillary block may be especially important in pediatric cases to prevent (often dense) amblyopia, and we hope this method achieves widespread attention.