Postlensectomy glaucoma linked to Schlemm’s canal alterations

Using anterior segment OCT, investigators examined the Schlemm’s canal and trabecular meshwork (TM) of children who developed glaucoma after undergoing a lensectomy.

Study design

This cross-sectional retrospective study included 50 healthy children age 4 to 16 years (124 eyes) and 48 children who had previously underwent lensectomy (72 eyes). Anterior segment OCT was performed at various accommodative efforts to determine the Schlemm's canal and trabecular meshwork dimensions.

Outcomes

In postlensectomy eyes, the horizontal Schlemm's canal area was reduced compared with healthy controls. Lensectomy was associated with a loss of the physiological dilatation of Schlemm's canal in response to accommodative effort.  

A subgroup analysis found that the horizontal diameter and cross-sectional area of Schlemm's canal was smaller in glaucomatous postlensectomy eyes, but not in those without postlensectomy glaucoma.

Limitations

This study was limited by its retrospective nature, as well as the heterogenous nature of indications for lensectomy. The effect of surgical technique was not fully controlled, nor was the role of incisional glaucoma surgery.

Clinical significance

This study provides the possibility of a biomechanical explanation for so-called aphakic glaucoma. A number of hypotheses exist as to the mechanism of this disease. With a better understanding of pathophysiology, targeted minimally invasive surgical techniques may be used to treat these vulnerable eyes.