A form of variable astigmatism induced by pseudopterygium

Pterygium and pseudopterygium have long been known to induce astigmatism and may do so without entering the visual axis. We present a case report of a 34-year-old man with a traumatic pseudopterygium which produced a "dynamic" astigmatism, varying in different fields of gaze. Due to the pseudopterygium's attachment to the lateral canthus, it produced a tethering effect with markedly decreased vision and wrinkling of Descemet's membrane when the eye was directed away from the anchoring point. This model may apply to other ocular diseases where perilimbal attachments and adnexal adhesions to the corneal surface may occur; such connections should be looked for in cases with unexplained low levels of visual acuity.