Lmx1b is required for murine trabecular meshwork formation and for maintenance of corneal transparency.

Studies of Lmx1b have shown that it is required for anterior segment formation during embryonic development and that reduction of Lmx1b may contribute to elevated intraocular pressure in the adult. However, whether Lmx1b is required for formation of anterior segment tissues that are associated with regulation of intraocular pressure has not been addressed due to the perinatal lethality of Lmx1b null allele. Here we use conditional deletion strategies to circumvent perinatal lethality. Our results indicate that Lmx1b is required in neural crest-derived periocular mesenchyme for formation of anterior segment tissues, including trabecular meshwork, a critical regulator of intraocular pressure. Furthermore, we show that Lmx1b is essential to maintain proper functioning of those tissues in the adult. Taken together, our results are the first to link a specific transcription factor to trabecular meshwork formation and the first to demonstrate specific requirements for Lmx1b in maintaining the integrity of adult anterior segment.