Contrary to the expected result, latanoprost seems to have a significant effect on TM cells. The transcription of the genes for MMP-1, -3, -17, and -24 is increased by latanoprost treatment. TIMP-2, -3, and -4 are also upregulated. The upregulation of these TIMPs may compensate for the increase of those MMPs. The absence of MMP-9 and concurrent upregulation of a greater number of TIMPs may explain the limited effect of latanoprost on TM outflow.

The transcription of the genes for MMP-3 and -17 is increased by latanoprost treatment. MMP-9 is present after latanoprost treatment and may also mediate ECM changes. TIMP-3 is upregulated and may compensate for the increase in MMPs. These coordinated changes could be expected to mediate the latanoprost-induced alteration of ECM in the ciliary body.