Mushy leaves on my Phalaenopsis?

[Tickolas]

Hey guys, just wanted to check if I should do anything about these leaves, seeing as how they're all mushy to the touch and yellowing slightly.

They're the original leaves from when I got the phal about a year and a half ago. By the way, the white line on one of the leaves is mechanical damage from when I last brought it back to the office.

I don't think it's doing too badly since it's shooting fresh roots all over the place and has two new spikes coming in and a fresh offshoot from an old spike. Also, all the newer leaves are very firm to the touch and a deeper green.

So, anything I should do?