Leopard Gecko Mouth Problem

Question

side view  

open mouth   Hi, I have a leopard gecko that is about 9-10 years old. Today I noticed some what appeared to be scabbing on the right side of her mouth. I attempted to moisten the area and some of the hard skin came off but then I noticed swelling inside the mouth as well. She has had trouble shedding the past 2 times around her mouth and head area so I thought it might be related to that. Or is this mouth rot? Do you have any suggestions as to how to proceed? Also, I have noticed her keeping her eyes closed a lot, which I do not know if it is normal for her as I have not had her that long.
 
About her environment:
She is kept in an aquarium with a cool side (avg. 75 degrees) and warm side (avg. 85-90 degrees) with hides on both sides.  She has a humid hide on the warm side that is bedded with vermiculite. The tank is covered with sand substrate. I use a heat lamp and heat pad both on the warm side.  I usually feed her superworms but last time I was at the petstore they were out so I bought her mealworms instead which she refused to eat. Yesterday, I bought superworms and I believe she has eaten since. I keep them in a bowl in her tank as she will not eat from me. I keep them in a mixture of oats, cornmeal, and calcium and she has a water dish.

Answer
Hello Amanda,

That is an awful looking area in her mouth.  
The crusted area looks painful.  You can clean that off with a diluted betadine solution, with a swab.  That can help clean the mouth area.
Do you leave crickets in the tank overnight with her?
If she has had trouble shedding & it retained, there could be an abscess in the mouth.  It looks like it is starting to spread to the eye area, too.
I would take the sand out though to help keep the mouth cleaner as well as cuts down on bacteria in the tank.  
The temperatures sound fine, are you using an undertank heater?  A 9-10 year old is doing good.  Let's try to get more years for her.

Let me know how she is doing.
Tracie