Can slt laser treatment be used repeatedly and effectively on a glaucoma patient?

Yes . Slt can be repeated however subsequent treatments may not be as efficacious . Some glaucoma patients may need to have their pressure reduced greater than slt can provide alone . Medication or filtering surgery may be necessary in some glaucoma patients.
Yes. If the initial iop lowering effect is acceptable and has adequate duration of effect, ie., several years, then the slt treatment may be repeated. The slt iop lowering effect tends to wear off approximately 10-20% per year.