I am confident you will find the probing system to hold differential value in your dry eye patients. I am getting this feedback from many ophthalmologists globally. It has completely changed my approach to dry eye patients and with accumulating experience taught me much about the meibomian gland in clinical practice.
I have been through a number of anesthetics to arrive at what is the best at this time. There is nothing on the commercial market now that is good enough for the majority of patients. Leiter’s Compounding Pharmacy in San Jose, California (1-800-292-6773) makes for me the 8% lidocaine with 25% jojoba in a petrolatum ointment base. Then:
- First place a drop of proparacaine 0.5% or tetracaine 0.5% solution in the conjunctival sac.
- Then place a generous amount of jojoba ophthalmic anesthetic ointment on the lower lid margin using a sterile cotton tipped applicator.
- Have the patient close their lids for 10-15 minutes. There will be some mild burning which gradually dissipates over 30 seconds. After the 15 minutes, the patient opens his/her eyes and place another drop of the topical anesthetic solution into the conj sac to eliminate mild burning from the ointment.
- Then start probing.
- Make sure you start with the shortest and stiffest probeäthe 1mm length.
To find difficult or occult orifices, try red free light at the slit lamp. You can also transilluminate the lid and try to visualize the duct this way. There are a few of us that have been able to use the probe to re-create or reconstruct an absent orifice as the probe is passed into the duct visualized with transillumination.
If your patient is very inflamed, you may want to inject decadron 4mg/ml into the ducts through the stainless steel intraductal tubes after completing the probing part of the treatment.
After completing the probing, I irrigate the ointment off the ocular surface with sterile preservative free saline eg Unisol, or BSS. Then I give them a bottle of preservative free artificial tears to use every hour until bedtime.
If there is concomitant aqueous tear deficiency, I also occlude puncta with cautery at same time. I have seen in a rare case, patients with combined MGD and untreated aqueous tear deficiency can get increased punctuate erosions and even a small horizontally oval epithelial defect in the inferior third peripheral cornea from their tear deficiency, the ointment and keeping the lids open during the procedureähence the use of post procedure artificial tears. Obviously, if they get a frank epithelial defect you should use prophylactic topical antibiotic, eg a fluoroquinolone BID until heals. The defect heals overnight without patch or bandage lens.