Dry Eye Dx and Tx
Going the Surgical Route to Treat Severe Dry Eye
BY WAZIHA SAMIN, BS, & AMBER GAUME GIANNONI, OD, FAAO
The case described below is a patient of Dr. Clarke Newman. The patient was seen by Ms. Samin, a student of Dr. Gaume Giannoni, during her optometry externship.
A 43-year-old hypothyroid female had severe, bilateral keratoconjunctivitis sicca (KCS). She tested negative for other autoimmune diseases but suffered from profound depression due to the constant, longstanding, and debilitating ocular pain that she experienced daily.
Her failed dry eye therapies included topical corticosteroids, cyclosporine ophthalmic emulsion, autologous serum, scleral contact lenses, meibomian gland support, punctal occlusion, and a myriad of artificial tears and gels. What other options are left after your patient has failed virtually every conceivable therapy?
A Surgical Option to Consider
Autologous salivary gland transplantation (ASGT) is a surgical option for KCS that involves removal of the lacrimal gland followed by transplantation of parotid gland or submandibular gland tissue to deliver saliva to the ocular surface. What might not be intuitive is that although the surgery is for patients who have severe KCS, it is also contraindicated in many dry eye patients. Individuals who have conditions tied to exocrine gland hypofunction, including Sjögren’s syndrome patients, are poor candidates because the transplanted salivary glands won’t perform optimally (Qin et al, 2013; Zhang and Yu, 2012). Our patient had submandibular gland tissue from the left side of her face transplanted to her left temporal fossa.
Salivary “Tears” Versus Lacrimal Tears While their flow rates are similar, salivary gland “tears” have a lower osmolarity and contain different concentrations of nutrients, enzymes, and proteins (Geerling et al, 2000). Salivary gland tears also contain amylase, an enzyme that converts starch and glycogen into simple sugars to aid digestion; however, no adverse events have been reported from its presence on the ocular surface (Geerling et al, 2000).
Success Rates and Complications The success rate of ASGT appears promising. In a study by Jacobsen et al (2008), 53% of patients reported satisfaction five years post-surgery, while 13% were indifferent and about one-third were dissatisfied.
Certainly, ASGT is not without potential complications. Patients are at risk for developing microcystic corneal edema due to the hypo-osmolar content of the new tears, which is especially true in cases of hypersecretion; these complications are often managed by surgically reducing the size of the transplanted gland or by the injection of botulinum toxin to reduce output (Qin et al, 2013). Other potential complications include duct obstruction and graft necrosis (Qin et al, 2013).
In addition, Qin et al showed that while the majority of transplants seem to be viable immediately after surgery, a large number of patients tend to experience a “latent period,” in which tear production significantly drops to pre-surgical levels. This latent period can last several months before tear production picks up again.
In the case of our patient, she reported significant symptomatic relief one month after surgery, and her tear production measured a whopping 30mm in the treated eye versus 5mm in the untreated eye. One month later, she complained of significant dryness, and her tear production was minimal. It has now been 10 months since her surgery, and she is very happy with the outcome. In fact, she will undergo ASGT for her right eye in the near future. CLS
For references, please visit www.clspectrum.com/references and click on document #246.
Ms. Samin is currently a student of the University of Houston College of Optometry Class of 2016. Her interests are specialty contact lens fitting and ocular disease, for which she will be pursing an ocular disease residency at the Cedar Springs Eye Clinic in Dallas. Dr. Gaume Giannoni is a clinical associate professor at the University of Houston College of Optometry and is the director of the Dry Eye Center at the University Eye Institute. She also sees patients in a private practice setting. She is a consultant or advisor to Alcon and Allergan.