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Wide range of treatments available to optimize ocular surface
The lid margin plays an important role in maintaining ocular surface health. Inflammation of the lid margin in the form of anterior or posterior blepharitis can cause ocular surface inflammation and degrade the quality of the tear film. Before any elective surgery such as cataract or laser refractive surgery, it is advisable to address the component of anterior blepharitis and meibomian gland dysfunction in order to improve the outcome of surgery.
Anterior and posterior blepharitis, also known as meibomian gland dysfunction (MGD), can coexist, as can the presence of aqueous tear deficiency with MGD. The treatment needs to be tailored based on the severity of each component. The treatment for anterior blepharitis is daily lid scrubs with warm water with or without the use of a diluted baby shampoo.
Recently, the use of medicated tissues/towelettes such as Avenova (hypochlorous acid, NovaBay), Blephaclean (Thea) and OcuSoft (OcuSoft) has simplified the process. Depending on the amount of inflammation of the lid margin, an antibiotic ointment alone or a combination of antibiotic ointment with steroid is used. The antibiotic ointment reduces the colonization of the flora on the lid margin and also reduces the inflammatory mediators released by the organism. A broad-spectrum antibiotic is generally preferred. Commonly used are bacitracin, fusidic acid and macrolides, including azithromycin. These have antibacterial, anti-inflammatory properties and also have beneficial effects for patients with MGD. Antibiotic ointment formulations are helpful in MGD because they add to the tear lipid layer with the presence of polar and non-polar lipids in their formulation.
In patients with cylindrical dandruff at the base of the lashes, the possibility of Demodex infestation should be considered. This should be treated with tea tree oil-based solutions. In patients with MGD, the severity of the problem with respect to the quality of meibum and the amount of surviving glands needs to be ascertained. When there is minimal gland dropout, simple hot/warm compresses with massage can help. The general guideline is to use warm compress of around 40°C for 5 minutes once or twice daily followed by lid massage to express the meibum.
Recently, infrared heating devices or moist eye warmer glasses/masks have been tried to standardize the procedure. The LipiFlow technique (TearScience) seems to be a promising alternative, resulting in subjective and objective improvement at least for a couple of months after a single session. If the gland dropout is significant, adding a lipid component to the ocular surface, such as the use of lipid-containing artificial tear supplements, has been tried but with limited success. The use of Restasis (cyclosporine ophthalmic emulsion 0.05%, Allergan) has had moderate success in patients with significant MGD and aqueous tear deficiency. This contributes partly to the lipid layer of the tears due to its vehicle. The anti-inflammatory properties also improve ocular surface health and aqueous tear production. Systemic doxycycline or minocycline helps in improving the quality of the lipids and improves the lipid layer thickness, as shown in tear interference images, along with its other anti-inflammatory effects on the ocular surface. It is useful especially in patients with ocular rosacea.
Omega-3 fatty acids have also been found to be useful in improving the stability of the tear film in patients with MGD. Various formulations of omega-3 fatty acids are available on the market. It is important to realize that the re-esterified triglyceride form has more bioavailability. In patients with moderate to severe dry eye, the option of decreasing the drainage outflow by using punctal plugs or lacrimal plugs can be considered. The choice of an absorbable or permanent plug depends on the severity of the dry eye state. In cases of borderline dry eye, we might use temporary plugs to decrease patient discomfort in the early postoperative period until the ocular surface stabilizes and reserve permanent plugs for severe dry eye patients.
Pterygium is a common ocular surface disease, and the only known effective treatment to date is surgical excision. Surgical excision combined with a conjunctival autograft or with the use of antimetabolites reduces the possibility of recurrence. However, the most important factor that improves surgical success is adequate perioperative control of inflammation.
Dry eye and ocular surface disease can be caused by other diseases such as keratoconus. When contemplating collagen cross-linking in a patient with keratoconus and ocular surface disease, close follow-up until epithelization occurs is recommended.
The role of LASIK and penetrating or anterior lamellar keratoplasty causing dry eye and ocular surface damage is well known. Descemet’s stripping endothelial keratoplasty might induce less dry eye and ocular surface damage due to its smaller corneal incision and unaffected anterior corneal tissue.
The increase in intravitreal injection for macular degeneration and macular edema has resulted in increased referral of patients postoperatively with ocular surface inflammation. This is probably due to the use of antibiotics and antiseptic medication in the perioperative period.
When attending to patients who have undergone cataract and refractive surgery performed by an anterior segment surgeon, we need to be aware of any potential diseases of the lid margin and ocular surface. These diseases need to be aggressively treated before we plan for any surgical intervention.
References:
Baudouin C, et al. Br J Ophthalmol. 2016;doi:10.1136/bjophthalmol-2015-307415.
Geerling G, et al. Invest Ophthalmol Vis Sci. 2011;doi:10.1167/iovs.10-6997g.
Oleñik A, et al. Clin Ophthalmol. 2014;doi:10.2147/OPTH.S62470.
Sutu C, et al. Curr Opin Ophthalmol. 2015;doi:10.1097/ICU.0000000000000227.
Zhao Y, et al. Eye Contact Lens. 2016;doi:10.1097/ICL.0000000000000228.
For more information:
Dennis S.C. Lam, MD, FRCOphth, can be reached at State Key Laboratory in Ophthalmology, Sun Yat-Yen University, 54 South Xianlie Road, Guangzhou 510060, People’s Republic of China; email: dennislam.gm@gmail.com.
Disclosures: Srinivasan and Lam report no relevant financial disclosures.