#6 of 10: Top Reasons for Poor Premium IOL Outcomes and How to Remedy Them: Managing the Ocular Surface
Managing patient expectations, the preoperative evaluation, corneal astigmatism, posterior capsular opacification, and addressing cystoid macular edema are all critical in making the premium patient happy with a premium outcome. However, ignoring the ocular surface, one of the remaining reasons for poor premium IOL outcomes, will lead to a dissatisfied patient from a preoperative, intraoperative, and/or postoperative perspective.
Dry eye syndrome (DES), blepharitis/meiboimian gland dysfunction (MGD), allergy, and epithelial basement membrane disease (EBMD) are the most common causes for poor ocular surface function in the premium IOL patient. Approaching the ocular surface from a tear layer approach will help manage and prevent many of the problems associated with such a problem.
Recently, the International Delphi Panel/DEWS redefined dry eye as being a multifactorial disease of the ocular surface that results in symptoms of discomfort, visual disturbance, and tear film instability with potential damage to the ocular surface.¹ Furthermore, dry eye is accompanied by an increase in tear film osmolarity and inflammation of the ocular surface. Dry eye affects approximately 20.7 million people in the United States² and is most commonly observed in older women over the age of 50.³
Other common causes of dry eye are the American “fast food” diet high in bad omega-6 and low in good omega-3 fatty acids, LASIK/other corneal refractive surgery procedures, diabetes mellitus, vitamin A deficiency, hepatitis C infection, low blink rate (Parkinson’s disease, computer vision syndrome, cosmetic blepharoplasty, contact lenses, and medications (diuretics, antihistamines, BCPs, tricyclic antidepressants, anticholinergics, antispasmodics, HRT).
The preoperative evaluation must include a global evaluation of the patient, because a poor ocular surface can affect the accuracy of preoperative critical measurements such as keratometry, corneal topography and axial biometry. The PHACO study (prospective health assessment of cataract patients’ ocular surface) led by William B. Trattler, MD, and colleagues confirmed that most patients who undergo cataract surgery are asymptomatic, but 62% have a tear breakup time of less than 5 seconds, 50% have central corneal staining, and 21% have abnormal Schirmer test scores of less than 5 mm. As much as 1 D to 2 D of error in IOL power calculations as a result of such poor data acquisition can definitely hinder the ideal outcome, especially in premium IOL patients.
My approach to the ocular surface is that of a tear layer etiology and management, which typically is overlapping, requiring multiple treatment modalities in order to achieve an improved ocular surface.
The lipid layer is most commonly affected by patients with acne rosacea or some ocular variant of such creating what we coin as blepharitis, meibomitis, MGD, or simply lid margin disease. Management of such includes warm compresses, lid massage, lid scrubs, topical azithromycin (Azasite Plus, ISV-502, Insite Vision) and/or tobramycin/dexamethasone/loteprednol (Tobradex ST. Alcon/Zylet, Bausch & Lomb), artificial tears that replace the oily layer (Systane Balance, Alcon/Retaine, Ocusoft), low dose doxycycline 50 mg/day, the Maskin meibomian gland probing/expressor technique (Rhein), and/or the potentially new curative Lipiflow thermal pulsation system (Tear Science).
The aqueous layer is typically affected by autoimmune disease such as lupus, rheumatoid arthritis, ulcerative colitis, diabetes, and thyroid disease. Management options include concomitant internist/rheumatologist/endocrinologist care, topical cyclosporine (Restasis, Allergan), punctual plugs, topical steroids such as loteprednol (Lotemax, Bausch & Lomb), and omega 3 fish oil nutrition. Tear film osmolarity is now easily detected with the Tear Lab device no more difficult than a tonopen IOP measurement. If osmolarity is elevated, I may customize my artificial tear regimen to include Blink tears (Abbott Medical Optics) as it has a beneficial effect on tear osmolarity. ⁵
The mucin layer insult is usually seen with vitamin A deficient, Stevens Johnson syndrome, graft versus host disease, and ocular cicatricial pemphigoid (OCP) conditions. Treating the underlying condition, topical cyclosporine due to its enhanced goblet cell density effect, and topical Freshkote (Focus Labs) are my treatments of choice in these circumstances. The latter also aids those with epithelial basement membrane dystrophy (EBMD) due to an enhanced oncotic pressure gradient effect at this level. Lastly, ocular allergy though fairly easy to treat will always aggravate dry eye and selecting a more specific H-1 receptor antihistamine/mast cell stabilizing pharmaceutical such as Lastacaft (Allergan) or Bepreve (Ista) will limit such side effects in the dry eye patient.
In the end, managing the ocular surface is crucial in not only obtaining accurate diagnostic data preoperatively but improving visual quality postoperatively by managing each patient based on a tear layer etiologic approach. Stay tuned for my next remedy for the premium IOL problem blog: managing IOL calculations with special attention to the post-refractive surgery patient.
¹Lemp M et al. Ocular Surface 2007; 5: 75-92. ²Market Scope. Report on the Global Dry Eye Market. St. Louis, Mo: Market Scope, July 2004. ³Schaumberg DA, Sullivan DA, Buring JE, Dana MR. Prevalence of dry eye syndrome among US women. Am J Ophthalmol. 2003; 136: 2318-2326.⁴Trattler W, Goldberg D, Reilly C. Incidence of concomitant cataract and dry eye prospective health assessment of cataract patients. Presented at World Cornea Congress April 8, 2010 Boston, MA.
