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r u l e i t o u t . No n - o b v i o u s M G D (NOMGD) may be present, so I always push the lower eyelid gently to express the glands, which often reveals a problem — even in otherwise normal- appearing eyelids. Clinical Testing ■ Schirmer I and II: I sometimes use the S chirmer test to evaluate aqueous tear production, especially for patients referred by rheumatologists b e c a u s e t h e y u s u a l l y r e q u e s t a Schirmer's test. In theory, Schirmer I, performed with anesthetic, evaluates baseline secretion, while Schirmer II, performed without anesthetic, measures baseline plus refex secretion. More than 10 mm of moisture on the filter paper after 5 minutes is considered a normal test result. ■ C o r n e a l a n d c o n j u n c t i v a l staining: I always have my patients remove their contact lenses so I can use a staining dye. Fluorescein will stain to reveal defects in the corneal and conjunctival epithelium. Rose bengal will stain dead conjunctival c e l l s o r c e l l s u np r o t e c t e d b y a normal mucin layer. It also stains the conjunctiva more than the cornea. The degree of staining correlates well with the degree of aqueous tear defciency, tear breakup time (TBUT), and reduced mucus production by conjunctival goblet cell and non- goblet epithelial cells. Lissamine green works by the same mechanism as rose bengal but tends to be less irritating for the patient. If I see staining in a patient who wants to wear contact lenses for the first time, I treat the ocular surface first, then schedule the contact lens fitting for a later date, especially if multifocal lenses are the goal. Another helpful aspect of staining in contact lens patients is that it reveals l i d w ip e r e pit hel i op at hy ( LW E ) . 3 (Te "lid wiper" is the portion of the upper eyelid marginal conjunctiva that sweeps the ocular surface during blinking.) LWE is a frequent finding when patients have dry eye symptoms without accompanying dry eye signs (Figure 1). ■ Te a r b r e a k u p t i m e : T B U T is useful to evaluate at ever y visit when examining the ocular surface. It correlates with both aqueous and evaporative tear defciency. Although TBUT has been criticized f o r a l a c k o f r e p e a t a b i l i t y a n d standardization, I fnd it very useful for monitoring visit-to-visit improvement i n a w ay t h at i s i l lu s t r at i ve for patients. A TBUT of less than 10 seconds is abnormal, indicating tear film instability. A TBUT of less than 5 seconds is closely associated with dry eye symptoms. It is important to keep in mind that anesthesia decreases TBUT, and fuorescein can destabilize the tear flm. ■ Point-of-c are testing: Point- of-care testing is something many optometrists, including myself, find helpful for making dry eye diagnosis more accurate and efcient. Two such tests are InfammaDry (RPS) and the TearLab Osmolarity System. I n f l a m m a D r y i s b a s e d o n a quantif iable value of the amount o f m a t r i x m e t a l l o p r o t e i n a s e - 9 (MMP-9) in the tears. MMPs are proteolytic enzymes pro duced by stressed epithelial cells on the ocular surface, and MMP-9 is a marker for inf ammation. Te test has been shown to signifcantly and positively correlate wit h cor ne a l f luores cein st aining s c ore s an d abn or m a l s up e r f i c i a l corneal epithelia as seen with confocal microscopy. 4 Results are obtained in 10 minutes and easy to interpret. A red line is positive (>40 ng/ml of MMP-9) and a blue line is negative. The TearL ab osmolarity test is s i m i l arly qu i ck and e as y to us e, requiring only nanoliter volumes of tear fluid. It has been shown to be a s ol i d m e t r i c for d i a g n o s i ng an d classifying dry eye disease. 5 Osmolarity v a l u e s a b ov e 3 0 8 m O s m s / L a r e indicative of dr y eye. B ecause the results are a quantitative numerical value, this test is helpful for engaging patients in their care as we work toward improvement. ■ Anter i or s e g m ent i m a g i ng : Recent advances in anterior segment imaging de vices, such as corneal topographers and tomographers, have included ocular surface capabilities, such as tear meniscus assessment. In my practice, I use a Pentacam (Oculus) to evaluate tear flm regularity. Other available devices include the LipiView I I i nt e r f e r o m e t e r ( Te a r S c i e n c e ) , which measures lipid layer thickness, e va luates blin k rate, and enables visualization of meibomian gland structure to aid in earlier detection of MGD. The Medmont topographer is also able to evaluate the tear flm. The More Data the Better Dry eye afects many patients, not just contact lens wearers. Today's varied diagnostic to ols provide valuable information and, when coupled with an open patient dialogue, will not o n l y i m p r o v e d i a g n o s t i c a n d treatment abilities, but help boost your bottom line, creating a win-win for everyone involved. • REFERENCES 1. Dumbleton K, Caffery B, Dogru M, et al. The T F O S I n t e r n a t i o n a l Wo r k s h o p o n C o n t a c t Lens Discomfort: report of the subcommittee on epidemiology. Invest Ophthalmol Vis Sci. 2013;54(11):TFOS20-36. 2. Nichols KK, Foulks GN, Bron AJ, et al. The international workshop on meibomian gland dysfunction: executive summary. Invest Ophthalmol Vis Sci. 2011;52(4):1922-1929. 3. Korb DR, Herman JP, Greiner JV, et al. Lid wiper epitheliopathy and dry eye symptoms. Eye Contact Lens. 2005;31(1):2-8. 4 . C h o t i k a v a n i c h S , d e P a i v a C S , L i D e Q , e t a l . P r o d u c t i o n a n d a c t i v i t y o f m a t r i x metalloproteinase-9 on the ocular surface increase in dysfunctional tear syndrome. Invest Ophthalmol Vis Sci. 2009; 50(7):3203-3209. 5. Lemp MA, Bron AJ, Baudouin C, et al. Tear osmolarity in the diagnosis and management of dry eye disease. Am J Ophthalmol. 2011;151(5):792-798. Dr. Barnett is a principal optometrist at the University of California, Davis Eye Center in Sacramento, where she specializes in anterior segment disease and specialty contact lenses. She is a Fellow of the American Academy of Optometry, a Diplomate of the American Board of Certifcation in Medical Optometry (ABCMO) and serves on the Board of Women of Vision (WOV), Gas Permeable Lens Institute (GPLI), Ocular Surface Society of Optometry (OSSO) and The Scleral Lens Education Society (SLS). s o n h e c u l r a r k r f o r h a b e e n h o n o s v e l y e l a t e t a i n i n g m u p e r f i c i a l w i t h c o n a r e o b t a t o i n t e p 4 0 n g / m i s n e g a t i v a r L a b o s m q u i c k a n n g o n l y n a n f l u i d . I t h a s b e i d m e t r i c f o r a s s i f y i n g d r y e y e d i s e a l u e s a b o v e 3 0 8 n d i c a t i v e o f d r y e r e s u l t s a r e a q u a n t i v a l u e , t h i s t e s t i s h e l p l o n a g p a t i e n t s i n t h e i r c a r e a s w r k t o w a r d i m p r o v e m e n t . ■ A n t e r i o r s e g m e n t i m a g i n g : R e c e n t a d v a n c e s i n a n t e r i o r s e g m e n t i m a g i n g d e v i c e s , s u c h a s c o r n e a l M e t o n u b c o m m I V i 2 0 - 3 6 N i c o u l k , B r o n J , e t a l . e r n a t r k s h o p o n m e i b o m i a n g l a y n c t i o n : e x e c u t i v e s u m m a r y . I n v e s t O p h t h a l m o l V i s S c i . 2 0 1 1 ; 5 2 ( 4 ) : 1 9 2 2 1 9 2 9 3 . K o d w i p e r a t t h e B P e r m FEBRUARY 2016 | 7