Sruthi Srinivasan is a clinical research manager at the Centre for Ocular Research & Education, and a research assistant professor at the School of Optometry and Vision Science, University of Waterloo, Canada
Dry eye disease (DED) is a chronic condition affecting millions of people. The prevalence of DED is between 5% and 50%,1 a wide range as there is no gold standard for diagnosis of this condition.2-8 The Tear Film and Ocular surface Society (TFOS) Dry Eye Workshop II (DEWS II) report has recently updated the definition of DED as,
“a multifactorial disease of the ocular surface characterised by a loss of homeostasis of the tear film, and accompanied by ocular symptoms, in which tear film instability and hyperosmolarity, ocular surface inflammation and damage, and neurosensory abnormalities play etiological roles.”1
DED is a complex condition for which a single etiology is not known. The complexity of both the disease and its diagnosis makes it difficult to establish a single diagnostic test to diagnose DED. Hence, management strategies can also be challenging in certain cases of DED. This section provides an overview of the newest diagnostic tools for DED, as well as the latest approaches to management.
Clinicians rely to a large degree on their case history, with the patient’s input regarded as an important tool to diagnose and categorize patients with DED. Hence, symptoms of DED are a key factor in the diagnosis and management of DED. A variety of questionnaires are available for the evaluation of symptoms, which can aid in the diagnosis of DED and also monitor treatment effects. Of these, the TFOS DEWS II report recommends a positive score on a validated symptom questionnaire (either ≥ 6 on the Dry Eye Questionnaire (DEQ)-5 or ≥13 on the Ocular Surface Disease Index (OSDI)) for the diagnosis of DED.9 Questionnaires can be completed while the patient is in the waiting room, and interpreting the questionnaire results can be rapidly undertaken based on the questionnaire used.
It is also important to assess pain experienced in DED. Broadly, pain can be categorized into nociceptive and neuropathic pain. Nociceptive pain is signaled as a result of damage to tissues by noxious mechanical, thermal and chemical stimuli. In contrast, neuropathic pain is triggered by a lesion or disease of the somatosensory nervous system. This differentiation may improve clinical diagnosis and treatment efficacy of DED, as treatment for the pain and discomfort associated with DED is generally ineffective for ocular neuropathic pain.10
Tear film instability and increased tear osmolarity are key mechanisms in dry eye, regardless of the underlying etiology.1,11 Tear osmolarity is considered a single biophysical measurement that captures the balance of inputs and outputs of the lacrimal system.12 The ease of use and small tear sample required make newer in situ osmometers much more clinically accessible and the shorter contact time required to obtain tear samples is more comfortable for the patient.
Newer electrical impedance osmometers, such as the TearLab osmometer (TearLab), measure osmolarity by measuring the number of charged particles within a sample and can provide results from a small tear sample in less than a minute.13,14 The electrical impedance osmometer collects the tear sample by touching the tear meniscus with a small testing chip without the need for anaesthetic and without manipulation of the lids.
Another point-of-care tear osmometer that uses electrical impedance technology is the new i-Pen (I-MED Pharma Inc, OcuSOFT). Recent studies have not shown it to be as accurate in differentiating normal from dry eyes.15,16 The iPen has a flexible conductimetric sensor, constructed using microelectronic techniques, which is placed on the palpebral conjunctival membrane to measure the electrical conductivity of the tear fluid.17
InflammaDry, a new rapid immunoassay by Quidel Corporation is an in-office test that allows for the identification of inflammatory DED and ocular surface disease. It detects elevated levels of matrix metalloproteinase 9 (MMP-9), an inflammatory marker that is considered to be elevated in the tears of DED patients.18 A recent review on the role of ocular surface MMP-9 in DED and the implications of InflammaDry suggested that not all patients with symptoms of DED have increased (>40ng/ml) MMP-9 levels and that future studies are needed to clarify all the factors involved. This would allow eye care practitioners to understand how to best incorporate this in-office test into the dry eye testing routine to help in diagnosis and treatment decisions.19
The LipiView II (Johnson & Johnson Vision), Lipiscan (Johnson & Johnson Vision), Keratograph 5M (Oculus) EasyTearView+ (Easytear s.r.l.) and Ocular Surface Analyser (SBM Sistemi) are all instruments that have the capability of assessing the tear film and imaging the meibomian glands. These multi-functional devices provide space-saving options within eye care practices and it is likely that such devices will continue to be released that use a single platform to deliver multiple testing options.
Once diagnosed, a wide variety of management options exist to treat DED.20 This article discusses some of the recent developments in the management of DED.
Managing lid conditions
For the treatment of blepharitis, topical hypochlorous is now available as Avenova from NovaBay21,22 and also as Hypochlor from OCuSOFT.23 These products are designed for the removal of microorganisms and debris on and around the eyelid margins.21,23,24
Intense pulsed light (IPL) has been extensively studied and reported to have a beneficial effect on erythema and telangiectasia.25 Light energy absorbed by hemoglobin converts to heat and causes the destruction of superficial blood vessels (thrombosis). In meibomian gland dysfunction (MGD), the destruction of abnormal erythematous blood vessels decreases the inflammatory mediators, therefore removing a main cause of inflammation from the eyelids and meibomian glands.26
Also available is LipiFlow (Johnson and Johnson), which provides thermal pulsation therapy27 to rapidly melt the meibum and improve the MGD that is prevalent in several patients with dry eye. A recent study showed a single LipiFlow® treatment effect, with improved gland function and dry eye symptoms, can be sustained for up to 12 months.27 Another device which heats the meibomian glands is the MiBo Thermoflo (MiBo Medical Group).28 This device massages the outer area of the eyelids with continuous controlled heat.
BlephEx™ (Rysurg) is used as an in-office blepharitis treatment. The handheld device is fitted with a single-use, disposable sponge on its tip, which spins/rotates, effectively helping the clinician to microexfoliate the lid margins and lashes and is a less invasive method to mechanically remove debris and biofilm at the lid margins.29
Cyclosporine is an immunomodulatory drug with anti-inflammatory properties, with other actions relevant to managing DED.30,31 Cyclosporine is an inhibitor of T-cell proliferation and thereby inhibits T-cell-mediated immune responses.32 The availability of Restasis multidose™ (Cyclosporine Ophthalmic Emulsion) 0.05% was announced by Allergan recently. The unit dose format received FDA clearance in October 2016 and has been available since March 2017. It is one of the first FDA-approved, preservative-free prescription eye drops available in a multi-dose bottle with a patented unidirectional valve and air filter technology.33 Patients who find the single-dose unit difficult to handle may welcome the multi-dose bottle.
A new topical dry eye therapeutic agent – Lifitegrast ophthalmic solution 5.0% (Xiidra, Shire) hit the US market in 2016. Lifitegrast is approved by the FDA for the treatment of signs and symptoms of DED. It is a small molecule integrin antagonist, made to mimic intercellular adhesion molecule 1’s (ICAM-1’s) binding domain to lymphocyte function-associated antigen-1 (LFA-1) and serves as a competitive antagonist to block binding between LFA-1 and ICAM- 1. This results in inhibition of T cell migration into target tissues, reduction of cytokine release, and reduction of further T cell recruitment.34,35 Lifitegrast was studied in four 12-week, randomized, double-blind, vehicle-controlled clinical trials in a total of 2133 adult patients with DED.36-38 These trials showed improved patient-reported symptoms of DED, as measured by the symptom score and corneal fluorescein staining. The recommended dosage of one drop of solution instilled twice a day appears to be safe and effective in treating the signs and symptoms of DED.
An intranasal neuro-stimulation device (TrueTear Intranasal Tear Stimulator, Allergan), recently approved by the FDA, could be a useful treatment for DED. This portable, handheld device stimulates the production of tears that can return the ocular surface to a more normal condition. This device features a reusable base with a disposable tip that is inserted into the nose to contact the anterior nasal mucosa. The tip transmits a series of low-voltage electrical pulses to the trigeminal nerve, triggering the nasolacrimal reflex to stimulate natural tear production.39
ProKera amniotic membranes (BioTissue) is another alternative to speed up the healing of severe DED. The application of the amniotic membrane is a suture-free, in-office procedure.40 It is made by clipping a piece of amniotic membrane tissue in between two rings made out of a clear, flexible material. The amniotic membrane used here is thin and clear like the tissue on the surface of the eye and protects damaged tissue when inserted.
Although there are several novel approaches in the diagnosis and treatment of DED, to date, there is no single test known to conclusively diagnose DED. At the present time a “combination of subjective and objective dry eye tests” is necessary to determine the underlying etiology to arrive at a diagnosis. With the lack of association between the symptoms and signs of DED, poor test reproducibility of objective tests, variability with season and time of day, and even variability between eye care examinations, DED is an complicated disease process, and we are only starting to understand its intricacy. Researchers are working towards the development of simple, less cumbersome, clinician friendly, inexpensive, reliable, repeatable, and highly specific and sensitive diagnostic tools for DED. This may then lead to more specific management strategies for DED that could restore the homeostasis of the ocular surface.
- Craig JP, Nichols KK, Akpek EK, et al. TFOS DEWS II Definition and Classification Report. Ocul Surf. 2017;15(3): 276-83.
- Chia EM, Mitchell P, Rochtchina E, et al. Prevalence and associations of dry eye syndrome in an older population: the Blue Mountains Eye Study. Clin Experiment Ophthalmol. 2003;31(3): 229-32.
- Lin PY, Tsai SY, Cheng CY, et al. Prevalence of dry eye among an elderly Chinese population in Taiwan: the Shihpai Eye Study. Ophthalmol. 2003;110(6): 1096-1101.
- Schaumberg DA, Sullivan DA, Buring JE, Dana MR. Prevalence of dry eye syndrome among US women. Am J Ophthalmol. 2003;136(2): 318-26.
- Galor A, Feuer W, Lee DJ, et al. Prevalence and risk factors of dry eye syndrome in a United States veterans affairs population. Am J Ophthalmol. 2011; 152(3): 377-84 e372.
- Paulsen AJ, Cruickshanks KJ, Fischer ME, et al. Dry eye in the beaver dam offspring study: prevalence, risk factors, and health-related quality of life. Am J Ophthalmol. 2014;157(4): 799-806.
- Tan LL, Morgan P, Cai ZQ, Straughan RA. Prevalence of and risk factors for symptomatic dry eye disease in Singapore. Clin Experiment Optom. 2015;98(1): 45-53.
- Farrand KF, Fridman M, Stillman IO, Schaumberg DA. Prevalence of diagnosed dry eye disease in the United States among adults aged 18 years and older. Am J Ophthalmol. 2017;182: 90-8.
- Wolffsohn JS, Arita R, Chalmers R, et al. TFOS DEWS II Diagnostic Methodology report. Ocul Surf. 2017;15(3): 539-74.
- Belmonte C, Nichols JJ, Cox SM, et al. TFOS DEWS II pain and sensation report. Ocul Surf. 2017;15(3): 404-37.
- No authors listed. The definition and classification of dry eye disease: report of the definition and classification subcommittee of the international dry eye workshop. Ocul Surf. 2007;5(2): 75-92.
- Tomlinson A, Khanal S, Ramaesh K, et al. Tear film osmolarity: determination of a referent for dry eye diagnosis. Invest Ophthalmol Vis Sci. 2006;47(10): 4309-15.
- Tomlinson A, McCann LC, Pearce EI. Comparison of human tear film osmolarity measured by electrical impedance and freezing point depression techniques. Cornea. 2010;29(9): 1036-41.
- Jacobi C, Jacobi A, Kruse FE, Cursiefen C. Tear film osmolarity measurements in dry eye disease using electrical impedance technology. Cornea. 2011;30(12): 1289-92.
- Nolfi J, Caffery B. Randomized comparison of in vivo performance of two point-of-care tear film osmometers. Clin Ophthalmol. 2017;11: 945-50.
- Rocha G, Gulliver E, Borovik A, Chan CC. Randomized, masked, in vitro comparison of three commercially available tear film osmometers. Clin Ophthalmol. 2017;11: 243-8.
- Maharaj R. In vivo ocular surface osmolarity in a dry eye population. Clin Refrac Optom. 2017;28(1):3-6.
- Sambursky R, Davitt WF, 3rd, Friedberg M, Tauber S. Prospective, multicenter, clinical evaluation of point-of-care matrix metalloproteinase-9 test for confirming dry eye disease. Cornea. 2014;33(8): 812-18.
- Lanza NL, Valenzuela F, Perez VL, Galor A. The matrix metalloproteinase 9 point-of-care test in dry eye. Ocul Surf. 2016;14(2): 189-95.
- Jones L, Downie LE, Korb D, et al. TFOS DEWS II management and therapy report. Ocul Surf. 2017;15(3): 575-628.
- Avenova product information. https://novabay.com/products/avenova/. 2018:Accessed February 2018.
- Epstein A, Pang L, Najafi-Tagol K, et al. Comparison of bacterial lipase activity in the presence of eye lid cleansers. Invest Ophthalmol Vis Sci. 2015;56(7): e-abstract 4446.
- OCuSOFT® HypoChlor™ & the Facts About Hypochlorous Acid http://www.ocusoft.com/ocusoft-hypochlor-the-facts-about-hypochlorous-acid-2. 2015: Accessed February 2018.
- Navitsky C. Adjunct treatments for dry eye disease. CRST Europe. 2016: 16-18.
- Papageorgiou P, Clayton W, Norwood S, et al. Treatment of rosacea with intense pulsed light: significant improvement and long-lasting results. Br J Dermatol. 2008;159(3): 628-32.
- Dell SJ. Intense pulsed light for evaporative dry eye disease. Clin Ophthalmol. 2017;11: 1167-73.
- Blackie CA, Coleman CA, Holland EJ. The sustained effect (12 months) of a single-dose vectored thermal pulsation procedure for meibomian gland dysfunction and evaporative dry eye. Clin Ophthalmol. 2016;10: 1385-96.
- Mibo Thermoflo. http://www.mibomedicalgroup.com/mibothermoflo.html. 2016: Accessed February 2018.
- Connor CG, Choat C, Narayanan S, et al. Clinical effectiveness of lid debridement with BlephEx treatment. Invest Ophthalmol Vis Sci. 2015;56(7): 4440.
- Donnenfeld E, Pflugfelder SC. Topical ophthalmic cyclosporine: pharmacology and clinical uses. Surv Ophthalmol. 2009;54(3): 321-38.
- Matsuda S, Koyasu S. Mechanisms of action of cyclosporine. Immunopharmacol. 2000;47(2-3): 119-25.
- Perry HD, Donnenfeld ED. Topical 0.05% cyclosporin in the treatment of dry eye. Expert Opin Pharmacother. 2004;5(10): 2099-107.
- Restasis Multidose (Cyclosporin Ophthalic Emulsion) 0.05%. https://www.restasis.com/about-restasis/restasis-multidose. Accessed February 2018.
- Zhong M, Gadek TR, Bui M, et al. Discovery and development of potent LFA-1/ICAM-1 antagonist SAR 1118 as an ophthalmic solution for treating dry eye. ACS Med Chem Lett. 2012;3(3): 203-6.
- Perez VL, Pflugfelder SC, Zhang S, et al. A novel integrin antagonist for treatment of dry eye disease. Ocul Surf. 2016;14(2): 207-15.
- Semba CP, Torkildsen GL, Lonsdale JD, et al. A phase 2 randomized, double-masked, placebo-controlled study of a novel integrin antagonist (SAR 1118) for the treatment of dry eye. Am J Ophthalmol. 2012;153(6): 1050-60 e1051.
- Sheppard JD, Torkildsen GL, Lonsdale JD, et al. Lifitegrast ophthalmic solution 5.0% for treatment of dry eye disease: results of the OPUS-1 phase 3 study. Ophthalmol. 2014;121(2): 475-83.
- Tauber J, Karpecki P, Latkany R, et al. Lifitegrast ophthalmic solution 5.0% versus placebo for treatment of dry eye disease: results of the randomized phase III OPUS-2 study. Ophthalmol. 2015;122(12): 2423-31.
- Friedman NJ, Butron K, Robledo N, et al. A non-randomized, open-label study to evaluate the effect of nasal stimulation on tear production in subjects with dry eye disease. Clin Ophthalmol. 2016;10: 795-804.
- Suri K, Kosker M, Raber IM, et al. Sutureless amniotic membrane ProKera for ocular surface disorders: short-term results. Eye Contact Lens. 2013;39(5): 341-7.