Eye Tech
By: Paul M. Karpecki, OD, FAAO
Director of Education – PECAA
It seems fitting to finish the year with an update on some of the great developments and research of 2014. It is also said that over 60% all patients seek help and insights on the internet before visiting their eye doctors. Sometimes that search leads to very recent technology or future developments. Having the answers and sometimes the technology will always keep you as their eye doctor. We’ll take a whirlwind look at some of the more recent and future innovations in eye care.
Stem Cell Research
Limbal stem cells have long been known to be the precursor to epithelial cell growth and their damage from trauma including chemical burns or contact lens overwear/ inappropriate fit has led to epitheliopathies and persistent epithelial defects. The importance of proper contact lens fitting based on horizontal visible iris diameter cannot be overlooked as anywhere from 17-25% of patients have measurements that do not fit most standard contact lens sizes or modulus. 1
Limbal stem cell transplantation (from viable existing cells otherwise cadaver eyes) has led to recovery of stem cells and epithelia healing and recovery in corneas that had previously been opacified. 2 And the future is even more impressive with potential surrounding pluripotent skin stems cells being programmed as RPE stem cells for the treatment of macular degeneration. 3 Although early in progress, the possibilities are life changing.
Contact Lens Advances
In the near future doctors will be able to monitor intraocular pressure via a contact lens. Wireless devices can be inserted that measure minute changes in corneal curvature that may be translated into IOP alterations (Sensimed TriggerFish). 4 This might be extremely helpful for diurnal pressure measurements and drug response.
But technologies ranging from contact lenses with anti- infective properties to glucose monitoring devices for diabetics may reach our offices. Amniotic membrane is in essence an active bandage contact lens – especially cryopreserved versions such as ProKera (BioTissue). Amnion is the inner lining of the placenta and can be processed to preserve the tissue and used on the ocular surface. The tissue has anti-scarring, antibiotic, anti-adhesion and anti-inflammatory properties for conditions that could lead to corneal scarring. Patients with diseases ranging from recalcitrant recurrent corneal erosion, LSCD, non-responsive epithelial defects and advanced ocular surface disease/persistent corneal staining have responded favorably. 5
Point-of-Care (POC) Diagnostics
POC Diagnostics are here to stay given the success many clinicians are seeing in eye care and the acceptance in general medicine for over a decade. New innovations have changed how we practice from determining the presence of adenovirus (AdenoPlus) to inflammatory markers like MMP-9 (InflammaDry). Knowing the diagnosis before seeing the patient leads to prompt and accurate treatments as well as patient acceptance. TearLab has changed how we manage dry eye/MGD making osmolarity an essential measurement in the diagnosis and monitoring of the disease.
Although it is the most accurate clinical dry eye test available 6, the disease requires it be used in combination with other tests similar to how tonometry is used in glaucoma. Where the test is very valuable is in patients who do not have dry eye to where the reading is low (under 300) and within 5mOsmol/L between the two eyes. 7 8 In these cases it is best to search for other causes and move down those treatment paths.
In-office diagnostic tests available today include a test known as SJO, which looks for novel blood markers related to lacrimal and salivary proteins to help make an earlier diagnosis of Sjogrens’ Syndrome. Other exciting technology includes the ability to measure for diabetes via autofluorescence of the crystalline lens (ClearpathDx – Freedom Meditec). Recent data has shown this test may help alert diabetes and border-line diabetes by as much as 5-7 years earlier than standard blood testing available today. 9 Future devices will measure amyloid in the crystalline lens to diagnose Alzeihemer’s disease (Cognoptix).
Next month we’ll look at a new series of tests that can treat everything from Migraine headaches to more accurate refraction systems.
We live in an incredibly technology driven world and advances in eye care are no exception. “Eye-Tech” may indeed be one of the areas that have advanced the most. These remarkable innovations and those of the near future will help us to better diagnose, treat or manage ocular disease and improve quality of our patient’s lives.
1 Hall LA, Young G, Wolffsohn et al. The influence of corneoscleral topography on soft contact lens fit. Invest Ophthalmol Vis Sci. 2011 Aug 29;52(9):6801-6
2 Ramachandran C Basu S, Sangwan VS et al. Concise review: the coming of age of stem cell treatment for corneal surface damage. Stem Cells Transl Med. 2014 Oct;3(10):1160-8.
3 Kamao H, Mandai M, Okamoto S., et al Characterization of human induced pluripotent stem cell-derived retinal pigment epithelium cell sheets aiming for clinical application. Stem Cell Reports. 2014 Jan 23;2(2):205-18.
4 Mansouri K, Medeiros FA, Tafreshi A et al. Continuous 24-hour monitoring of intraocular pressure patterns with a contact lens sensor: safety, tolerability, and reproducibility in patients with glaucoma. Arch Ophthalmol. 2012 Dec;130(12):1534-9
5 Kheirkhah A, Casas V, Raju VK et al. Sutureless amniotic membrane transplantation for partial limbal stem cell deficiency. Am J Ophthalmol. 2008 May;145(5):787-94.
6 Bron A, Tomlinson A, Foulks GN et al. Rethinking dry eye disease: a perspective on clinical implications. Ocul Surf. 2014 Apr;12(2 Suppl):S1-31
7 Keech A, Senchyna M et al. Invest Ophthalmol Vis SCi 2010;51
8 Keech A, Senchyna M, Jones L. Impact of time between collection and collection method on human tear fluid osmolarity. Curr Eye Res. 2013 Apr;38(4):428-36
9 Cahn F, Burd J, Ignotz K et al. Measurement of Lens Autofluorescence Can Distinguish Subjects With Diabetes From Those Without. J Diabetes Sci Technol. 2014 Jan 1;8(1):43-49
