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Home / Clinicals

TFOS DEWS II – Definition and Classification Report

February 16, 2023 by Lisa Dockray

Jennifer P. Craig, MCOptom, PhD, Kelly K. Nichols, OD, PhD, Esen K. Akpek, MD, Barbara Caffery, OD, PhD, Harminder S. Dua, MD, PhD, Choun-Ki Joo, MD, PhD, Zuguo Liu, MD, PhD, J. Daniel Nelson, MD, Jason J. Nichols, OD, PhD, Kazuo Tsubota, MD, PhD, Fiona Stapleton, MCOptom, PhD

ABSTRACT:

The goals of the TFOS DEWS II Definition and Classification Subcommittee were to create an evidence based definition and a contemporary classification system for dry eye disease (DED).

The new definition recognizes the multifactorial nature of dry eye as a disease where loss of homeostasis of the tear film is the central pathophysiological concept. Ocular symptoms, as a broader term that encompasses reportsof discomfort or visual disturbance, feature in the definition and the key etiologies of tear film instability, hyperosmolarity, and ocular surface inflammation and damage were determined to be important for inclusion in the definition. In the light of new data, neurosensory abnormalities were also included in the definition for the first time.

In the classification of DED, recent evidence supports a scheme based on the pathophysiology where aqueous deficient and evaporative dry eye exist as a continuum, such that elements of each are considered in diagnosis and management. Central to the scheme is a positive diagnosis of DED with signs and symptoms, and this is directed towards management to restore homeostasis. The scheme also allows consideration of various related manifestations, such as non-obvious disease involving ocular surface signs without related symptoms, including neurotrophic conditions where dysfunctional sensation exists, and cases where symptoms exist without demonstrable ocular surface signs, including neuropathic pain.

This approach is not intended to override clinical assessment and judgment but should prove helpful in guiding clinical management and research.

(J.P. Craig et al. / The Ocular Surface 15 (2017) 276-283)

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Filed Under: Clinicals

Tear Film Osmolarity: Determination of a Referent for Dry Eye Diagnosis

February 16, 2023 by Lisa Dockray

Alan Tomlinson, Santosh Khanal, Kanna Ramaesh, Charles Diaper, and Angus McFadyen

● PURPOSE: To determine new referents, or cutoff levels for tear film hyperosmolarity in the diagnosis of keratoconjunctivitis sicca (KCS) and to assess their effectiveness in independent patient groups.

● METHOD: A meta-analysis was performed on published data for tear osmolarity in samples of normal eyes and various subtypes of dry eye, and pooled estimates of the mean and standard deviations for normal and (all) dry eye subjects were determined. Diagnostic referents were derived from the intercept between the distributions of osmolarity in the two samples and from receiver operator characteristic (ROC) curves. This referent was tested for effectiveness of diagnosis in independent groups with normal and dry eyes.

● RESULTS: An osmolarity referent of 315.6 mOsmol/L was derived from the intercept of the distribution curves, and 316 mOsmol/L from the ROC curve. When applied to independent groups of normal and dry eye subjects a value of 316 mOsmol/L was found to yield sensitivity of 59%, specificity of 94%, and an overall predictive accuracy of 89% for the diagnosis of dry eye syndrome.

● CONCLUSIONS: Tear hyperosmolarity, defined by a referent of 316 mOsmol/L, was superior in overall accuracy to any other single test for dry eye diagnosis (Lactoplate, Schirmer test, and Rose Bengal staining), even when the other test measures were applied to a diagnosis within the sample groups from which they were derived. For overall accuracy in the diagnosis of dry eye, the osmolarity test was found to be comparable with the results of combined (in parallel or series) tests.

(Invest Ophthalmol Vis Sci. 2006;47:4309–4315) DOI:10.1167/iovs.05-1504)

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Filed Under: Clinicals

Tear Osmolarity in the Diagnosis and Management of Dry Eye Disease

February 16, 2023 by Lisa Dockray

MICHAEL A. LEMP, ANTHONY J. BRON, CHRISTOPHE BAUDOUIN, JOSÉ M. BENÍTEZ DEL CASTILLO, DAVID GEFFEN, JOE TAUBER, GARY N. FOULKS, JAY S. PEPOSE, AND BENJAMIN D. SULLIVAN

● PURPOSE: To evaluate the use of tear osmolarity in the diagnosis of dry eye disease.

● DESIGN: A prospective, observational case series to determine the clinical usefulness of tear osmolarity and commonly used objective tests to diagnose dry eye disease.

● METHODS: A multicenter, 10-site study consisting of 314 consecutive subjects between 18 and 82 years of age. Bilateral tear osmolarity, tear film break-up time (TBUT), corneal staining, conjunctival staining, Schirmer test, and meibomian gland grading were performed. Diagnostic performance was measured against a composite index of objective measurements that classified subjects as having normal, mild or moderate, or severe dry eye. The main outcome measures were sensitivity, specificity, area under the receiver operating characteristic curve, and intereye variability.

● RESULTS: Of the 6 tests, tear osmolarity was found to have superior diagnostic performance. The most sensitive threshold between normal and mild or moderate subjects was found to be 308 mOsms/L, whereas the most specific was found at 315 mOsms/L. At a cutoff of 312 mOsms/L, tear hyperosmolarity exhibited 73% sensitivity and 92% specificity. By contrast, the other common tests exhibited either poor sensitivity (corneal staining, 54%; conjunctival staining, 60%; meibomian gland grading, 61%) or poor specificity (tear film break-up time, 45%; Schirmer test, 51%). Tear osmolarity also had the highest area under the receiver operating characteristic curve (0.89). Intereye differences in osmolarity were found to correlate with increasing disease severity (r2 = 0.32).

● CONCLUSIONS: Tear osmolarity is the best single metric both to diagnose and classify dry eye disease. Intereye variability is a characteristic of dry eye not seen in normal subjects.

(Am J Ophthalmol 2011;151:792–798. © 2011 by Elsevier Inc. All rights reserved.)

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Filed Under: Clinicals

Analytic and clinical performance of two compact cholesterol-testing devices

February 16, 2023 by Lisa Dockray

Volles DF, McKenney JM, Miller WG, Ruffen D, Zhang D.

ABSTRACT:

Several relatively inexpensive compact analyzers for measuring cholesterol are available for use outside of the clinical laboratory. We evaluated the analytic and clinical performance of total cholesterol assayed with the AccuMeter (ChemTrak) and the LDX (Cholestech). Accuracy of both devices was evaluated by collecting capillary and venous whole blood from 100 subjects and assaying for total cholesterol.

Results were compared with the Centers for Disease Control standardized reference laboratory method. Mean percent bias, mean absolute percent bias, and percentage of subjects with total error above +/- 8.9% were calculated and results were compared with recommendations from National Cholesterol Education Program (NCEP) for total cholesterol measurements. Precision was evaluated by assay of three pooled serum samples with both devices in duplicate in two runs/day for 20 days. The CV for each serum pool for each device was calculated and compared with NCEP recommendations for precision for total cholesterol measurements. Results with the two devices were compared. The total cholesterol mean percent bias for capillary samples was 2.1% for the LDX and -1.0% for the AccuMeter (p<0.01), and for venous samples 1.6 and -2.0%, respectively (p<0.001). The mean absolute percent bias for capillary samples was 5.4 and 5.2%, respectively (p=0.29), and for venous samples was 5.0 and 5.7% (p=0.79). Each device had an excessive number (12-22%) of individual results that exceeded NCEP recommended total error for a single cholesterol measurement (+/- 8.9%).

In the precision analysis the average CV from all three serum pools was 4.0% and 5.3% for the LDX and AccuMeter, respectively (p<0.05). Thus both devices failed to meet the NCEP recommendation for precision of 3% CV. They both provided total cholesterol results that correctly classified individual patients into appropriate risk groups 95% of the time or better if values within +/- 8.9% of NCEP cut points for risk classification were ignored. Both devices met the NCEP +/- 3% requirement for total cholesterol mean percent bias but did not meet the +/- 3% requirement for CV as a measure of precision. Because of the variability in results, both devices had excessive numbers of individual subjects with total cholesterol results greater than the recommended total error limit of +/- 8.9% difference from the standardized method.

Despite variability in some individual results, the rate of clinical misclassifications for coronary heart disease risk was relatively low for both devices if results near the NCEP cut points were repeated.

(Pharmacotherapy. 1998 Jan-Feb;18(1):184-92.)

Filed Under: Clinicals

Variability among five over-the-counter blood glucose monitors

February 16, 2023 by Lisa Dockray

Kimberly MM, Vesper HW, Caudill SP, Ethridge SF, Archibold E, Porter KH, Myers GL.

ABSTRACT:

● Background: The American Diabetes Association recommends that people with diabetes use self-monitoring to control their blood glucose concentration. To assess the need for standardization, we evaluated the variability among 5 of the most common monitors: MediSense Precision Xtra, Ascencia Dex, Prestige Smart System, OneTouch Ultra, and Accu-Chek Advantage.

● Methods: We took steps to minimize preanalytical variation. We also eliminated user variability by using one trained operator to collect samples and perform all testing. Each monitor was used twice with each participant; one test was performed using an aged strip and the other using a fresh strip. We compared monitors using a separate ANOVA for each concentration range and strip lot.

● Results: The total CVs and the within-strip lot CVs were not statistically different among monitors, ranging from 3.1% to 11.3% and from 2.1% to 8.5%, respectively. There were statistically significant differences among monitors for among-strip lot CVs, which ranged from nearly 0% to 7.5%. The degree of significance increased as the concentration range increased [3.9-5.5 mmol/l: p<0.05; 5.6-7.7 mmol/l: p =0.003; 7.8-11.1 mmol/l: p < 0.001]. The average percent difference between monitor pairs was statistically significant (p < 0.05) in more than half of the paired comparisons, with significant differences ranging from 5.7% to 32.0%.

● Conclusions: Monitor results can vary significantly so that agreement among them is poor. Standardization is necessary to minimize variability and to improve patient care.

(Clin Chim Acta. 2006 Feb;364(1-2):292-7. Epub 2005 Sep 6.)

Filed Under: Clinicals

Ensure your Omega-3 recommendation provides the clinically proven 2000mg EPA and DHA per daily dose

January 10, 2023 by Lisa Dockray

Products available on the market other than PRN often require more than the recommended daily intake in order to deliver 2000 mg or higher dosage of product in patients with Dry Eye Disease. On the other hand, with just 3 soft gels or 1 teaspoon of PRN, your patient gets a 3:1 ratio of EPA and DHA Omega-3 fatty acids, which is clinically proven to assist in Dry Eye Disease.

In this video clip, Dr. Friedman explains why PRN Omega-3’s formulation is clinically superior and convenient for your patients.






Dr Kimberly K. Friedman, OD FAAO

Kimberly Friedman, OD is a founding partner of Moorestown Eye Associates, a private group optometric practice in New Jersey, and the Director of The Dry Eye Clinic at Moorestown Eye. She is a past president of the New Jersey Society of Optometric Physicians, a fellow in the American Academy of Optometry, a Diplomate of the American Board of Optometry, and a past Clinical Director for the NJ and National Special Olympics Opening Eyes Program.






PRN Omega-3

PRN Physician Recommended Nutriceuticals® is the leading developer of specialty omega-3 products. Developed and endorsed by medical thought leaders, PRN® products are supported by clinical evidence and are unmatched in quality and purity.

Filed Under: Clinicals

All Omega-3s are not created equal

January 10, 2023 by Lisa Dockray

All Omega-3s are created differently due to the process of detoxification of fish oil and their chemical structure. This difference affects their bioavailability and thus clinical efficacy.

In this video clip, Dr. Friedman explains what form of Omega-3 is the most absorbable and clinically proven to work.






Dr Kimberly K. Friedman, OD FAAO

Kimberly Friedman, OD is a founding partner of Moorestown Eye Associates, a private group optometric practice in New Jersey, and the Director of The Dry Eye Clinic at Moorestown Eye. She is a past president of the New Jersey Society of Optometric Physicians, a fellow in the American Academy of Optometry, a Diplomate of the American Board of Optometry, and a past Clinical Director for the NJ and National Special Olympics Opening Eyes Program.






PRN Omega-3

PRN Physician Recommended Nutriceuticals® is the leading developer of specialty omega-3 products. Developed and endorsed by medical thought leaders, PRN® products are supported by clinical evidence and are unmatched in quality and purity.

Filed Under: Clinicals

Literature Review: Use of Plasma Rich in Growth Factors (PRGF) in Ophthalmology

February 9, 2022 by Lisa Dockray

 

Progress in the use of plasma rich in growth factors in ophthalmology: from ocular surface to ocular fundus.

Anitua E, de la Sen-Corcuera B, Orive G, Sánchez-Ávila RM, Heredia P, Muruzabal F, Merayo-Lloves J. Expert Opin Biol Ther. 2021 Jul 19:1-15. doi: 10.1080/14712598.2021.1945030. Epub ahead of print. PMID: 34275392.

Introduction: The use of blood derivatives and especially Plasma rich in growth factors (PRGF), for regenerative purposes has been a common trend along the last decades in the field of oral surgery, dermatology, orthopedics, and more recently in ophthalmology.

Areas covered: PRGF is a type of platelet-rich plasma that is being explored for the treatment of ocular injuries. The present review article highlights 50 ophthalmology-related publications about the application of PRGF in the treatment of acute and chronic pathologies in ophthalmology as well as most relevant challenges and future prospects.

Expert opinion: PRGF technology provides a wide range of formulations that can be used therapeutically in many different acute and chronic ocular pathologies. In addition to eye drops enriched with autologous growth factors, PRGF enables the preparation of both immunologically safe and fibrin-based formulations. Recent advances in the field have promoted PRGF storage for 12 months under freezing conditions, its daily use for 7 days at room temperature and the freeze-dried formulation. The thermally treated immune-safe formulation has shown promising clinical results for the treatment of several diseases such as Sjögren syndrome, graft versus host disease or cicatrizing conjunctivitis. In addition, several fibrin formulations have been pre-clinically evaluated and clinically incorporated as an adjuvant to ocular surface or glaucoma surgeries, dermal fat graft procedures, limbal stem cell expansion and retinal surgeries. The present review explores the latest scientific and clinical data, current challenges, and main prospects of this technology for the treatment of several ocular injuries.


 

*PRGF compared with Autologous Serum (Pre-Clinical Evidence):

Plasma rich in growth factors (PRGF) eye drops stimulates scarless regeneration compared to autologous serum in the ocular surface stromal fibroblasts.

Anitua E, de la Fuente M, Muruzabal F, Riestra A, Merayo-Lloves J, Orive G. Exp Eye Res. 2015 Jun;135:118-26. doi: 10.1016/j.exer.2015.02.016. Epub 2015 Feb 21. PMID: 25708868.

Conclusion/Findings: “…significant higher levels of all growth factors analyzed in PRGF eye drops compared to AS. Moreover, PRGF eye drops enhanced significantly the biological outcomes of both HK and HConF, and reduced TGF-b1-induced myofibroblast differentiation in contrast to autologous serum eye drops (AS). In summary, these results suggest that PRGF exerts enhanced biological outcomes than AS. PRGF may improve the treatment of ocular surface wound healing minimizing the scar formation compared to AS. Results obtained herein suggest that PRGF protects and reverses the myofibroblast phenotype while promotes cell proliferation and migration.”


 

*PRGF compared with Autologous Serum and PRP (Pre-Clinical Evidence):

Corneal wound healing promoted by 3 blood derivatives: an in vitro and in vivo comparative study.

Freire V, Andollo N, Etxebarria J, Hernáez-Moya R, Durán JA, Morales MC. Cornea. 2014 Jun;33(6):614-20. doi: 10.1097/ICO.0000000000000109. PMID: 24727633.

Conclusion/Findings: In vitro data show statistically significant differences in the healing process with all the derivatives compared with the control, but 2 of them (AS and s-PRGF) induced markedly faster wound healing. In contrast, although the mean time required to complete in vivo reepithelization was similar to that of AS and s-PRGF treatment, only wounds treated with s-PRGF were significantly smaller in size from 2.5 days onward with respect to the control treatment. …the corneal wound-healing progresses differently with each derivative, being faster in vitro under AS and s-PRGF treatment and producing in vivo the greatest decrease in wound size under s-PRGF treatment.”


 

*Endoret PRGF: Safety and Efficacy in Ocular Surface Disorders (Clinical Evidence)

Safety and Efficacy of Autologous Plasma Rich in Growth Factors Eye Drops for the Treatment of Evaporative Dry Eye.

Merayo-Lloves J, Sanchez-Avila RM, Riestra AC, Anitua E, Begoña L, Orive G, Fernandez-Vega L. Ophthalmic Res. 2016 Jul;56(2):68-73. doi: 10.1159/000444496. Epub 2016 May 28. PMID: 27229893.

Description: This retrospective study included patients with EDE treated between January 2011 and December 2013. Outcome measures including signs and symptoms of the disease were evaluated before and after treatment. The influence of some of the patient’s clinical variables on results was assessed. Safety assessment was also performed.

Findings & Conclusions: Eighty-three patients with a total of 156 eyes were evaluated. Statistically significant reductions in the Ocular Surface Disease Index (38.2%), best-corrected visual acuity (27.4%), Visual Analogue Scale scores for frequency (32%) and severity (34%), and a significant improvement in the Schirmer test scores (177.5%) were observed (p < 0.05). The results were stratified according to the identified potential effect modifiers. Only four adverse events were reported. All of them were mild and resolved within a few days.

Results suggest that PRGF eye drops could be a safe and effective treatment in reducing EDE signs and symptoms.


 

*Endoret PRGF: Safety and Efficacy in Ocular Surface Disorders (Clinical Evidence)

Treatment of patients with neurotrophic keratitis stages 2 and 3 with plasma rich in growth factors (PRGF-Endoret) eye-drops.

Sanchez-Avila RM, Merayo-Lloves J, Riestra AC, Fernandez-Vega Cueto L, Anitua E, Begoña L, Muruzabal F, Orive G. Int Ophthalmol. 2018 Jun;38(3):1193-1204. doi: 10.1007/s10792-017-0582-7. Epub 2017 Jun 15. PMID: 28620707.

Description: This retrospective study included patients with stages 2-3 of NK treated with PRGF eye-drops. Primary endpoint was the resolution time of corneal ulcer defect. Outcome measures including percentage of ulcer closure at 4 weeks, Ocular Surface Disease Index (OSDI), Best-Corrected Visual Acuity (BCVA) and Visual Analogue Scale (VAS) were also evaluated before and after treatment with PRGF. The influence of some patients’ clinical variables on results was assessed. Safety assessment was also performed reporting all adverse events.

Findings & Conclusions: Thirty-eight treated eyes in a total of thirty-one patients were evaluated, of which five cases had no prior response to autologous serum treatment. Most cases (97.4%) achieved the complete resolution of corneal defect/ulcer. Mean resolution time was 11.4 weeks (SD = 13.7). A statistical significant (p < 0.05) reduction in OSDI (60.9%), VAS frequency (59.9%), VAS severity (57.0%) and improvement in BCVA (52.8%) was observed. The results were stratified according to the pathology stage and to the identified potential effect modifiers variables. Only one adverse event was reported in one patient (2.6%).

PRGF eye-drops could be a safe and effective therapeutic option for patients with stages 2-3 of NK, showing high rates of corneal defect/ulcer resolution in short times, either in reducing signs and symptoms of NK, and therefore preventing the progression of NK to greater ocular complications.

Filed Under: Clinicals Tagged With: Plasma rich in growth factors, PRGF, Endoret

Augmented Dried versus Cryopreserved Amniotic Membrane as an Ocular Surface Dressing

October 15, 2019 by labtician

Claire L. Allen, Gerry Clare, Elizabeth A. Stewart, Matthew J. Branch, Owen D. McIntosh, Megha Dadhwal, Harminder S. Dua, Andrew Hopkinson

Abstract:

Purpose: Dried amniotic membrane (AM) can be a useful therapeutic adjunct in ophthalmic surgery and possesses logistical
advantages over cryopreserved AM. Differences in preservation techniques can significantly influence the biochemical
composition and physical properties of AM, potentially affecting clinical efficacy. This study was established to investigate
the biochemical and structural effects of drying AM in the absence and presence of saccharide lyoprotectants and its
biocompatibility compared to cryopreserved material.

Methods: AM was cryopreserved or dried with and without pre-treatment with trehalose or raffinose and the antioxidant
epigallocatechin (EGCG). Structural and visual comparisons were assessed using electron microscopy. Localisation,
expression and release of AM biological factors were determined using immunoassays and immunofluorescence. The
biocompatibility of the AM preparations co-cultured with corneal epithelial cell (CEC) or keratocyte monolayers were
assessed using cell proliferation, cytotoxicity, apoptosis and migration assays.

Results: Drying devitalised AM epithelium, but less than cryopreservation and cellular damage was reduced in dried AM
pre-treated with trehalose or raffinose. Dried AM alone, and with trehalose or raffinose showed greater factor retention
efficiencies and bioavailability compared to cryopreserved AM and demonstrated a more sustained biochemical factor time
release in vitro. Cellular health assays showed that dried AM with trehalose or raffinose are compatible and superior
substrates compared to cryopreserved AM for primary CEC expansion, with increased proliferation and reduced LDH and
caspase-3 levels. This concept was supported by improved wound healing in an immortalised human CEC line (hiCEC) cocultured
with dried and trehalose or raffinose membranes, compared to cryopreserved and fresh AM.

Conclusions: Our modified preservation process and our resultant optimised dried AM has enhanced structural properties
and biochemical stability and is a superior substrate to conventional cryopreserved AM. In addition this product is stable
and easily transportable allowing it to be globally wide reaching for use in clinical and military sectors.

Read the full article here

Filed Under: Clinicals

Scientific and Clinical Support for the Use of Dehydrated Amniotic Membrane in Wound Management

June 17, 2019 by labtician

Donald E. Fetterolf, MD; and Robert J. Snyder, DPM, MSc

Abstract:

Amniotic membrane has been employed in the treatment of wounds for almost 100 years, beginning with early application of natural amniotic membrane obtained from labor and delivery to various types of burns and wounds. Amniotic membrane is rich in collagen and various growth factors that support the healing process to both improve wound closure and reduce scar formation. Unique properties of the material include the lack of immunologic markers, conferring an “immune privileged” status on the allografts; antibacterial properties; and the ability to reduce pain on application. The resurgence of interest in the use of amniotic membrane in a number of applications, including wound treatment, has occurred following improved techniques for preserving the natural membrane. Recently, techniques have been developed to dehydrate the material while preserving many of these wound-healing attributes, to produce a temperature-stable allograft. Future research will continue to yield more information on the unique properties of the amniotic membrane allografts.

Read the full article here

Filed Under: Clinicals

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