The central hypothesis is that inflammation mediators are biomarkers of both systemic diabetes and Diabetic Retinopathy (DR) progression in the aqueous and that sustained topical ketorolac application reduces/suppresses those inflammatory mediators thereby reducing the progression of Diabetic Retinopathy.
Study goals include confirming inflammation mediators are biomarkers of both systemic diabetes and DR progression in the aqueous. Like the vitreous humor, the aqueous reflects localized ocular inflammation, however, is technically easier to collect with less risk. The investigators will also determine the long-term effects of sustained ketorolac application on intraocular cytokine levels, DR progression, and diabetic macular edema (DME) incidence. The proposal is the first to use a cornea-permeable Nonsteroidal anti-inflammatory drug (NSAID) for the treatment of DR. It is believed local inflammation control in the eye will transform future treatment options for diabetic patients facing blindness. Tracking and inhibiting local inflammatory mediators through all DR stages has the capacity to reduce or prevent disability in millions of patients per year. 164 adult type II diabetic mellitus (T2DM) patients, aged 18 years or greater will be enrolled to measure aqueous PGE2 and inflammatory cytokines. Because the pathophysiology of type I disease and the population it effects are different, type I diabetic patients will be excluded. Diabetic retinopathy is broadly categorized as nonproliferative (NPDR) and proliferative (PDR). The international Clinical Disease Severity Scale is a standard classification system consisting of two categories and five stages: the nonproliferative category, stage 1-4 and proliferative category, stage 5. Stage 1 is characterized as "no apparent retinopathy." The nonproliferative stage is further grouped into stage 2 (mild), stage 3 (moderate), and stage 4 (severe). Stage 5 is final stage, PDR. Of the 164 patients enrolled for aqueous PGE2 and inflammatory cytokine measurements, the diabetic participants corresponding to stages 1, 3, and 5 will be classified as patients with no DR (23 patients), with PDR (23 patients), and with moderate NPDR (118 patients). The 118 participants with moderate NPDR will be randomized for Aim 2 described below. In addition, 100 age-matched patients without diabetes who are undergoing unilateral vitrectomy surgery for non-inflammatory conditions such as epiretinal membrane or macular hole will be enrolled as controls. Aim 1 of this project is to measure aqueous PGE2 and inflammatory cytokines during DR progression. Aim 2 of this project is two-fold: 1. Investigate the long-term effects of daily topical application of ketorolac on PGE2 and cytokine levels. 2. Determine how topical application of ketorolac influences DR progression and development of DME.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
DOUBLE
Enrollment
164
Ketorolac 0.45% ophthalmic solution 1 drop instilled in both eyes twice daily for 3 years in double-masked fashion.
Preservative free artificial tears ophthalmic solution 1 drop instilled in both eyes twice daily for 3 years in double-masked fashion.
After topical anesthetic, antibiotic and 5% povidone-iodine application, a 30 gauge needle on a 1 ml tuberculin syringe will be inserted into the anterior chamber and used to collect 0.1 ml of aqueous fluid from each eye. Aqueous PGE2 and Inflammatory cytokines will be measured
Vanderbilt University Medical Center
Nashville, Tennessee, United States
PGE2 level during Diabetic Retinopathy progression
Aqueous samples will be analyzed using liquid chromatography electrospray ionization tandem mass spectrometry to measure all PGE2 levels. PGE2 will be measured every 4 months during 1 year of study to determine whether their mean mediator levels associate with DR severity stage using a linear mixed effects model. The DR severity stage will be included as a continuous or categorical variable, and potential confounding factors as well as baseline measurements for each inflammatory mediator, will be adjusted in the analysis.
Time frame: 1 year
Vascular Endothelial Growth Factor (VEGF) level during Diabetic Retinopathy progression
Aqueous samples will be analyzed using a microparticle bead-based multiplex assay will be used to measure VEGF levels. VEGF will be measured every 4 months during 1 year of study to determine whether their mean mediator levels associate with DR severity stage using a linear mixed effects model. The DR severity stage will be included as a continuous or categorical variable, and potential confounding factors as well as baseline measurements for each inflammatory mediator, will be adjusted in the analysis.
Time frame: 1 year
Interleukin 6 (IL-6) level during Diabetic Retinopathy progression
Aqueous samples will be analyzed using a microparticle bead-based multiplex assay will be used to measure IL-6 levels. VEGF will be measured every 4 months during 1 year of study to determine whether their mean mediator levels associate with DR severity stage using a linear mixed effects model. The DR severity stage will be included as a continuous or categorical variable, and potential confounding factors as well as baseline measurements for each inflammatory mediator, will be adjusted in the analysis.
Time frame: 1 year
Interleukin 8 (IL-8) level during Diabetic Retinopathy progression
Aqueous samples will be analyzed using a microparticle bead-based multiplex assay will be used to measure IL-8 levels. VEGF will be measured every 4 months during 1 year of study to determine whether their mean mediator levels associate with DR severity stage using a linear mixed effects model. The DR severity stage will be included as a continuous or categorical variable, and potential confounding factors as well as baseline measurements for each inflammatory mediator, will be adjusted in the analysis.
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Time frame: 1 year
Progression of Diabetic Retinopathy (DR)
To determine progression of DR, we will analyze data from the 118 diabetic patients randomized to either Ketorolac or placebo. Diabetic retinopathy progresses in discrete steps defined by the Early Treatment Diabetic Retinopathy Study (ETDRS) severity scale (15-step scale: minimum value of 10 and maximum value of 65, with higher scores meaning a worse outcome). With each advancing level, the risk of developing DME and/or PDR increases. A 2-stage or more worsening on the ETDRS severity scale is associated with an increased risk of vision loss.
Time frame: 3 years
Severity of Diabetic Retinopathy (DR)
A blinded sub-investigator will grade DR by utilizing the 15-step severity scale established by the ETDRS. A 2-step or more increase or decrease in severity scale, observed on 2 consecutive follow-up appointments, will define a change in DR (progression or improvement).
Time frame: 3 years
Incidence of Diabetic Macular Edema
To determine incidence of Diabetic Macular Edema, we will analyze data from the 118 diabetic patients. An increase in macular thickness (determined by OCT as ≥ 40%) will determine development of DME.
Time frame: 3 years
Progression of Diabetic Macular Edema
To determine progression of Diabetic Macular Edema, we will analyze data from the 118 diabetic patients. An increase in macular thickness (determined by OCT as ≥ 40%) will determine progression of DME.
Time frame: 3 years