Centrifuged-Concentrated Intravitreal Slurry Triamcinolone Acetonide: An Inexpensive, Easy, and Viable Alternative to Long-Term Steroid Delivery

Abstract

Purpose: This work reports the duration, safety, and viability of intravitreal slurry triamcinolone acetonide (TA; 1.0 mL of 40-mg/mL TA centrifuge concentrated into a 0.1-mL pellet) to treat cystoid macular edema (CME). Methods: A retrospective, consecutive review was conducted of patients undergoing intravitreal slurry TA injections, July 2009 to December 2018. Results: In 143 eyes of 120 patients, slurry TA resolved CME for a mean of 327.15 (SD = 213.11) days, or 10.76 (SD = 7.00) months, per intravitreal injection (n = 466). In 100 eyes requiring multiple injections (n = 423), mean duration was 270.95 (SD = 177.14) days, or 8.91 (SD = 5.82) months, between injections. In 43 single-injection eyes, duration was 749.30 (SD = 483.17) days, or 24.63 (SD = 15.88) months. Mean duration decreased from 337.89 (SD = 210.46) days, or 11.11 (SD = 6.92) months, in nonvitrectomized eyes to 279.74 (SD 179.63) days, or 9.20 (SD = 5.91) months, in vitrectomized eyes (n = 74 injections, t = 2.24, P = .014, 1-tailed). Central foveal thickness as shown on optical coherence tomography decreased by 173.89μ (SD = 147.56μ), from 459.16μ (SD = 47.14μ) to 285.27μ (SD = 77.27μ; t = –25.31, P < .001), within 43.41 days (SD = 36.86). Visual acuity improved from 20/100 (logMAR 0.70, SD = 0.33) to 20/74 (logMAR 0.57, SD = 0.31; SD = 0.21; t = –11.01, P < .001), within 33.98 (SD 24.98) days. Fifteen of 31 phakic eyes (48.39%) underwent cataract extraction. Fifty-seven eyes (39.86%) developed a steroid response (> 10 mm Hg increase from baseline) 94.79 days (SD = 85.52 days), or 3.11 (SD = 2.81) months, following injection. Conclusions: A single injection of slurry TA lasted on average 10.76 months with significant improvement of CME and visual acuity. Adverse ocular effects were comparable to currently available, long-term, implantable steroids. Slurry TA appears to be an easily reproducible, safe, and cost-effective alternative to long-term intraocular steroid delivery.

An ultralow-cost portable centrifuge from discarded materials for medical applications

“…As evidence of the real-world utility of our paper material-based centrifuge for therapeutic applications, we demonstrate rapid and reliable sedimentation of triamcinolone acetonide (TA) suspension for injection of pelleted drug into the vitreous of the eye—an established low-cost intervention for long-term management of various ocular conditions 1 , 3 . Sedimentation results after 3 min of CentREUSE use were comparable to those achieved after 12 h of gravity-mediated sedimentation.…”

“…The choice of this application as proof of concept is inspired by the ongoing need for improved access to long-term intravitreal steroids in resource-poor settings. Intravitreal steroids are used widely for management of several ocular disorders, including diabetic macular edema, age-related macular degeneration, retinal vascular occlusion, uveitis, radiation retinopathy, and cystoid macular edema 3 , 12 . Of steroids available for injection into the vitreous, TA remains the most commonly used worldwide 12 .…”

“…Of steroids available for injection into the vitreous, TA remains the most commonly used worldwide 12 . Although preservative-free TA (PF-TA) formulations are available (e.g., Triesence [40 mg/mL, Alcon, Fort Worth, USA]), benzyl-alcohol-preserved formulations (e.g., Kenalog-40 [40 mg/mL, Bristol-Myers Squibb, New York City, USA]) remain most popular 3 , 12 . Of note, the latter group of formulations are only approved by the United States Food and Drug Administration (FDA) for intramuscular and intraarticular use; thus, intraocular administration is considered off-label 3 , 12 .…”

“…Herein, we describe the design, assembly, and experimental validation of a centrifuge constructed from commonly discarded materials, termed the CentREUSE, that builds on the paperfuge to allow for use in therapeutic applications—situations that commonly require sedimentation of larger volumes 1 , 3 . As proof of concept, we test the device by means of a real-world ophthalmic intervention: sedimentation of triamcinolone acetonide (TA) suspension for subsequent injection of pelleted drug into the vitreous of the eye.…”

“…As proof of concept, we test the device by means of a real-world ophthalmic intervention: sedimentation of triamcinolone acetonide (TA) suspension for subsequent injection of pelleted drug into the vitreous of the eye. Although centrifuge-concentrated TA is an established low-cost intervention employed for long-term management of several ocular conditions, the need for a commercial centrifuge during drug preparation represents a significant barrier to use of the therapy in resource-poor settings 1 – 3 . Sedimentation results achieved with our centrifuge are compared to those produced by conventional commercial centrifugation.…”