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Since the first peer-reviewed publication on MicroPulse® Transscleral Laser Therapy (MP-TLT) in 2010, authors worldwide have used a wide range of treatment parameter combinations with varying clinical efficacy in terms of the magnitude of intraocular pressure reduction, success rate, durability, and safety profile. This has made it difficult to determine the proper parameters necessary to optimize efficacy and safety, and has made comparison of results from one investigation to another difficult. The first goal of this paper is to explain and highlight the impact of the choices of exposure time and the number of sweeps per hemisphere in terms of "sweep velocity" on energy delivery to the eye. These treatment parameters are underreported in the literature. The second goal is to introduce fluence as a "dose" metric, that combines all the treatment parameters and constants into a single number. Fluence may be a better light-dose metric and a more reliable indicator of clinical outcomes compared to total energy.
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PURPOSE: Self-administration of topical ophthalmic therapies remains challenging for many patients as errors due to improper technique are common. The aim of the current studies was to evaluate a novel electromechanical topical ocular drug delivery device designed to facilitate precise dosing and accurate delivery with substantially lower drug exposure than conventional eye drops. PATIENTS AND METHODS: Two randomized Phase 1 studies were performed to evaluate the efficacy and safety of a single dose of a topical ophthalmic solution administered as a ~9 µL microfluid stream via the test device compared with a ~30-40 µL drop delivered via conventional dropper in healthy subjects (Trial 1) and glaucoma patients (Trial 2). In Trial 1, a 1% tropicamide/2.5% phenylephrine solution was administered via the test device in one eye and by conventional dropper in the contralateral eye. Pupil dilation was measured at 30 min intervals post-instillation and subject comfort was assessed using a visual analogue scale (range, 0-100). In Trial 2, patients were randomized to receive latanoprost 0.005% via the test device or conventional dropper. Intraocular pressure was measured at baseline and 4-8 hrs post-instillation. RESULTS: In Trial 1 (N=20), mean (SD) pupil diameter 30 mins post-instillation increased by 3.4 (0.9) and 3.5 (1.0) mm in the test and control eyes, respectively. The mean comfort score was 81.7 for the test device versus 57.3 for conventional dropper delivery. In Trial 2 (N=18), the mean change in intraocular pressure following administration of latanoprost was -5.0 (1.8) and -4.3 (3.3) mm Hg in the test and control groups, respectively. No serious adverse events were observed in either study. CONCLUSION: Administration of a single dose of topical ophthalmic therapy via an electromechanical drug delivery device resulted in comparable effects on pupil dilation and intraocular pressure with lower drug exposure and increased patient comfort compared with conventional dropper delivery.
RESUMO
BACKGROUND AND OBJECTIVE: A novel computer-guided laser treatment for open-angle glaucoma, called patterned laser trabeculoplasty, and its preliminary clinical evaluation is described. PATIENTS AND METHODS: Forty-seven eyes of 25 patients with open-angle glaucoma received 532-nm laser treatment with 100-µm spots. Power was titrated for trabecular meshwork blanching at 10 ms and sub-visible treatment was applied with 5-ms pulses. The arc patterns of 66 spots rotated automatically after each laser application so that the new pattern was applied at an untreated position. RESULTS: Approximately 1,100 laser spots were placed per eye in 16 steps, covering 360° of trabecular meshwork. The intraocular pressure decreased from the pretreatment level of 21.9 ± 4.1 to 16.0 ± 2.3 mm Hg at 1 month (n = 41) and remained stable around 15.5 ± 2.7 mm Hg during 6 months of follow-up (n = 30). CONCLUSION: Patterned laser trabeculoplasty provides rapid, precise, and minimally traumatic (sub-visible) computer-guided treatment with exact abutment of the patterns, exhibiting a 24% reduction in intraocular pressure during 6 months of follow-up (P < .01).