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Hyperosmolar Eye Drops for Diurnal Corneal Edema in Fuchs' Endothelial Dystrophy
TAKE-HOME MESSAGE
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This double-blind RCT examined central corneal thickness 1 hour after eye opening in the morning in 68 participants (59 eyes treatment, 55 eyes placebo) scheduled to undergo Descemet membrane endothelial keratoplasty. Data showed that the use of hyperosmolar eye drops did not significantly reduce morning stromal edema in Fuchs' endothelial dystrophy.
- Given that the use of these drops was uncomfortable and that the stromal edema resolved as the morning progressed in both the hyperosmolar group and the control group, the reader must conclude that the use of hyperosmolar eye drops to reduce stromal edema in Fuchs' dystrophy is not indicated.
abstract
This abstract is available on the publisher's site.
Access this abstract now Full Text Available for ClinicalKey SubscribersPURPOSE
The Eye Drops for Early Morning-Associated Swelling (EDEMAS) trial assessed the efficacy of hyperosmolar eye drops on corneal edema resolution.
DESIGN
Double-blind randomized-controlled trial of hyperosmolar eye drops vs. placebo.
PARTICIPANTS
Participants with Fuchs' dystrophy scheduled for Descemet membrane endothelial keratoplasty.
METHODS
One eye was randomized to hyperosmolar eye drops (treatment); the fellow eye was randomized to artificial tears (placebo). After baseline exam in the afternoon, corneas were examined using Scheimpflug tomography after eye opening in the morning. Participants received eye drops twice. Imaging was repeated every 30 minutes up to four hours.
MAIN OUTCOME MEASURES
Decrease in central corneal thickness one hour after eye opening (primary endpoint); corneal thickness, subjective visual function, glare, visual acuity, and adverse events (secondary endpoints).
RESULTS
68 participants received the allocated intervention (59 eyes treatment, 55 eyes placebo). All eyes had stromal edema; none had epithelial edema. Corneal thickness was 626 μm in the treatment arm and 622 μm in the placebo arm after eye opening, indicating an early-morning edema compared to baseline of +21 μm and +24 μm, respectively. Decrease in corneal thickness after one hour was -10.5 μm in the treatment arm (95% CI, -12.8 to -8.2) and -11.2 μm (95% CI, -13.6 to -8.9) in the placebo arm (between-arm difference, 0.7 μm, 95% CI, -2.0 to 3.5; p = 0.59), indicating no clinically relevant effect of hyperosmolar eye drops on early-morning corneal edema. Results were not compatible with a relevant treatment effect on corneal thickness, visual acuity, and glare over the entire course of the study. Increase in subjective visual function was less rapid in the treatment arm than in the placebo arm. Adverse events, most commonly burning after eye drop application, were more common with treatment (30 eyes) than placebo (1 eye; risk difference, 49 percentage points; 95% CI, 36 to 62).
CONCLUSIONS
In this double-blind randomized-controlled trial, resolution of early-morning stromal edema was not accelerated by hyperosmolar eye drops, which frequently caused adverse events. These results are not compatible with a clinically relevant effect of hyperosmolar eye drops and do not support their routine use.
Additional Info
Disclosure statements are available on the authors' profiles:
Hyperosmolar Eye Drops for Diurnal Corneal Edema in Fuchs' Endothelial Dystrophy: A Double-Blind Randomized-Controlled Trial
Ophthalmology 2021 Apr 20;[EPub Ahead of Print], D Zander, D Böhringer, M Fritz, V Grewing, PC Maier, T Lapp, T Reinhard, K WackerFrom MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
Early morning corneal edema remains an issue for patients with Fuchs' corneal dystrophy. Clinicians often prescribe hyperosmolar saline with the rationale that it may reduce corneal swelling and clear vision. But do the drops actually work? This trial with a clever name—EDEMAS, which stands for Eye Drops for Early Morning Associated Swelling—sought to find an answer to this question.
EDEMAS was a double-blind randomized controlled trial of hyperosmolar eye drops versus placebo that included 68 patients with Fuchs' corneal dystrophy awaiting Descemet membrane endothelial keratoplasty (DMEK). All patients had advanced Fuchs' with stromal edema (modified Krachmer grade 4). Baseline measurements were performed 4 hours after waking on the day before DMEK. The median baseline corneal thickness was 598 μm (IQR, 561–630) in the treatment eyes versus 626 μm (IQR, 586–642) in the placebo eyes. On the day of DMEK surgery, 2 eye drops (treatment or control) were given within 1 hours of waking and measurements taken at 30, 60, 90, and 120 minutes. The eyes, one of which had received hyperosmolar drops (NaCl 5%; n = 59) and the fellow eye artificial tears (hyaluronic acid 0.1%, placebo; n = 55) were examined in the morning with Scheimpflug tomography to determine central corneal thickness. The osmolality of the drops was 1793 mOsm/kg in the treatment drops versus 317 mOsm/kg in the placebo drops, a difference of 5.7 times. Over the morning the edema decreased in both groups; 1 hour after eye opening, the decrease in corneal thickness was –10.5 μm in the treatment eyes (95% CI, –12.8 to –8.2) compared with –11.2 μm (95% CI, –13.6 to –8.9) in the placebo eyes. There were no statistical or clinically relevant improvements in corneal thickness, visual acuity, or glare over the study. Improvement in subjective visual acuity after eye opening was slower in eyes randomized to hyperosmolar drops. Adverse events occurred more commonly in the treatment group (30 eyes) versus the placebo group (1 eye), particularly burning.
Clinicians may need to re-evaluate how they manage Fuchs' patients with stromal edema. The use of hyperosmolar eye drops was not supported for the resolution of early-morning stromal edema, and patients suffered with a burning sensation on drop instillation. This study also highlighted that natural resolution of the corneal edema occurs on waking, and this may give the impression that eye drops are clearing the edema.