Corneal stiffness plays a critical role in shaping the cornea with respect to intraocular pressure and physical interventions. However, it remains difficult to measure the mechanical properties noninvasively. Here, we report the first measurement of shear modulus in human corneas in vivo using optical coherence elastography (OCE) based on surface elastic waves. In a pilot study of 12 healthy subjects aged between 25 and 67, the Rayleigh-wave speed was 7.86 ± 0.75 m/s, corresponding to a shear modulus of 72 ± 14 kPa. Our data reveal two unexpected trends: no correlation was found between the wave speed and IOP between 13–18 mmHg, and shear modulus decreases with age (− 0.32 ± 0.17 m/s per decade). We propose that shear stiffness is governed by the interfibrillar matrix, whereas tensile strength is dominated by collagen fibrils. Rayleigh-wave OCE may prove useful for clinical diagnosis, refractive surgeries, and treatment monitoring.
Sustained delivery of latanoprost by contact lenses is at least as effective as delivery with daily latanoprost ophthalmic solution. More research is needed to determine the optimal continuous-release dose that would be well tolerated and maximally effective. Contact lens drug delivery may become an option for the treatment of glaucoma and a platform for ocular drug delivery.
Purpose To perform a cost analysis comparison for managing common ocular disorders in an eye emergency department (ED) versus an urgent care setting using a time-driven activity-based cost model (TDABC) to assist physicians and staff in appropriate allocation of resources at their own institution.
Design Retrospective analysis.
Setting Massachusetts Eye and Ear (MEE) ED and Same-Day Services (SDS), which runs as an urgent care clinic.
Population Patients diagnosed with corneal abrasions, dry eyes, conjunctivitis, and styes were identified between April 2014 and August 2015 (n = 2,408 [ED], 26 [SDS]). We determined resources used in delivery of care, which included personnel, consumables, space capacity, and equipment. Costs were identified based on time the patient spent with each resource.
Main Outcome Average visit length and associated personal, space, equipment, and consumable costs.
Results Average visit length was 196 and 53 minutes, respectively, primarily due to longer wait times in the ED. Personnel and space costs were higher in the ED compared with SDS ($68.92 vs. $51.37 and $24.44 vs. $12.86, respectively). This led to an overall higher total resource cost for patients seen in the ED compared with SDS ($108.41 vs. $81.53, respectively).
Conclusion For common ocular disorders, total SDS costs were 25% less than ED costs at MEE primarily due to personnel and space utilization. Treating patients with nonemergent ocular problems outside the ED can lead to shorter visit times for patients as well as lower overall costs.
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