(The only FDA Approved Nasolacrimal Compression Device)
Eyedrops are like excessive tear that naturally drain through the tear ducts into the throat. Eyedrops medications rely on you to keep the eyedrops in your eyes so that the medications will infuse fully into your eyes to be effective rather than partially drain through the tear ducts into the throat causing possible systemic side effects. The delivery of eyedrops medication will improve when nasolacrimal drainage is blocked. Therefore, pressing of nasolacrimal ducts with fingers while putting in eyedrops is the standard of care Eyedrop Tips recommended by glaucoma specialists. However, this procedure is too burdensome to be practical for most of patients, especially for those who use multiple drops. We, therefore, invented a device, named “Nasolacrimal Compression Device” to be used, instead of using fingers, to compress the nasolacrimal ducts. This device has been awarded U.S. Patent 8147467 in 2012 and subsequently received FDA Product Classification in 2016 with a common name: Nasolacrimal Compression Device and a trade name: Tear Duct OccluderTM. The device frame was made of PVC coated soft iron wire and required a licensed eyecare professional to fit it to each patient.
The One-Size-Fit-All Device
The fitting of the original Tear Duct OccluderTM to individual patient is too burdensome for a licensed eyecare professional to handle and render many unfit cases. After one year of clinical trials, a “one size fits all” Tear Duct Occluder was developed. The geometry of the device was clinically established to fit all patients regardless how sunken their eyes are. This device has a stainless steel and is pre-formed in the factory to be “one size fits all.” The only adjustment, if any, would be widening or narrowing the nose pad gap across the nose which can be done by patients.
Human Factors and Usability Engineering (HFE/UE)
Practicing Nasolacrimal Occlusion (NLO) while applying eyedrops has been clinically proven being effective to improve eyedrops efficacy and prevent adverse systemic side effects from eyedrops (,  Page E-9.) FDA has approved the original Tear Duct Occluder for performing NLO since 2016 and classified it under 21 CFR 886.5838 for Rx only Use because it requires eyecare professionals to fit each device to individual patients and validate the fitness. This HFE/UF study aimed at investigating the actual efforts of eyecare professionals in the use of this device and seeking opportunities to minimized their efforts. Both clinical and in-home use were applied in human factor validation testing. The validation consists of 3 phases: the first phase took 1 year to investigate the use problems of the original Tear Duct Occluder at 3 university medical centers, 1 medical conference and several local eye clinics; the second phase took 9 months to fit the device to 38 patients in an eye clinic and seek design improvements on the Tear Duct Occluder; the third phase took 2 years to collect the user experiences about the new version of Tear Duct Occluder in 23 states, 1 U.S. territory and 20 foreign countries.
The study concluded that using this new Tear Duct Occluder was as safe and effective as the original Tear Duct Occluder but without requiring eyecare professional’s effort to fit it to patents. The evidences that supported this argument are as follow:
- The depression curves along the nasal aspect of the orbital rim were found to be the same for all patients – this finding enabled us to design a unique nose pad shape which fits all patients.
- The device fit all patients – over past 2 years of commercial distribution, patients (of diverse races, genders and ages) either used it “as is” or occasionally made minor adjustment on the nose pad gaps across the nose. The silicone rubber surface of the nose pads adapted to patient’s orbital rim contour seamlessly. No doctors were involved in fitting the device. No unfit issues nor other adverse effects have ever been reported.
- Patients used the device -patients routinely used this device at home without doctor’s supervision. They liked this device because it produced anticipated results had alleviated the burden of using fingers to press nasolacrimal ducts while applying eyedrops.
- Patients maintained the device – When patients advertently messed up the device (while packing for travel), they either fixed it by hands or ordered a replacement. A messed-up device would not perform as well but had not harmed any patients.