Abstract
This cohort study describes data from a drive-through clinic designed to measure intraocular pressure while maintaining patient safety during the coronavirus disease 2019 pandemic.
Ophthalmology has experienced the largest percentage decrease in visits of all ambulatory subspecialties during the coronavirus disease 2019 (COVID-19) pandemic.1 Intraocular pressure (IOP) levels are difficult to measure in the telehealth setting. However, these data are critical in guiding the care of patients with glaucoma, patients receiving long-term steroid therapy, patients with chronic ocular inflammatory disease, and those in an ophthalmologic postoperative period. In these instances, determination of IOP alone might allow for the assessment of appropriateness of a telehealth visit. In our opinion, this may be especially beneficial for the most vulnerable populations, including those with advanced age and comorbidities.
To adapt to broader public health initiatives, we developed a drive-through IOP screening clinic. This novel protocol minimizes COVID-19 exposure for patients and clinicians by measuring eye pressure in the unconventional setting of a clinic parking lot.
Methods
Patients in the drive-through IOP clinic were scheduled with consecutive appointments to optimize workflow. Prior to encountering patients, clinicians donned N95 masks, eye protection, and gloves. Patients remained in their vehicles and presented identification. All patients wore masks. Tonometry was performed using the Icare ic200 and TA01i model rebound tonometers (Icare Finland Oy). Tonometers were disinfected and individual-use tips were replaced between patients.
If the eye pressure exceeded a predetermined threshold value, the patient was brought into the clinic immediately for a Goldmann applanation. The treating physician indicated the threshold value specific to a patient’s care. For eyes known to have healthy optic nerves, a general threshold of 29 mm Hg was elected. If eye pressure levels were unremarkable, the patient departed and a telehealth follow-up was performed to discuss any changes in therapy. For those patients who required multiple visits on separate days, each visit was counted as distinct for analysis.
Data collection occurred from April 2020 to June 2020. Descriptive statistics were used to analyze and report the data. Data were analyzed with Excel version 16.43 (Microsoft).
Results
A total of 151 visits with 135 patients were conducted over 9 weeks. The median age of patients was 51 (range, 3-83) years. Most were female (82 [60.7%]). Indications for monitoring visits are listed in the Table. The mean (SD) intraocular pressure was 18.2 (6.3) mm Hg. Fourteen eyes (4.7%) were found to have a pressure greater than 30 mm Hg. Of the eyes exceeding screening IOP thresholds, 5 (36%) were found to have a pressure greater than 30 mm Hg on repeated measurement by applanation. Overall, 46 of 151 visits (30.5%) resulted in a change in management based on findings.
Table. Indications for Eye Pressure Monitoring.
| Indication | Patients, No. (%) | |
|---|---|---|
| Unilateral | Bilateral | |
| Patient visits, No. | 151 | NA |
| Long-term topical steroid use | 51 (33.8) | 66 (43.7) |
| Uveitis | 26 (17.2) | 52 (34.4) |
| Chronic corneal or external disease, No. | 12 (7.9) | 49 (32.5) |
| Ocular rosacea | 1 | 11 |
| Allergic conjunctivitis | 0 | 13 |
| Keratoconjunctivitis sicca | 0 | 3 |
| Ocular cicatricial pemphigoid | 0 | 2 |
| Graft-vs-host disease | 0 | 2 |
| Viral keratitis | 8 | 1 |
| Glaucoma | 5 (3.3) | 15 (9.9) |
| Ocular hypertension | 11 (7.3) | 19 (12.6) |
| Postoperative status | 5 (3.3) | 2 (1.3) |
Abbreviation: NA, not applicable.
Discussion
This protocol allowed for continued management of patients with vision-threatening disease during the COVID-19 pandemic. Compared with Tonopen tonometry and pneumotonometry, iCare permits dropless IOP evaluation, eliminating the risk of contamination. While Goldmann applanation tonometry is the gold standard for IOP measurement, iCare and Tonopen tonometry have been shown to be excellent alternatives.2,3 Previous studies demonstrate that iCare is comparable with applanation within normal IOP ranges but tends to overestimate as IOP increases.2,3 Thus, only those patients with IOP greater than set thresholds received immediate applanation in the clinic. We also emphasize that rebound tonometry was used as a triage tool and not to fine-tune the care of chronic glaucoma.
There were limitations to the workflow. In some populations, patients rely on public transportation rather than transit by car. In this case, a walk-through alternative was instituted but not commonly used. Inclement weather may also limit this protocol’s feasibility. Additionally, this setting does not allow for comprehensive ophthalmic care.
The drive-through IOP clinic has proven to be a tremendous asset to clinical operations during the COVID-19 pandemic. Although conceived out of necessity, this innovative approach to patient care may continue to serve our patients’ needs well beyond this crisis.
References
- 1.Strata Decision Technology . National patient and procedure volume tracker. Published May 11, 2020. Accessed November 8, 2020. https://www.stratadecision.com/wp-content/uploads/2020/05/National-Patient-and-Procedure-Volume-Tracker-and-Report_May2020.pdf
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