Purpose: To investigate the precision and accuracy of IOP measurements using a pneumatonometer and a tonometer tip cover (Tono-Pen Ò tip cover) acting as a membrane between a cadaver eye model and pneumatonometer probe. Methods: A total of 480 paired IOP measurements, with and without a Tono-Pen cover, were collected across 4 pressure levels of 7, 10, 20 and 30 mmHg. IOP measurements were obtained by three different pneumatonometer units paired with three different masked operators (three configurations). Four eyes were sampled for each eye pressure level. The sequence of eye pressure, configuration, and measurements with vs. without the Tono-Pen cover was randomized. Results: With the Tono-Pen cover in place, there was a negative bias with a mean IOP difference of-1.18 mmHg for all 480 paired samples compared with the measurements absent the cover. Compared with the test pressure settings (i.e., 7, 10, 20, 30 mmHg), the overall mean bias was ? 0.35 mmHg with the Tono-Pen cover present. With the Tono-Pen cover present, the overall repeatability %CV (percent coefficient of variation) was 3.4% and the reproducibility %CV was 3.8% compared with a repeatability %CV of 3.2% and reproducibility %CV of 5.7% without the Tono-Pen cover. Conclusion: Measurement of IOP via pneumatonometry with a Tono-Pen cover in place, also known as the excursion test method, yields precise, accurate and reproducible results. This developed method of pressure measurement is an acceptable and reliable form of IOP measurement.

Purpose To determine the preference of patients undergoing bilateral LASIK for either the dexamethasone intracanalicular insert or topical prednisolone acetate for control of postoperative symptoms and ocular surface signs. Methods In this randomized clinical trial, one eye was randomized to receive the dexamethasone insert or topical prednisolone acetate 1% four times daily for one week and 2 times daily for a second week; the fellow eye received the alternate therapy. One month postoperatively, patient preference for these two therapies was assessed using an adapted COMTOL questionnaire. Ocular comfort was assessed using the SPEED questionnaire. Corneal staining and uncorrected distance visual acuity (UDVA) were also assessed. Results Twenty patients participated. At Month 1, 80% of patients preferred the dexamethasone insert, 10% preferred prednisolone acetate, and 10% expressed no preference (p<0.001). SPEED scores measuring ocular comfort/discomfort related to dry eye symptoms were similar between groups (p=0.72), and both the incidence of patient-reported ocular dryness and the corneal staining scores were similar between groups. Both groups attained the same final UDVA. Conclusion Patients undergoing elective bilateral femtosecond LASIK surgery overwhelmingly (by an 8-to-1 margin) preferred the dexamethasone insert to topical prednisolone acetate for postoperative treatment. The insert produced comparable ocular comfort, corneal staining, and visual acuity outcomes to topical prednisolone. The insert is an appropriate means of postoperative symptom control in this quality of life-conscious population.

PURPOSE: To compare prediction error outcomes between the Optiwave Refractive Analysis System (ORA) (Alcon Laboratories, Inc) and two modern intraocular lens (IOL) formulas (Hill-RBF2.0 [HRBF] and Barrett Universal II [BUII]), and further analyze IOL selection in scenarios of disagreement between methods. METHODS: Patients with no previous history of corneal refractive surgery who underwent cataract extraction and had intraoperative aberrometry measurements between October 2016 and December 2019 were analyzed. The prediction error for the ORA, HRBF, and BUII were calculated based on the postoperative manifest refraction. Further analysis was performed evaluating prediction error for scenarios of disagreement between the three methods. RESULTS: After exclusions, 281 eyes were included. The mean absolute prediction errors were 0.28 diopters (D) (ORA), 0.31 D (HRBF), and 0.33 D (BUII) ( P < .05). In instances when the IOL recommended by the ORA was in disagreement with what was selected preoperatively, there was no benefit when the lens recommended by the ORA was selected based on anecdotal experience. When further analyzing these instances of disagreement, selecting the ORA-recommended lens when it is higher in power results in improved refractive outcomes: the ORA resulted in more eyes within ±0.25 diopters (D) of predicted spherical error (65% ORA, 37% HRBF, 32% BUII; P = .004) and fewer hyperopic surprises (5% ORA, 15% HRBF, 24% BUII; P = .009). CONCLUSIONS: In normal eyes without previous corneal refractive surgery, intraoperative aberrometry is not different from to two modern preoperative IOL formulas. Placing the ORA-recommended lens when it is higher in power than that selected preoperatively results in better refractive outcomes. [ J Refract Surg . 2022;38(5):304–309.]

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