Lifestyle predictive of PAL preference

Contact Lenses and Eyewear

DENVER – Patient lifestyle and daily visual needs have an impact on preferences in a progressive-addition lens (PAL), according to a study presented here at the American Academy of Optometry meeting.

Padmapriya Ramamoorthy, BSOptom, and colleagues sought to determine whether PAL preference varied according to visual needs and daily activities.

In the study, 34 PAL wearers were divided into two groups based upon whether they had greater far or greater near visual needs. These classifications were made by self-screening. In a randomized, double-masked clinical trial, each subject was given two PAL designs – one with a large far viewing zone and the other with a large near viewing zone. For 2 weeks, the subjects wore each design. For 1 final week, the subjects simultaneously compared both designs.

Patient satisfaction and preference was assessed by questionnaires on vision and several visual tasks. The final overall preference was evaluated in comparison to the patients’ original preference based on visual needs.

The study found that for 24 out of the 34 subjects, the initial PAL preference based on individual visual needs matched the final preference. The far group showed more consistency, with 11 of the 13 accurately predicting the far PAL at the beginning. The near group was more variable, with a final near PAL preference in only 13 of 21 patients.

Through a regression analysis for prediction of final PAL preference with the subjects’ refractive data, it was shown that the amount of cylinder in a subject’s prescription (P = 0.01) affected the PAL preference. In 30 out of 34 (88.2%) of the patients, the prediction model accurately classified the final preference.

The researchers concluded that PAL design varies based on patient needs, and that subjects with far visual needs clearly prefer PAL designs with superior far characteristics, while patients with near visual needs prefer those PAL designs with superior near characteristics.

“Our findings demonstrate an opportunity to develop and dispense more customized PAL designs to serve the requirements of these segmented populations further,” Dr. Ramamoorthy concluded.