Subjective and Objective Refraction in Pseudophakic Patients

Agreement and Variability of Subjective Refraction, Autorefraction, and Wavefront Aberrometry in Pseudophakic Patients

Targeting of post-cataract refraction depends mainly on the prediction of the post-operative lens position, but also on the post-operative refraction itself. Hence, aim of this study is to evaluate the agreement and variability of subjective refraction performed by two independent examiners, autorefraction, and wavefront aberrometry in pseudophakic patients after uneventful cataract surgery.

One of the main goals of modern cataract surgery, beside removing the cataractous lens, is to achieve the patient's desired post-operative refraction. Targeting this post-operative refraction depends mainly on the prediction of the post-operative lens position and the post-operative refraction itself. Reason for the contributing effect of post-operative refraction in the error-propagation analyses is that refraction in phakic patients was shown to have only moderate reproducibility. In the past, different studies evaluated refraction methods. However, there is no study that included reproducibility of subjective refraction in pseudophakic patients and compares it with objective refraction methods (autorefraction, wavefront aberrometry). 100 eyes of 100 patients, which underwent uneventful cataract surgery, will be included in the study. Refraction of one eye of each patient will be tested using subjective refraction by two different examiners, autorefraction, and wavefront aberrometry at two separate occasions.

Evaluation of the agreement between the subjective refraction measurements (in dioptres) of two examiners

To show the number of measurements within the limits of agreement, Bland-Altman plots will be created for subjective refraction measurements in dioptres between examiner 1 and examiner 2.

Evaluation of reproducibility between the subjective refraction measurements between two study visits

To compare reproducibility of subjective refraction measurements between study visit 1 and study visit 2 Wilcoxon-signed rank test will be applied.

Evaluation of the agreement between the measurements performed by subjective refraction, autorefraction, and wavefront aberrometry (in dioptres)

To show the number of measurements within the limits of agreement, Bland-Altman plots will be created for subjective refraction measurements in dioptres between the 3 measurement methods.

Evaluation of the reproducibility between measurements done with subjective refraction, autorefraction, and wavefront aberrometry in dioptres

To compare reproducibility between the 3 measurement methods in dioptres, Friedman's multiple comparison will be applied.

Inclusion Criteria: Minimum age: 21 years Cataract surgery (at least 8 weeks post-surgery) written informed consent Exclusion Criteria: Complications during or after cataract surgery Ophthalmic diseases, that might interfere with measurements (macular degeneration, glaucoma, diabetic retinopathia) Ophthalmic surgery other than cataract surgery Clinically significant posterior capsule opacification

Ruiss M, Findl O, Draschl P, Harrer-Seely A, Hirnschall N. Agreement and variability of subjective refraction, autorefraction, and wavefront aberrometry in pseudophakic patients. J Cataract Refract Surg. 2021 Aug 1;47(8):1056-1063. doi: 10.1097/j.jcrs.0000000000000583.