OBJECTIVE

To compare the refractive absolute error when axial length (AL), anterior chamber depth (ACD) and keratometry (K) are sourced from different measuring devices (IOL Master vs a combination of automated keratometer and A-scan) and inputted into the Barrett Universal II or SRK/T formula.

METHODS

This was a retrospective study. Medical charts of eyes that underwent uncomplicated phacoemulsification with in-the-bag implantation of Envista or multifocal FineVision IOL were reviewed. The results of manifest refraction at 1 month after surgery were collected. The predicted refraction corresponding to the IOL power implanted was collected from 4 IOL sheets: using the SRK/T with AL, ACD, and K from IOL Master (Group A); SRK/T formula with AL and ACD from A-scan and K from the automated keratometer (Group B); Barrett formula with AL, ACD and K from IOL Master (Group C); and Barrett formula using with AL, ACD from A-scan and K from automated keratometer. For each group, the absolute error, prediction error, and variances of prediction error were computed.

RESULTS

A total of 132 eyes were included in the study: 56 in the monofocal group and 76 in the multifocal group. The means of manifest refraction spherical equivalent (MRSE) were 0.06 ± 0.38 D and –0.08 ± 0.31 D in the monofocal and multifocal groups, respectively. When AL and K were obtained from various sources and entered into the Barrett formula, the mean absolute error difference in both the monofocal (p = 0.70) and multifocal (p = 0.10) groups did not reach statistical significance. If the SRK/T formula was used, similar outcomes were observed (monofocal p = 0.97; multifocal p = 0.37). When compared to A-scan groups, the prediction error variances are significantly smaller in the groups that used the IOL Master as their data source. Among the four groups, the Barrett group using IOL Master as the data source showed the lowest overall variation of prediction error (monofocal F = 0.04; multifocal F = 0.03).

CONCLUSION

Though the refractive outcomes may not be statistically different, using the IOL Master as the source of AL and K makes the refractive outcomes more consistent and predictable. Combining the AL and K from the IOL Master with the Barrett Universal II formula further increases the predictability of refractive outcomes.

Human ; Anterior Chamber ; Cataract

Objective: Circulation patterns of influenza and other respiratory viruses have been globally disrupted since the emergence of coronavirus disease (COVID-19) and the introduction of public health and social measures (PHSMs) aimed at reducing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission. Methods: We reviewed respiratory virus laboratory data, Google mobility data and PHSMs in five geographically diverse regions in Australia and New Zealand. We also described respiratory virus activity from January 2017 to August 2021. Results: We observed a change in the prevalence of circulating respiratory viruses following the emergence of SARS-CoV-2 in early 2020. Influenza activity levels were very low in all regions, lower than those recorded in 2017–2019, with less than 1% of laboratory samples testing positive for influenza virus. In contrast, rates of human rhinovirus infection were increased. Respiratory syncytial virus (RSV) activity was delayed; however, once it returned, most regions experienced activity levels well above those seen in 2017–2019. The timing of the resurgence in the circulation of both rhinovirus and RSV differed within and between the two countries. Discussion: The findings of this study suggest that as domestic and international borders are opened up and other COVID-19 PHSMs are lifted, clinicians and public health professionals should be prepared for resurgences in influenza and other respiratory viruses. Recent patterns in RSV activity suggest that these resurgences in non-COVID-19 viruses have the potential to occur out of season and with increased impact.