Abstract
Purpose :
The purpose of this study is to compare the estimated anterior chamber depth (ACD) by oblique penlight examination (OPE) when compared to ACD measured by partial coherence interferometry (PCI).
Methods :
The study compromised a retrospective chart review of 172 eyes of 86 patients at VA Tennessee Valley Healthcare System who received an OPE and PCI as part of cataract surgery work-up. These patients had their eyes assessed with OPE by technician staff prior to dilation and received measurements that include ACD by PCI. All technicians received standardized training in performing OPE and had a standardized grading sheet available. Grading was from 1-4 (Grade 1> ¾ Anterior chamber shadow (ACS), Grade 2=1/3-3/4 ACS, Grade 3<1/3 ACS, Grade 4=no shadow). Patients who had prior intraocular surgery or ocular trauma were excluded from the study.
One-way ANOVA and correlation analysis of the data was performed to assess statistical significance. The data was also analyzed by t-test as to whether a dichotomous OPE result showed deeper average ACD by PCI in grade 4s versus all grades 1-3.
Results :
There were no grade 1s, eight grade 2s, five grade 3s and 159 grade 4s by OPE. The mean and median ACD by PCI were 3.43 and 3.28; with a range of 2.11 to 5.69.
When comparing all data, the one-way ANOVA analysis resulted in a p-value of 0.440014.
The correlation analysis resulted in a p-value of 0.496349. When comparing average ACD by PCI of all grade 4s (3.45) to all grades 1-3 (3.15), the results showed a p value of 0.203082 by t-test.
Conclusions :
The results of the one-way ANOVA and correlation analysis reveal no statistical significance that the OPE properly estimates the ACD in comparison to PCI. Additionally, when looking at average ACD of grade 4s versus grades 1-3, there was also no statistical significance. Although this study is limited by its sample size, this study shows OPE does not reliably estimate ACD. Further studies of larger sample sizes are likely to reveal similar results due to the user-error associated with the OPE technique.
This is a 2021 ARVO Annual Meeting abstract.