Correlating OCT With Lens Density and Cumulative Dissipated Energy Required During Cataract Extraction
Narrative Responses:
Purpose
Posterior segment OCT routinely records the signal strength during the exam. This measurement can be used as a marker of central density of the lens in otherwise clear media. The signal strength could prove to be a good surgical planning tool for patients potentially undergoing cataract extraction.
Methods
Patients without corneal, anterior segment, or vitreous opacities or abnormalities were identified. The cataracts were graded based on the LOCSIII scale. A macular cube OCT was obtained following cataract grading in all patients. If cataract surgery was performed, it was completed within two months by a single surgeon on a single phacoemulsification machine and the cumulative dissipated energy (CDE) and effective phacoemulsification time were recorded.
Results
Twenty-one eyes (15 operated) had nuclear sclerotic cataracts, 9 (9 operated) had a posterior subcapsular component, and 14 (8 operated) were predominately combined cortical and nuclear sclerotic cataracts. Purely nuclear cataracts had an r-squared value of 0.71 (p value <0.001) when OCT signal strength was compared to nuclear color rating and an r-squared value of 0.66 (p value <0.001) when OCT signal strength was compared to nuclear opalescence. The r-squared value of OCT signal strength to effective phacoemulsification time for combined cataracts was 0.72 (p-value 0.007) and the signal strength compared to CDE for combined cataracts was 0.75 (p-value 0.005).
Conclusion
OCT signal strength has a good correlation with nuclear cataract grading and good predictive value of energy required for cataract removal in combined cortical and nuclear cataracts.