When you see a patient with a dense central endo-nucleus, there are characteristic findings: a lens periphery that is relatively clear, central nuclear opalescence, and a myopic shift in the refraction. When doing cataract surgery in these patients, the challenge is that the central endo-nucleus behaves differently than the peripheral epi-nucleus.
The key in this type of case is to perform hydro-delineation to separate the dense central endo-nucleus from the soft outer epi-nucleus. Place the 27g cannula just outside the dense endo-nucleus and slowly inject BSS to perform hydro-delineation. Sometimes it is helpful for new surgeons to stay within the confines of the capsulorhexis to avoid just doing more hydro-dissection.
Success with hydro-delineation is confirmed by the golden ring as shown in this video. Then the central endo-nucleus can be removed with higher phaco energy while the outer epi-nuclear shell can be aspirated with primarily vacuum.
Click below to see the technique of hydro-delineation for a dense endo-nucleus: