Hydroexpression and viscoexpression of the nucleus through a continuous circular capsulorhexis

Area of Science:

• Ophthalmology
• Surgical Techniques
• Biomaterials

Background:

• Continuous circular capsulorhexis (CCC) can create a strong capsular rim, complicating conventional nucleus expression.
• Hydroexpression is an alternative, but its effectiveness depends on capsulorhexis opening size.

Purpose of the Study:

• To compare the safety and efficacy of hydroexpression versus viscoexpression for nucleus removal in cataract surgery.
• To evaluate the impact of capsulorhexis opening size on intraocular pressure during these procedures.

Main Methods:

• 16 pairs of human cadaver eyes were used.
• Hydroexpression with balanced salt solution (BSS) and viscoexpression with sodium hyaluronate (Healon Yellow) were performed.
• Capsulorhexis opening diameters ranged from 4 mm to 6 mm.
• Intraocular fluid pressure within the capsular bag was measured during both procedures.

Main Results:

• Intraocular pressure was higher during hydroexpression compared to viscoexpression.
• The pressure difference was most significant with smaller capsulorhexis openings (4-6 mm).
• This correlation between pressure and CCC size was statistically significant (P < .05).

Conclusions:

• Viscoexpression offers enhanced safety during nucleus removal, particularly in cases with small or challenging capsulorhexis openings.
• The use of viscoelastic agents may mitigate risks associated with hydroexpression in difficult cataract surgeries.