Volume measurement of the vitrectomised eye and its applications in practice

Purpose: To estimate the vitreous cavity replacement volume after pars plana vitrectomy and analyze its correlation with axial length and refractive error.

Methods: Observational cross-sectional study on 103 eyes undergoing vitrectomy. Fluid-air exchange was performed using a soft-tip cannula connected to a PVC tubing, the distal end of which opened into a 10-cc syringe without the plunger. The collected fluid was measured (and correction factors applied) to estimate the vitreous cavity volume.

Results: The mean axial length of 103 eyes was 23.43 ± 1.54 mm. The mean vitreous cavity volume was 4.46 ± 0.83 mL (2.8-8.1 mL). There was a strong positive correlation between axial length and vitreous volume, which was stronger for pseudophakic and aphakic groups than for phakic groups.

Conclusion: Accurate assessment of vitreous cavity volume can enable precise quantification of tamponade, intravitreal drugs, and intravitreal chemotherapeutic agents. This will allow better surgical outcomes, decreased toxicity, and increased cost-effectiveness due to lesser wastage.

Objective: To estimate the vitreous cavity replacement volume after pars plana vitrectomy and analyze its correlation with axial length and refractive error.