Purpose: To assess the relationship between the volume of the "lake" measured by spectral-domain anterior segment optical coherence tomography and the intraocular pressure (IOP) reductions after modified deep sclerectomy (D-lectomy).
Methods: We measured the 3-dimensional volume of the lake 3 to 6 months after D-lectomy using spectral-domain anterior segment optical coherence tomography in 37 eyes of 37 consecutive outpatients and compared the volume with the ratio of the IOP reduction 3 and 6 months after D-lectomy.
Results: The mean volume of the lake was 2.00 ± 1.98 mm, and the mean IOP reductions 3 and 6 months after D-lectomy were 33.2% and 35.9%, respectively. The correlations between the 3-dimensional volume of the lake and the ratio of the IOP reduction at 3 and 6 months were poor, and their correlation coefficients were as small as r=-0.073 (P=0.669) and r=-0.094 (P=0.593), respectively. The IOP reductions in eyes with (N=14) and without (N=23) the filtering bleb were 38.2% and 30.1% at 3 months, and 39.9% and 33.2% at 6 months, respectively. The IOP reduction in eyes with no bleb also did not correlate with the volume of the lake at 3 months (r=0.007, P=0.98) and 6 months (r=0.02, P=0.92).
Conclusions: The correlation between the volume of the lake and the rate of IOP reduction was poor after D-lectomy. Thus, the transscleral outflow to the subconjunctival space may be a minor factor in the mechanism of IOP reduction after D-lectomy.