Purpose:
To evaluate the anatomical characteristics of deep sclerectomy and their relationship to intraocular pressure (IOP) at long-term follow-up by ultrasound biomicroscopy (UBM).
Materials and Methods:
Twenty-five eyes of 25 patients who underwent deep sclerectomy with mitomycin C were evaluated for intrascleral space volume, thickness of trabeculo-Descemet membrane (TDM), suprachoroidal hypoechoic area and types of subconjunctival filtering bleb. Surgical success was accepted when the IOP was < 22mm Hg. The relationship between UBM findings and surgery results was investigated.
Results:
The mean time between surgery and UBM examination was 42.4±4.2 months. The mean IOP decreased significantly from preoperative value of 25.1±4.6 to 16.4±3.2 mm Hg at the UBM (p=0.001). Complete success rate was 64%, success rate with or without medical treatment was 92%. The mean number of postoperative medications was significantly lower than the preoperative value (p=0.001). The mean number of medications in eyes with high reflective, low reflective, flattened conjunctival bleb were 0.5±0.2, 0.7±0.3 and 0.5±0.2, respectively. No significant difference in success rate was found between the different types of conjunctival bleb (p=0.695). The mean IOP in eyes with high reflective, low reflective, flattened, encapsulated bleb and with suprachoroidal hypoechoic area were 16.1±1.1, 16.2±1.3, 17.2±1.2, 18 mm Hg and 14.5±0.9 mm Hg, respectively. Complete success rate in eyes with suprachoroidal hypoechoic area was significantly higher than that in eyes without (p=0.002). No significant correlation was found between intrascleral space volume (r2= 0.143) (p=0.345), TDM thickness (r2=0.0022) (p=0.554) and mean IOP.
Conclusion:
At long-term UBM follow-up evaluation of eyes following deep sclerectomy, the complete success rate in cases with suprachoroidal hypoechic area was significantly higher and no significant relationship was found between surgical success rate and other variables.(Turk J Ophthalmol 2011; 41: 299-303)
Keywords: Deep sclerectomy, mitomcin C, ultrasound biomicroscopy