ABSTRACT
Purpose: To evaluate the eff ect of different aspiration flow rates (AFR) and bottle heights (BH) on vitreous face (AVF) during phacoemulsifi cation. Methods: Experimental study in 20 porcine eyes. Transzonular viscodissection was performed between the posterior capsule(PC) and AVF to dissect out the Berger's space. Triamcinolone acetonide was injected into this space to aid visualization with ultrasound B-Scan(USG). Realtime USG was performed during phacoemulsifi cation. Eyes were divided randomly into–Group I: Low parameters(AFR = 20 cc/min, BH = 90 cm, vacuum = 400 mmHg),and Group II: High parameters (AFR = 40 cc/min, BH = 110 cm, vacuum=650 mm Hg). Results: 15 eyes were analysed (8 in Group I; 7 in Group II). In all eyes, forward and backward movement of the PC was seen when going from foot position 0 to 1, or on occlusion break. Amplitude of these movements was much greater in Group II compared to Group I. There was no PC rupture in either group. In 2 of the 7 eyes in Group II, USG showed a sudden, spontaneous dispersion appearance of sono-opaque echoes in the vitreous cavity alongwith disappearance of the well-defi ned, crescentic stained space despite an intact PC. This suggests rupture of the AVF, leading to dispersion of the triamcinolone into the entire vitreous cavity. No AVF rupture was seen in Group I. Conclusion: We report a rarely described entity of AVF rupture with intact PC. The use of high AFR and BH may have clinically invisible detrimental consequences to the anterior vitreous face.
ABSTRACT
Purpose: To measure levels of collagen-derived antiangiogenic factors (arresten, canstatin, tumstatin, endostatin) and matrix metalloproteinases (MMP-2 and MMP-9) in anterior lens epithelial cells (LECs) and anterior capsules of children with cataract and persistent fetal vasculature (PFV) as cases and cataract without PFV as controls. Methods: Anterior capsules harboring LECs were collected from pediatric cataract patients with (n = 13) and without PFV (n = 13) during surgery. Samples were immediately subjected to RNA extraction and cDNA preparation. Quantitative real time PCR was performed to determine the mRNA levels of antiangiogenic factors and matrix metalloproteinases. GAPDH (Glyceraldehyde 3-Phosphate Dehydrogenase) and ? Actin were used as the housekeeping control. The mRNA levels were expressed as a ratio, using the delta-delta method for comparing the relative expression results between controls and cases. The non-parametric Mann-Whitney U test was applied for statistical evaluation. P values < 0.05 were statistically significant. Results: The relative mRNA levels of arresten, canstatin, tumstatin, endostatin, MMP-2 and MMP-9 in cases were 6.20E-03 ± 0.003, 1.49E-01 ± 0.02, 1.70E-01 ± 0.007, 3.20E-03 ± 0.003, 1.11E-03 ± 0.0009 and 3.72E-04 ± 0.0001. The mRNA levels of arresten was 1.6 times lower (P = 0.01) while mRNA levels of MMP-2, tumstatin and canstatin were 4, 2.5, and 2.3 times higher in cases than in controls. No change was observed in mRNA levels of MMP-9 and endostatin (P = 0.82). Conclusion: A significant difference in the levels of arresten, canstatin, tumstatin, and MMP-2 was found in LECs with PFV.