Abhay R Vasavada1, Sheena A Dholakia. 1. Iladevi Cataract & IOL Research Centre, Raghudeep Eye Clinic, Memnagar Ahmedabad, India. shailad1@sancharnet.in
Abstract
PURPOSE: To evaluate incidence and risk factors for corneal hydration intra-operatively during phacoemulsification (CHIP). METHODS AND MATERIALS: This was a randomised, clinical trial, where 240 eyes of 240 patients with senile cataracts undergoing phacoemulsification were prospectively randomised to receive one of three possible types of incision architecture - single, two or three planes. Viscoelastic injection through paracentesis, before instruments were withdrawn from the main incision, was randomly done. Incision length was grouped into 1.5, 2 and 2.5 mm. CHIP was graded as nil, mild, moderate or severe: nil - no visible CHIP, mild-CHIP involving pillars of the incision, moderate - CHIP involving pillars and lateral extension, severe - extension of CHIP in front into the clear cornea. Moderate and severe categories were combined as 'significant' CHIP. Statistical analysis was done by logistic regression. RESULTS: The incidence of significant CHIP was 17.9 % (43 eyes out of 240). Five out of 80 eyes (6.25%) single plane, 8 out of 80 (10%) two plane and 30 out of 80 (37.5%) three- plane incisions developed significant CHIP (p = 0.005). Fifteen out of 120 (12.5%) with and 28 out of 120 (23.3%) without injection of viscoelastic developed significant CHIP (p = 0.044). Eighteen out of 43 (42.8%) and 25 out of 43(58.1%) with incision lengths 2 and 2.5 mm developed significant CHIP respectively (p<0.001). CONCLUSIONS: The incidence of significant CHIP was 17.9 %. Three-plane incisions, not injecting viscoelastic prior to retraction of instruments and incision length 2 mm or more are risk factors for significant CHIP.
RCT Entities:
PURPOSE: To evaluate incidence and risk factors for corneal hydration intra-operatively during phacoemulsification (CHIP). METHODS AND MATERIALS: This was a randomised, clinical trial, where 240 eyes of 240 patients with senile cataracts undergoing phacoemulsification were prospectively randomised to receive one of three possible types of incision architecture - single, two or three planes. Viscoelastic injection through paracentesis, before instruments were withdrawn from the main incision, was randomly done. Incision length was grouped into 1.5, 2 and 2.5 mm. CHIP was graded as nil, mild, moderate or severe: nil - no visible CHIP, mild-CHIP involving pillars of the incision, moderate - CHIP involving pillars and lateral extension, severe - extension of CHIP in front into the clear cornea. Moderate and severe categories were combined as 'significant' CHIP. Statistical analysis was done by logistic regression. RESULTS: The incidence of significant CHIP was 17.9 % (43 eyes out of 240). Five out of 80 eyes (6.25%) single plane, 8 out of 80 (10%) two plane and 30 out of 80 (37.5%) three- plane incisions developed significant CHIP (p = 0.005). Fifteen out of 120 (12.5%) with and 28 out of 120 (23.3%) without injection of viscoelastic developed significant CHIP (p = 0.044). Eighteen out of 43 (42.8%) and 25 out of 43(58.1%) with incision lengths 2 and 2.5 mm developed significant CHIP respectively (p<0.001). CONCLUSIONS: The incidence of significant CHIP was 17.9 %. Three-plane incisions, not injecting viscoelastic prior to retraction of instruments and incision length 2 mm or more are risk factors for significant CHIP.