Cataract surgery : complications and techniques

Abstract

Cataract surgery is one of the most common surgical procedures performed worldwide. Posterior capsul opacification (PCO) remains the most common postoperative complication that can deteriorate vision. Development of glistenings in the artificial intraocular lens (IOL) after cataract surgery is a phenomenon with the potential to reduce the outcome of an otherwise excellent final surgical result. Phacoemulsification has been the most common surgical technique performed to remove cataracts during the previous 25 years. The settings controlling the fluidics in the eye intraoperatively can affect the postoperative convalescence.

Since many people undergo cataract surgery annually and all of the previously mentioned issues can affect the final outcome, a better understanding and more studies comparing different IOLs and phacoemulsification settings will help surgeons choose better IOLs and surgical techniques and decrease postoperative complications.

In study I, we compared the development of PCO and glistenings associated with two hydrophobic acrylic IOLs, the Sensar AR40e (Abbott Medical Optics) and AcrySof SA60AT (Alcon), 5 to 7 years after cataract surgery. Both IOLs had a sharp posterior edge design. We also evaluated if there were correlations between the amount of glistenings and corrected distance visual acuity (CDVA) or contrast sensitivity and if subjective gradings of glistenings were correlated with the objective quantification of glistenings with Scheimpflug images. Eighty patients were included in this prospective randomized study. Fifty-six patients completed the follow-up visit from 5 to 7 years postoperatively. Glistenings were graded at the slit-lamp microscope and the amount of glistenings was quantified objectively using Scheimpflug images with subsequent processing in computer software. There were no significant differences in PCO area and severity or neodymium:yttrium-aluminium-garnet (Nd:YAG) capsulotomy rates between the IOLs. Significantly more glistenings were found in the AcrySof hydrophobic IOLs 5 to 7 years postoperatively. The glistenings were not correlated with the CDVA or contrast sensitivity.

In study II, we evaluated in a prospective randomized trial if there were any correlations between the amount of glistenings and CDVA or contrast sensitivity and compared the development of glistenings in two acrylic IOLs, a hydrophilic IOL (BL27, Bausch & Lomb) and a hydrophobic IOL (AcrySof SA60AT), 9 years after cataract surgery. One hundred and twenty patients were recruited, 78 completed the 9-year follow-up visit.

The amount of glistenings was quantified objectively using Scheimpflug images with subsequent processing in computer software. Glistenings were also subjectively graded at the slit-lamp microscope. The hydrophobic IOL had significantly more glistenings at the 9-year follow-up visit. The glistenings were not correlated with the CDVA or contrast sensitivity.

In study III, we compared the PCO area, severity, and survival time without Nd:YAG capsulotomy between a hydrophilic (BL27) and a hydrophobic (AcrySof SA60AT) acrylic IOLs 9 years after cataract surgery. One hundred and twenty patients were recruited, 78 completed the 9-year follow-up visit. The PCO area and severity were higher in the hydrophilic IOL. The survival time without Nd:YAG capsulotomy was longer in the hydrophobic IOL.

In study IV, we compared low and standard fluidics settings during phacoemulsification cataract surgery and evaluated the impact on the eye postoperatively by measuring parameters indicating surgical trauma. Forty-three patients were recruited and randomized into two groups, i.e., those that underwent phacoemulsification with low or standard fluidics settings. The central corneal thickness, macular thickness, and intraocular pressure were measured preoperatively, 1 day, 3 weeks, and 3 months postoperatively. The CDVA was measured preoperatively, 3 weeks and 3 months after surgery. Anterior chamber flare was measured preoperatively, 1 day and 3 weeks postoperatively. Endothelial cell density was measured preoperatively and 3 months postoperatively. The low-settings group had a significantly longer surgical time and higher amount of ultrasound energy used intraoperatively, but there were no significant differences in the outcome parameters between the two groups.