Abstract
Purpose: :
To compare the refractive outcomes of staged pars plana vitrectomy and phacoemulsification versus one–step combined phacoemulsification and vitrectomy.
Methods: :
Seventy–three patients underwent vitrectomy followed by phacoemulsification at a later date for various retinal disorders. Seventy–five patients underwent a one–step combined phacoemulsification with vitrectomy for similar retinal disorders. Ninety–six patients underwent phacoemulsification with lens implant (control group). A single surgeon operated on all patients using a standardised 20g self–sealing sclerostomy vitrectomy technique and clear corneal phacoemulsification with foldable acrylic IOL. Refractions were carried out three months post operatively. The spherical equivalent refractions (SER) aimed for at the time of the cataract surgeries were compared against those achieved post–operatively. The data collected in the two study groups were compared with a non–vitrectomised control group who had phacoemulsification with lens implant only.
Results: :
In the staged vitrectomy and phacoemulsification group the mean difference in SER between target refraction and that achieved was –0.42D (Range –2.46D to +2 D; SD 0.79). In the combined phacovitrectomy group the mean difference in the SER between the target refraction and that achieved was –0.51D (Range –3.75D to +2.87D; SD 1.29). The difference between aimed and achieved SER between these two groups were not significant. In the control group who had phacoemulsification with lens implant only, the mean difference in SER was +0.27D (Range –2.5 D to +4.75D; SD of 1.2). There was a significant difference in SER between the target refraction and that achieved between both vitrectomy groups and the control group with a relative myopic shift in the vitrectomy groups.
Conclusions: :
Combined phacoemulsification with vitrectomy offers equally good refractive results as a staged approach with vitrectomy first followed by phacoemulsification at a later date. There appears to be an unexplained myopic shift in targeted refraction in eyes undergoing phacoemulsification either combined with or following vitrectomy as compared to non–vitrectomised eyes undergoing phacoemulsification.
Keywords: vitreoretinal surgery • small incision cataract surgery • refraction