Visual and Refractive Outcomes After Lens Extraction and Multifocal Toric IOL Implantation in Astigmatic Patients
Narrative Responses:
Purpose
To evaluate the visual and refractive outcomes following lens extraction and implantation of a multifocal toric intraocular lens (IOL) for patients with keratometric astigmatism greater than 1.5D.
Methods
This is a retrospective study of the visual and refractive outcomes of all eyes that had lens extraction and a multifocal toric IOL implant in a private ophthalmic clinic from September 2009 to April 2013. All patients received the MFlexT intraocular lens implant (Rayner Intraocular Lenses Ltd, Sussex, UK), with either a +3 or +4 near add. Main outcome measures were unaided distance visual acuity (UDVA), corrected distance visual acuity (CDVA), post-operative unaided near visual acuity (UNVA), keratometry, and refraction.
Results
This study included a total of 16 eyes (10 patients). The mean preoperative UDVA and CDVA were 1.05 logMAR ± 0.54 (SD) and 0.21 ± 0.20 logMAR respectively. The mean postoperative UDVA improved to 0.20 ± 0.17 logMAR (p<0.01). Postoperative CDVA did not change significantly with a mean of 0.11 ± 0.09 logMAR (p=0.09). Mean postoperative UNVA was 0.21±0.12. Mean refractive cylinder decreased from 1.71 ± 0.85 D preoperatively to 0.70 ± 0.65 D postoperatively (p < 0.01). The mean preoperative keratometry cylinders were 2.26 ± 0.50 D (1.6D - 3.2D). One patient (two eyes) required corneal sutures post-operatively for floppy iris syndrome and if excluded (n=14), the mean postoperative UDVA is 0.15±0.09 logMAR, mean postoperative CDVA of 0.10±0.10 and mean postoperative refractive cylinder of 0.55±0.53D.
Conclusion
Use of a multifocal toric IOL effectively and significantly improved uncorrected distance visual acuity, and provided good near visual acuity in patients that exhibit high keratometric astigmatism. Such patients would be otherwise unsuitable to receive a multifocal lens implant or would require alternative methods to correct their astigmatism.