January consultation # 4
Article Outline
This case represents an unsatisfactory refractive outcome with night-vision complaints after toric pIOL implantation for myopic astigmatism in a 22-year-old woman. The 2 main issues are the cylindrical overcorrection and the night-vision complaints.
The topographies show induced surgical incisional astigmatism of the superior scleral tunnel incision of −1.00 × 119 and −0.75 × 104 in the right eye and left eye, respectively. The induced incisional astigmatism was not taken into account in the preoperative calculation of the cylinder portion of the Artisan pIOL, and this might have been partly responsible for the cylindrical overcorrection 4 weeks postoperatively. In addition, the preoperative refractive astigmatism may have been overestimated, as can happen in cases of corneal warpage (note some asymmetry in the preoperative topography) or as a result of variations in pupil diameter (see discrepancy between subjective refraction and 3.5 mm predicted phoropter refraction).
In this case, the disparity between scotopic and mesopic pupil sizes and the pIOL optic diameter was 2.34 mm and 2.42 mm, respectively, in the right eye and 1.93 mm and 1.82 mm, respectively, in the left eye. The quality of night vision after Artisan pIOL implantation is related to scotopic pupil size and residual refractive error; however, there does not appear to be a correlation between glare and the more “real-life” mesopic pupil size.1 Moreover, the mechanical restriction of the iris in the horizontal meridian after Artisan pIOL implantation (on average by 0.9 mm) can decrease optical zone–pupil size disparity and alleviate night-vision complaints.2
Even when the mesopic pupil sizes in this case are corrected for the mechanical restriction of the iris in the horizontal meridian, a disparity of approximately 1.0 mm remains in both eyes. Therefore, an exchange of both toric 5.0 mm pIOLs for pIOLs with a 6.0 mm spherical optic should be discussed. Postoperative residual astigmatism could then be treated with a large-zone corneal laser surgery procedure. Even though more than 90% of patients are very satisfied after Artisan pIOL implantation, it remains important to inform patients that in general, one third of patients report more bothersome glare after Artisan pIOL surgery.1
References
PII: S0886-3350(07)01824-X
doi:10.1016/j.jcrs.2007.11.006
© 2008 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.
