Abstract
Purpose: :
To compare intraocular lens (IOL) positioning in patients who have had scleral sutured posterior chamber IOLs (SS-PCIOL) with patients who have had in the bag placed IOLs, and to investigate postoperative refractive outcomes in the two groups.
Methods: :
The study design involved a retrospective chart review in patients who met inclusion criteria along with postoperative anterior segment OCT imaging. The spectral domain OCT’s (SD-OCT) anterior segment function was used to determine the distance between the anterior IOL surface and iris plane in eyes with SS-PCIOLs (group 1, 21 eyes) and those with in the bag IOLs (group 2, 44 eyes). Postoperative clinical refractions were used to compare final refractive outcomes in the two groups in order to further demonstrate how a change in anatomical location of the IOL alters lens effectivity. Preoperative and postoperative best corrected visual acuity (BCVA) in the two groups was also compared.
Results: :
In group 1, the average distance between the anterior IOL surface and the iris plane was 593.90/631.67µm and 516.32/559.47µm in the horizontal and vertical OCT image cuts, respectively, as measured at the two edges of the pupil margin. In group 2, the average distance was 622.25/608.61µm in horizontal OCT cuts and 591.85/584.67µm in vertical OCT cuts. No statistically significant difference was found in IOL positioning between the two groups (p=.789, p=.624), and IOL position variability in group 1 was quite high with a standard deviation of 405.32 compared to a standard deviation of 190.00 in group 2. The average postoperative spherical equivalent refractive error was -0.867 in group 1 compared to -0.180 in group 2 (p=.023). BCVA improved after surgery in both groups, from 0.97 logMar 0.28 logMar in group 1, and from 0.28 logMar to 0.10 logMar in group 2.
Conclusions: :
Although the predicted postoperative myopic shift was observed in scleral sutured posterior chamber IOL cases, a relative variability of IOL position was noted by anterior segment SD-OCT imaging. Due to this variability observed in lens positioning, it is concluded that the exact location of postoperative IOL positioning cannot be predicted. Therefore, reducing IOL power by up to 1 diopter, as is commonly employed with sulcus fixation, should not be routinely practiced in SS-PCIOL cases to avoid postoperative hyperopia. Significant visual improvement was observed in patients with scleral sutured as well as in the bag placed IOLs.
Keywords: intraocular lens • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)