Implantation of a posterior chamber phakic intraocular lens on Bruch's membrane opening-minimum rim width, retinal nerve fiber layer, and macular thickness.

AIM

To assess whether the implantation of a posterior chamber phakic intraocular lens produces changes in optical coherence tomography (OCT) measurements of macular thickness (MT) and two parameters that define the structure of the optic nerve, the peripapillary nerve fiber layer (RNFL) and the Bruch's membrane opening-minimum rim width (BMO-MRW).

METHODS

This nonrandomized prospective pre-post study included 86 eyes of 48 patients (age, 20-47y; axial length: 23.10-28.95 mm) scheduled for myopia or myopic astigmatism correction with implantation of the implantable collamer lens (ICL). Eyes with glaucoma or any other ocular disease that could alter OCT results were excluded. RNFL, BMO-MRW and MT were measured preoperatively, and at 1 and 6mo after surgery using spectral-domain OCT. Changes between preoperative and postoperative values were evaluated.

RESULTS

There was a significant increase in BMO-MRW at 1mo (mean change: 3.48±15.07 µm, =0.041). No significant changes were found during the rest of follow-up (1-6mo postop., =0.623). There was also a significant increase in RNFL thickness at 1mo after surgery (1.45±2.18 µm, <0.001), but with a significant reduction from 1 to 6mo postoperatively (=0.002). Regarding MT, it increased significantly at 1mo (2.46±3.76 µm, <0.001), with a significant decrease afterwards (=0.048). Measurements of the three parameters at 6mo were slightly superior to preoperative values (<0.01).

CONCLUSION

Minimal changes are induced in BMO-MRW, RNFL and MT after ICL implantation in healthy eyes, confirming the safety of the surgical procedure regarding the structure of the optic nerve head and the macula, and indicating that this phakic intraocular lens seems to have a slight impact on OCT measurements.