Results from this retrospective chart review demonstrated good uncorrected near visual acuity at and best-corrected distance visual acuity at 2 months postoperatively for patients with and without pre-existing pathology. Visual acuities favored the non-pathology group by approximately 1 line. Eyes with mild to moderate pathology showed better VA than eyes with severe pathology, although these eyes were also able to achieve average VA of 20/40. Visual acuity with spherical and toric IOL designs were statistically better for the non-pathology group; although differences were less than 1 line. Results suggest the Symfony IOL provides good corrected and uncorrected VA and can be an IOL option for patients with pre-existing macular pathology who desire an IOL with extended range of vision.
There were two pre-specified metrics we were interested in comparing. One was to compare UNVA results from the present study with those obtained in the pre-market clinical trials of the Symfony IOL, which had a more controlled population.A Our monocular UNVA results showed favorable results for non-pathology (0.07 logMAR) and pathology eyes (0.17 logMAR) when compared with those of the Symfony clinical trials (0.24 logMAR).A These results suggest patients with pre-existing pathology can be candidates for this IOL.
The second point of interest was to compare mean monocular CDVA in eyes with mild pathology versus those without pathology. Mean monocular CDVA in eyes with mild pre-existing pathology (0.05 logMAR) was comparable to the non-pathology eyes (0.02) in our study. These results demonstrate eyes with mild pre-existing pathology can achieve CDVA comparable to that of non-pathology eyes.
Results from the group of eyes without pathology were similar to those reported for other non-pathology eyes relative to UDVA, but less so for UNVA. In a study of 94 eyes with Symfony IOL implantation and no ocular pathology, mean monocular UDVA was 0.12 logMAR and UNVA was 0.34 logMAR.20 Comparatively, non-pathology and pathology eyes in our study showed better UDVA and UNVA by nearly two lines. The above-mentioned study also noted patients with lower levels of preoperative corneal astigmatism (< 1.0D) showed better VA outcomes, versus eyes with > 1.0 D of preoperative corneal astigmatism which is consistent with other previous reports of better results for MIOLs when with lower cylinder.20,21 The effect of preoperative astigmatism in patients with retinal pathology was also a of point of clinical interest in our study. Results with Symfony spherical and toric IOL designs were statistically better for the non-pathology group, although differences were less than 1 line. Results from our study support use of the Symfony toric IOLs in patients with co-existing retinal pathology.
At the time of this study, there are no published outcomes regarding retinal pathology and the Symfony IOL; moreover, there are limited publications of retinal pathology with other MIOL technologies. In a study of patients with idiopathic ERM who underwent combined phacovitrectomy and diffractive MIOL implantation, results showed improved VA with successful multifocality, after macular healing and PCO treatment.14 One study with refractive MIOL implantations in eyes with pathology showed that patients with pre-existing ocular pathologies, such as two branch retinal-vein occlusion and glaucoma, can still achieve good VA comparable with healthy eyes.7 In another case series of 13 patients with age-related macular degeneration showed promising outcomes with a myopia-targeted multifocal IOL approach, which improved or maintained near vision without severely compromising distance vision.22 Our study showed comparable VA results for eyes with mild to moderate pathology and normal eyes. Although visual acuities were better for the mild to moderate eyes, those with severe pathology were still able to achieve functional visual acuity. These results suggest that eyes with pre-existing pathology can be candidates for the Symfony IOLs.
This study has some noted limitations such as the retrospective, non-randomized nature of the study. However, a strength of this study is that it provides outcomes for patients typically excluded due pre-existing pathology. In particular, published outcomes for Symfony IOLs have excluded eyes with pathology, thus results provide outcomes in population under-represented in the literature. Additionally, this study reports on a larger sample size of Symfony IOL patients than previously seen in the literature, which provides a robust sampling for understanding visual dynamics in this population. This large sample size allowed us to see differences with the toric IOLs, but not necessarily a clinically relevant difference. These findings may be relevant for providers treating patients with ocular pathology and may be helpful when offering visual correction options. These outcomes suggest that patients with pre-existing ocular pathology can achieve good visual outcomes with this IOL if they desire a lens that provides extended range of vision. Moreover, these results are meaningful for patients that could potentially develop retinal co-morbidities after cataract surgery.
Future studies of the Symfony IOL could include other endpoints to evaluate quality of vision, such as contrast sensitivity, visual symptoms, and patient reported outcomes. Other studies have shown minimal visual symptoms with the Symfony IOL and acceptable contrast, thus it would be of interest to see if this patient population has similar outcomes.2,23−25 In addition, because retinal pathology could require additional or future surgical intervention after cataract surgery,(Yoshino) additional research concerning intraoperative visualization through the Symfony IOL would be of interest.