Visual Outcomes of Cataract Surgery in Patients with Previous History of Implantable Collamer Lens

Abstract

Background/Objectives: This retrospective case series analyzed visual outcomes in patients with a prior history of implantable collamer lens (ICL) implantation who underwent cataract extraction (CE). A secondary aim was to investigate the relationship between vault height and the rate of cataract development. Methods: Visual acuity and refraction measurements were collected after CE at one week, one month and six months. Vault height measurements were correlated to the time until symptomatic cataracts were removed. Results: A total of 44 eyes were analyzed at six months after CE with efficacy and safety indexes of 1.20 ± 1.11 and 1.50 ± 1.06, respectively. In addition, 70% of eyes had a post-operative uncorrected distance visual acuity (UDVA) within one line of pre-operative corrected distance visual acuity (CDVA). Refractive predictability at six months demonstrated that 43% and 69% of eyes were within ±0.25 D and ±0.50 D of SEQ target, respectively. Astigmatism measured by refractive cylinder was ≤0.25 D in 17% and ≤0.50 D in 34% of eyes pre-operatively compared to 40% and 60% of eyes, respectively, at six months post-operatively. Vault heights one week after ICL (p < 0.0081) and one week before CE (p < 0.0154) demonstrated a positive linear regression with the time until CE. Conclusions: This sample population achieved favorable visual outcomes six months after CE, similar to six months after ICL implantation. Patients with a history of ICL implantation will similarly have a good visual prognosis after CE.

Keywords: ICL; astigmatism; cataract surgery; myopia; refractive surgery; spherical equivalent; visual outcomes.

Figure A1

Types of Cataracts Associated with ICL. Presented by a percentage of patients with either a combination of cataract types or solely one type. ASC = anterior subcapsular cataract, ACC = anterior cortical cataract, PSC = posterior subcapsular cataract, NS = nuclear sclerosis. ICL = implantable collamer lens. (N = 58).

Figure 1

(a) Illustrates the distribution of axial length by percentage of patients within the following range: >30 mm = 11%, 28–30 = 17%, 26–28 = 62%, and <26 = 10%. (N = 58). (b) Demonstrates the distribution of Visian ICL V4 pIOL sizes. Three sizes of ICL were represented in our patient population. 12.1 mm = 34%, 12.6 mm = 62%, and 13.2 mm = 4%. (N = 55).

Figure 2

Visual Outcomes six months after CE (n = 44) (A) Post-operative uncorrected distance visual acuity (UDVA) versus pre-operative corrected distance visual acuity (CDVA). (B) Efficacy: change in Snellen lines from pre-operative CDVA to post-operative UDVA. (C) Safety: change in Snellen lines from pre-operative CDVA to post-operative CDVA. (D) Spherical Equivalent (SEQ) Accuracy: accuracy of post-operative spherical equivalent refraction to target. (E) Attempted versus achieved spherical equivalent refraction, with linear regression and correlation values; the black line represents the equation y = x, and the closer the regression line is to the black line, the more accurate the results. (F) Defocus Equivalent (DEQ) Accuracy (G) Change in refractive astigmatism. (H) TIA vs. SIA; Blue Line: target; Between green lines: within ±0.50 D of target; Between pink lines: within ±1.0 D of target. (I) Histogram of correlation Index; (J) Angle of Error. CE = Cataract Extraction, TIA = Target-induced astigmatism, SIA = surgically induced astigmatism, ICL = Implantable collamer lens, D = Diopter.

Figure 3

Regression model of the relationship between vault height and time from ICL implantation to cataract extraction (CE). (a) Demonstrates the vault one week after implantable collamer lens (ICL) vs square root of the time until ICL. (n = 48). (b) Regression model of the relationship between late vault and the square root of the time until CE. R² values = 0.16 (a) and 0.14 (b) (n = 36).