Abstract
Purpose :
Anterior capsular contraction syndrome (ACCS) is characterized by excessive contraction and fibrosis of the anterior lens capsule after phacoemulsification and intraocular lens (IOL) implantation, leading to phimosis of the anterior capsulotomy. Epithelial-to-mesenchymal transition (EMT) of lens epithelial cells and extracellular matrix remodelling (ECMR) are associated with ACCS. Zonular instability (ZI) is correlated with ACCS but it is unclear if zonulopathy (ZP) is caused by lens epithelial changes or if it is an independent risk factor. The aim of this cross-sectional study is to assess the associations of EMT, ECMR, and ZP with progressively smaller capsulorhexis diameter (CD) in post-mortem eyes.
Methods :
A total of 104 post-mortem pseudophakic human eyes from the MUHC-McGill University Ocular Pathology & Translational Research Laboratory were examined. Images of the eyes in Miyake-Apple view and region of interest analysis were done using ImageJ to measure capsule area (CA), ciliary ring area (CRA), and CD. Zonular stability was measured using CA over CRA ratio (CCR) and capsule-ciliary ring decentration (CCD). Capsular bags with IOLs were extracted, and EMT and ECMR were quantified via automated immunohistochemistry with anti-SMA (smooth muscle actin) and anti-FN (fibronectin), respectively. Slides were digitized and analyzed via the Positive Pixel Count v9 algorithm. Correlation was assessed via simple linear regression, one-way ANOVA, and two-sample t-test.
Results :
There was a statistically significant positive correlation between CCR and CD (p=0.0106, N=104) but not between CCD and CD (p=0.44842, N=104). No significant correlation between CD and FN (p=0.14213, N=75) or SMA (p=0.41087, N=75) was found. However, when comparing samples with the largest CD with samples of CD <2 standard deviations from the mean, FN staining was reduced in samples with a smaller CD (p=0.01171). There was no correlation between CCR or CCD with FN or SMA staining. Cataract-to-death time did not correlate with CCR (p=0.73958), CCD (p=0.14405), or FN (p=0.11619), but did have a positive correlation with SMA (p<0.0001).
Conclusions :
ZI, as indicated by a low CCR, had the strongest correlation with small CD in post-mortem pseudophakic eyes. Moreover, the degree of ZI does not seem to correlate with EMT or ECMR, suggesting that it may be an independent risk factor for smaller CD and, perhaps, the development of ACCS.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.