Pathology and immunohistochemistry of capsular bag in spontaneously late dislocated capsular bag-intraocular lens complex

Abstract

Purpose: Our study aims to evaluate the morphology, histopathology, and immunohistochemistry of the spontaneously late dislocated capsular bag-intraocular lens (CB-IOL) complex. Various etiologies and possible pathogenesis of the event are also discussed.

Methods: This was a tertiary-care setting and retrospective observational case series. The surgically explanted intact specimens of spontaneously late dislocated CB-IOL complex were studied. The demographics, duration of pseudophakia, IOL design/material, and specimen measurements were noted. Fresh specimens were photographed, and computer software was used for measurements. After processing, a detailed microscopic examination was carried out for three different sections of each specimen with hematoxylin and eosin (H and E), Masson's-trichrome, and immunohistochemistry stain for vimentin. The Mann-Whitney U-test was used for the statistical analysis.

Results: Of 12 specimens, the mean CB and capsulorhexis opening size were 8.32 ± 0.8 mm and 3.62 ± 0.61 mm, respectively. The average CB-IOL complex size of our study was significantly lower than the studies reported in the literature (P ≤ 0.001). All (n = 12, 100%) were acrylic IOLs with 11 (91.67%) having single-piece design. All specimens on H and E stain showed extensive subepithelial fibrosis while Masson's trichrome staining showed that none had any pseudoexfoliation material. The circumferential sphincter-like fibrous tissue arrangement was seen in all specimens. Immunohistochemical expression of vimentin suggested the mesenchymal metaplasia of epithelial A-cells.

Conclusion: Significant fibrotic contraction of the CB and phimosis of capsulorhexis may cause a progressive zonular tear. This is probably the most important etiology of spontaneous late dislocation of the CB-IOL complex.

Figure 1

Explanted specimen showing capsular tension ring and single piece intraocular lens in-the-bag. Capsulorhexis phimosis is also observed

Figure 2

Gross photograph of an explanted capsular bag-intraocular lens complex showing three-piece hydrophobic acrylic intraocular lens. A well-formed doughnut-shaped Soemmering ring, a phimosed oval-shaped capsulorhexis, and shrunken capsular bag is noticeable in the specimen

Figure 3

Gross picture showing a single-piece hydrophobic acrylic intraocular lens. Specimen shows fibrosis of anterior capsule (at the point of contact between anterior capsule and IOL optics as well as haptics), phimosis of capsulorhexis and shrunken capsular bag. The intraocular lens haptics appears compressed toward optic. Size of intraocular lens, capsular bag, and capsulorhexis is 9.29 mm, 9.29 mm, and 3.8 mm, respectively

Figure 4

(a) A light photograph showing folds in the anterior capsule and a phimosed capsulorhexis. Anterior capsular opacity seen universally at the contact site of intraocular lens and anterior capsule. (b) Histopathology of capsule with hematoxylin and eosin stain shows an intact capsular epithelium, accumulation of extracellular matrix, and subepithelial elongated fibroblast cell. (c) Masson's trichrome stained-negative for pseudoexfoliation material. (d) Immunohistochemistry shows expression of vimentin (brown stain)

Figure 5

(a) Severe capsular and continuous curvilinear capsulorhexis phimosis with anterior capsular wrinkles. (b and c) Magnified view shows sphincter-like arrangement of fibrous tissue around continuous curvilinear capsulorhexis. (d) Hematoxylin and eosin stain shows dense subcapsular fibrous tissue. (e) Masson's trichrome staining reveals basement membrane with nuclei in the lens epithelial cells (dark granules). Dense subcapsular fibrosis due to LEC metaplasia is also seen. (f) Immunohistochemistry detected the expression of Vimentin (brown)

Figure 6

(a) Contraction of capsular bag leading to haptic-optic approximation. (b) Diffraction microscopy shows vertical compression folds (yellow box) and torn zonules. (c and d) Fibrous tissue strands seen growing such as cords over the haptics (arrows). Migrating sheets of regenerative cortical E-cells ([e and f] asterix) and bladder cells ([g and h] arrow)