Suresh K Pandey

Surgical prevention of posterior capsule opacification. Part 1: Progress in eliminating this complication of cataract surgery.

PURPOSE To evaluate over almost 2 decades the success of a component of cataract surgery that represents a critical step in reducing the incidence of posterior capsule opacification (PCO); namely, the efficacy of cortical cleanup. SETTING Center for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Department of Ophthalmology, Medical University of South Carolina, Charleston, South Carolina, USA. METHODS Accessioned from the early 1980s to 1997, 3320 eyes obtained postmortem with posterior chamber intraocular lenses were analyzed with respect to formation of a postoperative Soemmerings ring. This anatomic lesion, the precursor of clinical PCO, represents an important and measurable indication of the quality of cortical cleanup. Its formation was documented using Miyake-Apple posterior photographic analysis. RESULTS The quality and thoroughness of cortical cleanup and overall effectiveness in eliminating retained and/or regenerating cortical cells, as measured by scoring of Soemmerings rings, showed virtually no net change since the early 1980s. The intensity of Soemmerings ring was higher in the most recent specimens than in those in the early 1980s. CONCLUSION The results indicate that renewed attention to cortical cleanup in cataract surgery is warranted for significant reduction in incidence or the elimination of PCO. More attention to the hydrodissection (cortical cleaving hydrodissection) step of the procedure is likely a practical, immediately implementable, and inexpensive remedy.

Surgical prevention of posterior capsule opacification. Part 3: Intraocular lens optic barrier effect as a second line of defense.

PURPOSE To emphasize an important aspect of preventing posterior capsule opacification (PCO), the barrier effect established by the optic of a posterior chamber intraocular lens (PC IOL), and present a new classification regarding capsular bag status after extra-capsular cataract extraction, including phacoemulsification. SETTING Center for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA. METHODS This analysis included 150 consecutive eyes obtained postmortem with United States-manufactured PC IOLs including (1) poly(methyl methacrylate), (2) silicone, and (3) hydrophobic acrylic designs that were accessioned in the Center from September 1995 to January 1, 1998. Gross photographs from behind (Miyake-Apple views) were taken and serial histologic sections prepared. RESULTS Microscopic analysis of the 150 eyes showed that the morphologic appearance of the capsular bag could be grouped into 2 categories: (1) those with little or no evidence of retained cortical material and cells, and (2) those with retained cortical material and cells in which a Soemmerings ring formed. With the latter, when a distinct barricade to cellular migration created by the IOL optic was noted, 2 discrete configurations occurred, depending on the different geometries of the optic components. With a classic biconvex optic with a curved and tapered edge, in many instances some ingrowth of cells proceeded posteriorly around the edge of the IOL optic in the direction of the central axis. With a lens optic that had a squared, truncated, and relatively thick edge, there was often abrupt termination of cells at the peripheral edge of the optic. The posterior capsule subtending the entire optic zone was therefore relatively or totally cell free. CONCLUSIONS The barrier effect of the IOL optic appears to be of critical importance in retarding ingrowth of cells, functioning as a second line of defense when cortical cleanup is incomplete. Analysis of PC IOLs obtained postmortem showed that a square, truncated optic edge seemed to provide the maximum impediment to cell growth behind the IOL optic.

Postoperative deposition of calcium on the surfaces of a hydrogel intraocular lens

OBJECTIVE To report clinical, pathological and histochemical features of 5 Hydroview intraocular lenses (IOLs) explanted from five patients who had visual disturbances caused by postoperative deposits on the lens surfaces. DESIGN Noncomparative small case series with clinicopathologic and histochemical correlations. PARTICIPANTS Five hydrophilic IOLs explanted from five different patients. All patients presented with decreased visual acuity and glare circa 12 months after uneventful phacoemulsification and IOL implantation, associated with a red-brown granularity on the optical surfaces of the IOLs. METHODS The lenses were explanted, fixed in buffered formaldehyde and examined by gross and light microscopy. MAIN OUTCOME MEASURES Staining of the IOLs with 1% alizarin red and with the von Kossa method (both stains for calcium). Two additional IOLs were also stained and included as controls. RESULTS The optical surfaces of all five IOLs were covered by a layer of irregular granular deposits, composed of multiple fine, translucent spherical-ovoid granules. The deposits stained positive for calcium in all cases. No deposit or positive staining was observed on the IOLs haptics. Staining of the control IOLs was also negative. CONCLUSION This is the first histopathological report of calcified deposits on the surfaces of this hydrogel IOL model. Further studies on other similar cases with this lens should be done to determine the incidence and possible mechanisms of this phenomenon.

Adhesion of fibronectin, vitronectin, laminin, and collagen type IV to intraocular lens materials in pseudophakic human autopsy eyes. Part 2 : Explanted intraocular lenses

Purpose: To evaluate fibronectin, vitronectin, laminin, and collagen type IV adhesion to poly(methyl methacrylate) (PMMA), silicone, hydrophobic soft acrylate, and hydrogel intraocular lenses (IOLs) in human pseudophakic autopsy eyes. Setting: Center for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA. Methods: Thirty‐two autopsy eyes containing PMMA, silicone, soft acrylate, or hydrogel IOLs were assessed. The IOLs were explanted from the capsular bag, and both sides of the IOLs were immunohistochemically stained for fibronectin, vitronectin, laminin, or collagen type IV. The number of cells on the IOL surfaces was counted. The capsular bag from 1 eye containing a soft acrylate IOL was examined for fibronectin and vitronectin. Results: Hydrophobic soft acrylate IOLs had significantly more fibronectin adhering to their surfaces than PMMA (P < .01) or silicone (P < .01) IOLs, as well as more vitronectin. Silicone IOLs had more collagen type IV adhesion than the other IOLs (P < .05–.06). Collective protein adhesion differed significantly between soft acrylate IOLs and PMMA and silicone IOLs, but not between PMMA and silicone IOLs. Conclusions: The greater amount of protein on the hydrophobic soft acrylate (AcrySof®) IOLs seems to support an adhesive mechanism for their attachment to the capsular bag. Fibronectin and vitronectin have functional domains to bind them to lens epithelial cells and the collagenous capsule. This kind of attachment could be a true bioactive bond and may be 1 reason the PCO and neodymium:YAG capsulotomy rates are lower in eyes with a soft acrylate IOL.

Adhesion of fibronectin, vitronectin, laminin, and collagen type IV to intraocular lens materials in pseudophakic human autopsy eyes: Part 1: histological sections

Purpose: To evaluate fibronectin, vitronectin, laminin, and collagen type IV adhesion to poly(methyl methacrylate) (PMMA), silicone, hydrophobic soft acrylate, and hydrogel intraocular lenses (IOLs) in pseudophakic human autopsy eyes. Setting: Center for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA. Methods: Thirty‐eight autopsy eyes containing PMMA, silicone, hydrophobic acrylate, or hydrogel IOLs were assessed. Histological sections were prepared from each eye, and immunohistochemical analyses were performed for fibronectin, vitronectin, laminin, and collagen type IV. One hundred fifty‐two specimens were analyzed. Results: A sandwich‐like structure (anterior or posterior capsule/fibronectin/1 cell layer/fibronectin/IOL surface) was seen in 12 of 14 autopsy eyes with soft acrylate IOLs, 3 of 10 with a PMMA IOL (P = .0094), 1 of 10 with a silicone IOL (P = .0022), and 0 of 4 with a hydrogel IOL (P = .0041). The thicker fibrocellular tissue on the inner surface of the anterior or posterior capsule that was in contact with silicone IOLs was lined with collagen type IV. Vitronectin and laminin were not found at the fibrocellular tissue–IOL interface in any specimen. Conclusions: This study seems to confirm the sandwich theory of posterior capsule opacification in eyes with an IOL and suggests that fibronectin may be the major extracellular protein responsible for the attachment of hydrophobic soft acrylate (AcrySof®) IOLs to the capsular bag. This may represent a true bioactive bond between the IOL and lens epithelial cells or between the IOL and the capsular bag and may be one reason the PCO and neodymium:YAG capsulotomy rates are lower in eyes with a soft acrylate IOL.

Anterior capsule opacification: Correlation of pathologic findings with clinical sequelae

OBJECTIVE To evaluate the degree of anterior capsule opacification (ACO) in human eyes obtained postmortem containing various rigid and foldable posterior chamber intraocular lens (PC-IOL) designs and compare the findings with clinical sequelae of capsular shrinkage. DESIGN Comparative autopsy tissue study with clinicopathologic correlations. MATERIALS Three hundred formalin-fixed human eyes containing the following PC-IOL styles were analyzed: (1) one-piece polymethyl methacrylate (PMMA) optic-PMMA haptic (n = 50), one-piece silicone-plate IOL, with large (2) or small (3) fixation holes (n = 35), (4) three-piece PMMA optic-Prolene haptic (n = 50), (5) three-piece acrylic optic-PMMA haptic (n = 55), three-piece silicone optic with PMMA (6) or polyimide (7) haptics (n = 30), and (8) three-piece silicone optic-Prolene haptic (n = 80) lenses. TESTING The eyes were sectioned in the equatorial plane for gross examination of the capsular bag from a posterior view. The cornea and iris were then excised for evaluation from an anterior view. MAIN OUTCOME MEASURES ACO was scored in each eye from 0 to IV, according to the degree/area of capsule opacification. Capsulorrhexis size and IOL decentration were measured with calipers. RESULTS The overall differences among the IOL groups regarding the three parameters were significant (ACO score: P < 0.001; capsulorrhexis diameter: P = 0.036; IOL decentration: P = 0.012). Mean ACO scores were highest with the large- and small-hole one-piece silicone-plate lenses (2.543 +/- 0.950) and lowest with the three-piece acrylic optic-PMMA haptic lenses (0.600 +/- 0.710). Of 10 cases of capsulorrhexis phimosis observed in the study, 7 cases were associated with three-piece silicone optic-Prolene haptic lenses, which also presented the highest mean decentration (0.375 +/- 0.601 mm). CONCLUSIONS Our results confirm previous histopathologic observations that the rate of ACO is the lowest with acrylic lenses and higher with plate-haptic silicone IOLs. Nevertheless, clinical sequelae of capsular shrinkage are also very important with three-piece silicone optic-Prolene haptic designs. Thus, IOL material and design are significant factors in the development of ACO, but they ultimately also influence the clinical presentation of capsular shrinkage.

Dense opacification of the optical component of a hydrophilic acrylic intraocular lens A clinicopathological analysis of 9 explanted lenses

Purpose: To report clinical, pathological, histochemical, ultrastructural, and spectrographic analyses of explanted hydrophilic acrylic intraocular lenses (IOLs) obtained from patients who had visual disturbances caused by postoperative opacification of the lens optic. Setting: Center for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA, and Ege University, Alsancak Izmir, Turkey. Methods: Nine hydrophilic IOLs (SC60B‐OUV, MDR Inc.) were explanted from 9 patients with decreased visual acuity. Most patients became symptomatic approximately 24 months after uneventful phacoemulsification and IOL implantation. Opacification was noted and appeared clinically to be associated with a fine granularity within the substance of the IOL optic. The IOLs were forwarded to the center and examined by gross and light microscopy. Full‐thickness cut sections of the optics were stained with 1% alizarin red and the von Kossa method (special stains for calcium). Some were submitted for scanning electron microscopy and energy dispersive x‐ray spectroscopy. Results: Microscopic analyses revealed multiple fine, granular deposits of variable sizes within the lens optics, usually distributed in a line parallel to the anterior and posterior curvatures of the optic, with a clear zone just beneath the optic surface. The deposits stained positive with alizarin red and the von Kossa method. Energy dispersive x‐ray spectroscopy of the internal substance of sectioned IOLs demonstrated the presence of calcium within the deposits. Conclusion: This is the first clinicopathological report of optic opacification occurring with this hydrophilic acrylic IOL model. Studies of similar cases with this lens should be done to determine the incidence and possible mechanisms of the phenomenon.

Anterior capsule opacification: a histopathological study comparing different IOL styles.

OBJECTIVE To compare the degree of anterior capsule opacification (ACO) in human eyes obtained post-mortem containing various rigid and foldable posterior chamber intraocular lens (PC-IOL) designs. DESIGN Comparative autopsy tissue study with clinicopathologic correlations. MATERIALS Four hundred sixty human globes containing the following PC-IOL styles were analyzed: (1) one-piece polymethylmethacrylate (PMMA) optic-PMMA haptic (n = 50), (2) one-piece silicone-plate IOL, large hole (n = 40), (3) one-piece silicone-plate IOL, small hole (n = 67), (4) three-piece PMMA optic-PMMA/Prolene haptic (n = 51), (5) three-piece acrylic optic-PMMA haptic (n = 96), (6) three-piece silicone optic-PMMA haptic (n = 24), (7) three-piece silicone optic-polyimide haptic (n = 40), and (8) three-piece silicone optic-prolene haptic (n = 92). TESTING The globes were sectioned in the equatorial plane for gross examination and then processed through paraffin; sectioned, and stained with hematoxylin-eosin, periodic acid-Schiff, and Massons trichrome stains; and examined by light microscopy. MAIN OUTCOME MEASURES Anterior capsule opacification was scored in each eye by grading the histologic sections from 0 to III, according to the amount (thickness) of proliferative tissue and cells measured in sagittal sections on the inner surface of the anterior capsule at the capsulorhexis margin. RESULTS The difference among the eight groups was significant (P < 0.0001). Mean ACO scores were highest with the large and small hole one-piece silicone-plate lenses (1.77 +/- 0.86 and 1.28 +/- 0.77, respectively). The lowest mean score was observed in the group of three-piece acrylic optic-PMMA haptics lenses (0.51 +/- 0.52). CONCLUSIONS Our results confirm previous clinical observations that the rate of ACO is relatively high with plate-haptic silicone IOLs. The lowest rate was noted with the three-piece acrylic optic-PMMA haptic IOL. The IOL design and IOL material are significant factors in the development of ACO.

Dye-enhanced cataract surgery: Part 1: anterior capsule staining for capsulorhexis in advanced/white cataract

PURPOSE To evaluate anterior capsule staining using 3 dyes to perform continuous curvilinear capsulorhexis (CCC) in postmortem human eyes with advanced/white cataract. SETTING Center for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA. METHODS In experimental closed-system surgery, CCC was performed in 12 postmortem human eyes with cataract after the anterior capsule was stained with 3 capsule dyes (fluorescein sodium 2%, indocyanine green [ICG] 0.5%, and trypan blue 0.1%). Two commonly used techniques for capsule staining were also compared: staining within an air bubble and intracameral subcapsular injection of dye. RESULTS In all globes, CCC was uneventful using the 3 dyes and with both techniques. With the intracameral subcapsular injection, the dye remained trapped in the subcapsular space in contact with the posterior surface of the anterior capsule, allowing enough time to perform any maneuver. The staining provided by ICG, at the concentration used, was slightly superior to that of the other dyes. Leakage of fluorescein sodium into the vitreous cavity was seen using the Miyake-Apple posterior video/photographic technique. CONCLUSION Intracameral subcapsular injection of ICG allowed the easiest recognition of the capsular flap by staining the posterior surface of the anterior capsule and without leaking into the vitreous cavity.

Interlenticular opacification: clinicopathological correlation of a complication of posterior chamber piggyback intraocular lenses.

PURPOSE To present a clinicopathological correlation of 2 pairs of piggyback posterior chamber intraocular lenses (PC IOLs) explanted because of opacification between the lens optics. SETTING Gayton Health Center, Eyesight Associates of Middle Georgia, Warner Robins, Georgia, and Center for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA. METHODS Two pairs of piggyback AcrySof lenses were explanted from 2 patients with significant visual loss related to opacification between the optics. They were submitted for pathological analysis. Gross and histopathological examinations were performed, and photomicroscopy was used to document the results. RESULTS Gross examination showed accumulation of a membrane-like white material between the lenses. Histopathological examination revealed that the tissue consisted of retained/proliferative lens epithelial cells (bladder cells or pearls) mixed with lens cortical material. CONCLUSION Piggyback PC IOLs were explanted in 2 cases because of a newly described complication, interlenticular opacification. Three surgical means may help prevent this complication: meticulous cortical cleanup, especially in the equatorial region; creation of a relatively large continuous curvilinear capsulorhexis to sequester retained cells peripheral to the IOL optic within the equatorial fornix; insertion of the posterior IOL in the capsular bag and the anterior IOL in the ciliary sulcus to isolate retained cells from the interlenticular space.