Effect of freezing on lens epithelial cell growth

Effect of anterior capsule polishing on the posterior capsule opacification–inhibiting properties of a sharp-edged, 3-piece, silicone intraocular lens

PURPOSE

To evaluate the long-term effects of anterior capsule polishing on regeneratory posterior capsule opacification (PCO), anterior capsule opacification (ACO), and fibrotic PCO with a silicone intraocular lens (IOL) with sharp optic edges.

SETTING

Department of Ophthalmology, Medical University of Vienna, Vienna, Austria.

METHODS

This prospective bilateral randomized patient- and examiner-masked clinical trial comprised 130 eyes of 65 patients with bilateral age-related cataract. All eyes had implantation of a 3-piece silicone IOL with a truncated, sharp-edged optic (CeeOn Edge 911A, Advanced Medical Optics). In 1 eye, the anterior capsule was extensively polished using an aspiration curette after phacoemulsification and cortex aspiration. Regenerative PCO was quantified objectively, while ACO and fibrotic PCO were graded subjectively 1, 2, 3, and 5 years postoperatively.

RESULTS

The mean ACO score was significantly lower in the eyes in which the anterior capsule had been polished (1 year, P<.02; 2 years, P<.03; 3 years, P<.01; 5 years, P<.01). The mean difference in regeneratory PCO and fibrotic PCO scores between the 2 groups was not statistically significant.

CONCLUSIONS

Three years after cataract surgery, eyes in which the anterior capsule had been polished had significantly less ACO. However, polishing did not lower PCO intensity when a sharp-edged CeeOn 911A IOL was implanted in the bag. Although results indicate that anterior capsule polishing may enhance the development of regeneratory PCO, this trend did not reach statistical significance.

Effect of anterior capsule polishing on fibrotic capsule opacification: three-year results

PURPOSE

To evaluate the long-term effect of anterior capsule polishing on anterior capsule opacification (ACO) and peripheral fibrotic posterior capsule opacification (PCO).

SETTING

Department of Ophthalmology, Medical University of Vienna, Vienna, Austria.

METHODS

This randomized double-blind study comprised 104 eyes of 52 patients with bilateral age-related cataract. All patients received round-edged intraocular lenses (IOLs); 26 received an SI-40 IOL (Advanced Medical Optics Inc.) in both eyes, and 26 received a Silens6 IOL (Domilens) in both eyes. Both IOLs consist of different silicone material and have different haptic angulation. The SI-40 IOL has 13.0 mm open-loop poly(methyl methacrylate) (PMMA) haptics angulated by 10 degrees. The Silens6 IOL has 12.5 mm open-loop PMMA haptics with no angulation. In 1 eye, the anterior capsule was extensively polished. The anterior capsule was left unpolished in the contralateral eye, which acted as a control. Digital slitlamp photographs of the ACO and fibrotic PCO were taken with a standardized technique for 3 years postoperatively. The intensity of ACO was measured objectively (score 0% to 100%) using Adobe Photoshop software. Fibrotic PCO was graded subjectively (score 0 to 4).

RESULTS

The mean ACO was 17% in the polished eyes and 26% in the control eyes (P = .0001). The mean fibrotic PCO score was 0.5 and 1.0, respectively (P = .0007). The mean ACO was 15% in the polished SI-40 eyes and 26% in the control SI-40 eyes (P = .01). It was 19% in the polished Silens6 eyes and 26% in the control Silens6 eyes (P = .003). The mean fibrotic PCO score was 0.4 in the polished SI-40 eyes and 1.1 in the control SI-40 eyes (P = .0006). It was 0.6 in the polished Silens6 eyes and 0.9 in the control Silens6 eyes (P = .08).

CONCLUSIONS

Three years after surgery, eyes in which the anterior capsule was extensively polished had less ACO and fibrotic PCO with both round-edged silicone IOLs. In eyes with Silens6 IOLs, however, the reduction in fibrotic PCO was not significant.

Anterior capsule opacification and lens epithelial outgrowth on the intraocular lens surface after curettage

PURPOSE

To evaluate the long-term difference in lens epithelial cell (LEC) outgrowth on the anterior surface of a hydrogel intraocular lens (IOL) after curettage of the entire or one half of the circumference of the anterior capsule.

SETTING

Department of Ophthalmology, University of Vienna, Austria.

METHODS

Forty eyes with senile cataract only were randomly assigned to Group A, which had curettage of the entire anterior capsule, or Group B, which had curettage of the nasal half of the anterior capsule. Rentsch capsule curettes (Geuder) were used, a straight one for the nasal half and a bent model for the temporal half. One surgeon performed all standardized procedures with a temporal clear corneal incision, phacoemulsification, and in-the-bag implantation of a hydrogel IOL. Two years after surgery, the anterior surface of the IOL was examined by specular microscopy in a double-blinded fashion, and LEC outgrowth was graded semiquantitatively. Anterior capsule opacification (ACO) was also graded semiquantitatively.

RESULTS

In Group A, grade 2 ACO was observed in 53% of patients and grade 1 ACO in 47%. Similar results were achieved in Group B (59% and 41%, respectively). Two years after IOL implantation, the typically circumferential monolayer outgrowth of LECs on the hydrogel IOL surface was present in 80% in Group A and 60% in Group B. The ongrowth was less dense in the other IOLs; however, no significant differences between the groups were observed.

CONCLUSIONS

Mechanical removal of residual LECs with a Rentsch capsule curette from the entire or from one half of the anterior capsule did not reduce LEC outgrowth 2 years after IOL implantation. Furthermore, the ACO grade was not significantly different. Lens epithelial cell proliferation in the germinative region and consecutive migration might be the cause of this outgrowth.

Neodymium: YAG capsulotomy rates after phacoemulsification with silicone posterior chamber intraocular lenses

PURPOSE

To retrospectively evaluate the incidence of neodymium: YAG (Nd:YAG) laser capsulotomies for posterior capsule opacification (PCO) in eyes receiving one of two types of capsular-bag-fixated silicone posterior chamber intraocular lenses (IOLs) over 7 years.

SETTING

John Moran Eye Center, University of Utah, Salt Lake City.

METHODS

Four hundred eighty-eight eyes that had cataract extraction with a continuous curvilinear capsulorhexis and implantation of one of two kinds of silicone posterior chamber IOLs were evaluated to assess the incidence of PCO. One hundred thirty-nine received a one-piece, plate-type IOL (Staar) and 349, a three-piece, modified C-loop IOL (AMO).

RESULTS

With an average follow-up of 84.3 weeks in the Staar IOL group and 93.5 weeks in the AMO IOL group, the incidence of posterior Nd:YAG laser capsulotomy for PCO was 30.2% and 39.1%, respectively.

CONCLUSION

The incidence of Nd:YAG laser capsulotomy after phacoemulsification with implantation of a silicone posterior chamber IOL was still relatively high with long-term follow-up. Although the proportion of patients with a one-piece silicone IOL requiring Nd:YAG capsulotomy was less than that in the three-piece silicone IOL group, the difference was not statistically significant.

Effect of intraocular lens size on posterior capsule opacification after phacoemulsification

Posterior capsule opacification (PCO) is one of the most common complications of phacoemulsification with intraocular lens (IOL) implantation. This retrospective study evaluated the incidence of neodymium: YAG (Nd:YAG) laser capsulotomies for PCO in two groups of patients with different sizes of poly(methyl methacrylate) (PMMA), capsular bag-fixated IOLs. We evaluated 437 eyes that had phacoemulsification with continuous curvilinear capsulorhexis over a four-year period. Patients were placed in one of two groups, based on IOL size: large IOL (lens length 13.5 mm or greater) and small IOL (lens length less than 13.5 mm). In the large IOL group, 106 of 280 patients (38%) required YAG laser posterior capsulotomy; in the small IOL group, 25 of 157 patients (16%) did. This difference was statistically significant even though the average follow-up was 84.1 weeks in the large IOL group and 54.1 weeks in the small IOL group.

Posterior capsule opacification

A complication of extracapsular cataract extraction with or without posterior chamber intraocular lens (PC-IOL) implantation is posterior capsule opacification. This condition is usually secondary to a proliferation and migration of residual lens epithelial cells. Opacification may be reduced by atraumatic surgery and thorough cortical clean-up. Clinical, pathological and experimental studies have shown that use of hydrodissection, the continuous curvilinear capsulorhexis and specific IOL designs may help reduce the incidence of this complication. Capsular-fixated, one-piece all-polymethylmethacrylate PC-IOLs with a C-shaped loop configuration and a posterior convexity of the optic are effective. Polymethylmethacrylate loops that retain "memory" create a symmetric, radial stretch on the posterior capsule after in-the-bag placement, leading to a more complete contact between the posterior surface of the IOL optic and the taut capsule. This may help form a barrier against central migration of epithelial cells into the visual axis. Various pharmacological and immunological methods are being investigated but conclusive data on these modalities are not yet available.

Polishing the posterior capsule after extracapsular extraction of senile cataract

Posterior capsular polishing is performed to delay or prevent capsular opacification. To study its effectiveness, a prospective study of 412 patients with bilateral senile cataracts was conducted. Each patient had bilateral extracapsular cataract extraction with laser ridge, posterior chamber lens implantation. The right eye of each patient had posterior capsular polishing using the Tennessee-Freeman polisher. The posterior capsule in the left eye was not polished. All patients above the age of 80 years (22 patients) had bilateral opacification within 16 months postoperatively. For patients less than 80 years old (390 patients), the cumulative capsulotomy rate in the polished capsule group was 9.2% (36 eyes); in the unpolished capsule group the rate was 12.0% (47 eyes) for the same follow-up time (average 30 months). There was no statistical difference in the incidence of posterior capsular opacification between the polished and unpolished groups. Polishing the posterior capsule after lens cortex cleaning had no significant role in delaying or preventing capsular opacification.

Pathogenesis of posterior capsular opacification. Part II: Histopathological and in vitro culture findings

The most interesting sources of information about the pathogenesis of posterior capsular opacification seem to be histopathological studies and in vitro tissue cultures. Since our surgical technique is extracapsular cataract extraction, the explants we used for tissue culture consisted of the anterior capsule epithelial sheet without the equatorial germinative zone. We successfully overcame several problems by using the autologous plasma clot culture method. This medium, considered the optimal one for this type of culture, allowed us to study the heterogeneous behavior of the epithelial cells in culture. Using the plasma clot culture method, we were able to demonstrate in vitro fibroblastic transformation of the epithelial cells. Histopathological findings of particular cases of posterior capsule opacification and immunohistochemistry of the human lens are also reported.

Capsular bag distension after endophacoemulsification and posterior chamber intraocular lens implantation

Six cases of capsular bag distension after capsulorhexis, endophacoemulsification, and posterior chamber intraocular lens (IOL) implantation are presented. Five cases had prominent posterior subcapsular cataracts preoperatively. In three cases, the anterior chamber depths were shallower and the apparent refractive errors were more myopic than normal after surgery. All six cases exhibited an apparent early complete sealing of the anterior capsular remnant against the anterior IOL optic. In each case, the capsular bag contained moderate particulate debris and flare while the adjacent vitreous and anterior chambers were clear. I suspect the particles are epithelial cell and cortical debris suspended in a fluid comprising lens epithelial protein, cellular breakdown products, balanced salt solution, and water. Five cases have received no specific treatment. In one case, a neodymium:YAG laser anterior capsulotomy allowed a forward egress of fluid from the distended capsular bag and a return to normal pseudophakic anatomy.