Posterior Capsule Opacification and Nd:YAG Rates with Two Acrylic Intraocular Lenses after Age-Related Cataract Treatment: Three-year Results

[Influence of models of hydrophobic acrylic intraocular lenses on the development of posterior lens capsule opacifications (preliminary results)]

The search for optimal design and material of the intraocular lens (IOL) that would prevent posterior capsule opacification (PCO) is still a relevant problem.

PURPOSE

To compare the influence of three models of hydrophobic acrylic IOLs on the development of PCO within one year after phaco surgery.

MATERIAL AND METHODS

The study included 72 patients (91 eyes) who were followed up for 12 months after implantation of one of three models of posterior chamber hydrophobic acrylic IOLs: MIOL-2 (Reper-NN, Russia, 24 eyes, 1^st group), SA60AT and US60MP (Alcon, USA, 41 and 26 eyes, 2^nd and 3^rd groups, respectively). Posterior capsule images were taken and then processed with the EPCO 2000 (Evaluation of Posterior Capsular Opacification) software. The area of posterior capsule adjacent to the center of IOL's optic of 4.0 mm in diameter was estimated. PCO score was calculated as the weighted sum of opacification areas multiplied by the degree (from 0 to 4).

RESULTS

Within 1 year of the follow-up, mean visual acuity was at least 1.0 (20/20). Significant PCO progression was observed as early as 3 months after surgery. Despite that, opacification density in all three groups at every follow-up visit did not exceed grade 2; maximal PCO score (0.0315, median) was seen 12 month after surgery in the 1^st group. At the same time, differences in PCO score between the groups were not significant. Nd:YAG laser posterior capsulotomy was performed only in one patient from the 1^st group 12 month after surgery. Difference in the percentage of clear posterior capsules was significant only 12 month after surgery between the 1^st and 3^rd groups (p=0.024).

CONCLUSION

All three models of hydrophobic acrylic IOLs showed comparably high vision outcomess during 12 months of the follow-up with somewhat better PCO score and percentage of clear posterior capsules in eyes with US60MP.

Posterior Capsule Opacification after Cataract Surgery in Children Over Five Years of Age with Square-edge Hydrophobic versus Hydrophilic Acrylic Intraocular Lenses: A Prospective Randomized Study

OBJECTIVE

To compare the effects of hydrophobic and hydrophilic materials in square-edged acrylic intraocular lenses (IOLs) on the development of posterior capsule opacification (PCO) after pediatric cataract surgery.

METHODS

Patients were randomly assigned to group 1 (hydrophobic acrylic square-edged IOLs; 13 eyes) or group 2 (hydrophilic acrylic square-edged IOLs; 13 eyes). The study evaluated PCO rates using Evaluation of Posterior Capsule Opacification (EPCO) 2000 software at one, three, six and 12 months postoperatively. Postoperative measurements also included corrected distance visual acuity (CDVA), neodymium:yttrium-aluminum-garnet (Nd:YAG) capsulotomy and postoperative complications other than PCO.

RESULTS

Both groups had significant increases in PCO rates after one year. Comparison of the groups showed no significant differences in the EPCO scores at three (group 1, 0.007±0.016 vs group 2, 0.008±0.014; p=0.830), six (group 1, 0.062±0.103 vs group 2, 0.021±0.023; p=0.184), or twelve months postoperatively (group 1, 0.200±0.193 vs group 2, 0.192±0.138; p=0.902). We also found no significant group differences regarding the change (delta, Δ) in EPCO scores between three and six months (group 1, 0.055±0.09 vs group 2, 0.013±0.02; p=0.113) or between six and twelve months postoperatively (group 1, 0.139±0.14 vs group 2, 0.171±0.14; p=0.567). Twenty-three percent of patients required Nd:YAG capsulotomy at the twelve-month visit.

CONCLUSIONS

No differences in PCO rates were found between hydrophobic and hydrophilic acrylic square-edged IOLs in children between five and twelve years of age at one year of follow-up.

Comparative study of induced changes in effective lens position and refraction after Nd:YAG laser capsulotomy according to intraocular lens design

Purpose

To evaluate and compare the changes in refraction and effective intraocular lens (IOL) position between a plate-haptic IOL and a c-loop single-piece IOL after neodymium-doped yttrium aluminium garnet (YAG) laser posterior capsulotomy.

Methods

In a prospective study, anterior chamber depth and subjective refraction were measured in 110 pseudophakic eyes from 110 patients, before and 1 month after YAG laser capsulotomy. Patients were divided into 2 groups according to the IOL design: group 1 (plate-haptic acrylic hydrophilic AT LISA tri 839MP^®) and group 2 (c-loop acrylic hydrophobic single-piece AcrySof^® SA60AT). Lens position was obtained through optical coherence biometry (Biograph WaveLight OB820^®).

Results

YAG laser capsulotomy was performed 37.8±9.8 months after surgery in group 1 and 40.6±8.6 months in group 2 (p=0.125). Significant changes were found in the lens effective position after treatment in the 2 groups. The YAG posterior capsulotomy led to a change of anterior chamber depth in group 1 from 4.03±0.32 mm to 3.86±0.34 mm (p=0.02) and in group 2 from 4.03±0.37 mm to 4.14±0.45 mm (p=0.025). After YAG laser posterior capsulotomy, no significant changes were observed in mean spherical equivalent, sphere or cylinder for both groups (p>0.05).

Conclusion

YAG laser posterior capsulotomy can induce a significant change in the IOL position according to the IOL type; however, the refractive change after treatment is clinically insignificant.

Human lens epithelial cell apoptosis and epithelial to mesenchymal transition in femtosecond laser-assisted cataract surgery

AIM

To evaluate human lens epithelium cell apoptosis and epithelial to mesenchymal transition (EMT) induced by femtosecond laser in femtosecond laser assisted cataract surgery (FLACS).

METHODS

Sixty cataract patients with N2 to N3 stage according to the LOCS III were enrolled in this study and divided into three groups randomly: FLACS1 group (cataract surgery by FLACS with LenSx), FLACS2 group (cataract surgery by FLACS with LensAR) and manual group (cataract surgery by phacoemulsification). Patients in two FLACS groups performed anterior capsulotomy by LenSx or LensAR laser system. Patients in the manual group were performed continuous curvilinear capsulorrhexis (CCC) manually. The anterior capsules were fixed right after moved out of eye. Hematoxylin-eosine staining, immunofluorescence staining and real-time PCR were performed in order to observe human lens epithelium cells changes after cataract surgery.

RESULTS

The capsule cutting edge was shown irregularity and roughness in two FLACS groups and smooth edge in manual capsulotomy by pathologic staining. Irregularities of the cell configuration with partly swollen and destroyed nuclei were observed in two FLACS groups. Femtosecond laser could induce a significantly higher cell apoptosis in human lens epithelium cell than manually performed CCC (P<0.05). Lens epithelium cells apoptosis were correlated with femtosecond laser duration according to Pearson correlation analysis. Decreased N-cadherin expression, alpha-SMA and FSP-1 level in two FLACS groups showed the inhibition of cell EMT.

CONCLUSION

Femtosecond laser may affect the apoptosis and EMT of lens epithelium cells which are under the peeled central lens capsule.