Nationwide multicentre comparison of preoperative biometry and predictability of cataract surgery in Japan.

AIM: To compare the preoperative biometric data and the refractive accuracy of cataract surgery among major surgical sites in a nationwide multicentre study. METHODS: We prospectively obtained the preoperative biometric data of 2143 eyes of 2143 consecutive patients undergoing standard cataract surgery at major 12 facilities and compared the preoperative biometry as well as the postoperative refractive accuracy among them. RESULTS: We found significant differences in most preoperative variables, such as axial length (one-way analysis of variance, p=0.003), anterior chamber depth (p<0.001), lens thickness (p<0.001) and central corneal thickness (p<0.001), except for mean keratometry (p=0.587) and corneal astigmatism (p=0.304), among the 12 surgical sites. The prediction error using the Sanders-Retzlaff-Kraff/Theoretical (SRK/T formula was significantly more hyperopic than that using the Barrett Universal II formula (paired t-test, p<0.001). The absolute error using the SRK/T formula was significantly larger than that using the Barrett Universal II formula (p=0.016). The prediction error using the SRK/T formula was significantly more hyperopic than that using the Barrett Universal II formula at 10 of 12 institutions, but significantly more myopic at one institution. The absolute error using the SRK/T formula was significantly larger than that using the Barrett Universal II formula at 4 of 12 institutions but significantly smaller at two institutions. CONCLUSIONS: Regional divergences of the preoperative biometry were not necessarily negligible, and the optimised intraocular lens power calculation formula was individually different among the 12 facilities. Our findings highlight the importance of individual optimisation of these formulas at each facility, especially in consideration of these biometric variations.Trial registration numberClinical Trial Registry; 000039976.

Influence of intraocular lens implantation on anterior capsule contraction and posterior capsule opacification.

PURPOSE: To evaluate whether and how intraocular lens (IOL) implantation influences the development of anterior capsule contraction and posterior capsule opacification (PCO). SETTING: Department of Ophthalmology, Dokkyo Medical University, Mibu, Tochigi, Japan. DESIGN: Experimental study. METHODS: Phacoemulsification was performed in 8-week-old white rabbits. A hydrophobic acrylate IOL (12.5 mm) (YA-60BBR) was implanted in 1 eye and no IOL was implanted in the fellow eye. Slitlamp microscopy and anterior segment analysis were performed to evaluate anterior capsule contraction after the surgery. Four weeks postoperatively, sections of the eyes were made, and the thickness of the proliferated lens epithelial cell (LEC) layer at the posterior capsule was measured to assess the PCO. In addition, LECs from white rabbits were cultured in medium containing 50% aqueous humor or in medium containing 50% saline to determine the influence of the aqueous humor on LECs and to compare the degree of LEC proliferation. RESULTS: Starting 2 weeks after surgery, anterior capsule contraction progressed more significantly in the IOL group than in the group without IOLs. Four weeks postoperatively, LEC thickness at the posterior capsule was significantly less in the group without IOLs than in the IOL group. In the culture study, LEC proliferation was more inhibited in the aqueous humor group than in the saline group. CONCLUSIONS: Progression of anterior capsule contraction and PCO is less likely in aphakic eyes than in IOL-implanted eyes. The mechanism of prevention may involve aqueous humor-induced inhibition of LEC proliferation.

Histologic findings of recipient corneas obtained via deep anterior lamellar keratoplasty.

PURPOSE: We sought to investigate the histologic findings of recipient corneas obtained via deep anterior lamellar keratoplasty (DALK). METHODS: The histology of three recipient corneas obtained from patients during DALK was investigated. In all cases, the Descemet membrane was successfully exposed without any perforation during surgery. The isolated corneal tissue was stained with hematoxylin-eosin and periodic acid-Schiff. In two cases, the tissues were examined using a transmission electron microscope. RESULTS: In one cornea obtained via DALK, only the corneal stroma was observed, and the Descemet membrane was not confirmed. In another case, the recipient cornea was detached within the Descemet membrane. In the third cornea, the banded layer membrane was partially confirmed. CONCLUSIONS: These findings suggest that the recipient corneas separated at different layers during the DALK procedure. With our surgical technique, the detachment of the Descemet membrane may occur at a mechanically weak segment. This separation site may not be between the Descemet membrane and the corneal stroma.

Analysis of surface whitening of extracted hydrophobic acrylic intraocular lenses.

PURPOSE: To identify the cause of light scattering on the surface (ie, whitening) of extracted AcrySof intraocular lenses (IOLs). SETTING: Department of Ophthalmology, Dokkyo Medical University, Tochigi, Japan. METHODS: Dislocated IOLs extracted from 3 patients were stored and the IOL surfaces examined under light microscopy. The effect of whitening on visual function was evaluated by measuring light transmission with a spectrophotometer. To determine the cause of opacification, the IOLs were examined for calcium phosphate deposits using an electron probe X-ray microanalyzer. The IOL surface, including the presence of organic deposits and evidence of hydrolysis, was also examined by Fourier-transform infrared spectrophotometry. The IOLs were then dried, immersed again in physiological saline, and serially examined for changes in opacification. RESULTS: The optic surfaces of all IOLs had opacification due to whitening. Light transmission in the visible range of 360 to 800 nm was 4% less than that of unused IOLs. The X-ray microanalysis showed no calcium phosphate deposits. Fourier-transform infrared spectrophotometry of the IOL optic material showed no evidence of hydrolysis. Opacification disappeared after the IOLs were dried and then reappeared over time when the IOL was immersed again in physiologic saline. CONCLUSIONS: The findings strongly suggest that whitening of the hydrophobic acrylic IOL was due to trace water molecules that infiltrate the optic. Within the 3-dimensional network of the polymeric lens material, the molecules are too small to form observable voids but can form water aggregates of sufficient size to scatter visible light, causing opacification (ie, whitening).

Efficacy of ophthalmic nonsteroidal antiinflammatory drugs in suppressing anterior capsule contraction and secondary posterior capsule opacification.

PURPOSE: To evaluate the efficacy of ophthalmic nonsteroidal and steroidal antiinflammatory drugs in preventing anterior capsule contraction and secondary posterior capsule opacification (PCO) using an experimental cataract model. SETTING: Department of Ophthalmology, Dokkyo Medical University, Tochigi, Japan. METHODS: Eight-week-old albino rabbits weighing about 2 kg each had phacoemulsification and intraocular lens implantation. After surgery, the rabbits were divided into 3 treatment groups: diclofenac sodium ophthalmic solution, bromfenac sodium ophthalmic solution, and betamethasone ophthalmic solution. In each group, the ophthalmic solution was applied to the left eye of each rabbit twice daily; the right eye served as an untreated control. To evaluate anterior capsule contraction, the percentage of incised anterior capsule opening area was calculated on diaphanoscopic images obtained with an EAS-1000 anterior segment analyzer. For evaluation of PCO, a tissue section was stained with hematoxylin-eosin and observed under a light microscope. The PCO was quantified on the basis of the thickness of the lens epithelial cell layer on the central subcapsular area and compared among groups. RESULTS: Fifteen albino rabbits were used in the study. Treatment with diclofenac sodium and bromfenac sodium ophthalmic solution prevented progression of anterior capsule contraction and PCO. Treatment with bromfenac ophthalmic solution did not prevent either complication. CONCLUSION: Postoperative treatment with ophthalmic nonsteroidal antiinflammatory drug solutions prevented anterior capsule contraction and PCO in rabbit eyes.

Comparison of anterior capsule contraction between 5 foldable intraocular lens models.

PURPOSE: To compare anterior capsule contraction in cataract patients having implantation of 1 of 5 foldable intraocular lens (IOL) models and evaluate lens epithelial cell (LEC) adhesion to each model. SETTING: Department of Ophthalmology, Dokkyo Medical University, Tochigi, Japan. METHODS: This study comprised 115 patients (126 eyes) without systemic or ocular complications who had phacoemulsification with IOL implantation. The eyes were randomly assigned to receive 1 of the following IOLs: acrylic MA60BM (Alcon), SA60AT (Alcon), AR40e (Advanced Medical Optics), or YA-60BBR (Hoya) or a silicone AQ310NV (Canon). Two weeks and 1, 3, and 6 months postoperatively, the anterior capsule opening area was measured using an anterior segment analysis system (EAS-1000, Nidek) and the percentage of anterior capsule contraction was compared for each postoperative period and IOL. Cell adhesion to each IOL type was evaluated using LECs from albino rabbits. RESULTS: The mean age of the patients was 73.6 years +/- 5.6 (SD). Eyes with the AQ310NV and AR40e IOLs had statistically significantly greater anterior capsule contraction. The rabbit study showed statistically significantly less LEC adhesion on these 2 IOL models. CONCLUSIONS: Anterior capsule contraction was significantly greater with the AQ310NV and AR40e IOLs than with the other IOLs. Results indicate that cell adhesion to the IOL is an important factor in preventing anterior capsule contraction.

An in vitro model of posterior capsular opacity: SPARC and TGF-beta2 minimize epithelial-to-mesenchymal transition in lens epithelium.

PURPOSE: This report presents a novel model for studies of extracellular matrix (ECM) in posterior capsular opacification (PCO) in vitro. Lens epithelial cells (LEC) were cultured with an intraocular lens (IOL) on a surface of type IV collagen in an evaluation of the importance of the ECM-cell interaction in formation of PCO. Abnormal migration, proliferation, and expression of proteins associated with the epithelial-to-mesenchymal transition (EMT) that characterizes PCO were observed in the presence and absence of the matricellular protein SPARC (secreted protein, acidic and rich in cysteine), which regulates matrix-cell interactions. METHODS: The model for PCO in vitro consisted of an IOL placed on a membrane coated with collagen IV, a major constituent of the lens capsule. LECs from the lenses of wild-type (WT) and SPARC-null (SP-null) mice were cultured in the presence or absence of 10 ng/mL TGF-beta2 and 20 mug/mL recombinant human SPARC (rhSP) for up to 6 days. The migration of LECs was quantified. Labeling with BrdU and the measurement of DNA synthesis were assays for cell proliferation. Expression of the EMT markers, collagen type I, fibronectin, and alpha-smooth muscle actin were assessed using immunocytochemistry or Western immunoblots. RESULTS: LEC migration, proliferation, and the synthesis of EMT markers were enhanced in SP-null compared with WT LECs. TGF-beta2 inhibited the migration and proliferation of both WT and SP-null LECs in the presence of rhSP. TGF-beta2 increased the production of collagen type I, fibronectin, and alpha-SMA. The responses of SP-null LECs were rescued by the addition of recombinant human (rh)SP. CONCLUSIONS: A simple IOL culture system was useful for the evaluation of the effects of SPARC and TGF-beta2 on PCO in vitro. The action of TGF-beta2 on LEC migration and proliferation is influenced by SPARC, a regulator of matrix-cell interactions. The results indicate a functional intersection between pathways activated by TGF-beta2 and SPARC in the formation of PCO.