Entomopathogenic fungus Beauveria bassiana-based bioinsecticide suppresses severity of powdery mildews of vegetables by inducing the plant defense responses

The entomopathogenic fungus Beauveria bassiana is used commercially as a microbial insecticides against a wide range of agricultural insect pests. Some strains of B. bassiana protect the plants from pathogens, but the underlying mechanisms are largely unknown. Here, we found that prophylactic sprays of commercial bioinsecticide Botanigard on cucumber, tomato, and strawberry plants suppressed the severity of economically damaging powdery mildews. On leaf surfaces, hyphal elongation and spore germination of cucumber powdery mildew, Podosphaera xanthii, were inhibited, but B. bassiana strain GHA, the active ingredient isolated from Botanigard, only inhibited hyphal elongation but had no effect on spore germination of P. xanthii. In addition, strain GHA suppressed powdery mildew symptoms locally, not systemically. Treatment with Botanigard and strain GHA induced a hypersensitive response (HR)-like cell death in epidermal cells of the cucumber leaves in a concentration-dependent manner and inhibited penetration by P. xanthii. Transcriptome analysis and mass spectrometry revealed that GHA induced expression of salicylic acid (SA)-related genes, and treatment with Botanigard and GHA increased the SA level in the cucumber leaves. In NahG-transgenic tomato plants, which do not accumulate SA, the biocontrol effect of tomato powdery mildew by GHA was significantly reduced. These results suggested that B. bassiana GHA induces SA accumulation, leading to the induction of HR-like cell death against powdery mildew and subsequent suppression of fungal penetration. Thus, Botanigard has the potential to control both insect pests and plant diseases.

Biocontrol Activity of Nonpathogenic Strains of Fusarium oxysporum: Colonization on the Root Surface to Overcome Nutritional Competition

Fusarium oxysporum is a soil-borne fungal pathogen that causes vascular wilts in a wide variety of crops. Certain nonpathogenic strains of F. oxysporum are known to protect crops against F. oxysporum pathogens. We assessed the biocontrol activities of nonpathogenic mutants of F. oxysporum ff. spp. melonis and lycopersici generated by disruption of the FOW2 gene, which encodes a Zn(II)2Cys6-type transcriptional regulator essential for their pathogenicity. Pre-inoculation of melon or tomato roots with strain ΔFOW2 conidia markedly reduced disease incidence caused by the parental wild-type strain in a concentration-dependent manner of conidial suspensions of ΔFOW2 strains. The biocontrol effect caused by the ΔFOW2 pre-inoculation lasted for at least 7 days. Pre-inoculation of melon roots with the wild-type or ΔFOW2 strain of F. oxysporum f. sp. lycopersici and nonpathogenic F. oxysporum strain also led to biocontrol activity against F. oxysporum f. sp. melonis, indicating that the biocontrol activity of ΔFOW2 strains is due to its nonpathogenic nature, not to the FOW2 disfunction. Conidial germination and hyphal elongation of only the wild-type strain were inhibited on melon root surface pre-inoculated with conidia of strains nonpathogenic to melon plants. Expression of defense-related genes was not significantly induced in roots and aboveground parts of melon seedlings preinoculated with ΔFOW2 conidia. Carbon source competition assay showed that nonpathogenic strains competed with the wild-type strain for a carbon source in soil. Strain ΔFOW2 also competed with the oomycete pathogen Pythium aphanidermatum for carbon source and protected melon plants from P. aphanidermatum. Our results suggest that the biocontrol activity of the nonpathogenic F. oxysporum strains used in this study mainly depends on their extensive colonization of the root surface and outcompeting pathogens for nutrients.

Identification and characterization of three microsporidian genera concurrently infecting a silkworm, Bombyx mori, in Brazil

Microsporidia are important entomopathogens known for infecting insects such as the silkworm (Bombyx mori) thus impairing global silk production. This study aimed to identify and characterize the microsporidia isolated from a diseased larva of silkworm, collected from a sericulture farm in southern Brazil. Identification was performed by phylogenetic analysis of the nucleotide sequences of the SSU rRNA genes. Characterization was performed by analyzing spore sizes, tissue tropism, internal and external symptoms, and pathogenicity against B. mori. Microsporidia belonging to three different genera were identified, namely, Endoreticulatus, Nosema and Tubulinosema. After inoculation of the mixed spores of the microsporidian isolates into B. mori larvae, a high prevalence of Tubulinosema spp. was observed. This isolate showed high prevalence on the silk glands and a late mortality, initially of around 10% until the 20th day post-inoculation but reaching 91.5% upon pupation. Therefore, we demonstrated that Tubulinosema spp. causes chronic infection with slow pathogenicity. We identified for the first time three different microsporidians concurrently infecting B. mori in Brazil. Tubulinosema is of particular interest because of its potential threat to silk production; it affects the formation of silk glands in B. mori while not presenting distinguishable external symptoms or causing the immediate death of these insects. Further studies focusing on this species, mainly regarding its life cycle within the host and the sublethal effects of surviving individuals, demonstrate the importance of describing it as a new species and improving the characterization of the disease in order to prevent its spread.

Epiphytic and endophytic colonisation of tomato plants by the entomopathogenic fungus Beauveria bassiana strain GHA

Beauveria bassiana, known for its entomopathogenic characteristics, is the most widely used biocontrol agent against many insect pests and may also be active against soil-borne pathogens. It inhabits the surfaces or inner tissues of various plant species without causing any visible signs or symptoms. Here we show that B. bassiana strain GHA, the active ingredient of a commercial microbial insecticide, colonises tomato plants. GHA grew on intact leaf surfaces of tomato in high humidity, but never entered stomata. Viable hyphae and conidia were detected, and the population on inoculated leaves significantly increased until 14 days after inoculation. On tomato leaves, GHA conidiated normally via conidiophores and phialides, and also via microcycle conidiation (conidiophores and phialides form directly from germ tubes and produce conidia). Hyphae were also detected inside the rachis, even more frequently after plant surfaces were scarified. These results suggested that B. bassiana strain GHA can grow epiphytically and endophytically on tomato plants.

Isolation of Metarhizium spp. from rhizosphere soils of wild plants reflects fungal diversity in soil but not plant specificity

Understanding the abundance and diversity of fungal entomopathogens associated with plant species is critical for improving their field efficacy as microbial insecticides. Metarhizium is a cosmopolitan entomopathogenic fungus, with some species in this genus showing rhizosphere competencies. This study sought to determine the abundance and diversity of Metarhizium spp. in rhizosphere soils of wild plants in a field in Japan. Metarhizium spp. were detected in 76.2% of 151 rhizosphere soil samples collected from 41 plant species using a plating method. The mean density of Metarhizium spp. in rhizosphere soils was 1.2 × 10⁴ colony forming units/g soil [base 10 logarithm of the mean = 4.06 (S.D. = 0.88)]. There was no significant difference in the densities and detection rates between Asteraceae and Poaceae as well as among two aster and one grass species. The fungal isolates were identified as five species, of which M. pingshaense was the most frequently detected and abundant species. No significant specific associations were recognised between the isolated Metarhizium spp. and the examined aster and grass species. Our findings demonstrated the high occurrence and abundance of M. pingshaense in rhizosphere soils of wild plants at the sampling site irrespective of host plant taxa.

Species associations and distributions of soil entomopathogenic fungi Metarhizium spp. in Japan

Metarhizium Sorokīn (Hypocreales: Clavicipitaceae) is a genus of facultative parasites of insects found in soils from various environments and is used for pest management. Understanding the habitat selection of Metarhizium spp. is critical to improve the efficacy and persistence of these fungi as microbial insecticides. This study sought to determine the habitat preferences of Metarhizium spp. in Japan. We identified 302 isolates of Metarhizium spp. as eight species by a combination of PCR–RFLP and phylogenetic analysis of DNA sequences. M. pingshaense was the predominant species in Japan and was most frequently isolated from both forest and agricultural environments. On the other hand, M. brunneum and M. pemphigi were comparatively restricted to forest environments. A similar species association was detected in a small area that was intensively investigated, where 7 species including 14 genotypes were isolated from soil. The results of this study have revealed different habitat preferences among Metarhizium spp. in Japan.

Comparison of the germination rates of Metarhizium spp. conidia from Japan at high and low temperatures

The knowledge of the growth characteristics of entomopathogenic fungi at different temperatures is very important for understanding their ecology and field efficacy as biological control agents. However, the relationships between their DNA-based phylogenetic tree classifications and growth characteristics at different temperatures have not been adequately investigated. In this study, we compared the phylogenetic relationships between Metarhizium anisopliae sensu lato and M. flavoviride isolates obtained from soils in various environments in Japan and the germination rates of their conidia on agar medium in hot and cold conditions. The results showed that the 89 Japanese isolates belonged to the clade of eight species, according to the molecular phylogenetic analysis. The germination rates of isolates belonging to the M. brunneum and M. flavoviride var. pemphigi clades were higher at lower temperatures (9·7-11·0°C) and lower at higher temperatures (34·3-35·2°C) compared with the other six species. The isolates of these two species originated from different geographical regions in Japan, despite their uniform germination characteristics. This study detected the clear interspecific differences in the in vitro germination characteristics of the Japanese isolates of Metarhizium spp. at two different temperature regimes.

SIGNIFICANCE AND IMPACT OF THE STUDY

The relationships between the growth characteristics and phylogenetic placements have not been adequately investigated in species of the entomopathogenic fungus Metarhizium. This study determined the relationships between the germination rates in hot and cold conditions and the phylogenetic placements of 89 Japanese soil isolates of Metarhizium spp. Fourteen isolates each of M. brunneum and M. flavoviride var. pemphigi, identified by molecular phylogenetic analysis, showed relatively high germination rates at lower temperatures and low germination rates at higher temperatures compared with isolates, which were identified as six other species. This study detected a strong relationship between the phylogenetic placements of Japanese Metarhizium spp. isolates and their in vitro germination characteristics.

[Influence of intraocular lens material and design on the development of posterior capsule opacification]

Based on the literature of 1999-2005, we attempted to clarify the influence of material and design of an intraocular lens (IOL) on the development of posterior capsule opacification (PCO) and identify the future problems to be solved. The sharp edge design of an IOL has significantly reduced PCO in recent years. Histopathological studies showed that a sharp capsular bend was formed at the sharp posterior optic edge, and the migration of lens epithelial cells was obviously inhibited at the site. Experimental and clinical studies suggest that the sharper the edge is, the sharper the capsular bend, and the greater the preventive effect, regardless of IOL material. The sharp capsule bend appears to represent a physical hindrance, which may induce contact inhibition of cell movement. How material participates in the preventive effect should be clarified in a future study. Thus, at the moment, the formation of capsular bend at the posterior optic edge appears to be the decisive criterion to evaluate the influence of IOL material and design on the development of PCO. Optimization of design and material of an IOL, which facilitates capsular bend formation as sharply and quickly as possible, may reduce PCO to a clinically negligible level.

Capsular bending ring to prevent posterior capsule opacification: 2 year follow-up

PURPOSE

To evaluate the preventive effect of a capsular bending ring on anterior and posterior capsule (PCO) opacification in a 2 year clinical study.

SETTING

Jinshikai Medical Foundation, Nishi Eye Hospital, Osaka, Japan.

METHODS

This study comprised 60 patients with senile cataract (35 women, 25 men) with a mean age of 69 years. An open poly(methyl methacrylate) capsular bending ring with a truncated edge profile designed to create a sharp bend in the equatorial capsule was implanted in 1 eye of patients with a hydroxyethyl methacrylate intraocular lens (IOL). The contralateral eye, which acted as a control, received an IOL but no ring. Patients were examined 6 months (n = 52), 1 year (n = 48), and 2 years (n = 42) postoperatively. Anterior capsule opacification was determined by slitlamp evaluation. Anterior capsule shrinkage (area within the capsulorhexis) and PCO were evaluated and scored using a computer software package for image analysis. Posterior capsule opacification was also measured by the rate of neodymium:YAG (Nd:YAG) capsulotomies.

RESULTS

Anterior capsule opacification and shrinkage were significantly less in eyes with the ring. The mean PCO score was 0.235 +/- 0.215 (SD), 0.287 +/- 0.200, and 0.398 +/- 0.248 with the ring and 0.530 +/- 0.190, 0.670 +/- 0.225, and 1.111 +/- 0.298 without the ring at 6 months, 1 year, and 2 years, respectively (P <.01 at each follow-up). An Nd:YAG laser capsulotomy was performed in 4 eyes with and 17 eyes without the ring after 2 years (P <.01).

CONCLUSIONS

The capsular bending ring significantly reduced anterior capsule fibrosis and shrinkage as well as PCO. The ring may be useful in patients who are at high risk of developing eye complications from capsule opacification that require Nd:YAG laser capsulotomy, in those expected to have vitreoretinal surgery and photocoagulation, and in cases of pediatric cataract.

Inhibition of lens epithelial cells by Fas-specific antibody activating Fas-Fas ligand system

PURPOSE

To detect cell specific apoptosis factors, Fas and Fas ligand, and the common intracellular apoptosis modulators, interleukin-1 beta converting enzyme (ICE)-like protease (caspase 1), Bcl-2, Bcl-xL and Bax in lens epithelial cells (LEC) of human cataracts. To study the effects of Fas-stimulating monoclonal antibody on inhibition of LEC proliferation.

METHODS

Reverse-transcriptase-polymerase chain reaction (RT-PCR) was used to detect Fas, Fas ligand, caspase 1, Bcl-2, Bcl-xL and Bax, after cDNA was synthesized from the total RNA isolated from human cataractous LEC obtained by capsulotomy during cataract surgery. Fas-stimulating monoclonal antibody was added at the concentrations of 10, 30, 100, 300 and 1000 ng/ml to the incubation medium of human cataractous LEC; and the specimens were incubated for 24 h at 37 degrees C with 5% CO(2) circulation and 100% humidity. The specimens were then stained with Hoechst 33342, and the number of apoptotic cells was counted.

RESULTS

Fas, caspase 1, Bcl-2, Bcl-xL and Bax mRNA were detected by RT-PCR. Fas ligand mRNA was not detected by RT-PCR. At each concentration, Fas-stimulating monoclonal antibody significantly inhibited LEC proliferation.

CONCLUSIONS

Human cataractous LEC expressed mRNA of Fas and various modulators of apoptosis pathways. Fas-stimulating monoclonal antibody may have the potential to prevent posterior capsule opacification after cataract surgery by inhibiting LEC proliferation.

Effect of round-edged acrylic intraocular lenses on preventing posterior capsule opacification

PURPOSE

To clarify the extent to which the adhesiveness of an acrylic material influences the formation of posterior capsule opacification (PCO).

SETTING

Jinshikai Medical Foundation, Nishi Eye Hospital, Osaka, Japan.

METHODS

Two types of AcrySof(R) intraocular lenses (IOLs) were prepared: round edged and tumbled. The AcrySof with round edges was implanted in 1 eye in a group of 4 rabbits and the tumbled IOL, in 1 eye in a group of 5 rabbits. In both groups, the contralateral eye received a conventional AcrySof with sharp optic edges. A histopathological examination was performed 3 weeks after surgery.

RESULTS

With the round-edged AcrySof IOL, no capsular bend formed at the optic edge and abundant lens epithelial cells (LECs) migrated posteriorly. With the sharp-edged AcrySof lens, a sharp capsular bend formed and LEC migration was significantly inhibited. In eyes with a tumbled IOL, a capsular bend was created, but it was less marked than that created by the sharp-edged lens and there was slightly more LEC migration posteriorly.

CONCLUSIONS

The AcrySof IOL lost its preventive effect on PCO when the optic was rounded. The effect of the AcrySof lens in preventing PCO is mainly a result of its rectangular, sharp-edged optic design. The acrylic material may play a complementary role by helping create a sharp capsular bend. Capsular bend formation is the key to the PCO preventive effect of an IOL.

Preventing lens epithelial cell migration using intraocular lenses with sharp rectangular edges

PURPOSE

To compare the preventive effect on posterior capsule opacification (PCO) of an acrylic intraocular lens (IOL) and a silicone IOL, both with sharp rectangular optic edges.

SETTING

Jinshikai Medical Foundation, Nishi Eye Hospital, Osaka, Japan.

METHODS

After phacoemulsification, an acrylic IOL (AcrySof(R)) was implanted in 1 eye and a silicone IOL (CeeOn 911) in the contralateral eye of 7 rabbits, one of which was omitted from evaluation.

RESULTS

The Miyake-Apple view and histopathological findings 3 weeks after surgery revealed that the lens capsule wrapped tightly around the optic edges, conforming to a distinctly sharp bend, with both IOL types in 5 rabbits. Migrating lens epithelial cells (LECs) were inhibited at the site. The AcrySof IOL had a better capsular bend effect in the histological sections, but there was no apparent difference in PCO development between the 2 IOLs.

CONCLUSIONS

The CeeOn 911 silicone IOL, with sharp rectangular optic edges, showed an effect on preventing PCO that was similar to that of the AcrySof IOL. When a discontinuous capsular bend is created by an IOL with sharp optic edges, the bend may induce contact inhibition of migrating LECs regardless of the lens' material composition.

Expression of transforming growth factor (TGF)-alpha, TGF-beta(2) and interleukin 8 messenger RNA in postsurgical and cultured lens epithelial cells obtained from patients with senile cataracts

BACKGROUND

Testing our hypothesis that residual lens epithelial cells (LEC) participate in the pseudophakic inflammation by producing cytokines, prostaglandins (PG) or both, we detected interleukin-1 (IL-1), IL-6, b-FGF and PGE(2) in the incubation medium of cultured LEC. This paper describes our subsequent work on the expression of TGF-alpha, TGF-beta(2), IL-4 and IL-8 mRNA in postsurgical and cultured LEC.

METHODS

The anterior lens capsule with attached LEC was obtained by anterior capsulotomy during cataract surgery and cultured. Specimens in serum-free medium immediately after surgery or those in serum-added medium after 2 weeks of culture were used. Reverse transcriptase-polymerase chain reaction (PCR) and electrophoresis were used to detect mRNA coding for TGF-alpha, TGF-beta(2), IL-4 and IL-8 in human cataract LEC.

RESULTS

Electrophoresis of the PCR products showed that appropriately sized amplification products were specific for TGF-alpha and TGF-beta(2) in the specimens immediately after surgery and after culturing, and IL-8 in the cultured LEC. IL-4 was not detected in either group of specimens.

CONCLUSIONS

Human cataract LEC synthesize TGF-alpha and TGF-beta(2) mRNA in situ and after culturing, and the cultured LEC also synthesize IL-8 mRNA. These cytokines may be synthesized by LEC in vitro and play an important role in an autocrine or paracrine manner in the proliferative process of LEC after cataract surgery, which can cause inflammation and aftercataract.

Preventing posterior capsule opacification by creating a discontinuous sharp bend in the capsule

PURPOSE

To clarify which factor--intraocular lens (IOL) design or material--contributes most to the inhibition of migrating lens epithelial cells (LECs).

SETTING

Jinshikai Medical Foundation, Nishi Eye Hospital, Osaka, Japan.

METHODS

After phacoemulsification, an acrylic IOL with sharp optic edges was implanted in 1 eye and a poly(methyl methacrylate) (PMMA) IOL with an optic design similar to that of the acrylic IOL in the contralateral eye of 4 rabbits.

RESULTS

The Miyake view and histopathological findings 3 weeks after surgery revealed that the lens capsule wrapped tightly around the optic edges, conforming to a distinctly sharp rectangular bend there with both IOL types in all rabbits. The migrating-LECs were inhibited at the site, and a massive Soemmering's ring cataract was formed.

CONCLUSIONS

The discontinuous sharp capsule bend created by the sharp optic edges in both IOL types appeared to induce contact inhibition of the migrating LECs. The preventive effect of an acrylic IOL on posterior capsule opacification may be design dependent.

Posterior capsule opacification. Part 1: Experimental investigations

Posterior capsule opacification (PCO) is the most frequent complication associated with decreased vision after cataract surgery. Previous methods of preventing PCO have not proven to be practical, effective, and safe for routine clinical procedure, but some novel concepts and methods have recently been developed. This 2-part review looks at clinical and experimental investigations of PCO, focusing on developments since 1992. Clinical aspects will be presented in a later issue. This paper addresses (1) in vitro models for PCO research; (2) pathophysiology and molecular biology of lens epithelial cells (LECs); (3) prevention of PCO. Of special interest are methods of culturing human LECs obtained by capsulotomy during cataract surgery, including those obtained with an intact capsular bag, to provide an in vitro model for investigating the pathophysiology of LECs; the effect of a sharp bend in the lens capsule that induces contact inhibition of migrating LECs; more specific inhibition of migrating LECs using an immunotoxin, b-FGF-saporin, or EDTA and RGD-peptides.

Accommodation amplitude after lens refilling with injectable silicone by sealing the capsule with a plug in primates

OBJECTIVE

To restore accommodation in primate eyes by refilling the lens capsule with injectable silicone compounds.

MATERIALS AND METHODS

Eight eyes of 8 monkeys (Macaca fascicularis) were treated by the lens refilling procedure. To prevent leakage of the injected liquid silicone before it polymerized in the capsule in vivo, a silicone plug for sealing the capsular opening was developed. After endocapsular phacoemulsification following an upper minicircular capsulorhexis, the plug was introduced into the capsulorhexis opening. A silicone mixture was injected into the capsular bag through the delivery tube of the plug. Automated refractometry was performed 1 week and 3 months after surgery. Accommodation amplitude was determined as the difference between the refractions before and 1 hour after topical application of 4% pilocarpine chloride.

RESULTS

Five of 8 eyes could be refilled. In 4 of 5 eyes, refraction could be measured. Accommodation amplitude ranged from 1.0 to 4.5 diopters, with a mean of 2.3 +/- 1.3 diopters (8.0 +/- 2.0 preoperative values). At 3-month examination, thick posterior capsule opacification precluded refractometry in all eyes.

CONCLUSIONS

The lens refilling procedure with the use of a silicone plug for sealing the capsular opening was feasible in primate eyes. The accommodation amplitude attained was a small fraction of the value before surgery. This may result from the loss of so-called intracapsular accommodation, ie, active participation of lens fiber cells in accommodation. However, since the obtained accommodation may be sufficient for near vision after cataract surgery, this lens refilling procedure warrants further study. Elucidation of the mechanism of intracapsular accommodation may also be necessary.

Capsule-bending ring for the prevention of capsular opacification: a preliminary report

BACKGROUND AND OBJECTIVE

To report the preliminary results of a study on the preventive effect of the capsule-bending ring on anterior and posterior capsule opacification (ACO and PCO, respectively).

PATIENTS AND METHODS

The ring is an open, band-shaped, circular polymethylmethacrylate (PMMA) ring measuring 11 mm in diameter with pre-tension (13 mm in diameter when the ring is open), 0.2 mm in thickness, and 0.7 mm in width. To retain sharp edges, the ring is not polished. The sharp edges should create a sharp, discontinuous capsular bend in the fornix, which induces contact inhibition of migrating lens epithelial cells after cataract surgery. This capsule-bending ring is inserted into the capsular fornix following phacoemulsification, prior to the implantation of an intraocular lens (IOL). In a multicenter trial, 100 patients were scheduled to undergo phacoemulsification and IOL implantation in both eyes within 1 month. The procedure was performed with the ring in 1 eye and without the ring in the other eye of each patient.

RESULTS

The anterior capsule was prevented from coming into contact with the IOL, and ACO was significantly reduced in the eyes with the ring, rendering the capsular opening larger 3 months after surgery. PCO was obviously reduced on slit-lamp examination in the follow-up period up to 6 months, but needs to be evaluated during a longer period.

CONCLUSION

This band-shaped, sharp-edged capsule-bending ring may be useful for cases that need good fundus visualization for photocoagulation or expected vitreoretinal surgery and for the prevention of PCO.

Lens refilling with injectable silicone in rabbit eyes

PURPOSE

To evaluate the technique of refilling the lens capsule with injectable silicone and assess the postoperative findings.

SETTING

Jinshikai Medical Foundation, Nishi Eye Hospital, Osaka, Japan.

METHODS

The lens capsules in the eyes of 16 rabbits weighing 1.5 to 2.0 kg were refilled with 0.2 mL of silicone polymer (about 66% bag volume) after endocapsular phacoemulsification through an upper minicircular capsulorhexis 1.5 to 1.8 mm in diameter. The capsule opening was sealed with a silicone plug to prevent leakage of the injected silicone. Main outcome measures were surgical success rate, inflammation, endothelial cell loss, refractive change after pilocarpine 4% instillation, and capsule opacification.

RESULTS

The lens capsule could be refilled in 10 eyes. The failures were caused by capsule rupture during phacoemulsification (n = 3) and profuse leakage of the injected silicone. Silicone that leaked minimally during surgery was easily washed away. Silicone that leaked and polymerized in the anterior chamber postoperatively (n = 3) was easily removed by surgery the following day. Mean endothelial cell loss was 10.2% 1 month after surgery. Aqueous flare intensity was significantly lower on days 2 and 4 than after conventional intraocular lens implantation in a control group. The respective mean preoperative and postoperative refractions were 0.7 diopters (D) +/- 1.0 (SD) and 19.1 +/- 1.0 D and the mean change (difference between the refractions before and after topical application of pilocarpine 4%), -0.4 +/- 0.6 and 1.1 +/- 0.4 D (P < .01). Posterior capsule opacification (PCO) was noted after 3 weeks in all eyes.

CONCLUSIONS

Lens capsule refilling and capsular plug use to prevent silicone leakage was shown to be feasible and avoided complications caused by leakage. Refractive changes suggest that the procedure could yield accommodation in primates> Although neodymium: YAG laser capsulotomy did not cause herniation of the injected silicone, PCO prevention is an essential issue in lens refilling because the capsulotomy may annul the attained accommodation.

Inhibition of migrating lens epithelial cells at the capsular bend created by the rectangular optic edge of a posterior chamber intraocular lens

BACKGROUND AND OBJECTIVE

To study the mechanism of the reportedly low incidence of posterior capsule opacification (PCO) in eyes treated with a posterior chamber intraocular lens (PC IOL).

MATERIALS AND METHODS

Various IOL designs, including the PC IOL, were studied using scanning electron microscopy. Rabbit lens capsules were studied histopathologically 2, 3, and 4 weeks after implantation of a PC IOL in one eye and a biconvex polymethylmethacrylate (PMMA) IOL in the contralateral eye as a control.

RESULTS

The optic edge of the PC IOL was sharp and rectangular, whereas that of the biconvex PMMA or silicone IOLs from various manufacturers had been smoothed and rounded by polishing. PCO was significantly reduced in the eye with a PC IOL in all rabbits. The lens capsule wrapped tightly around the optic edge of the PC IOL so that it conformed to the same shape and thereby created a distinct rectangular bend in the capsule or a rectangle between the optic edge and the posterior capsule. Migrating lens epithelial cells (LECs) were obviously inhibited at that site.

CONCLUSIONS

A discontinuous capsular bend or rectangle created by the sharp, square optic edge of the PC IOL may have induced contact inhibition to migrating LECs and reduced PCO. How, whether, and to what extent this design-dependent effect is influenced by features of the IOL material needs to be clarified by comparison with results achieved with an IOL made from the same material in a different design and vice versa.

Capsular bag distention syndrome noted 5 years after intraocular lens implantation

PURPOSE

To describe a case of capsular bag distention syndrome with opaque contents noted 5 years after intraocular lens implantation.

METHODS

A 66-year-old man underwent phacoemulsification after circular capsulorhexis and intraocular lens implantation in the left eye. Five years later, the posterior capsule was vaulted far posteriorly, the capsular opening was apparently sealed by the lens optic, and the bag contents were slightly opacified. Two years later, the contents of the hyperdistended capsular bag showed intensified opacity, causing definite blurred vision.

RESULTS

The opacified medium was emptied from the capsular bag posteriorly into the vitreous after Nd:YAG laser capsulotomy, and the distended capsule was restored.

CONCLUSIONS

Our findings suggest that the contents were collagens produced by residual lens epithelial cells or necrotic and/or apoptotic autolyzed lens epithelial cells.

The inhibition of lens epithelial cell migration by a discontinuous capsular bend created by a band-shaped circular loop or a capsule-bending ring

BACKGROUND AND OBJECTIVE

This study investigated the inhibitory effect of a discontinuous capsular bend created by an intraocular lens (IOL) with a band-shaped loop or a capsule tension ring on migrating lens epithelial cells (LECs).

MATERIALS AND METHODS

To create a sharp bend in the capsule, the round form (shown on cross section) of the open-circular loop of a polymethylmethacrylate IOL was changed to a band-like shape, 1.0 mm wide and 0.2 mm thick. A capsule tension ring of the same shape (on cross section) with a 14-mm diameter was also made. After cataract surgery, this IOL or ring was implanted into the capsular bag in 5 rabbit eyes. The same IOL with an unmodified haptic or conventional capsule tension ring was implanted in the contralateral eye as a control. After 8 weeks, Miyake view and histopathologic examinations were performed.

RESULTS

LECs accumulated at the equatorial corner outside the haptic or ring, showing the inhibition of LEC migration. In the control eyes, LECs accumulated inside the haptic or ring, forming a Soemmering's ring cataract, thus showing markedly less inhibition of LEC migration on macroscopic and microscopic observations.

CONCLUSIONS

A discontinuous bend in the capsule significantly inhibited LEC migration in rabbit eyes. The creation of a capsular bend through the appropriate design of the IOL-haptic or capsule tension ring might significantly decrease the incidence of posterior capsule opacification for humans.

Capsule opacification after refilling the capsule with an inflatable endocapsular balloon

PURPOSE

To describe the features of capsule opacification in rabbits and cynomolgus monkeys after the capsules were refilled with an inflatable endocapsular balloon.

SETTING

Nishi Eye Hospital, Jinshikai Medical Foundation, Osaka, Japan.

METHOD

Capsule opacification was evaluated by slitlamp examination, Miyake view, and histopathological examination in 15 eyes of 15 rabbits and 16 eyes of 13 primates from 4 to 32 months after the lens capsule had been refilled.

RESULTS

The incidence of capsule opacification was 94%. In the eyes that did not have lens epithelial cell (LEC) removal, a monolayer of LECs was seen on the posterior capsule when the lens capsule was tautly refilled, whereas a thick layer was seen when the lens capsule was moderately or poorly refilled. In the eyes that had LEC removal, the opacification was generally less marked regardless of the amount of refilling. In two rabbit capsules that were refilled moderately or tautly and had LEC removal, the capsule remained clear. Neodymium:YAG capsulotomy in two eyes did not cause herniation of the injected silicone.

CONCLUSIONS

Filling the capsule tautly and removing the LECs effectively reduced capsule opacification but could not completely inhibit LEC migration. This suggests the need for more efficient and thorough LEC removal or even a pharmaceutical approach to prevent capsule opacification after lens refilling.

Inhibition of migrating lens epithelial cells by blocking the adhesion molecule integrin: a preliminary report

PURPOSE

To evaluate the preventive effect of blocking integrins by sustained release of RGD peptide (arginine-glycin-aspartic acid sequence) or a combination of RGD peptide and ethylenediaminotetraacetic acid (EDTA) on lens epithelial cell (LEC) migration.

SETTING

Nishi Eye Hospital, Jinshikai Medical Foundation, Osaka, Japan.

METHOD

A polylactic-glycolic acid disk containing 4% RGD or a combination of 23% EDTA and 10% RGD was implanted in the capsular bag in five rabbit eyes following standard cataract surgery. The release rate in vitro was 4.4 microg/h for RGD peptide alone and 7.8 and 7.6 microg/h for combined EDTA and RGD peptide, respectively. The contralateral eye received a disk without agents as a control.

RESULTS

After 1 month, a slight inhibition of LEC migration onto the posterior capsule was observed histopathologically in eyes receiving RGD peptide. A significant inhibition was observed in eyes with combined EDTA and RGD.

CONCLUSIONS

Application of RGD peptide and EDTA and RGD peptide may inhibit LEC migration by inhibiting the integrins expressed on the LECs. Blocking adhesion molecules expressed on LECs may reduce posterior capsule opacification.

Controlling the capsular shape in lens refilling

OBJECTIVES

To investigate control of the capsular shape by determining the ability of the lens capsule to mold injected silicone and to evaluate the relationship among the volume of silicone injected, refraction, and the amplitude of accommodation.

METHODS

After endocapsular phacoemulsification following an upper, minicircular capsulorhexis, the lens capsule of a pig eye was refilled with a silicone mixture that polymerizes in vitro in 2 hours. The minicircular capsulorhexis opening was sealed by a small silicone plug to prevent leakage. The anterior capsule curvature and refraction of the lens were measured by a Scheimpflug camera and lensometer, respectively, with and without zonular tension. Zonular tension was created using a ciliary ring sutured to the ciliary bodies and expanded.

RESULTS

The mean (+/- SD) anterior curvature of the lenses without zonular tension was 6.50 +/- 0.07 mm after 17 hours and 6.54 +/- 0.04 mm after 42 hours; with zonular tension it was 7.01 +/- 0.11 mm and 7.23 +/- 0.24 mm, respectively. The curvature became flatter when zonular tension was applied or steeper when zonular tension was abolished momentarily during measurements after 17 hours, but after 42 hours the curvature was unaffected by the application or removal of zonular pressure. The mean (+/- SD) amplitude of accommodation (the difference between refraction without zonular tension and that with it) was 3.2 +/- 0.5 diopters (D), 6.1 +/- 1.8 D, 4.8 +/- 0.8 D, and 2.8 +/- 1.3 D, when the lens was refilled with a silicone volume corresponding to 45%, 55%, 75%, and 95%, respectively, of the mean normal lens volume.

CONCLUSIONS

The lens capsule possesses some ability to mold the injected silicone during its polymerization. When the eye is atropinized, the lens capsule may conform to its nonaccommodated state. Accommodation could be obtained by various degrees of refilling. Moderate refilling yields a greater amplitude of accommodation than does more complete refilling. Using a silicone plug to seal the capsular opening facilitates lens refilling with excellent reproducibility and seems to be useful in research.

Detection of cell adhesion molecules in lens epithelial cells of human cataracts

PURPOSE

To detect the expression of cell adhesion molecules (CAMs), including beta integrins, intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1, leukocyte-endothelial cell adhesion molecule-2, E-cadherin, and CD44, in cultured lens epithelial cells (LECs) of human cataracts. To show that LECs attach to cells or extracellular matrix components by the detected adhesion molecules.

METHODS

A circular section of the anterior capsule with attached LECs obtained by anterior capsulotomy during cataract surgery was cultured in a well of an eight-chamber slide. The LEC immediately after surgery and the cell outgrowth beyond the capsular margin at 2 weeks of culture were observed after the culture was stained immunohistochemically. Functional assays of LEC growth on collagen- or laminin-coated plates were performed in the presence and absence of the antibody blocking the detected adhesion molecules.

RESULTS

beta 1 integrin, ICAM-1, and CD44 were detected in both the original specimens and the cultured cells. When the antihuman anti-beta 1 integrin monoclonal antibody (mAb), anti-ICAM-1 mAb, or anti-CD44 mAb was added at 10 micrograms/ml to the incubation medium, LEC migration and proliferation were inhibited significantly on the collagen- or laminin-coated plates. When the mAb blocking these three CAMs were added each at 1 microgram/ml, LEC proliferation also were inhibited.

CONCLUSIONS

beta 1 integrin, ICAM-1 and CD44 are all involved in LEC attachment and growth on collagen and laminin in vitro. It can be assumed that these CAMs are involved in adhesion of LECs to extracellular matrix components of the lens capsule. Understanding the characteristics of the adhesion molecules in LEC may lead to the development of a new approach to inhibit secondary cataract formation.

Explantation of endocapsular posterior chamber lens after spontaneous posterior dislocation

The management of spontaneous posterior dislocation of an intraocular lens (IOL) (11.0 mm in overall diameter) encapsulated within the remaining lens capable is presented. The patient was a 55-year-old man who had had phacoemulsification following continuous curvilinear capsulotomy for monocular cataract 3 years earlier. The dislocated, encapsulated IOL was lifted up by hooking the fibrotic capsular opening with a bent disposable needle following vitrectomy and then explanted. A conventional posterior chamber lens with modified C-loops was inserted and sutured in the ciliary sulcus. This technique may be an alternative treatment for a posteriorly dislocated IOL. Histopathological examination clearly revealed that lens epithelial cell migration stopped at the planoconvex optic edge. This finding may be consistent with reports that the incidence of posterior capsule opacification with the planoconvex IOL is lower than with the bioconvex IOL.

Effect of intraocular sustained release of indomethacin on postoperative inflammation and posterior capsule opacification

PURPOSE

To assess whether the sustained release of indomethacin significantly reduces postoperative inflammation and posterior capsule opacification (PCO).

SETTING

Nishi Eye Hospital, Jinshikai Medical Foundation, Osaka, Japan.

METHODS

A 7 mm diameter, 1 mm thick polylactic-polyglycolic acid disk containing 7 mg of indomethacin was implanted in five rabbit eyes after continuous curvilinear capsulorhexis and phacoemulsification. The disk and an IOL placed above it were implanted in the capsular bag. The contralateral eyes, which served as controls, received a disk without indomethacin and the same type IOL in the same manner.

RESULTS

The indomethacin was fully released within 3 weeks in vitro, a release rate of about 14 micrograms/h. Postoperatively, aqueous flare intensity was significantly lower at days 2, 3, and 4 and at weeks 1, 2, and 3. Prostaglandin E2 was not detectable in the aqueous humor of the indomethacin-treated eyes on day 3 and at week 4. In the control eyes, mean concentration was 491 pg/ml +/- 54 (SD) and 990 +/- 243 pg/ml, respectively. Histopathological examination showed no significant decrease in PCO.

CONCLUSION

Although sustained release of indomethacin significantly decreased inflammation, it did not reduce PCO.

Synthesis of interleukin-1, interleukin-6, and basic fibroblast growth factor by human cataract lens epithelial cells

PURPOSE

To assay the following cytokines in an incubation medium of cultured lens epithelial cells (LECs) derived from human cataracts: interleukin-1 alpha (IL-1), interleukin (IL-6), basic fibroblast growth factor (b-FGF), tumor necrosis factor-alpha (TNF-alpha), and epidermal growth factor (EGF).

SETTING

Nishi Eye Hospital, Jinshikai Medical Foundation, Osaka, Japan.

METHODS

The anterior lens capsule with attached LECs was obtained by capsulotomy during cataract surgery and cultured. The incubation medium was changed on days 1 and 2 of culture and thereafter weekly up to 7 weeks. The media collected from a specific number of cultures at each medium change were pooled and assayed for cytokines by enzyme-linked immunosorbent assay.

RESULTS

Interleukin-1 alpha was detected in one of the two pools of the 2 week cultures (207 pg/10(6) cells), in two of the three pools of the 3 week cultures (120 pg/10(6) and 139 pg/10(6) cells), and in one of the two pools of the 4 week cultures (111 pg/10(6) cells). Interleukin-6 was detected in one pool of the 1 week cultures (195 pg/10(5) cells) and in one pool of the 7 week cultures (81.6 pg/10(5) cells). Basic FGF was detected in the incubation media from three series of samples during the culture time course: 87 pg/ml in the 1 day cultures in the first series; 478, 310, and 269 pg/ml in the 1 day, 2 day, and 1 week cultures, respectively, in the second series; and 98 and 83 pg/ml in the 1 and 2 day cultures, respectively, in the third series. The TNF-alpha and EGF were not detected in any sample.

CONCLUSION

After cataract surgery, IL-1, IL-6, and b-FGF may be produced in vivo by residual LECs, causing postoperative inflammation and LEC proliferation.

Decreased prostaglandin E2 synthesis by lens epithelial cells cultured on heparin-surface-modified poly(methyl methacrylate)

PURPOSE

To evaluate whether heparin surface modification reduces prostaglandin E2 (PGE2) synthesis by lens epithelial cells (LECs) after intraocular lens (IOL) implantation.

SETTING

Nishi Eye Hospital, Jinshikai Medical Foundation, Osaka, Japan.

METHODS

The prostaglandin E2 (PGE2) concentration was determined in an incubation medium of human cataract LECs cultured on heparin-surface-modified (HSM) poly(methyl methacrylate) (PMMA) plates at 1, 2, 3, and 4 weeks of culture. A medium without heparin served as a control.

RESULTS

The PGE2 concentration was significantly lower in the HSM than in the control medium at 3 and 4 weeks of culture.

CONCLUSION

The results are consistent with the clinical observation of significantly decreased inflammation in eyes with HSM IOLs, indicating that such modification increases PMMA's biocompatibility with LECs.

Inhibition of migrating lens epithelial cells by sustained release of ethylenediaminetetraacetic acid

PURPOSE

To evaluate the effect of the sustained-release of ethylenediaminetetraacetic acid (EDTA) chelating Ca++ on lens epithelial cell (LEC) migration.

SETTING

Nishi Eye Hospital, Jinshikai Medical Foundation, Osaka, Japan.

METHODS

Polylactic-glycolic acid disks containing 10% EDTA were placed in saline solution for about 2 weeks in vitro. About 60% (7 micrograms/hour) of the EDTA was released during that time. The disks with a posterior chamber intraocular lens placed above were implanted in the capsular bag in five rabbit eyes after continuous curvilinear capsulorhexis and phacoemulsification. A disk without EDTA and the same lens type were placed in the bag in the contralateral eyes, which served as controls.

RESULTS

After 2 to 3 months, opacification in the central posterior capsule was significantly reduced in all eyes that received the disk with EDTA.

CONCLUSION

The deprivation of Ca++ disrupted interaction between the posterior capsule and migrating LECs by inactivating the adhesion molecule integrin synthesized by LECs, significantly reducing LEC migration onto the posterior capsule.

Effects of the cytokines on the proliferation of and collagen synthesis by human cataract lens epithelial cells

AIMS

To assess the effects of the cytokines, interleukin-1 (IL-1), IL-1 receptor antagonist (IL-1ra), transforming growth factor-beta 2 (TGF-beta 2) and basic fibroblast growth factor (b-FGF), on the mitosis of and collagen synthesis by lens epithelial cells (LECs) of human cataracts.

METHODS

The anterior lens capsule with attached LECs was obtained by capsulotomy during cataract surgery and cultured. The cultures at 2 to 3 weeks before confluency were used for the experiments. To quantify the mitosis and collagen synthesis, the incorporation of 3H-thymidine and 3H-proline, respectively, into the LECs was measured by a scintillation counter at 48 hours and 24 hours, respectively, after addition of the cytokine at various concentrations into the incubation medium.

RESULTS

IL-1 and b-FGF increased the mitosis and collagen synthesis significantly, but IL-1ra significantly decreased the mitosis while leaving the collagen synthesis intact. TGF-beta 2 decreased the mitosis significantly, but increased the collagen synthesis significantly.

CONCLUSION

These cytokines may play an important role in an autocrine or paracrine pathway in the proliferation of residual LECs after cataract surgery. Elucidation of the role of these cytokines may lead to the development of new therapies for the prevention of secondary cataract.

Effect of the cytokines on the prostaglandin E2 synthesis by lens epithelial cells of human cataracts

BACKGROUND

Lens epithelial cells (LECs) derived from human cataracts have been reported to produce various cytokines and prostaglandin E2 (PGE2) in culture. The effects of IL-1, TGF-beta, and b-FGF on the PGE2 synthesis by LECs have been studied.

METHODS

A circular piece of the anterior capsule with attached LECs was obtained by capsulotomy during cataract surgery and cultured. The primary, almost confluent, cultures were used for the study. The PGE2 concentration of the culture media for 24 h was measured after the addition of recombinant human IL-1 alpha, TGF-beta 2, or b-FGF at various concentrations. The PGE2 concentration was also measured in the media to which each cytokine and rabbit polyclonal anti-human antibodies against the corresponding cytokine had been added.

RESULTS

The PGE2 concentration of the culture media after addition of IL-1 alpha at the concentration of 100 or 500 pg/ml (1765 (768) and 3071 (1121) pg/10(4) cells) or TGF-beta 2 at the concentration of 10 or 100 ng/ml (689 (264) and 750 (189) pg/10(4) cells) was significantly increased compared with that in the controls (67 (20) pg/10(4) cells). These effects were suppressed by the corresponding anticytokine antibodies. Basic FGF and anti-human b-FGF showed no significant effect on the PGE2 concentration. IL-1 and TGF-beta increased but b-FGF did not affect the PGE2 synthesis by LECs in culture.

CONCLUSION

IL-1 and TGF-beta may participate in postoperative inflammation after cataract surgery by increasing PGE2 synthesis by residual LECs.

Types of collagen synthesised by the lens epithelial cells of human cataracts

AIMS/BACKGROUND

Residual lens epithelial cells (LECs) undergo fibrous proliferation after cataract surgery, resulting in capsular fibrosis. The purpose of this study was to determine the types of collagen produced in cultured LECs derived from human cataract LECs.

METHODS

A circular section of the anterior capsule, about 5 mm in diameter, with LECs attached was obtained by anterior capsulotomy during cataract surgery and cultured directly without dispersion of the cells in a well, on the bottom of which a disc-shaped, thin plate of poly(methyl methacrylate) had been placed. At 5 to 6 weeks of culture, the proliferated cells of the culture were stained immunohistochemically with antibodies against human collagens I-VI by the avidin-biotin-peroxidase complex method.

RESULTS

Collagens I, IV, V, and VI were positive in the cultured cells. Types IV and V were strongly present in almost all the cells whereas types I and VI were only observed in a few cells. Collagens II and III were negative.

CONCLUSIONS

Since the lens capsule is known to be comprised of collagen IV, collagens I, V, and VI seem to be produced newly in culture. The capsular fibrosis seen after cataract surgery in vivo as a wound healing process of the lens capsule, may contain these types of collagens. The present culture model is useful for studying secondary cataract formation.

Effect of indomethacin-coated posterior chamber intraocular lenses on postoperative inflammation and posterior capsule opacification

We implanted indomethacin-coated intraocular lenses (IOLs) in rabbit eyes to ascertain how the sustained release of the drug affects postoperative inflammation and posterior capsule opacification (PCO). A preoperative resolution test showed that 1% indomethacin-coated IOLs placed in balanced salt solution released a mean 14.0 +/- 0.6 micrograms of the drug within 24 hours. Postoperatively, aqueous flare intensity in eyes with 0.1% indomethacin-coated IOLs and in eyes with 1.0% indomethacin-coated IOLs was significantly less at day 2 and at days 2 and 3, respectively, than in control eyes with uncoated lenses. In another group of eyes, histopathological examination showed that those with 1.0% indomethacin-coated lenses had significantly less PCO than the contralateral control eyes with uncoated IOLs.

Effects of diclofenac sodium and indomethacin on proliferation and collagen synthesis of lens epithelial cells in vitro

We investigated the effects of diclofenac sodium and indomethacin on the proliferation of and collagen synthesis by lens epithelial cells (LECs) of human cataracts in culture. The anterior capsule with attached LECs, obtained by anterior capsulotomy during cataract surgery, was cultured directly without cell dispersion. When the culture became almost confluent, diclofenac sodium or indomethacin at various concentrations was added to the incubation medium. The incorporation of 3H-thymidine and 3H-proline into the LECs was measured after the cells were labeled with these radioactive materials. Both drugs greatly suppressed the incorporation of 3H-thymidine and of 3H-proline, indicating that they inhibit cell division and collagen synthesis by LECs. Both drugs may help prevent posterior capsule opacification.

Effects of platelet activating factor on mouse embryo implantation in vitro

PURPOSE

Our purpose was to assess the role of platelet activating factor (PAF) in embryo implantation, we examined the effects of PAF and a PAF antagonist on the in vitro implantation of mouse embryos, using an in vitro embryo culture system in the absence of the endometrium.

METHODS

BDF1 mouse pronuclear-stage embryos were cultured until they developed to the two-cell, the four- to eight-cell, or the morula stage in the absence of PAF or its antagonist CV6209. The medium was then changed and supplemented with PAF or CV6209 at various concentrations. We also examined the reversible effects of PAF addition to the media containing the PAF antagonist.

RESULTS

The addition of PAF to the culture from the two-cell stage significantly (P < 0.05) increased the rates of embryo implantation in vitro (control, 69.8%; 10(-10) M PAF, 90.1%; 10(-9) M PAF, 95.5%). Similarly, the addition of PAF to the cultures from the four- to eight-cell and morula stage also significantly (P < 0.05) increased their rates of implantation in vitro. In contrast, the addition of CV6209 to the culture significantly (P < 0.01) decreased the rates of embryo implantation in vitro. CV6209 also decreased the rate of blastocyst formation. The degree of inhibition by CV6209 decreased with the advancing stage of embryos. The addition of PAF to media containing CV6209 reversed the inhibition and restored the implantation rate in vitro.

CONCLUSIONS

These results suggest that PAF may act directly on the mouse embryo and favor its implantation like an autocrine activating factor, irrespective of the presence or absence of the endometrium.

Effect of interleukin 1 receptor antagonist on the blood-aqueous barrier after intraocular lens implantation

Interleukin 1 (IL-1) possesses as an intercellular signal a wide spectrum of inflammatory, metabolic, haematopoetic, immunological, and reparative properties and can be a mediator not only of host defence but also of disease. Reduction of IL-1 can decrease the inflammatory host response. A human recombinant IL-1 receptor antagonist (IL-1ra) was used to block IL-1 after intraocular lens implantation in rabbits. Seventeen rabbits underwent intercapsular phacoemulsification and posterior chamber lens implantation. A 100 micrograms dose (0.1 ml) of IL-1ra (1 mg/ml) was injected into the anterior chamber at the end of surgery in seven rabbits. The 10 rabbits serving as the controls received no IL-1ra. Postoperatively, all rabbits were observed with a slit-lamp, and the aqueous flare intensity was measured with a laser flare cell meter at 12 hours, 1, 2, 3, and 4 days and thereafter at 1, 2, 3, and 4 weeks. Aqueous flare intensity was significantly lower on days 2 and 3, and fibrin deposition much less marked in the eyes treated with IL-1ra, compared with the controls. The results suggest that IL-1 is involved in the postoperative inflammation that occurs after intraocular lens implantation and the use of the IL-1ra would be valuable for reducing this problem.

Amplitudes of accommodation of primate lenses refilled with two types of inflatable endocapsular balloons

OBJECTIVE

To investigate the maintenance of ocular accommodation by refilling the lenses of the eyes of youthful primates with inflatable endocapsular balloons.

METHODS

The lenses of 21 cynomolgus monkeys were refilled following endocapsular phacoemulsification with a balloon that either approximates the shape of the non-accommodated lens or the accommodated crystalline lens.

RESULTS

In nine of 15 successfully refilled lenses, we were able to perform automated refractometry to determine the amplitude of accommodation, ie, changes in refraction before and 1 hour after application of topical 4% pilocarpine hydrochloride to alter lens shape. At 2 weeks, 2 to 3 months, and 6 to 12 months after operation, mean (+/- SD) accommodation was 4.6 +/- 2.5, 2.5 +/- 0.5, and 1.7 +/- 0.7 diopters (D), respectively, in the lenses refilled with the nonaccommodation balloon (n = 5; preoperative value, 15.2 +/- 1.3 D), and it was 1.9 +/- 0.5, 1.3 +/- 0.9, and 1.8 +/- 0.9 D, respectively, in the lenses refilled with the accommodation balloon (n = 4; preoperative value, 17.0 +/- 2.9 D).

CONCLUSION

The greater yield of accommodation with the nonaccommodation balloon is consistent with the recent theory on the mechanism of accommodation. Although the obtained accommodation was a small fraction of values determined prior to the operation and the small amplitude of accommodation decreased over time, the feasibility of refilling the lens with an inflatable endocapsular balloon, allowing at least some accommodation in the eyes of youthful primates, was demonstrated. Applied to humans, this procedure may allow accommodation following cataract surgery.

Intraocular lens encapsulation by shrinkage of the capsulorhexis opening

A 57-year-old man with retinitis pigmentosa and subcapsular cataract had phacoemulsification with a continuous curvilinear capsulorhexis and implantation of a poly(methyl methacrylate) intraocular lens. Six months later, the patient presented with blurred vision and severe anterior capsule fibrosis which led to complete posterior chamber lens encapsulation.

[Induction of prostaglandin E2 by interleukin 1 in human lens epithelial cells]

The authors proposed the hypothesis that pseudophakic inflammation, including the fibrin reaction, may be caused by interleukin (IL)-1, IL-6, other cytokines and/or prostaglandins (PGs), synthesized by residual lens epithelial cells (LEC). In testing our hypothesis, we have already detected IL-1 alpha, IL-6 and PGE2 in the culture media of human LEC obtained by capsulotomy during cataract surgery. In this paper, we studied the time course of PGE2-synthesis and interaction between IL-1 and PGE2. PGE2 concentration was measured by radioimmunoassay in the culture media to which rabbit antihuman IL-1 polyclonal antibody was added after culture for 6 h, 1 day, 1, 2, 3, 4, 5 and 6 weeks. There was no increase of PGE2, whereas in the untreated control culture media significant increase of PGE2 was confirmed. The results show that the antihuman IL-1 polyclonal antibody suppressed PGE2-synthesis. Thus, IL-1 induces PGE2 synthesis in human LEC culture.