[Endothelial cell loss after retropupillary iris-claw intraocular lens implantation]. / Endothelzellverlust nach retropupillar fixierter Irisklauen-Linse.

BACKGROUND: The aim of this study was to evaluate the indication, visual and refractive outcome, endothelial cell loss and complication rate after implantation of a posterior iris-claw aphakic intraocular lens (IOL). PATIENTS AND METHODS: This retrospective study comprised 62 eyes of 56 patients without adequate capsular support undergoing posterior iris-claw aphakic IOL implantation (Verisyse™/Artisan®) between 2006 and 2012. Mean follow-up was 34 months (range from 13 to 78 months). RESULTS: The IOLs were inserted during primary lens surgery in 11 phakic eyes (17.8 %), during an IOL exchange procedure for dislocated posterior chamber IOLs in 34 eyes (54.8 %), and as a secondary procedure in 17 aphakic eyes (27.4 %). The final best spectacle-corrected visual acuity (BSCVA) in logMAR (mean 0.24 ± 0.45) improved significantly (p < 0.001) compared to the preoperative BSCVA (mean 0.61 ± 0.65). The mean spherical equivalent improved from preoperative 7,25 ± 5,04 diopters (D) (range - 10.25 to + 16.0 D) to - 0.21 ± 1.01 D (range - 4.0 to 3.0 D) postoperatively. Mean central endothelial cell density was 1844 ± 690 cells/mm(2) preoperatively. After surgery mean endothelial cell density decreased statistically not significant with a loss of 5.5 % to 1743 ± 721 cells/mm(2) (p > 0.05) at last follow-up visit. Complications included cystoid macular oedema in 4 eyes (6.4 %), early postoperative hypotony in 2 eyes (3.2 %), pupil ovalisation in 2 eyes (3.2 %), traumatic iris-claw IOL disenclavation in 2 eyes (3.2 %) and spontaneous IOL disenclavation in one eye (1.6 %). CONCLUSIONS: Retropupillar iris-claw IOL provides good visual and refractive outcomes with a low endothelial cell loss and can be used for a wide range of indications in eyes without adequate capsular support.

[Bioptics with multifocal lenses and Lasek]. / Bioptics mit Multifokallinsen und Lasek.

PURPOSE: Good functional results with multifocal lenses need exact postoperative emmetropia. Therefore, it seems reasonable to perform additional refractive surgery to correct minimal spherical or cylindrical postoperative ametropia (bioptics). But concerns could arise about additional photoptic phenomena or loss of contrast. The literature contains only a few reports about bioptics after multifocal lens implantation. METHOD: In eight eyes of seven patients, laser subepithelial keratomileusis (Lasek) was done after multifocal lens implantation. Pre-Lasek and 6 months postoperatively, we performed the following examinations in addition to visual acuity: contrast sensitivity (Pelli-Robson charts), low-contrast visual acuity (Humphrey AR 570), glare visual acuity (Humphrey AR 570), and night-driving ability (Mesoptometer II, Oculus). RESULTS: Preoperative contrast sensitivity was 1.2-1.65; postoperatively it was 1.35-1.65. Low-contrast visual acuity measured 50-70% preoperatively and 57-70% postoperatively. Glare visual acuity measured 12.5-50% preoperatively and 28.5-57% postoperatively. Mesoptometer measurements did not change after Lasek; they revealed night-driving ability under strict criteria for four patients. CONCLUSIONS: Bioptics as a combination of multifocal lens implantation and Lasek does not cause a functional decline in low-contrast or glare visual acuity, but it minimizes postoperative ametropia. It seems superior to exclusive multifocal lens implantation.

[Significance of cyclosporin A absorption for effective immunomodulatory therapy after high-risk keratoplasty]. / Bedeutung der Cyclosporin-A-Absorption für eine effektive immunmodulatorische Therapie nach Hochrisikokeratoplastik.

AIM: Cyclosporin A (CsA) is applied as an immune modulator in transplantation medicine, including high-risk keratoplasty. We examined the C(0) and C(2)-CsA serum levels after high-risk keratoplasty. The rate of so-called low absorbers was determined, and the importance of low absorption for the survival and rejection freedom of corneal grafts was examined. METHODS: Follow-up of 89 high-risk cornea grafts in the patient group (n=32) ranged from 1 to 72 months postoperatively. The evaluation included data about serum levels of CsA C(0) (24 h after oral CsA application) and C(2) (2 h after oral CsA application) and clinical follow-ups. Using statistical methods, CsA C(0) and C(2) levels and clinical data were examined. Low absorbers did not reach the target C(2) levels by CsA dose adjustment. OUTCOMES: High intraindividual and interindividual variance of CsA C(0) and C(2) values was observed in the examined group of patients. A rate of up to 34.4% (n=11) represented the low absorbers. There was no significance of the low-absorption factor for clear graft survival, rejection freedom, or the rate of side effects observed. An acute endothelial rejection was observed in 23% of grafts and caused 37% of graft failures. In the patients without rheumatic corneal ulcers (n=27), 89% of the corneal grafts remained clear after 12 months, and 52% remained clear after 36 months. CONCLUSIONS: In our study, with a low number of patients and multiple cofactors, the influence of low-absorption CsA on the clear corneal graft survival and rejection rates could not be proved statistically. Due to the specific immune status of the cornea, the influence of low absorption may be lower than in organs such as the kidney and liver. In our study, the C(2) serum level of CsA after high-risk keratoplasty did not provide any helpful information about the prognosis of the corneal grafts or CsA treatment monitoring.

Characterization of Staphylococcus aureus strains isolated from bovine milk in Hungary.

Staphylococcus aureus is a major foodborne pathogen due to its capability to produce a wide range of heat-stable enterotoxins. The primary purpose of this research was to characterize S. aureus isolates recovered from mammary quarter milk of mastitic cows and from bulk tank milk produced on Hungarian dairy farms of different sizes. Macrorestriction analysis of chromosomal DNA from S. aureus isolates was performed using the restriction enzyme SmaI followed by pulsed-field gel electrophoresis (PFGE). The prevalence rates of nine S. aureus enterotoxin genes (sea, seb, sec, sed, see, seg, seh, sei, and sej) and of the toxic shock syndrome toxin 1 gene (tst) were determined by multiplex polymerase chain reaction (PCR). The bulk tank milks of 14 out of 20 farms were contaminated with S. aureus at levels of up to 6.0x10(3 )CFU/ml. Farm size had no significant effect (P>0.05) on the S. aureus counts in bulk milk. The prevalence rates of penicillin resistance were 88.9% and 20.0% among the S. aureus recovered from mastitic quarter milk and bulk tank milk, respectively. After phenotypic characterization, a total of 59 S. aureus isolates were selected for genotyping. PFGE analysis revealed 22 distinct pulsotypes, including 14 main types and 8 subtypes, at a similarity level of 86%. Only one or two main types were observed on each of the farms tested, indicating a lack of genetic diversity among S. aureus isolates within farms, and there were only two pulsotypes which occurred on more than one farm. The PFGE patterns showed genetic relatedness between the S. aureus strains recovered from quarter milk and bulk milk on two large farms, implying that on farms having a high number of mastitic cows, S. aureus from infected udders may contaminate bulk milk and, subsequently, raw milk products. Sixteen (27.1%) of the S. aureus isolates tested by multiplex PCR were found to be positive for enterotoxin genes, with 15 of them carrying just one gene and one strain carrying two genes (seg and sei). The most commonly detected toxin genes were seb, sea, and sec, whereas none of our isolates possessed the see, seh, sej, or tst genes. On 75% of the dairy farms surveyed, no enterotoxigenic staphylococci were recovered from either mastitic quarter milk or bulk tank milk.

[A new posterior chamber intraocular lens for sutureless iris-fixated ciliary sulcus implantation in aphakic eyes without capsular support]. / Neue Hinterkammerlinse zur sulkusgestützten und nahtlos irisfixierten Implantation in aphake Augen ohne Kapselstrukturen.

PURPOSE: To avoid anterior chamber lens implantation in aphakic eyes without capsular or zonular support, the laborious scleral fixation of a standard posterior chamber intraocular lens (IOL) is widely used, despite a large range of possible complications (macular edema, IOL tilt/decentration, suture erosion, vitreous hemorrhage). A sutureless iris-fixed ciliary sulcus implantation of a posterior chamber IOL (Binder-IOL, Fa. Iolution, Itzehoe) designed especially for such cases represents an alternative. METHOD: At the end of both haptics of this IOL, with a 6 mm optic zone, a T-shaped anchor is mounted at an angle of 45 degrees from the optical plane. These anchors are inserted from behind the iris into peripheral iridotomies performed preoperatively with a YAG-laser or intraoperatively with a vitrectomy cutter. The long, C-shaped haptics are thus secured in the ciliary sulcus. RESULTS: After slight modification of the technique, the implantation can be performed securely and reproducibly. In the 22 implantations performed to date, the IOL was well centered and stable, even in cases with only residual iris stroma. If the iridotomies are been performed too centrally, an ovalisation of the pupil may occur. No further side effects have been observed. CONCLUSION: The technique of sutureless sulcus fixation presented here leads to less complications than scleral suture fixation. A prerequisite for safe implantation of the anchors is good visibility of the peripheral iris. The implantation of the Binder-IOL is especially suitable for aphakic eyes with a loosened iris diaphragm.

[A new technique to facilitate donor preparation for DMEK surgery]. / Eine neue Technik zur Optimierung der Spenderpräparation bei der DMEK.

BACKGROUND: Descemet membrane endothelial keratoplasty (DMEK) is becoming more and more the method of choice to treat corneal endothelial diseases in specialized centers. The reasons that prevent this technique from becoming widespread are the delicate donor tissue preparation. By inverting the curvature of the cornea from convex to concave after mounting onto an artificial anterior chamber, we developed a combined manual delamination and hydrodissection technique, which allows a rapid and endothelium-preserving method of separating donor Descemet membranes from the underlying stroma. MATERIAL AND METHODS: Experiments were perfomed with 60 donor corneas that were not suitable for transplantation. Donor age ranged between 42 and 94 years. Two experimental groups were formed: 1 inverse manual delamination (n = 16) and 2 combined manual delamination and hydrodissection (n = 44). All experiments were undertaken by an experienced surgeon who was, however, not experienced with these techniques. We examined the frequency of Descemet membrane rupture as well as the amount of induced endothelial damage (trypan blue staining with quantitative image analysis). RESULTS: Significant lesions of Descemet's membrane that would have led to a loss of the graft occurred in 25% of the manual delamination cases and in 4.5% using the combined technique. Endothelial damage induced by both techniques was low (6 and 5.2%, respectively). CONCLUSION: For DMEK donor preparation, a combination of manual delamination and hydrodissection was shown to be a safe and endothelium-protective technique to separate Descemet membranes from the underlying stroma. A very rapid learning curve for the combination technique is of specific additional interest for beginners in DMEK surgery.

Characterization of Listeria monocytogenes isolates from 50 small-scale Austrian cheese factories.

One hundred eighty-one small-scale cheese factories (annual production < 100,000 kg) were tested for the presence of Listeria monocytogenes in cheese and smear samples from 1997 to 2000. In total, 2615 samples were drawn. Fifty (27.6%) of 181 enterprises yielded L. monocytogenes. From 14 of the cheese-making facilities, we obtained more than four L. monocytogenes isolates. A total of 182 mostly cheese- and smear-borne L. monocytogenes strains were characterized by serotyping and pulsed-field gel electrophoresis. In 12 of 14 cheese factories, over half of the L. monocytogenes isolates were genetically indistinguishable by pulsetype. On average, genetically indistinguishable isolates were recovered for 11.9 months. Regarding serotypes, 27.3% of the isolates were of serovar 4b. Inadequate personal hygiene could explain the high prevalence of serovar 4b isolates in small-scale cheesemaking facilities. Forty-two percent of the serovar 4b isolates recovered from epidemiologically unlinked facilities (in comparison to 40 and 29% of the 1/2a and 1/2b isolates, respectively) were genetically indistinguishable from at least one other isolate. Indistinguishable serovar 1/2a and 1/2b isolates belonged to five and six different pulsetypes, respectively, whereas serovar 4b isolates belonged to only two pulsetypes. This finding suggested a wide distribution of genetically homologous serovar 4b isolates among the facilities tested in our study.

[Reconstruction of skin defects in the eyelid and periorbital region using four triangular advancement flaps. An alternative to free skin grafts]. / Rekonstruktion von Hautdefekten in der Lid- und Periorbitalregion mittels vier Dreiecksverschiebelappen. Eine Alternative zum freien Hauttransplantat.

PURPOSE: This report presents a procedure as an alternative to free skin grafts for reconstruction of rhomboid skin defects in the lid region. METHOD: Ten consecutively treated patients were included who had skin defects after resection of eyelid tumors such as basaliomas. The skin defects were rhomboid and had the same horizontal and vertical diameter (medium 1.5 cm) and were therefore too large for a horizontal advancement flap. The defects were closed by preparation of four triangular skin flaps that were sutured crosswise into the defect. RESULTS: The procedure was adequate for reconstruction of the defect in all ten cases. There were no lid malpositions and the cosmetic results were favorable in all cases. The medium operation time was significantly shorter in comparison to free skin grafts. CONCLUSIONS: Application of free skin grafts is a standard procedure for reconstruction of anterior lamellar lid defects. Triangular transposition flaps can be a timesaving alternative with good cosmetic results.

Retrospective contralateral study comparing Descemet membrane endothelial keratoplasty with Descemet stripping automated endothelial keratoplasty.

PURPOSE: In this retrospective study, the visual outcomes and postoperative complications after Descemet stripping automated endothelial keratoplasty (DSAEK) and Descemet membrane endothelial keratoplasty (DMEK) in the fellow eye were compared. The patient's satisfaction was evaluated. METHODS: A retrospective analysis of 10 patients, who underwent DSAEK in one eye and DMEK surgery in their fellow eye, was performed. Intraoperative and postoperative complications were recorded. Visual and refractive outcomes were evaluated, including higher-order aberrations (HOA) and contrast thresholds. A subjective questionnaire was used to evaluate patient satisfaction. RESULTS: Best-corrected visual acuity (BCVA) was significantly better in DMEK when compared with DSAEK (0.16±0.10 vs 0.45±0.58 logMAR, P=0.043). Contrast threshold was significantly higher after DMEK than after DSAEK (0.49±0.23 vs 0.25±0.18, P=0.043). Post-keratoplasty astigmatism, mean spherical equivalent, and HOA did not differ. Nine out of ten patients preferred the DMEK procedure. Visual outcome (4.80±1.14 vs 4.50±1.58, P=0.257), surgery associated pain and burden (DMEK: 1.30±0.48 vs DSAEK: 1.30±0.48, P=1.0), estimated time for recovery and rehabilitation (27.6±54.0 vs 24.9±54.8 days, P=0.173), and mean patient satisfaction (5.40±0.84 vs 5.00±1.05, P=0.257) were evaluated equally. CONCLUSION: Patient satisfaction reached high, equal values after DMEK and after DSAEK. Nevertheless, patients preferred DMEK, if given a choice. Reasons for the preference may include better uncorrected and BCVA, and especially a better contrast sensitivity.

A new test for endothelial viability. The Janus green photometry technique.

A new in vitro technique was developed to measure, by simple photometry, the amount of Janus green extracted with absolute alcohol from isolated corneas after vital staining. The amount of stain corresponded to the percentage of damaged endothelial cells and was a reliable parameter of endothelial viability. More rapid and easier to perform than the usual cell counting of devitalized cells, this technique can be used to study the endothelial damage induced, for example, by experimental surgery, intraocular solutions, intraocular lens material, corneas storage solutions. As an example of application, results of the endothelial status after medium-term preservation of pig corneas (n = 40) in a modified McCarey-Kaufman medium at 4 degrees C were determined. The mean +/- endothelial damage was 8.5% +/- 1.8% (mean +/- SD) after 4 days, 29.5% +/- 3.7% after 7 days, 45.5% +/- 5.5% after 10 days, 69.3% +/- 3.7% after 14 days, and 100% after 20 days of storage in McCarey-Kaufman medium.

Corneal endothelial toxicity of different lidocaine concentrations.

PURPOSE: To examine the potential damaging effect on the corneal endothelium of unpreserved lidocaine in concentrations of 1%, 5%, and 10%. SETTINGS: Department of Ophthalmology, Charité Medical Faculty, Humboldt University, Berlin, Germany. METHODS: Experimental porcine corneas (n = 18) were exposed to 100 microL of unpreserved lidocaine hydrochloride at concentrations of 1%, 5%, and 10% for 60 minutes. Additional corneas (n = 6) were treated with lidocaine hydrochloride 1% for 30 minutes to simulate clinical conditions. Balanced salt solution (BSS((R))) served as a control to evaluate corneal endothelial cell damage using Janus Green photometry. Morphology, damage pattern, and changes in the ultrastructural appearance of corneal endothelial cells were examined by light and scanning electron microscopy. RESULTS: Lidocaine 1% used for 30 or 60 minutes did not cause significantly more corneal endothelial damage (mean 3.00% +/- 0.76% [SD] and 3.26% +/- 1.00%, respectively) than in the control group (mean 3.32% +/- 0. 86%) (P >.01). Significant corneal endothelial cell loss was observed with lidocaine 5% (mean 10.7% +/- 6.4%) (P <.001) and lidocaine 10% (42.3% +/- 17.0%) (P <.001). CONCLUSION: Experimental exposure of corneal endothelial cells to higher concentrations of lidocaine resulted in significant cell loss, indicating that the 1% concentration only should be used clinically.

Corneal wound healing modulation using basic fibroblast growth factor after excimer laser photorefractive keratectomy.

Photorefractive keratectomy with the 193-nm excimer laser is one of the most promising innovations in refractive surgery. However, routine clinical application is hindered by two main obstacles, i.e., postoperative subepithelial opacity and possible regression of the refractive result. Because we have previously demonstrated beneficial effects of basic fibroblast growth factor (bFGF) on corneal epithelial healing in different in vivo models, we investigated the influence on both epithelial and stromal healing of topical bFGF after excimer laser keratomileusis in a rabbit model. After 7-mm circular deepithelialization, the eyes of 24 New Zealand White rabbits received identical deep stromal laser ablations (depth 50 microns, 6 D, diameter 5 mm) and were randomly assigned to one of four treatment groups [control (phosphate-buffered saline, PBS), bFGF 10 micrograms/application, dexamethasone 0.1%, bFGF + dexamethasone, n = 12 eyes/group]. All treatments were administered four times daily--bFGF until complete epithelial healing, dexamethasone and PBS until 3 months postsurgery. Wound surface regression on time was determined by means of computer-assisted image analysis of fluorescein-stained corneas. Corneal opacity was observed biomicroscopically and graded using a previously established scoring system. After bFGF application for 2-3 days only, a highly significant acceleration in epithelial wound healing speed was found compared with the rate of the other three treatment groups (p < 0.001). A combined therapy (bFGF + steroid) had no effect on the healing rate. Compared with control values, mean scores for subepithelial haze in the other groups were found to be nearly 50% lower during the first 2 postoperative months.(ABSTRACT TRUNCATED AT 250 WORDS)

Human recombinant bFGF stimulates corneal endothelial wound healing in rabbits.

We have previously shown that bovine, human placenta extracted and recombinant human basic Fibroblast Growth Factor (bFGF) are effective in enhancing corneal epithelial wound healing in vivo. In the present study, we investigated the effect of rh-bFGF on the regeneration of injured rabbit endothelium. A standardized wound was created by scraping of endothelial cells with a special device within the boundaries of a central epithelial trephine mark of 7 mm in diameter. A single dose of 1.5 micrograms rh-bFGF was injected into the anterior chamber immediately after wounding, while control eyes received the vehicle only (n = 27). Functional recovery and wound closure rates were assessed by means of ultrasonic pachymetry, corneal button wet weight, endothelial vital staining as well as direct computer assisted surface analysis of Janus green stained corneal buttons. Measurements were carried out 1, 2, 4, and 7 days after injury. Morphological evaluation and cell counts at D4 and D7 were also performed. Significant stimulation of endothelial regeneration in rh-bFGF treated eyes, was observed with all methodological approaches. These results demonstrate the effectiveness of rh-bFGF in enhancing experimental corneal endothelial wound healing and advocate for a possible clinical application of this growth factor in order to preserve endothelial cell function or to promote healing of this important monolayer in case of disease or injury.

Determinations of serum tumor necrosis factor alpha in corneal allografts.

Corneal allograft rejection culminates in a series of interactions between different classes of antigen presenting cells, cytokines and leukocytes. Tumor necrosis factor-alpha (TNF-alpha) was recently reported to be elevated in acute rejection of solid organ transplants. This cytokine is released early in immune activation and may be detected in the peripheral circulation. Serial determinations of TNF-alpha serum levels were performed following experimental corneal allografts. Lewis rats received 3.5 mm orthotopic corneal grafts of MHC-incompatible Wistar-Furth donors. TNF-alpha concentrations were measured in serum samples collected pre- and postoperatively and measured by micro ELISA. Clinical observations revealed graft rejection in 65.5% of corneal transplants 14 +/- 4 days following grafting. The mean serum level of TNF-alpha in control animals without corneal graft (group I) was 41 +/- 12 pg/ml. Animals following keratoplasty without allograft rejection (group II) showed a mean TNF-alpha level of 54 +/- 16 pg/ml that did not differ from group I. The rejection group III displayed significantly higher TNF-alpha levels (98 +/- 16 pg/ml, p < 0.05). These significantly elevated levels were found even before the diagnosis of rejection was established by clinical criteria. These data suggest systemic immunoreactivity to corneal allografts. Elevated levels of cytokines may provide valuable information in recipients undergoing rejection and may also provide a rationale for systemic immunotherapy in some instances.

[Wound healing of the corneal endothelium in vivo after intraocular injection of recombinant human bFGF]. / Wundheilung des Hornhautendothels in vivo nach intraokularer Injektion von rekombinantem humanem bFGF.

In the present study, we investigated the potential role of recombinant human basic fibroblast growth factor (rh-bFGF) on the regeneration of corneal endothelium in the rabbit. For in vivo wound-healing experiments, standardized wounds were created by mechanically scraping the endothelial cells within the boundaries of a central epithelial trephine mark. A single dose of 1.5 micrograms rh-bFGF was injected into the anterior chamber of the right eye immediately after wounding, while the left eyes received the ointment vehicle only (n = 27 rabbits). Functional recovery and wound closure rates were assessed by means of ultrasonic pachymetry, cell counts after endothelial vital staining and direct computer-assisted surface analysis of Janus green-stained endothelial lesions. Measurements were carried out 0, 1, 2, 4, and 7 days after injury. For the time points day 2 and day 4, significant stimulation of endothelial regeneration in rh-bFGF treated eyes was observed with all parameters measured. These results demonstrate that rh-bFGF could prove to be useful in clinical conditions, e.g. to conserve endothelial function after intraocular surgery or as a supplement to corneal intermediate preservation media.

[Peribulbar anesthesia versus topical anesthesia in cataract surgery: comparison of the postoperative course]. / Peribulbäranästhesie versus topische Anästhesie bei der Kataraktoperation. Vergleich des postoperativen Verlaufes.

BACKGROUND: Phacoemulsification with topical anesthesia is a proven alternative to peribulbar or retrobulbar anesthesia. Application of lidocaine in the anterior chamber before surgery is one method to achieve good intraoperative analgesia. The purpose of this study was to find out whether there are any differences in the postoperative course between patients with peribulbar injection and patients with topical anesthesia. PATIENTS AND METHODS: A total of 186 patients scheduled to undergo elective cataract surgery were included in the study. The patients were randomly assigned to receive sponge-anesthesia and intraocular injection of 0.15 ml lidocaine 1% or a peribulbar injection of 6 ml Xylonest 2%. Uncorrected visual acuity was measured 30 min after surgery. On the first postoperative day, the cornea and ocular inflammation affecting the anterior chamber were examined with a slit lamp; best corrected visual acuity and postoperative pain were documented. RESULTS: Thirty minutes after surgery, the uncorrected visual acuity was significantly better in the lidocain group. At 1 day we saw no differences concerning visual acuity. Descemet folds occurred in 6.5% of the peribulbar group and 20.5% in the lidocain group. CONCLUSION: Topical anesthesia with sponge anesthesia and intraocular application of 0.15 ml lidocain 1% circumvents the complications of a peribulbar/retrobulbar injection. The patient profits from rapid visual rehabilitation.

[Proliferation and wound healing of retinal pigment epithelium cells in vitro. Effect of human thrombocyte concentrate, serum and PDGF]. / Proliferation und Wundheilung von RPE-Zellen in vitro. Einfluss von humanem Thrombozytenkonzentrat, Serum und PDGF.

PURPOSE: Biological agents like human serum or autologous platelets have recently been employed as adjuvants for macular hole surgery. However, the role of these agents on the retinal cellular level remains unclear. In the present study, we investigated the effect of human platelets, serum and PDGF on RPE migration and proliferation in cell culture. METHODS: Human RPE were cultured in DMEM + 2% FCS and experiments performed at passages 2-4. Human platelet concentrate (PC) and serum (HS) were isolated from blood of patients previewed for macular hole surgery; human PDGF-BB was from Pepro Tech. PC and HS at protein concentrations ranging from 50-1000 micrograms/ml and PDGF at 1 and 10 ng/ml were added to 5000 cells/well in the proliferation assay and to a confluent RPE monolayer on which a central mechanical "wound" (5 mm diameter) was made. Incubation times ranged from 1 h to 5 days. Cell numbers at D 5 were indirectly determined by protein measurements. In the wound model, the cells inside the wound area were counted and results compared to the control cultures that received no supplements. RESULTS: Cell proliferation was significantly stimulated over controls by all concentrations of PC, HS and PDGF with any incubation time. Compared to PC and PDGF, HS revealed less proliferation after 1-6 h of incubation; there was no significant difference from PC with other incubation times. In the wound model, both PC and PDGF significantly increased the number of cells migrating into the denuded area after 1 h incubation with the culture medium; longer incubation times had no further effect compared to controls. CONCLUSION: The present study is the first to demonstrate that human platelet concentrate induces proliferation and migration of RPE cells in vitro. However, PDGF, a growth factor which is abundantly present in platelets, was found to be at least equally effective. We assume that the majority of the mitogenic effect of platelet concentrate is due to PDGF.

[Effect of prostaglandin F2 alpha on proliferation of corneal endothelial cells in vitro]. / Effekt von Prostaglandin-F2 alpha auf die Proliferation von Hornhautendothelzellen in vitro.

INTRODUCTION: Prostaglandins, especially PG-F2 alpha, have recently been introduced as a new local glaucoma medication. The modulation of cell proliferation and collagen synthesis in various tissues are the major effects of these agents. However, it is unknown whether PG-F2 alpha also modulates the proliferation of the corneal endothelium. METHODS: Bovine corneal endothelial cells (BCEC) were cultured according to established protocols. Experiments were performed after the 1st passage under serum-reduced conditions. A total of 10(4) cells/well were seeded and the cells were then incubated with different (5 x 10(-6) bis 5 x 10(-4) mg/ml) concentrations of PG-F2 (Sigma). The number of cells was determined every 24 h until day 5. Toxicity tests were performed by means of the trypan blue exclusion assay. RESULTS: PG-F2 alpha induced a significant stimulation of BCEC proliferation with all concentrations tested. At the highest concentration of PG-F2 alpha, a 2-fold increase in cell number was found after 5 days only compared to unsupplemented control cultures. No signs of cellular toxicity or morphological alterations could be detected in PG-F2 alpha-supplemented cells. DISCUSSION: For the first time, the present study demonstrates a stimulatory effect of PG-F2 alpha on the corneal endothelium. It appears that this effect is also induced by the PG-F2 alpha concentration determined in the aqueous humour of patients after topical latanoprost application. However, due to the strong contact inhibition of endothelial cells in situ, these results cannot be directly extrapolated to the situation in patients with topical latanoprost treatment.

[Effect of recombinant human basic fibroblast growth factor (rh-bFGF) on wound healing of the corneal epithelium]. / Effekt von rekombinatem humanem basischem Fibroblastenwachstumsfaktor (rh-bFGF) auf die Wundheilung des Hornhautepithels.

Prior to a possible clinical trial in humans, we studied the wound-healing effect of RH-bFGF in vivo. Healing-rate measurements on 24 deepithelialized rabbit corneas were performed by means of computer-assisted image analysis. A significantly increased healing rate (P = 0.004) was revealed for the 200 ng FGF treated group (rate 1.57 mm2/h) compared to the control group (1.12 mm2/h). To assess the long-term (side) effects of FGF (50 ng topically applied, 2 times daily), 7 rabbits were involved in a model with repeated epithelial scraping of an anterior keratectomy wound (performed with Draeger's rotokeratom to a depth of 0.15 mm). Light and transmission electron micrographs of treated corneas showed an increased fibrogenesis in the anterior stroma with more pronounced activation of keratocytes. No evidence of abnormal neovascularization or inflammation was observed when compared to control corneas. We suggest that topical RH-bFGF promotes corneal wound healing with virtually no detectable adverse reactions. These results seem to be of considerable interest for the possible therapeutic use of rh-bFGF in patients with superficial corneal epithelial lesions.

[Effect of suramin on proliferation and migration of lens epithelial cells in vitro]. / Effekt von Suramin auf Proliferation und Migration von Linsenepithelzellen in vitro.

BACKGROUND: New approaches for the treatment of secondary cataract focus on a pharmacological therapy to prevent posterior capsule opacification. In this study we investigated the effect of the naphthylurea suramin in vitro in a cell culture model. MATERIAL AND METHODS: Cell proliferation was measured using a proliferation assay and cell migration with a migration assay. Analyses of suramin toxicity were carried out using trypan blue staining. RESULTS: A significant dose-dependent effect of suramin on the inhibition of LEC proliferation and migration was found even after short (1 or 2 h) incubation times ( p<0.01). Cell lysis reflecting a cytotoxic effect of suramin was not found even with high concentrations. However, preincubation of lens capsules with suramin did not prevent LECs from migrating compared to control cultures. CONCLUSION: These results demonstrate the efficiency of suramin in vitro to inhibit migration of HLEC which can be explained by blocking growth factor-mediated effects on the cells. However, further investigations on the pharmacokinetic properties of suramin and possible side-effects on other intraocular tissues must follow.