Biomedical subjects

Peter Szurman

Publications and source records attributed to Peter Szurman.

At least 19 recordsLinked to original sources

PubMed2007

Effects of the protein tyrosine kinase inhibitor genistein and taurine on retinal function in isolated superfused retina.

BACKGROUND: Genistein has the potential to act as an intraocular antiangiogenic agent. Its therapeutical use, however, is limited by toxic side effects on the retina. This study was designed to evaluate the simultaneous use of taurine as a neuroprotective drug. METHODS: Bovine retinas were isolated and perfused with an oxygen-preincubated nutrient solution. The electroretinogram (ERG) was recorded as a transretinal electrical potential using Ag/AgCl electrodes. At stable ERG amplitudes, genistein at concentrations of 11, 37, and 150 microM was added to the nutrient solution for 45 min, in the absence or presence of taurine (3 mM). Thereafter, the retina was reperfused with the nutrient solution for another 100 min. The percentage of b-wave reduction during genistein and genistein/taurine application was calculated. RESULTS: The b-wave amplitude was reduced by a smaller amount during the application of genistein (11 and 37 microM) in the presence of taurine compared with genistein alone. For both, genistein/taurine and genistein alone the b-wave recovered completely during the wash-out of the drugs. However, during the application of the highest tested concentration of genistein (150 microM), taurine did not protect completely, leading to an irreversible b-wave reduction. CONCLUSIONS: The adjuvant use of taurine reduces the genistein-induced retinal toxicity to a certain degree. However, the protective effect of taurine is limited and there is only a narrow therapeutic index for a combined intravitreal administration of genistein in coapplication with taurine to inhibit pathological ocular neovascularization.

Animals↗

PubMed2007

Compound subretinal prostheses with extra-ocular parts designed for human trials: successful long-term implantation in pigs.

BACKGROUND: Subretinal implants aim to replace photoreceptor function in patients suffering from degenerative retinal disease like retinitis pigmentosa by topically applying electrical stimuli in the subretinal space. This study-as a last step before upcoming human trials-explored a newly developed surgical technique for permanent implantation of complex subretinal implants with extra-ocular parts. METHODS: The implant consisted of a microphoto-diode array (MPDA) with 1550 electrodes and a 4x4 array of gold electrodes for direct electrical stimulation; both were mounted onto a polyimide foil for transscleral placement into the subretinal space. The foil carried connection lanes to a silicone cable that was implanted under the skin and led to a stimulator box in the animal's neck. Surgery was performed in 11 domestic pigs. Improved vitreo-retinal surgical technique consisted of a 180 degrees peripheral retinotomy and use of diathermy to penetrate the choroid in order to avoid choroidal haemorrhage. Subretinal forceps were used to place the implant safely onto the retinal pigment epithelium before the retina was flattened, peripheral laser photocoagulation was applied and the eye was filled with silicon oil. The implant was stabilized by a scleral fixation patch, use of a metal clamp with bone screws on the animal's skull and a tissue ring under the animal's skin in the neck. Behaviour was observed in the freely moving animals after direct subretinal electrical stimulation and funduscopy, optical coherence tomography, fluorescein angiography and histology were performed. RESULTS: All implants were successfully placed subretinally. In three animals a proliferative vitreo-retinopathy was observed after approximately 2 weeks. Otherwise, funduscopy and OCT demonstrated complete retinal attachment and FA showed no retinal vascular abnormalities over and around the implant. The animals showed clear behavioural reactions to electrical stimulation over the whole examination period. Histological examination failed to show any voltage-induced alteration in the cellular architecture of the retina overlying the stimulation electrodes. CONCLUSIONS: This study demonstrates the feasibility of a new surgical procedure for highly safe and controlled implantation of complex subretinal devices with extra-ocular parts. The new implant design proved to be safely implantable in free-moving pigs for an observation period of 4 weeks.

Animals↗

PubMed2007

Full macular translocation versus photodynamic therapy with verteporfin in the treatment of neovascular age-related macular degeneration: 1-year results of a prospective, controlled, randomised pilot trial (FMT-PDT).

BACKGROUND: The purpose of this study was to compare full macular translocation (FMT) with photodynamic therapy (PDT) in the treatment of neovascular age-related macular degeneration (AMD). METHODS: In a prospective, randomised, non-masked, mono-center, pilot-trial, 50 eyes of 50 patients were assigned to either FMT or PDT. Baseline and control examinations in 3-monthly intervals over a 12-month period included standardized protocol refraction, visual acuity testing and fluorescein angiography. Primary outcome measurements were made to establish the change in distant visual acuity from the baseline to the 12-month examination. The statistical analyses were carried out on the intent-to-treat principle. RESULTS: The improvement of one or more ETDRS lines was 56% (14/25) of the eyes in the FMT and 16% (4/25) of the eyes in the PDT arm (P = 0.007). Twenty eyes (80%) in the FMT and 16 eyes (64%) in the PDT group had less than three ETDRS lines of vision loss (P = 0.35). Retinal detachment (six eyes) and diplopia (five patients) were recorded in the FMT group. None of the eyes treated in the FMT group had phtysis. CONCLUSION: This pilot study showed that no statistically significant difference existed between the FMT and PDT in terms of the vision loss of less than three ETDRS lines in eyes with neovascular AMD. The chance of vision improvement was significantly higher for the patients in the FMT group. However, in the era of promising therapy with anti-vascular endothelial growth factor for neovascular AMD, FMT should not be offered as a standard primary procedure for neovascular AMD.

Aged↗

PubMed2006

A case of cutaneous melanoma metastatic to the vitreous cavity: possible pathomechanism and review of the literature.

BACKGROUND: Isolated vitreous metastases are extremely rare and the pathogenesis of metastasis is still unclear. Here we present the detailed description of the disease progression in a 68-year-old patient with vitreous seeding of a metastatic cutaneous melanoma beginning at a very early stage. METHODS: Interventional case report and review of the literature. RESULTS: The initial retrohyaloidal metastatic lesion was identified adjacent to a small epiretinal hemorrhage. As the disease progressed golden brown spherules appeared in the posterior vitreous emanating from the area of the lesion. Further progression led to a dense metastatic infiltration of the entire vitreous cavity and a decline of the visual acuity to 20/1200. Diagnostic and therapeutic pars plana vitrectomy was performed to confirm the diagnosis and preserve the eye and useful vision. CONCLUSIONS: For the first time the formation of vitreous metastases derived from cutaneous melanoma was carefully studied beginning at a very early stage. This made it possible to analyze the rare mechanism of vitreous metastasis, which has not been conclusively known till now. The features of metastatic cutaneous melanoma to the vitreous are discussed in context of a review of the literature that resulted from the study of 17 patients with 22 affected eyes.

Aged↗

PubMed2006

Influence of different purification techniques on triamcinolone yield and particle size spectrum.

BACKGROUND: To systematically investigate the common purification techniques for commercially available triamcinolone acetonide preparations and the influence of different filter parameters on final yield, reproducibility and particle size spectrum. METHODS: Two non-filter techniques using either sedimentation or centrifugation, and two different filter techniques were tested. Filters with different characteristics were investigated with the pore size ranging from 0.1 to 5.0 microm, and the filter diameter ranging from 4 to 30 mm. Only sterile standard syringe filters with low adsorptive characteristics (hydrophilic cellulose filter membranes) for pharmaceutical use were employed. For quantification, triamcinolone acetonide was dissolved in 60% methanol and measured spectrophotometrically at 239 nm. The crystal size spectrum was determined using a particle size analyzer that combines electronic pulse area analysis and resistance measurement. RESULTS: Depending on the purification technique used the resulting triamcinolone doses differed significantly. While the centrifugation method achieved purification without relevant loss, the sedimentation method yielded only 28.7% compared to the original commercial suspension, and in addition, the predictability was low (range 8.1-17.2 mg). With filter techniques high and consistent doses with a good reproducibility were achieved, but results were highly dependent on the filter characteristics. The final triamcinolone amount inversely correlated with the filter diameter due to a uniform loss of crystalline particles. In contrast, enlarging the pore size caused a substantial shift in the particle size spectrum due to a selective loss of small crystalline particles. CONCLUSIONS: The most common purification techniques vary notably in regard to final triamcinolone doses, reproducibility and particle size spectrum. The appropriate choice of the filter parameters seems to be more important than assumed, as pore size and filter diameter substantially influence both the final TA doses and the particle size of the TA crystals.

Centrifugation↗

PubMed2006

Differential toxic effect of dissolved triamcinolone and its crystalline deposits on cultured human retinal pigment epithelium (ARPE19) cells.

The aim of the study was to evaluate the antiproliferative and cytotoxic properties of triamcinolone acetonide (TA) on human retinal pigment epithelium cells (ARPE19) and the role of epicellular crystalline deposits. Monolayer cultures of ARPE19 cells were used. Purified or unpurified crystalline TA suspension (0.01-1.0 mg/ml) or the vehicle alone (benzyl alcohol, 0.025%-0.00025%), diluted in culture medium, were added to the cells that were either grown on cell culture dishes covered by a protecting membrane filter insert or without a filter. After 1, 3, 5 and 7 days mitochondrial activity was measured using the MTT assay and the morphology assessed microscopically. Cellular proliferative activity was monitored by BrdU-incorporation into cellular DNA. For cytotoxicity assays ARPE19 cells were grown to confluence and then cultured in a serum-deficient medium to ensure a static milieu. Annexin V-FITC and propidium iodide co-staining was performed and analyzed by flow cytometry. Exposure to TA without direct cellular contact showed a moderate antiproliferative activity resulting in a dose-dependent suppression of DNA synthesis (maximum 42.7%), but not a cytotoxic effect. In contrast, adherent deposits of crystalline TA particles on top of the cell layer caused a rapid-progressive and dose-dependent cell death preceded by an early phosphatidylserine externalization to the outer leaflet of the plasma membrane. Within a healthy, confluent cell layer the number of viable cells decreased by 14.2, 20.8 and 68.8%, respectively, after one day of direct exposure. Exposure to the vehicle alone caused only a slight growth inhibitory effect in a proliferating cell layer, but early signs of cell death were detected even at the lowest concentration tested. In conclusion, the effect of the vehicle is less pronounced than formerly assumed, but not negligible, thus indicating a beneficial effect of purification. While non-adherent TA, if purified, appears to be safe in clinically used concentrations, direct physical contact with crystalline particles might cause a local, rapid-progressive cytotoxicity that involves the induction of the apoptotic cascade. Therefore, epiretinal deposits after intravitreal TA administration might be critical in terms of long-term biocompatibility.

Anti-Inflammatory Agents↗

PubMed2006

Iris pigment epithelial translocation in the treatment of exudative macular degeneration: a 3-year follow-up.

OBJECTIVE: To report the functional and anatomical outcome of 20 patients who underwent surgical removal of choroidal neovascularization combined with transplantation of autologous iris pigment epithelial cells to the subretinal space 3 years after treatment. METHODS: Freshly isolated autologous iris pigment epithelial cells were translocated to the subretinal space in 20 patients after membrane extraction. Patients were followed up by funduscopy, angiography, microperimetry, and visual acuity testing. RESULTS: After a follow-up of 3 years, 1 patient showed improved visual acuity, 13 patients retained stable visual acuity, and 3 patients had reduced visual acuity. No macular edema or recurrent choroidal neovascularization was apparent at any time during the follow-up. CONCLUSIONS: Transplanted autologous iris pigment epithelial cells were well tolerated for 3 years and stabilization of visual acuity was achieved in most patients. These results suggest that iris pigment epithelial cells may serve as a substitute for retinal pigment epithelial cells after choroidal neovascularization removal in patients with exudative macular degeneration; however, whether these cells will be of any value for the restoration of vision and possible protection against choroidal neovascularization recurrence awaits further clinical observation and additional research.

Adult↗

PubMed2006

Sutureless amniotic membrane fixation using fibrin glue for ocular surface reconstruction in a rabbit model.

PURPOSE: Amniotic membrane transplantation has become an important treatment option for corneal surface reconstruction. However, suture fixation of the transplant has various disadvantages like corneal irritation, scarring, graft loss due to membrane shrinkage, and the need for subsequent suture removal. Replacement of sutures by bioadhesives might be an advantageous alternative. This controlled study was designed to evaluate a new sutureless technique for amniotic membrane fixation onto the corneal surface by using fibrin glue. METHODS: Standardized disks of cryopreserved amniotic membranes were transplanted onto the deepithelialized cornea of 12 rabbits using either conventional suture fixation or a new fibrin glue technique. The rabbits were followed-up with slit-lamp examination and fluorescein staining until epithelialization was completed. Consecutively, the rabbits were killed and the eyes processed for histology and immunohistochemistry for cytokeratin-3. RESULTS: All membranes of both groups stayed in place throughout the follow-up time and showed a progressive graft epithelialization that was completed after 12 days. Whereas suture-fixated membranes showed progressive tissue shrinkage, fibrin-glued sheets remained unaltered. In the bioadhesive group, histology revealed a smooth fibrin layer in the graft-host interface and a continuous, stratified layer of cytokeratin-3 expressing corneal epithelial cells on the membrane surface. In contrast, suture-fixated membranes showed contracted and prominent membrane edges with epithelial ingrowth into the submembrane interface. CONCLUSION: Our results demonstrate the general feasibility of reproducible and reliable sutureless amniotic membrane fixation onto the corneal surface in rabbits. Stable adherence is maintained until epithelialization is completed. The sutureless technique gives sufficient manipulation time for the sheet before the final cross-linking process is completed. Furthermore, several advantageous characteristics could be demonstrated as increased biocompatibility, better epithelialization pattern and the lack of membrane shrinkage.

Amnion↗

PubMed2006

Ultrastructural changes after artificial retinal detachment with modified retinal adhesion.

PURPOSE: Artificial retinal detachment is increasingly used in submacular surgery. However, overcoming physiological retinal adhesiveness by subretinal fluid injection is suspected to cause cellular damage and thus to limit visual rehabilitation. This experimental study was designed to examine the ultrastructural changes induced by retinal detachment under vitrectomy conditions and to evaluate factors that reduce adhesiveness and minimize cellular damage. METHODS: Twenty-one pigmented rabbits underwent vitrectomy, and the vitreous cavity was perfused for 10 minutes with various solutions. These included variations in osmolarity (314 and 500 mOsM), Ca(2+) ion concentration (Ca(2+)-supplemented, low Ca(2+), active Ca(2+) deprivation via 1 mM EDTA), temperature (19 degrees C and 34 degrees C), and ischemia (5 minutes). Nonvitrectomized eyes served as the control. Consecutively, an artificial bleb detachment was created underneath the visual streak by injecting 1 mL of buffered saline solution subretinally. Eyes were enucleated within 3 minutes, fixed with 2% glutaraldehyde/0.1 M cacodylate buffer (pH 7.4) containing 100 mM sucrose and processed for transmission electron microscopy and scanning electron microscopy. RESULTS: If a Ca(2+)-containing standard solution was used during vitrectomy, retinal adhesiveness was strong, and a forced bleb detachment caused substantial cellular damage characterized by swollen and fragmented photoreceptor outer segments and disruption of retinal pigment epithelial cells. Use of a Ca(2+)-free solution moderately reduced the adhesive strength with consequently less ultrastructural damage. Active Ca(2+)-deprivation further reduced the retinal adhesion, but may have induced damage as suggested by intracellular vacuolization. Hyperosmolarity and ischemic conditions had toxic effects on both the photoreceptors and RPE cells. In contrast, the use of a preheated Ca(2+)-free solution (34 degrees C) substantially reduced retinal adhesiveness under vitrectomy conditions and hence ultrastructural damage. CONCLUSIONS: Artificial retinal detachment causes substantial ultrastructural damage in eyes with physiological retinal adhesiveness if performed under vitrectomy conditions similar to surgery in humans. The use of a preheated Ca(2+)-free physiologic saline solution seems to be suitable to reduce retinal adhesion sufficiently, without causing significant cellular damage.

Adhesiveness↗

PubMed2005

Experimental implantation and long-term testing of an intraocular vision aid in rabbits.

OBJECTIVE: To develop an intraocular vision aid to provide artificial vision in severely traumatized eyes, where neuroretinal function could be preserved but irreversible anterior segment opacification resulted in blindness. METHODS: The basis of an intraocular vision aid is in principle a telemetric circuit to bridge the opaque cornea and to allow for artificial light stimulation of the retina. The visual prosthesis comprises an external high-dynamic range complementary metal oxide semiconductor camera and digital signal processing unit and an intraocular miniaturized light-emitting diode array to project the image onto the retina. For in vivo testing of long-term function and biocompatibility, silicone-encapsulated active photodiodes were implanted in 13 pigmented rabbits and were followed up for up to 21 months. RESULTS: Lens extraction and stable fixation of the device in the ciliary sulcus were successful in all cases. For up to 21 months inductive energy transmission and wireless stimulation of the implants could be maintained. Electrophysiologic data and histology demonstrated a good tissue biocompatibility in the long-term follow-up. CONCLUSION: The results demonstrate the general feasibility and biocompatibility to implant and fixate an intraocular light-emitting diode prosthesis. Inductive energy transmission to the intraocular device and wireless light stimulation are assured in the long term but depend on meticulous water-impermeable encapsulation of the delicate microelectronic components. Clinical Relevance An intraocular vision aid compound system with a high-resolution light-emitting diode matrix might be a future treatment option to restore vision in blind eyes with severe anterior segment disorders.

Animals↗

PubMed2005

Decorin modulates wound healing in experimental glaucoma filtration surgery: a pilot study.

PURPOSE: To analyze the effect of perioperative decorin in an experimental setting of glaucoma filtration surgery. METHODS: Glaucoma filtration surgery, similar to that performed in clinical practice, was performed on 35 chinchilla rabbits (ChBB:CH). The animals received a unilateral subconjunctival injection of decorin (40-100 microg) or the vehicle alone before surgery and at different time intervals thereafter. Antifibrotic efficacy was established by clinical response and histologic examination. The animals were killed on day 14, and the eyes processed for histology. RESULTS: Both the vehicle and the decorin solution were well tolerated. No adverse effects such as inflammation or blurring of the optical media were observed. Conjunctival scarification occurred within 1 week in the control groups but was suppressed in the experimental groups. The intraocular pressure correlated with the fibrotic process and reached normal levels within 7 days after surgery in control animals, but remained significantly (P <0.001) reduced in the experimental groups. Histologic examination of the surgical area 14 days after surgery disclosed massive fibrosis in the control animals, but little deposition of extracellular matrix in the experimental groups. CONCLUSIONS: The data of this pilot study suggest that perioperative subconjunctival decorin applications significantly affect conjunctival scarring and surgical outcome of glaucoma filtration treatments in rabbits.

Animals↗

PubMed2004

Immunohistopathologic evaluation of choroidal neovascular membranes following verteporfin-photodynamic therapy.

PURPOSE: To evaluate the vascularization and proliferative activity in choroidal neovascular membranes due to age-related macular degeneration after verteporfin photodynamic therapy and submacular removal. DESIGN: Interventional case series. METHODS: In a retrospective review of seven patients who underwent removal of subfoveal classic choroidal neovascular membranes after treatment with photodynamic therapy 3 to 146 days earlier, membranes were stained for CD 34, CD 105, and Ki-67 and correlated with clinical pictures and fluorescein angiography. RESULTS: Fluorescein angiography performed on the day of surgery disclosed nonperfusion of the treated area 3 days after photodynamic therapy, but perfusion and leakage were seen at greater post-photodynamic therapy intervals. Membranes excised 3 days after photodynamic therapy showed CD34 and CD105 positive, mostly occluded vessels. The endothelial cells appeared damaged. Ki-67 activity was low. In membranes excised 34 to 146 days after photodynamic therapy, all vessels appeared patent and were lined by healthy endothelial cells with strong expression of CD34 and CD105. Ki-67 expression was elevated after 34 days but decreased thereafter. CONCLUSION: Photodynamic therapy did not cause a general or complete occlusion of vessels within the choroidal neovascular membranes, as suggested by fluorescein angiography 3 days postintervention, but the endothelial cells appeared to be severely damaged. Proliferative activity within these specimens was reduced. At longer intervals after photodynamic therapy, the fibrovascular tissue seemed to recover; perfusion, hyperfluorescence, and leakage of the choroidal neovascular membranes could be detected by fluorescein angiography. The clinical appearance showed a correlation with the immunohistologic characteristics of an increased proliferative activity and patent vascularization.

Aged↗

PubMed2004

Expression of endoglin in choroidal neovascularization.

Endoglin (CD105) is a membrane protein involved in the TGF-beta receptor signalling pathway with predominant expression by proliferating endothelial cells. The aim of this study is to analyze the expression of Endoglin in choroidal neovascularization membranes (CNVM) and to compare it to the overall proliferative status of CNVM. Thirty surgically excised CNVM, secondary to age-related macular degeneration, were investigated using light microscopic immunohistochemistry and confocal immunofluorescence microscopy using verified antibodies directed against the endothelial cell markers Endoglin, von Willebrand factor (vWF) and CD34 and the proliferation marker Ki-67. Donor eyes were used as controls. A selective expression of CD34 and vWF as well as Endoglin was found in endothelial cells. Endoglin expression was elevated in vascular endothelial cells contained within CNVM, but a moderate Endoglin expression could also be visualized in quiescent CD34 and vWF positive ocular vasculature. Ki-67 positive cells were detected in CNVM, but these were rarely endothelial cells. Endoglin expression in endothelial cells of CNVM is increased, but rarely associated with a concomitant expression of the proliferation marker Ki-67. The elevated expression of Endoglin in surgically excised CNVM suggests a persisting post-mitotic activation in an advanced stage of this neovascular tissue.

Antigens, CD↗

PubMed2004

Contact lens, hyperopia and endothelial changes. A case report.

INTRODUCTION: We report on a 62-year-old healthy woman who suffered from bilateral predescemetic opacities, where the underlying disorder could not be identified. She had bilateral keratopathy with corneal edema, a diffuse predescemetic avascular haze and deszemetic folds. Because of high hyperopia (right +7.50/left +7.75) she weared soft contact lenses for years. METHODS: Removal of contact lenses. Treatment with local steroids and tear substitutes. RESULTS: One year after cessation of contact lenses VA recovered from RE 0.3/LE 0.1 to 0.8/0.63, the deep stromal opacity cleared up, the corneal edema recessed slightly. DISCUSSION: The differential diagnosis concludes either a pure contact lens change that is not completely reversible or a possible posterior polymorphous dystrophy that worsens with long-term contact lens wear and improves on cessation.

Contact Lenses, Hydrophilic↗

PubMed2004

Histological findings in experimental macular surgery with indocyanine green.

PURPOSE: To analyze the effect of different concentrations and application intervals of indocyanine green (ICG) on the retina in an experimental setting of macular surgery. METHODS: Twenty-one porcine eyes were used within 5 hours after enucleation. The eyes were hemisected and the vitreous removed. Different doses of ICG (up to 1 mg) were applied over the trephined macula, and the remainder of the eyecup was filled with a balanced salt solution (BSS). Both the ICG solution and the BSS were drained after 30 or 60 seconds and the complete eyecup irrigated and filled with fresh BSS. The posterior pole was then illuminated with a standard surgical light pipe and light source at maximum power for 3 minutes. Both the ICG-treated retina and the nontreated surrounding retina were processed for histology. RESULTS: Exposure of the retina at different concentrations of ICG either for 30 or 60 seconds, followed by illumination, caused no histologically detectable damage compared with the controls. No microarchitectural disorganization or cellular disruption was detected. The vitreoretinal interface seemed unaffected. CONCLUSIONS: Previously described severe damage to the inner retina of human donor eyes could not be found with even higher doses of ICG in this porcine model. Although differences within the species may contribute to these contradictory results, it is conceivable that the postmortem time and the vitality of the tissue influence the outcome in this ex vivo system.

Animals↗

PubMed2003

Outcome of combined penetrating keratoplasty with vitreoretinal surgery for management of severe ocular injuries.

PURPOSE: To assess the effectiveness of a combined procedure (pars plana vitrectomy with temporary keratoprosthesis, vitreoretinal surgery, and penetrating keratoplasty) and to determine which factors influence corneal transplant success rates. METHODS: Records for 34 severely injured eyes of 31 consecutive patients who underwent penetrating keratoplasty in combination with vitreoretinal surgery between 1991 and 1998, with a follow-up of at least 12 months, were evaluated retrospectively. Analysis was focused on ocular history, functional and anatomic anterior and posterior segment outcome, and complications. RESULTS: Penetrating keratoplasty was performed in 10 eyes (29%) within 8 weeks of trauma and in 24 eyes (71%) as a secondary procedure. Initial improvement in visual acuity (VA) was achieved in 47% of eyes; at the end of the follow-up, 74% of the eyes had attained equal or better VA than the initial postsurgical VA. Reasons for poor final VA were hypotony or phthisis (35%) and recurrent retinal detachment (11%). Corneal grafts remained clear for 1 year in 65% of eyes. Transplant failure was less in eyes that did not need a permanent silicone oil tamponade, when the retina was attached before surgery, and in eyes that were grafted later after trauma and received no further surgery. These were some conditions that were associated with a longer mean graft survival time, but without statistical significance. There was no difference in eyes according to the trauma mechanism, preoperative intraocular pressure, or graft size. CONCLUSIONS: Penetrating keratoplasty in severely injured eyes is often complicated by ciliary body malfunction and secondary transplant failure. Although the functional outcome of a combined procedure is limited by primary and secondary tissue destruction, preserving ambulatory vision is possible and thus improves the quality of life, at least in patients with single remaining eyes.

Adolescent↗

PubMed2002

Combined penetrating keratoplasty and vitreoretinal surgery with silicone oil: a 1-year follow-up.

BACKGROUND: The aim of this study was to assess the functional outcome of eyes with corneal and vitreoretinal diseases following combined surgical procedures (pars plana vitrectomy with temporary keratoprosthesis, vitreoretinal surgery, and penetrating keratoplasty with intravitreal silicone oil tamponade) and to evaluate the factors preserving the clarity of grafts. METHODS: Fifty-three eyes from 49 consecutive patients, operated on between 1991 and 1998 and followed up for at least 12 months, were evaluated retrospectively. The evaluation focused on ocular history, visual acuity (VA), intraocular pressure, anterior and posterior anatomical outcome, and complications. RESULTS: The average follow-up was 28.4 months+/-18.8 months (range 12-84 months); at the final visit 58% of the eyes had better VA, and 73% had equal or better acuity; the cornea remained clear in 68% of the eyes. A decrease in VA was caused by: loss of light perception in 2 eyes, one of which had to be enucleated because of painful phthisis; hypotony or phthisis in 23 eyes; recurrent retinal detachment in 4 eyes that were operated because of trauma; and immunological reaction in 2 eyes. Preoperative factors that contributed to a clear graft, but were not significant, were: lack of trauma (74%), no actual silicone oil filling (78%), preoperative VA of hand movement or better (79%), and attached retina (73%). Further surgery was needed in 55% of cases. The risk of transplant failure was significantly lower in eyes that did not undergo additional surgery (p=0.0001). CONCLUSION: The long-term results of combined surgery with penetrating keratoplasty in eyes that would otherwise be untreatable is often limited by anterior segment complications, mainly secondary graft failure and ciliary body malfunction. For optimal preservation of graft clarity, stable ocular status should be achieved before transplantation to minimize the necessity for further surgery.

Adolescent↗

PubMed2002

Macular translocation with 360 degrees retinotomy for exudative age-related macular degeneration.

BACKGROUND: Macular rotation surgery comprises surgical extraction of choroidal neovascular membranes in age-related macular degeneration (AMD) and translocation of the foveal neural retina over adjacent retinal pigment epithelium. OBJECTIVE: To determine whether macular translocation with 360 degrees retinotomy can stabilize and/or improve visual acuity in patients with subfoveal choroidal neovascularization (CNV) secondary to AMD. DESIGN: This study consisted of a standardized surgical procedure on a series of 90 consecutive patients and follow-up examinations at fixed intervals for 12 months. PARTICIPANTS: All patients in this study had experienced recent visual loss resulting from subfoveal CNV caused by AMD. Twenty-six patients had major macular subretinal hemorrhage, 39 patients had occult subfoveal CNV, and 25 patients had classic subfoveal CNV. METHODS: Macular translocation surgery was performed between 1997 and 1999. The patients were examined preoperatively and at 3, 6, and 12 months postoperatively, including visual acuity, microperimetry, angiography, and orthoptic assessment. RESULTS: Visual acuity increased by 15 or more letters in 24 patients, remained stable in 37 patients, and deteriorated by 15 or more letters in 29 patients at 12 months postoperatively. A secondary procedure was necessary in 17 patients because of severe complications; proliferative vitreoretinopathy was observed in 17 eyes, macular pucker in 5 eyes, and macular hole in 1 patient. CONCLUSION: Macular translocation is a technically demanding surgical procedure. Although the procedure has a high rate of surgical and postoperative complications, the functional and anatomical results appear to be promising for selected patients with subfoveal CNV secondary to AMD.

Aged↗