PubMed Health⌕ Search

Biomedical subjects

Jan C van Meurs

Publications and source records attributed to Jan C van Meurs.

15 recordsLinked to original sources
PubMed2006

Histological evidence for revascularisation of an autologous retinal pigment epithelium--choroid graft in the pig.

BACKGROUND: Translocation of a free autologous graft consisting of retinal pigment epithelium (RPE), Bruch's membrane, choriocapillaris and choroid in patients with exudative age-related macular degeneration is currently being evaluated in clinical practice. Angiographic studies in these patients suggest that their grafts become revascularised. AIM: To investigate the histological evidence of revascularisation of the graft in a porcine model. METHODS: In 11 pigs (11 eyes), an RPE-choroid graft was translocated from the mid-periphery to an intact or an intentionally damaged RPE and Bruch's membrane at the recipient site. The eyes were enucleated 1 week or 3 months after surgery. Tissue sections were evaluated using immunohistochemistry. RESULTS: Bridging vessels between recipient layer and graft were identified from 1 week to 3 months after surgery. This reconnection occurred regardless of whether the Bruch's membrane of the recipient site was left intact or intentionally damaged at the time of transplantation. The vasculature of the graft appeared open and perfused. Vessels with transcapillary pillars and conglomerates of small new vessels were present in the graft. CONCLUSIONS: This study showed histological evidence for revascularisation by angiogenesis of a free autologous RPE-choroid graft.

Animals↗
PubMed2006

Relationship between retinal detachment and biometry in 4262 cataractous eyes.

PURPOSE: To assess risk factors for retinal detachment (RD) in eyes that previously underwent cataract surgery. DESIGN: Retrospective cohort study. PARTICIPANTS: Four thousand two hundred sixty-four eyes of 3094 patients who underwent extracapsular cataract extraction with intraocular lens (IOL) implantation at the Department of Ophthalmology, Erasmus MC, University Medical Center Rotterdam. METHODS: From January 1, 1993, through March 31, 1999, 3094 patients (4262 cases) of extracapsular cataract extraction with IOL implantation were enrolled. Through review of ophthalmic patient records, the role of preoperative and intraoperative data as well as neodymium:yttrium-aluminum-garnet (Nd:YAG) capsulotomy was assessed with respect to development of an RD. MAIN OUTCOME MEASURES: Axial length (AL), anterior chamber depth (ACD), crystalline lens thickness, mean keratometric power, spherical equivalent, intraoperative complications, Nd:YAG laser posterior capsulotomy, RD. RESULTS: Of 4262 eyes that underwent cataract extraction, 3921 eyes (2794 patients) were available for analysis. Twenty-two patients experienced RD after surgery, resulting in an overall cumulative incidence of 0.62%. Multivariate binary logistic regression analyses showed the following factors to be associated with an increased risk of RD after cataract surgery: an accidental posterior capsular rupture at the time of surgery (odds ratio [OR] = 16.26; P<0.001), an increased AL (OR = 1.25; P = 0.013), and a deeper anterior chamber (OR = 4.02; P = 0.016). Older age was found to be a protective factor for the development of RD (OR = 0.95; P = 0.003). CONCLUSIONS: Cataract surgery at a young age with an accidental posterior capsular rupture and a deeper ACD are the most important predisposing conditions for pseudophakic RD after cataract surgery. The overall cumulative incidence of 0.62% for postoperative RD is low.

Adult↗
PubMed2006

Association of connective tissue growth factor with fibrosis in vitreoretinal disorders in the human eye.

OBJECTIVE: To investigate the expression of the profibrotic connective tissue growth factor (CTGF) in relation to severity of intraocular fibrosis and neovascularization in human vitreoretinal disorders for the identification of potential therapeutic targets to prevent fibrosis. METHODS: Concentrations of CTGF were measured by enzyme-linked immunosorbent assay in 119 vitreous samples from patients with proliferative diabetic retinopathy, proliferative vitreoretinopathy, epiretinal membrane, and macular hole. Clinical data, including degree of intraocular fibrosis and neovascularization, were collected using standardized forms. RESULTS: Multifactorial analysis revealed that only CTGF levels correlated highly significantly with degree of fibrosis in the various vitreoretinal disorders studied (P<.001; R2= 47.7%). Likewise, variation in degree of fibrosis was best predicted by CTGF levels (P<.001). CONCLUSION: The strong correlation between CTGF levels and degree of fibrosis in vitreoretinal disorders suggests that CTGF is an important factor in ocular fibrosis, similar to its role in pathologic fibrosis in other organs. CLINICAL RELEVANCE: Connective tissue growth factor may be a therapeutic target for prevention of sight-threatening vitreoretinal scarring in the eye.

Connective Tissue Growth Factor↗
PubMed2006

Topical ibopamine in the treatment of chronic ocular hypotony attributable to vitreoretinal surgery, uveitis, or penetrating trauma.

PURPOSE: To study whether topical ibopamine effectively increases the intraocular pressure in patients with ocular hypotony after vitreoretinal surgery, uveitis, or penetrating trauma. DESIGN: A prospective randomized, double-blind, placebo controlled, crossover study. METHODS: In ten patients with ocular hypotony, an ibopamine 2% solution or placebo eyedrop was administered at 8 am and frequent applanation tonometry was performed during 10 hours on 2 days, 2 weeks apart. RESULTS: The mean IOP integral after administration of ibopamine was 2.4 mm Hg higher (95% CI for median difference in AUC over 480 minutes [P = .010]) compared with placebo. CONCLUSIONS: The results of the study show that an ibopamine 2% eyedrop twice a day may increase the IOP for a period of over 8 hours in patients with hypotony.

Administration, Topical↗
PubMed2005

Intravitreal dexamethasone as adjuvant in the treatment of postoperative endophthalmitis: a prospective randomized trial.

PURPOSE: To study whether intravitreal dexamethasone as adjuvant to intravitreal antibiotics improves the outcome in patients with suspected postoperative bacterial endophthalmitis. DESIGN: Prospective randomized clinical trial. SETTING: Tertiary referral center. PATIENT POPULATION: Twenty-nine consecutive patients with suspected postoperative bacterial endophthalmitis within 6 weeks of cataract surgery. INTERVENTION: Patients underwent a vitreous biopsy followed by intravitreal injection of antibiotics (0.2 mg vancomycin and 0.05 mg gentamicin) and 400 microg dexamethasone or placebo. After 3-4 days the intravitreal injection of antibiotics and dexamethasone or placebo was repeated. PRIMARY OUTCOME MEASURE: Snellen visual acuity at 3 and 12 months after treatment. RESULTS: In 20/29 patients (69%) the vitreous cultures were positive. 13/29 patients received dexamethasone. Seven patients had a functionally lost eye (final vision of hand movements or less), in four due to retinal detachment. Visual acuity tended to be better in the dexamethasone treated patients than in those given placebo, at both 3 months (P=0.055) and 12 months (P=0.080). CONCLUSION: This small prospective, placebo-controlled series showed a trend towards a better visual outcome in patients with suspected bacterial endophthalmitis when treatment with intravitreal antibiotics was combined with intravitreal dexamethasone. Our findings justify a larger multicenter randomized study.

Aged↗
PubMed2005

Effect of intravitreal dexamethasone on vitreous vancomycin concentrations in patients with suspected postoperative bacterial endophthalmitis.

PURPOSE: To study intravitreal dexamethasone and vancomycin concentrations, when used together in patients with suspected postoperative bacterial endophthalmitis. Animal studies had suggested that dexamethasone might decrease the concentration of vancomycin. DESIGN: Prospective randomized clinical trial in a tertiary referral center. METHODS: Twenty-nine consecutive patients with suspected postoperative bacterial endophthalmitis underwent a vitreous biopsy followed by intravitreal injection of antibiotics (0.2 mg vancomycin, 0.05 mg gentamicin) and 400 mug dexamethasone or placebo. After 3-4 days, the intravitreal injection of antibiotics and dexamethasone or placebo was repeated. In 18 patients, a second biopsy was taken for repeat culture and measurement of vancomycin and dexamethasone concentrations. RESULTS: In 20/29 patients (69%) the first vitreous cultures were positive; the second culture was negative in all cases. Thirteen out of 29 patients received dexamethasone. Dexamethasone concentrations showed an average of 25 ng/ml 3 days after injection, with an estimated half-life of 5.5 h. Vancomycin concentrations in patients given dexamethasone tended to be higher compared with those in the placebo group (P=0.061). CONCLUSION: Intravitreal dexamethasone does not lead to decreased vancomycin concentrations, when given simultaneously in the treatment of patients with suspected bacterial endophthalmitis.

Aged↗
PubMed2005

Symptoms and findings predictive for the development of new retinal breaks.

OBJECTIVE: To validate the conclusion of our previous prospective study of 250 patients with isolated posterior vitreous detachment: follow-up visits are only necessary if patients mention symptoms of flashes in combination with multiple floaters or a curtain or cloud at the initial examination, or an increase in number of floaters after the initial examination. METHODS: Prospective study of 270 consecutive patients with symptomatic isolated posterior vitreous detachment. All patients completed a questionnaire detailing their symptoms and had a full eye examination at the initial examination and at follow-up visits. Logistic regression with backward elimination was used for statistical analysis. We also performed pooled analysis of our previous and present study data. RESULTS: New retinal breaks developed in 10 patients (3.7%). Multiple floaters, a curtain or cloud, hemorrhages (retinal or vitreous) at the initial examination, and an increase in the number of floaters after the initial examination were found to be predictive factors for the development of new retinal breaks. These factors were also the only significant predictors after pooled analysis of both studies (520 patients, 23 breaks). CONCLUSIONS: We assume we can formulate a safe policy for scheduling patients with isolated posterior vitreous detachment: only patients with multiple floaters, a curtain or cloud, or hemorrhages (retinal or vitreous) at the initial examination should be scheduled for reexamination. All other patients should return only if the number of floaters increases.

Aged↗
PubMed2004

An unexpected experimental pitfall in the molecular diagnosis of bacterial endophthalmitis.

General primer-mediated ribosomal DNA amplification during endophthalmitis may improve the quality of diagnostic microbiology. However, extreme care needs to be taken not to introduce contaminating bacterial DNA during surgery procedures. The use of decontaminating iodine solutions can lead to such contamination due to the presence of DNA from Pseudomonas-like organisms.

Anti-Infective Agents, Local↗
PubMed2003

Persisting uveitis antedating psoriasis in two boys.

UNLABELLED: Two young boys had a severe uveitis which was difficult to treat. They both developed psoriasis located in the pubic area almost 1 year and several years later respectively. One boy also developed arthritis of an intermittent character. Both boys were ANA and HLA-B27 negative. CONCLUSION: in children, the possible association between uveitis and psoriasis with or without arthritis has to be kept in mind.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2003

Slit-lamp visualization of aqueous flow through an inferior iridectomy.

PURPOSE: To demonstrate how an inferior iridectomy prevents a pupillary block in aphakic patients with a silicone oil tamponade. DESIGN: Observational case series. METHODS: Photographs of two patients who had undergone vitrectomy, lensectomy, membrane peeling, silicone oil tamponade, and inferior iridectomy for a complex retinal detachment were evaluated. RESULTS: In the thin layer of erythrocytes covering the endothelium, we observed an arc clear of erythrocytes anterior to the inferior iridectomy. CONCLUSIONS: With silicone oil blocking the pupil, aqueous humor was channeled through the inferior iridectomy with sufficient force to sweep the endothelium anterior to the iridectomy clean of erythrocytes, thus visualizing the mechanism that prevents a pupillary block glaucoma.

Aqueous Humor↗
PubMed2003

Autologous retinal pigment epithelium and choroid translocation in patients with exudative age-related macular degeneration: short-term follow-up.

PURPOSE: To evaluate the feasibilty of translocating autologous retinal pigment epithelium cells and choroid after the removal of a subfoveal choroidal neovascular membrane in patients with exudative age-related macular degeneration. DESIGN: Interventional case series. METHODS: This was a prospective evaluation of six patients with a follow-up of 7 to 13 months. All patients had large (> 1 disk diameter) subfoveal choroidal membranes, five with subretinal hemorrhage. Preoperative visual acuity ranged from 20/400 to 20/200. After the extraction of the neovascular complex, an autologous peripheral full-thickness patch of retinal pigment epithelium, Bruch membrane, choriocapillary, and choroid was cut out from the midperiphery and repositioned under the macula. Functional tests included Early Treatment Diabetic Retinopathy Study vision testing, fixation testing on a optical coherence tomography monitor, fluorescein and indocyanine green angiography, and scanning laser ophthalmoscopy autofluorescence. RESULTS: The retinal pigment epithelium patch appeared flat and had a brown furry aspect in four patients. Fixation was on the patch in these four patients. Postoperative vision ranged from 20/200 to 20/64, with a 2-line increase in three patients. Revascularization was visible on fluorescein and indocyanide angiography in three patients examined in this manner. Normal retinal pigment epithelium autofluorescence was present over the patch in four patients. CONCLUSIONS: The translocation of a full-thickness patch with autologous peripheral retinal pigment epithelium to the macula after choroidal neovascular membrane extraction was feasible and may result in a surviving and functioning graft for more than 1 year. Longer follow-up to evaluate its long-term benefit is necessary, as well as refinement of the surgery.

Aged↗
PubMed2002

Intraocular penetration and systemic absorption after topical application of dexamethasone disodium phosphate.

PURPOSE: To study the dexamethasone concentration in aqueous humor, vitreous, and serum of patients after repeated topical application of dexamethasone disodium phosphate. DESIGN: Prospective nonrandomized comparative trial. PARTICIPANTS: Twenty phakic patients scheduled for a first vitrectomy. METHODS: All participants received dexamethasone disodium phosphate drops according to an application schedule intended to result in steady-state drug concentrations. Starting on the preoperative day, they received 1 drop of dexamethasone disodium phosphate (0.1%) every 1 hours until the time of vitrectomy (total, 10 or 11 drops). At night, ointment containing dexamethasone (0.3 mg/g) and gentamicin (5 mg/g) was administered once. From 7 AM on, the drop application schedule was resumed. At the start of the vitrectomy, samples were taken from the aqueous humor, vitreous, and blood. MAIN OUTCOME MEASURES: The dexamethasone concentrations in the aqueous humor, vitreous, and serum measured by radioimmunoassay. RESULTS: The mean dexamethasone concentrations in the aqueous humor, vitreous, and serum were 30.5 ng/ml (range, 7.1-57.7; standard deviation [SD] 15.0), 1.1 ng/ml (range, 0.0-1.6; SD 0.4), and 0.7 ng/ml (range, 0.0-1.2; SD 0.4), respectively. CONCLUSIONS: Compared with previously tested administration routes (peribulbar or subconjunctival injection or oral administration), the penetration of dexamethasone into the vitreous after repeated drop application is negligible. Despite the frequent dosing schedule, the dexamethasone concentration in the aqueous humor is far lower than after a subconjunctival injection with dexamethasone disodium phosphate. Systemic uptake is low.

Absorption↗
PubMed2002

Postoperative laser coagulation as retinopexy in patients with rhegmatogenous retinal detachment treated with scleral buckling surgery: a prospective clinical study.

PURPOSE: To evaluate postoperative laser photocoagulation as retinopexy mode in patients with rhegmatogenous retinal detachment treated with scleral buckling surgery. METHODS: The authors conducted a prospective feasibility study of consecutive patients with rhegmatogenous retinal detachment treated with scleral buckling surgery and postoperative laser during an 18-month period with a minimal follow-up of 6 months. Outcome measures were total retinal reattachment and the occurrence of proliferative vitreoretinopathy (PVR). RESULTS: A total of 123 patients (124 eyes) were included in this study. Seventy-six percent were phakic and 24% were pseudophakic. Fifty percent presented with one horseshoe tear, 15% with multiple tears, 30% with round breaks, and 5% with no identifiable break. Ten percent presented with a vitreous hemorrhage and 25% with three or four quadrants of detached retina. Six patients had PVR C1. Twelve patients required a postoperative gas injection, five patients received an additional buckle, and five patients underwent a vitrectomy, in four because of PVR. In all patients the retina was fully reattached at the end of follow-up. Planned postoperative laser coagulation took place 1 day to 10 weeks (median 3(1/2) weeks) after buckling surgery. Buckling material was removed in three patients without redetachment. CONCLUSION: Postoperative laser coagulation is a feasible alternative retinopexy mode in scleral buckling surgery, with encouraging anatomical results and a low incidence of PVR.

Cryosurgery↗