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Biomedical subjects

E Peperkamp

Publications and source records attributed to E Peperkamp.

At least 19 recordsLinked to original sources
PubMed2001

Randomized clinical trial of cryotherapy versus laser photocoagulation for retinopexy in conventional retinal detachment surgery.

PURPOSE: To investigate whether the method of retinopexy influences the visual recovery rate and the breakdown of the blood-ocular barrier after conventional retinal detachment surgery. METHODS: Forty-eight patients (48 eyes) with primary rhegmatogenous retinal detachment entered into the study. All eyes were phakic, had an attached macula, and were scheduled for conventional scleral buckling surgery. Patients were randomly assigned to have either laser or cryotherapy for retinopexy. All visual acuity and flare measurements were performed by a masked observer. The interventional procedure was cryopexy at the time of scleral buckling surgery or postoperative (4 weeks) laser photocoagulation. Visual acuity testing with ETDRS chart and aqueous flare measurement with laser flare photometry were performed by a masked observer at standard intervals: preoperatively and 1 day, 7 days, 4 weeks, and 10 weeks postoperatively. Analysis of covariance by multiple linear regression was used for statistical evaluation. RESULTS: Postoperative flare values from patients receiving cryotherapy were significantly higher at each measurement point in time (P < or =.001). The visual recovery was slower in the patients receiving cryotherapy (1 week, P =.003; 4 weeks, P =.03; 10 weeks, P =.081). CONCLUSION: Laser flare photometry proved sufficiently sensitive to quantify an increase in aqueous flare after limited external retinal cryotherapy. Postoperative flare, as a measure of blood-ocular barrier breakdown, was significantly higher and visual recovery slower in the cryotherapy group. Visual acuity after 10 weeks was not significantly different between both groups.

Blood-Retinal Barrier↗
PubMed1999

Follow-up of functionally lost eyes after vitrectomy and silicone oil tamponade for tractional retinal detachment.

BACKGROUND: Is there any association between, on the one hand, retention or removal of silicone oil or any specific ocular finding in patients with functionally lost eyes after vitrectomy and silicone oil tamponade for tractional retinal detachment and, on the other, a greater chance of preservation of the eye? This information is important in deciding whether to remove silicone oil, as well as in counseling patients about their individual chances of preserving their eye. METHODS: Seventy-three consecutive patients with a functionally lost eye with a minimum follow-up of 3 years were retrospectively studied. The relation between the variables at study entry or the removal of silicone oil during the follow-up period and a subsequent intervention (enucleation, evisceration or conjunctival cover with a scleral shell) were tested for statistical significance with Cox proportional hazards analysis. RESULTS: The absence or removal of silicone oil was not associated with a greater chance of finally preserving the eye. Nor could we identify other factors which predicted better chances of preservation. CONCLUSION: The notion that functionally lost eyes after treatment with vitrectomy and silicone oil tamponade for complicated tractional retinal detachment have better chances of preservation of the eye without silicone oil is not supported by our study.

Blindness↗
PubMed1996

Rubeosis of the iris in proliferative vitreoretinopathy.

PURPOSE: The authors report the findings and clinical course of rubeosis in patients with essentially reattached retinas after vitrectomy and silicone oil for proliferative vitreoretinopathy (PVR). METHODS: From 1989 on, the authors prospectively noted all patients with rubeosis and with attached retina posterior to the buckle after vitrectomy and silicone oil for PVR as a complication of rhegmatogenous retinal detachment. RESULTS: Thirty-eight patients (38 eyes) were studied. Mean follow-up after the appearance of rubeosis was 27 months (range, 6-66 months) in all patients, peripheral residual retinal detachment coexisted with rubeosis. Hypotony occurred in six patients. Cyclocryocoagulation for neovascular glaucoma had been performed in four patients. The peripheral detached retina was removed in 16 patients, resulting in total disappearance of rubeosis in 7 patients and regression in 4 more patients. In patients with visible, nonradially oriented iris vessels, the authors found vessels in the anterior chamber angle crossing the trabecular meshwork. The frequently present anterior synechiae in association with vessels never totalled more than three clock hours (except in the four patients who underwent cyclocryocoagulation). CONCLUSIONS: Detached retina peripheral to dense photocoagulation scars was present in all of these patients. Removal of this peripheral detached retina was statistically significantly associated with disappearance of rubeosis, which suggests that the peripheral detachment was a causative factor. Extensive anterior synechiae are not formed frequently in this condition. This may explain the infrequent (11%) occurrence of neovascular glaucoma. However, hypotony is more frequent.

Fluorescein Angiography↗
PubMed1994

Cytokines in vitreous humor: interleukin-6 is elevated in proliferative vitreoretinopathy.

PURPOSE: To measure the levels of interleukins (IL) 1 beta, 6, and 8, and tumor necrosis factor-alpha (TNF alpha) in the vitreous of patients with proliferative vitreoretinopathy (PVR), proliferative diabetic retinopathy (PDR), vitreous hemorrhage, and macular pucker. METHODS: Vitreous samples were collected, undiluted, from patients with PVR, PDR of varying severity, and miscellaneous lesions (vitreous hemorrhage from trauma, macular degeneration, vein occlusion, and non-PVR patients with giant tear, retinal detachment, and macular pucker). Immunoreactive levels of the cytokines, IL-1 beta, IL-6, IL-8, and TNF alpha were determined by enzyme-linked immunoadsorbent assays, and samples were analyzed for protein and hyaluronic acid content using standard assays. RESULTS: The levels of TNF alpha were below detection limits of the assay (< 3 pg/ml). In 45 of the 47 samples tested, IL-1 beta levels also were below detection limits of the assay (< 3 pg/ml). IL-6 levels ranged from < 30 to 5487 pg/ml, with the highest values observed in the PVR patients. IL-8 levels ranged from < 20 to 1900 pg/ml, and were consistently high in the miscellaneous group. Some of the PVR patients with C2 and C3 level severity also exhibited IL-8 levels exceeding 100 pg/ml. In a second study, IL-6 content of vitreous from miscellaneous and PVR patients was compared. In this study, significantly elevated levels of IL-6 were observed in the PVR patients (91.5 +/- 18 pg/ml) compared to the miscellaneous group (10.3 +/- 3.7 pg/ml) CONCLUSIONS: Elevated levels of IL-6 in the vitreous occur in PVR, implicating a role for this cytokine in the pathogenesis of this ocular disorder.

Adult↗
PubMed1993

Changes in refraction after retinal detachment surgery corrected by extended wear contact lenses for early visual rehabilitation.

The encircling band used in conventional retinal detachment surgery creates a circular indentation of the eye and thus may increase the anterior-posterior axial length. The myopia induced by encircling elements in retinal detachment surgery varies between 0 and 3 D. In a series of 25 patients, the average change in refraction after surgery was -2.25 D. To achieve early visual rehabilitation, patients were fitted with extended-wear soft contact lenses 7 to 10 days after surgery. The patients were followed for up to 6 months and contact lenses were exchanged according to changes in refraction. Visual rehabilitation using extended-wear lenses was immediate and excellent. The contact lenses were tolerated well. Two patients developed a minor corneal infiltrate under the soft lens and were withdrawn from the study.

Adult↗
PubMed1993

Five-year results of vitrectomy and silicone oil in patients with proliferative vitreoretinopathy.

The purpose for this study was to evaluate the results of silicone oil use in patients who have undergone vitrectomy for proliferative vitreoretinopathy (PVR). The authors reviewed the 5-year results of 50 consecutive patients (52 eyes) with grade C1/D3 PVR operated on in 1987. Silicone oil has been removed in 42 eyes. The retina remained attached in 38 eyes. Visual acuities were finger counting in 12 eyes and 0.1 or greater in 19 eyes. Glaucoma was thought to be the major cause of loss of visual acuity after an initial improvement (9 eyes), as well as the most frequent complication of surgery (13 eyes). Silicone oil was deemed nonremovable in 10 operated eyes. A questionnaire was developed to determine the patients' perceptions of the use of silicone oil, and 46 patients responded to the questionnaire. Four patients indicated that they would not have elected to have surgery again. Six patients thought that surgery was not worthwhile, but would permit treatment again. Most patients thought that a modest amount of improvement had taken place and that vision was stable. Subjectively, most patients believed that surgery was worthwhile.

Evaluation Studies as Topic↗
PubMed1992

Endophthalmitis: incidence, therapy and visual outcome in the period 1983-1992 in the Rotterdam Eye Hospital.

From 1983 to 1992, 134 patients were treated for clinically suspected endophthalmitis. 61% of this endophthalmitis population consisted of cases that were referred to our clinic. In this nine year period antibiotic treatment was carried out according to three consecutively used guidelines. These three treatment schemes differed in antibiotic spectrum and mode of antibiotic delivery. In 68 patients we performed vitrectomy on account of clinical deterioration under antibiotic treatment. We did not find significant differences in visual outcome between the three treatment groups. The incidence of endophthalmitis following cataract or vitreous surgery did not change throughout the study period. There was however a dramatic decrease in incidence of post-traumatic endophthalmitis following the introduction of a prophylactic antibiotic treatment scheme consisting of fortified gentamicin and cefazolin eyedrops, and intravenously and subconjunctivally administered gentamicin, cefazolin, and clindamycin. In 55 of 68 cases in which vitrectomy was performed in conjunction with intravitreal antibiotics, a vitreous or anterior chamber specimen was cultured. 36 patients had a positive culture result. In the group with positive culture result 42% had better visual acuity in the post-treatment period than before treatment. In the group with a sterile culture result 79% had better vision after treatment.

Anti-Bacterial Agents↗
PubMed1992

Plasma prorenin as an early marker of microvascular disease in patients with diabetes mellitus.

To test the hypothesis that a high plasma prorenin can be used as an early marker of microvascular complications in patients with diabetes mellitus plasma prorenin was measured in 44 patients with urinary albumin excretion between 30 and 300 mg/24 h (microalbuminuria) and 120 patients with urinary albumin excretion below 30 mg/24 h (normoalbuminuria). A high plasma prorenin was associated with diabetic retinopathy, particularly the proliferative type, serum creatinine and the 24 h urinary albumin excretion rate. Plasma prorenin was not correlated with age, duration of diabetes, glycosylated hemoglobin, blood glucose, and blood pressure. The association between elevated plasma prorenin and retinopathy remained significant after adjustment for serum creatinine and albumin excretion. Independent of the presence or absence of microalbuminuria, the mean plasma level of prorenin was not above normal in patients without retinopathy and was 2 to 3 times normal in patients with proliferative retinopathy. Thus retinopathy appears to be an important determinant of abnormally high plasma prorenin. Angiotensin converting enzyme (ACE) was elevated in the patients with diabetes mellitus as compared to control subjects but the plasma levels of ACE in diabetics with normoalbuminuria was not significantly different from the group with microalbuminuria. Plasma prorenin was not associated with ACE. A plasma level of prorenin of 225 mU/L had a sensitivity of 0.84 and a specificity of 0.82 for detecting the presence of microalbuminuria.

Adult↗
PubMed1991

Analysis of local antibody production in the vitreous humor of patients with severe uveitis.

We analyzed the local antibody production in vitreous humor samples collected during vitrectomy in patients with severe vision-threatening uveitis. In 24 patients, paired serum and undiluted vitreous humor samples were collected and tested for antibodies against Toxoplasma gondii, herpes simplex virus, varicella-zoster virus, cytomegalovirus, Epstein-Barr virus, and Toxocara canis. Total IgG and the Goldmann-Witmer coefficient were determined. The initial diagnosis of ocular toxoplasmosis could be confirmed in six of the seven patients. The seventh patient showed a local antibody production against herpes simplex virus. One of the three patients with chronic panuveitis at initial diagnosis showed a local antibody production against T. gondii. These last two findings resulted in a change in medical treatment. Analysis of local antibody production in vitreous humor samples is a valuable diagnostic tool.

Animals↗
PubMed1991

Retinal folds through the macula.

In a series of 137 consecutive conventional primary retinal detachment repairs we postoperatively found retinal folds through the macula in four cases (2.8%). All four patients had presented with an acute, bullous, superior detachment, and had been treated with an encircling band, drainage of subretinal fluid, injection of an air/gas mixture, cryocoagulation, and a radial buckle to close the largest retinal tear. Redundant retina (created by the encircling band and possibly by stretching in the bullous detachment) became folded either by compression by the gas-bubble in the recumbent patient, or by a steam roller action of the bubble when the patient sat up. In acute bullous detachments, we try to avoid this complication by using an air/gas bubble which is not greater than necessary to tampon the retinal break, and by positioning the patient in such a way that residual subretinal fluid is pressed away from the posterior pole.

Follow-Up Studies↗
PubMed1990

High plasma prorenin in diabetes mellitus and its correlation with some complications.

Plasma prorenin is abnormally high, whereas renin is normal or even low, in many patients with long-standing diabetes mellitus complicated by microvascular disease. Nephropathy or autonomic neuropathy has been put forward as a cause. We found that in 223 consecutive diabetics prorenin correlated positively with serum creatinine, the presence of macroalbuminuria (greater than 250 mg/L), and the presence of diabetic retinopathy, particularly the proliferative type. This correlation did not depend on the presence of neuropathy or whether the patient was receiving insulin. It was also independent of sex, age, duration of diabetes, blood pressure, and blood levels of glucose and hemoglobin-A1c. The association between elevated prorenin and retinopathy remained significant after adjustment for creatinine and the presence of macroalbuminuria. Of the whole group of diabetics 94 consecutive patients were assessed for the presence of microalbuminuria (30-300 mg/24 h). Independently of the presence of micro- or macroalbuminuria, the mean level of prorenin was not above normal in the patients without retinopathy and was 2-3 times normal in those with proliferative retinopathy. Thus, retinopathy appears to be a more important determinant of abnormally high prorenin than nephropathy. In addition, the renal vein to artery ratio of prorenin in 7 diabetics with both advanced nephropathy and proliferative retinopathy was not elevated, despite the high peripheral venous prorenin level and the impaired renal perfusion. Thus, the abnormally high prorenin level in these patients could not be explained by abnormal secretion by the kidneys. Finally, prorenin was not high in 16 nondiabetics with loss of sympathetic activity due to chronic autonomic neuropathy, which indicates that in the absence of diabetes, this type of autonomic failure is not sufficient to cause the high prorenin levels seen in diabetics. Our findings are evidence that abnormally high plasma prorenin levels in diabetics are not an immediate consequence of altered glucose metabolism. This abnormality is related to the development of microvascular disease in the eye and kidney and is at least in part due to decreased clearance of prorenin from the circulation, increased production from extrarenal sources, or both.

Albuminuria↗
PubMed1989

Renin, prorenin, and immunoreactive renin in vitreous fluid from eyes with and without diabetic retinopathy.

Renin, prorenin, and immunoreactive renin were present in vitreous and subretinal fluid of eyes from subjects with and without diabetic retinopathy. Renin substrate, albumin, transferrin, and immunoglobin G were also found in these ocular fluids. In many samples renin levels were close to the detection limit of the assay. The levels of renin substrate, albumin, transferrin, and immunoglobulin G varied widely among ocular fluid samples, but in each individual sample the levels were, relative to each other, similar to those in plasma. In contrast, the prorenin level in ocular fluid was up to 100 times higher than expected on the basis of the plasma protein content of ocular fluid. Moreover, there was little difference in prorenin concentrations between samples with low and high plasma protein contents. Prorenin, relative to albumin and other plasma proteins, was higher in vitreous fluid from eyes with proliferative diabetic retinopathy complicated by traction retinal detachment than in eyes of nondiabetic subjects with spontaneous retinal detachment. It appears that prorenin (and possibly renin) in ocular fluid is controlled by an active and specific process, possibly local synthesis within the eye. In view of the vascular actions of angiotensin II, an intraocular renin-angiotensin system may play a role in diabetic retinopathy.

Adult↗
PubMed1987

Basal iridectomy at 6 o'clock in the aphakic eye treated with silicone oil: prevention of keratopathy and secondary glaucoma.

In the aphakic eye, with intact iris diaphragm, silicone oil has frequently caused a pupillary block. In this situation aqueous humour accumulates behind the iris and forces silicone oil through the pupil into the anterior chamber. An iridectomy at the 6 o'clock position can effectively prevent this pupillary block. The iridectomy allows free passage of aqueous to the anterior chamber which remains free of silicone oil. No permanent contact with silicone oil and the cornea is established, and development of keratopathy is prevented. The effect of this iridectomy in 62 eyes with intact iris diaphragm in patients in Rotterdam (35 cases) and Nagoya (27 cases) is demonstrated. Only in 6.5% of the cases was silicone oil present in the anterior chamber at the end of the follow-up period of 7 months.

Aphakia, Postcataract↗
PubMed1982

Immune electron microscopy and a cultural test in the diagnosis of adenovirus ocular infection.

Immune electron microscopy (IEM) and virus isolation in cell culture were compared in the diagnosis of adenovirus ocular infection during an outbreak of the disease in 1979. Eleven of 14 patients with a keratoconjunctivitis clinically indicative of adenovirus infection had IEM evidence of adenovirus infection or had the virus isolated from ocular swabs. The IEM was positive in 8 patients. Virus as isolated from 10 patients. IEM was positive in one culture negative patient. Since IEM provides a rapid and sensitive method for the detection of adenovirus in human tears, it may be a valuable diagnostic tool for the clinician.

Adenoviridae Infections↗
PubMed1982

[Liquid silicone in amotio surgery (II). Report on 280 cases - further development of the technic].

Indications, results, modified techniques and complications in 280 cases treated with fluid silicon are reported. In about 80% of the cases intravitreal silicon injection under binoscopic control was performed according to the principles described by J. Scott. In the most difficult cases a vitrectomy was carried out and silicon was used only as an internal tamponade. In certain situations the retina itself was treated. The new techniques developed for that purpose are discussed. The follow-up period was between six months and four years. An anatomic success was achieved in more than 70% of the cases. Causes of late complications with the first 100 patients who underwent surgery are discussed. Removal of silicon after a certain period appears a real possibility in spite of initial complications.

Humans↗
PubMed1979

Experiences with laser trabeculopuncture.

54 eyes with glaucoma simplex and 21 eyes with secondary chronic glaucoma were treated once by laser trabeculopuncture and followed up for at least 1 year. The results in the first group were encouraging, in the second group disappointing. L.T.P. appears to be a technique with which, in the majority of cases of glaucoma simplex, a sustained moderate decrease in pressure can be obtained.

Follow-Up Studies↗