Biomedical subjects

C Ohrloff

Publications and source records attributed to C Ohrloff.

At least 37 records · Page 2Linked to original sources

PubMed1997

Comparison of phacoemulsification and planned extracapsular extraction.

76% of cataract surgeons in German speaking countries use phacoemulsification (phaco) as the procedure of choice for cataract extraction while the other 24% still use the planned extracapsular extraction (ECCE). The opening technique of the anterior capsule is chosen accordingly: for phaco capsulorhexis is preferred, while for ECCE can opener or letter box technique is usually done. The length of the sclerocorneal incision is 3.2 mm in phaco, 6.2 mm for a PMMA posterior chamber lens implantation and 9-13 mm for the ECCE. We prospectively compared both procedures with each group including 100 consecutive patients. The mean irrigation volume was 96.6 +/- 48.8 ml in the phaco group as opposed to 48.1 +/- 26 ml in the ECCE group. The mean duration of irrigation was 130 +/- 67 s in the first versus 129 +/- 76 s in the second group; mean endothelial cell loss was 7.9 versus 7.1%. No correlation was found between endothelial cell loss and duration of irrigation. Mean postoperative astigmatism measured 1.0 +/- 0.49 in the first group as compared to 3.3 +/- 1.7 dpt in the second group. Except for the astigmatism, our study could not detect significant differences regarding the outcome between both procedures. There are advantages to the phacoemulsification procedure, however, such as a smaller incision (e.g. tunnel technique), a closed irrigation-aspiration system, controlled intraocular pressure and the more frequent use of capsulorhexis. Preferred indications are zonulolysis or previously performed fistulating surgery.

Astigmatism↗

PubMed1997

Opportunistic infections of the eye in immunocompromised patients.

All opportunistic infections of the eye have their origin in the suppression of the immune system of the host. The immunosuppression can be acquired through the human immune deficiency virus or as a result of immunosuppressive therapy in solid-organ transplant recipients with a maintenance therapy of cyclosporin and prednisone or during chemotherapy in patients with myeloproliferative disorders. Generally, in less than 2% could severe opportunistic infections of the eye, like cytomegalovirus (CMV) or herpes virus infection, be found in transplant and cancer patients with chemotherapy. About 35-70% of patients with AIDS exhibit ocular manifestations of disease, so the most notable opportunistic infection with an incidence of 35% would be CMV retinitis. Less frequent are progressive outer retinal necrosis syndrome, Kaposi's sarcoma and optic neuropathies. This paper reviews recent advances in the diagnosis and special local therapies of the worst opportunistic infections in immunocompromised hosts.

AIDS-Related Opportunistic Infections↗

PubMed1996

[Ultrasound biomicroscopy--image of the capsule supporting ring in pseudophakia].

SCOPE OF THE STUDY: We studied the possibility to examine position and determination of IOL and capsular bag supporting ring. PATIENTS AND METHODS: We showed in ten human eyes the identification of capsular bag supporting ring (PMMA, 12,5 mm open diameter) and intraocular lenses (IOL, 13,5 mm diameter) and haptics by ultrasound biomicroscopy in radar and limbus parallel scans 12 to 18 months post operation. RESULTS: Both alloplastic implantates show typical sceems of reflection and could be differentiated by ultrasoundbiomicroscopy. In eyes with zonulolysis up to 6 hours a good centration of capsular bag supporting ring and IOL had been seen, with more zonulolyses a slight subluxation could been shown. CONCLUSION: Ultrasound biomicroscopy is a good method to determine the position of intraocular lens and capsular bag supporting ring.

Humans↗

PubMed1996

[Regulation of glutathione level in venous plasma and aqueous humor in cataracta senilis provecta].

UNLABELLED: Glutathione is a major component of the mechanisms protecting the eye against oxidants. To analyse the functional status and the regulation of the glutathione system in the eyes of patients with advanced cataract, glutathione concentrations were quantified in venous plasma and aqueous humor. METHODS: In all, 42 patients with advanced cataract (29 women, 13 men; mean age (+/- SEM) 70 +/- 2 years; vision < or = 0.3) were evaluated. Aqueous humour and venous plasma were obtained at the beginning of cataract surgery. RESULTS: Levels of total glutathione [reduced (GSH) + oxidized glutathione (GSSG)] in plasma were 2.34 +/- 0.23 microM. There was 2.08 +/- 0.15 microM in the reduced form and 0.27 +/- 0.17 microM oxidized glutathione, which means that 94.7 +/- 2.1% of the total glutathione was GSH, the form fully functional as an antioxidant. Levels of total glutathione in the aqueous humor were 1.2 +/- 0.16 microM, i.e. 54.5 +/- 4.8% of plasma levels. Surprisingly, the percentage of GSSG in aqueous humor (0.24 +/- 0.07 microM, 31 +/- 10.5% of the total glutathione) was much higher than that in plasma (P < 0.001). The correlation between glutathione concentrations in plasma and aqueous humor was on the borderline of significance (rs = 0.32, P < 0.04). CONCLUSION: The proportion of oxidized glutathione is higher in aqueous humor than in plasma of patients with advanced senile cataracts, indicating increased oxidant stress in the eye. Further, the regulation of the glutathione system in the eye, at least in aqueous humor, is dependent on plasma glutathione levels. This correlation reflects the importance of sufficient glutathione levels in venous plasma and suggests the possibility of modulating the glutathione system in the eye via manipulation of plasma glutathione levels.

Aged↗

PubMed1996

[Effect of cataracts on contrast pattern reversal stimuli exemplified by the pattern electroretinogram].

A cataract changes pattern-evoked contrast responses to a mostly unknown extent by a blurred retinal image. Pattern electroretinograms (P-ERG), evoked by a reversing checkerboard pattern, were measured (a) in 12 healthy volunteers with a cataract simulated by Bangerter foils; (b) pre- and postoperatively in 44 cataract eyes without retinal damage; and (c) in 13 healthy contralateral eyes. Slight media opacities (visual acuity 1.0 to 0.8) already diminished the amplitudes of the pattern ERG significantly, whereas the latencies did not react significantly. This can be explained by a decrease more in contrast than in luminance. Postoperatively, the amplitudes continued to increase during the first 10 weeks, when the visual acuity remained stable. The postoperative amplitudes did not reach the amplitudes of comparable healthy contralateral eyes. It is recommended that eyes be checked for cataracts before an interpretation is made.

Adolescent↗

PubMed1995

The blood-ocular barrier in type I diabetes without diabetic retinopathy: permeability measurements using fluorophotometry.

For the evaluation of a possible malfunction of the blood-retinal (BRB) and the blood-aqueous barrier (BAB) in type I diabetes without manifest angiopathy, after i.v. injection of sodium fluorescein, the permeability of BRB (P) and the diffusion coefficient of BAB [P(a)] were studied simultaneously by fluorophotometry in 34 eyes of 34 type I diabetics (HbA1c = 6.6 +/- 0.9%) without retinopathy whose ages ranged from 19 to 38 years (30.5 +/- 5); diabetes' duration was between 5 and 18 years. Fluorescein angiography was performed to exclude nonperfused areas. In all, 34 eyes of 34 healthy volunteers whose ages ranged between 23 and 34 years (28.5 +/- 3.3) served as controls; in this group, fluorophotometry was performed twice to evaluate reproducibility. The mean BAB diffusion coefficient in diabetics [P(a) = 5.3 +/- 1.8/min] was significantly increased (p = 0.00003) as compared to controls [P(a) = 3.7 +/- 0.7/min]; BRB permeability in diabetes (P = 3.2 +/- 1.4 x 10(-7) cm/s) was raised with this elevation being of lower significance (p = 0.019; controls: P = 2.6 +/- 0.7 x 10(-7) cm/s). We found a decrease in BRB permeability depending on diabetes' duration (r = -0.15; p = 0.007) that was not significant in BAB (r = -0.1; p = 0.24). No correlation was found to exist between permeability and HbA1c values either in BAB or in BRB. The reproducibility in controls was 9% in BRB determinations and 12% in BAB measurements. These results may suggest that early structural alterations without the manifestation of retinopathy possibly cause elevation in BRB permeability and are even more obvious in BAB permeability. Whereas the reliability of vitreous fluorophotometry in detecting early BRB malfunction has to be judged critically, anterior segment fluorophotometry is a reliable procedure for the monitoring of BAB affection in type I diabetes without retinopathy.

Adult↗

PubMed1995

[Long-term stability of astigmatism after suture correction in penetrating keratoplasty].

Severe astigmatism after penetrating keratoplasty is frequently a major problem. If one uses a technique to adjust a single running 10-0 nylon suture in the early period after keratoplasty, the suture tension can be redistributed and astigmatism reduced. Eighteen eyes with an average of 8.8 D of postkeratoplasty astigmatism underwent suture adjustment. The mean keratometric astigmatism before suture removal was 3.1 D. After suture removal with an follow-up of 25 months, the mean corneal astigmatism was 3.2 D, only one eye did the suture break during adjustment. No infection, vascularization or rejection occurred.

Adolescent↗

PubMed1995

[The aqueous humor-vitreous body barrier and the blood-aqueous humor barrier after YAG laser capsulotomy in capsular sac vs ciliary sulcus fixation of the intraocular lens].

UNLABELLED: An intact posterior capsule between aqueous and vitreous may act as a barrier to substances of low and high molecular weight, e.g., prostaglandins, hyaluronic acid, or the angiogenic factor. After phacoemulsification followed by posterior YAG capsulotomy, an increased diffusion rate of such molecules into the vitreous and increased permeability of blood aqueous barrier (BAB) may occur. These barriers were quantified in eyes that underwent YAG capsulotomy after sulcus or intracapsular IOL implantation in order to determine the safest surgical procedure with respect of maintenance of these barriers. PATIENTS AND METHODS: Between 2 to 6 h after topical fluorescein application, the time-dependent decrease in dye concentration ratio between aqueous and anterior vitreous leads to the diffusion rate D(av) [10(-3)min-1] between aqueous and vitreous; D(av) was evaluated fluorophotometrically before and 3 weeks after capsulotomy (3 to 5 mm) in human eyes of each group. In order to quantify BAB function, aqueous laser flare was measured in eyes with sulcus and capsular fixation of IOL before, 3 h, and 3 weeks after YAG capsulotomy. RESULTS: After YAG surgery D(av) increased 2.7-fold (P < 0.001) in eyes with a sulcus implant compared to the values obtained in the group that had an intracapsular PCL. Aqueous laser flare was increased to 140% (P < 0.001) in eyes with sulcus fixation and to 95% (P < 0.001) in eyes with capsular fixation of PCL. Laser flare values became normal 3 weeks after laser treatment (P > 0.05). CONCLUSION: Intracapsular PCL implantation more effectively maintains the protective aqueous vitreous barrier and BAB after posterior capsulotomy than sulcus implantation. This possibly reduces the incidence of cystoid macular edema (diffusion of prostaglandins), retinal detachment (loss of hyaluronic acid of the vitreous), endophthalmitis (spread of bacteria) or rubeosis iridis (angiogenic factor) after YAG capsulotomy.

Aqueous Humor↗

PubMed1995

[Balloon dilatation of relative postsaccal lacrimal duct stenoses].

In ten patients with incomplete postsaccal stenosis radiology examined by digital subtraction dacryocystorhinography, an overpressure ballooning was done with a small foot vessel balloon with hydrophilic surface under image intensiver control. The balloon was inflated with a diluted suspension for visualization of the balloon and widening of the stenosis. In eight patients recovery was continuous without any treatment, in one with topical application of vasoconstrictor eye drops. In one patient there was a recurrence. Balloon of incomplete postsaccal lacrimal pathway dilatation stenosis is an adequate and minimally invasive therapy.

Angiography, Digital Subtraction↗

PubMed1995

[Selective inhibition of replication of human cytomegalovirus by desferrioxamine in vitro and in vivo (case report)].

UNLABELLED: In AIDS patients cytomegalovirus (HCMV) retinitis is one of the most frequent opportunistic infections. Antiviral therapy aims at preserving vision as long as possible, but more and more HCMV isolates are proving to be resistant to ganciclovir (GCV) and foscarnet (PFA) in vitro. We tested whether desferrioxamine (DFO), an iron chelator with antiherpetic activity, can inhibit clinical virus isolates and laboratory strains. Clinical isolates were obtained from urine samples of AIDS patients with HCMV retinitis. The concentrations of DFO required for 50% and 90% reduction of the production of HCMV in several HCMV strains ranged from 3.1 to 4.9 microns and from 14.2 to 17.3 microns, respectively, Inhibitory effects of DFO on HCMV replication were completely prevented by co-incubation with stoichiometric amounts of FE3+. CASE REPORTS: DFO was administered by daily dose of 1 g i.v. to a patient with AIDS in whom HCMV retinitis continued to progress despite combination therapy with GCV and PFA. The addition of DFO to the combination inhibited progression of the disease. No relapse of HCMV retinitis was seen with 3 months of DFO therapy. The treatment was free of side effects.

AIDS-Related Opportunistic Infections↗

PubMed1995

[Vitreous involvement in cytomegalovirus retinitis].

In our outpatient department we often see patients with vitreous inflammation. Recent reports emphasize that vitreous inflammation is very rare, so we looked for patients with cytomegalovirus (CMV) retinitis and vitreous inflammation. We investigated 359 HIV-positive patients for at least 1 year; all patients reached the stage of AIDS disease. We included patients without any retinal signs of CMV retinitis at the beginning or CMV recurrence during the study. A slit-lamp investigation, binocular funduscopy and b-picture ultrasound were done at regular intervals. The results show an increase in vitreous inflammation with the frequency of CMV retinitis recurrences. Patients very often develop retinal detachment. Vitreous inflammation is a critical factor when examining CMV retinitis. In the future a larger series of patients should be examined.

AIDS-Related Opportunistic Infections↗

PubMed1994

[Importance of an intact posterior capsule for the vitreous body. Complication of posterior capsulotomy].

The various extracapsular cataract surgery techniques keep the anatomy and physiology of the eye largely untouched, since both the intact posterior capsule and the crystalline lens form a diaphragm between the aqueous humour and the vitreous. If the posterior capsule opacifies--which occurs in up to 50% within five years postoperatively--a capsulotomy becomes necessary. This increases the rate of retinal detachment and cystoid macular edema. To date no pharmacologic or immunologic means exist to prevent posterior capsule opacification. Implanting the IOL into the capsule bag and the biconvex lens design by itself reduce the incidence of opacification. The biconvex optic of the IOL seals the gap in the capsule, if a capsulotomy has been performed; fluorophotometry shows us that the diaphragm function remains intact after in the bag implantation as compared to sulcus fixated IOL.

Cataract↗

PubMed1994

[Front-loading rt PA thrombolytic therapy in central or venous branch occlusions of the retina].

UNLABELLED: Although central retinal vein occlusion and branch retinal vein occlusion are among the most common vascular disorders affecting the retina, there is a great deal of confusion about their management. In view of the histopathological features of ischemic retinal vein occlusions, the use of fibrinolytic agents such as rt-PA (recombinant tissue-plasminogen activator) appears to be the most promising therapeutic approach. PATIENTS: In nine patients with ischemic retinal vein occlusion, 50 mg of rt-PA were given i.v. over a period of 60 min. Simultaneously, heparin was infused at 1200 U/h. The i.v. heparinization was continued over a period of 8 days. RESULTS: The clinical course was assessed by documenting visual acuity, fluorescein angiographies and fundal examinations. Additionally, several coagulation parameters were measured. No hemorrhagic complications were observed. In 8 cases, an improvement of visual acuity and retinal perfusion was noted. CONCLUSION: Based on our results, we would recommend the fibrinolytic therapy with rt-PA and heparin in the treatment of ischemic retinal vein occlusions.

Adult↗

PubMed1994

In vitro anti-human cytomegalovirus activity of liposome-encapsulated foscarnet.

Foscarnet is a pyrophosphate analogue that possesses substantial activity against human cytomegalovirus (HCMV) in patients with CMV retinitis. In this in vitro study we tested whether liposome encapsulation of foscarnet would provide the drug with anti-HCMV activity comparable with that of nonencapsulated foscarnet. The drug was entrapped in large unilamellar vesicles of homogeneous size at a concentration of 10 mg/ml. The vesicles were prepared by the method of fast and controlled dialysis of mixed detergent-lipid micelles using N-Octyl--D-glucopyranoside as the detergent. The activity of drugs against two laboratory HCMV strains (AD169 and Towne) was tested in a plaque-reduction assay using monolayers of human foreskin fibroblasts. The dose of encapsulated or nonencapsulated foscarnet required for a 50% reduction in the number of plaques (IC50) for the AD169 strain was 106 and 113 mumol/l, respectively. For the HCMV Towne strain the dose was 112 and 109 mumol/l, respectively. Treatment with concentrations of up to 400 mumol/l (maximal concentration tested) demonstrated that foscarnet is released at efficient doses from liposomes and that it is not toxic in the range of concentrations tested.

Cells, Cultured↗

PubMed1993

[The blood-retina barrier and blood-aqueous humor barrier in type I diabetic patients without retinopathy. Determination of permeability using fluorophotometry and laser flare measurements].

BACKGROUND: Possibly early functional disruption of the blood-ocular barrier in eyes of insulin dependent type I diabetics without manifestation of retinopathy can be detected using fluorophotometry and laser flare measurement. MATERIAL AND METHODS: In order to evaluate blood-retinal (BRB) and blood-aqueous-barrier (BAB) permeability fluorophotometry was performed in 34 eyes of 34 insulin-dependent type-I diabetics without retinopathy, additionally the aqueous laser flare was measured. 34 normal eyes of 34 age-matched subjects served as controls. RESULTS: BRB permeability (3.2 +/- 1.3 x 10(-7) cm/s) was increased with low significance (p = 0.019) in diabetic eyes (controls: 2.6 +/- 0.7). The permeability coefficient of BAB was found to be increased in diabetics (5.3 +/- 1.8 x 10(-4)/cm) with higher significance (controls: 3.7 +/- 0.7; p = 0.00003); laser flare values in diabetic eyes (5.0 +/- 1.2 photon counts/ms) were significantly higher than in controls (4.1 +/- 1.0; p = 0.003). In diabetics there was a significant correlation (r = 0.3; p = 0.014) between the laser flare values and the permeability coefficient of BAB. CONCLUSIONS: In type-I diabetics without retinopathy BRB permeability seems to be increased slightly as well as laser flare in the aqueous; the BAB permeability coefficient seems to be the most sensitive parameter in a beginning affection of the blood-ocular barrier.

Adult↗

PubMed1993

[Comparison of phacoemulsification and planned extracapsular cataract extraction].

40% of cataract surgeons in German speaking countries use phacoemulsification as the procedure of choice for cataract extraction while the other 60% still use the planned extracapsular extraction. The more procedures a surgeon performs the stronger is the tendency toward performing phacoemulsification. The opening technique of the anterior capsule is chosen accordingly: for phacoemulsification capsulorhexis is preferred, while for the planned extracapsular extraction can opener - or letter box - technique is usually done. The length of the sclero-corneal incision is 3.2 mm in phacoemulsification, 6.2 mm for a PMMA posterior chamber lens implantation and 9-13 mm for the planned extracapsular extraction. We prospectively compared both procedures with each group including 100 consecutive patients. The mean irrigation volume was 96.6 +/- 48.8 ml in the phacoemulsification group as opposed to 48.1 +/- 26 ml in the planned extracapsular extraction group. The mean duration of irrigation was 130 +/- 67 sec in the first versus 129 +/- 76 sec in the second group; mean endothelial cell loss was 7.9% versus 7.1%. No correlation was found between endothelial cell loss and duration of irrigation. Mean postoperative astigmatism measured 1.0 +/- 0.49 in the first group as compared to 3.3 +/- 1.7 dpt in the second group. Except for the astigmatism, our study could not detect significant differences regarding the outcome between both procedures. There are advantages to the phacoemulsification procedure, however, such as a smaller incision (e.g. tunnel technique), a closed irrigation-aspiration system, controlled intraocular pressure and the more frequent use of capsulorrhexis. Preferred indications and possible advantages regarding intra- and postoperative complications are discussed.

Aged↗

PubMed1993

[Results of preventive Nd:YAG laser iridotomy of the partner eye in glaucoma].

Recent findings suggest that prophylactic ND:YAG laser iridotomy constitutes a valuable therapeutic alternative for the prevention of acute glaucoma in the unaffected eye of a patient with one glaucomatous eye. In our study we tried to evaluate the effectiveness of this non-surgical treatment. We examined 23 patients between 34 and 89 years of age. The clinical course was documented by the assessment of intraocular pressure and visual acuity, slit-lamp examination and gonioscopy. Throughout the entire follow-up period not a single glaucoma attack occurred. In 20 eyes the intraocular pressure remained normal in the absence of any supportive therapy. There was no change in visual acuity and no synechiae or alterations of the anterior chamber were observed. It therefore seems that prophylactic ND:YAG laser iridotomy is a valuable therapeutic procedure for the prevention of acute glaucoma in the fellow eye of one already found to be affected by glaucoma.

Adult↗

PubMed1993

Permeability of the blood-retinal barrier and the blood-aqueous barrier in type I diabetes without diabetic retinopathy: simultaneous evaluation with fluorophotometry.

For the evaluation of a possible malfunction of the blood-retinal barrier (BRB) and the blood-aqueous barrier (BAB) in type I diabetes without manifest angiopathy after i.v. injection of sodium fluorescein, the permeability of the BRB (P) and the permeability coefficient of the BAB [P(a)] were simultaneously determined by fluorophotometry in 34 eyes of 34 type-I diabetics [hemoglobin (Hb)A1c = 6.6% +/- 0.9%] without retinopathy whose age ranged from 19 to 38 years (mean, 30.5 +/- 5 years); the diabetes duration was between 5 and 18 years. Fluorescein angiography was performed to exclude nonperfused areas. In all, 34 eyes of 34 healthy volunteers whose age ranged between 23 and 34 years (mean, 28.5 +/- 3.3 years) served as controls; in this group, fluorophotometry was performed twice to evaluate reproducibility. The mean BAB permeability coefficient in diabetics [P(a) = 5.3 +/- 1.8 x 10(-4)/min] was significantly increased (P = 0.00003) as compared with control values [P(a) = 3.7 +/- 0.7 x 10(-4)/min]; BRB permeability in diabetics (P = 3.2 +/- 1.4 x 10(-7) cm/s) was raised, with this elevation being of lower significance (P = 0.019; controls, P = 2.6 +/- 0.7 x 10(-7) cm/s). We found a decrease in BRB permeability depending on diabetes duration (r = -0.15; P = 0.007) that was not significant in the BAB (r = -0.1; P = 0.24). No correlation was found to exist between permeability and hemoglobin (Hb)A1c values either in the BAB or in the BRB. The reproducibility in controls was 9% in BRB determinations and 12% in BAB measurements.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗