SEARCH · PubMed Health

Results for “Intraocular fluid”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 955 records · Page 53Linked to original sources

PubMed2005

Dynamic intraocular pressure measurements during vitrectomy.

OBJECTIVES: To directly measure dynamic intraocular pressure (IOP) during vitrectomy and to determine whether disposable pressure transducers placed in the infusion line can indirectly measure with accuracy the dynamic IOP during vitrectomy. METHODS: Experimental clinical study of 10 patients undergoing vitrectomy. Dynamic IOP was sampled via an extra pars plana incision with a catheter transducer equipped to measure direct IOP during vitrectomy by attaching a metal flange near the pressure-sensing tip. Disposable blood pressure transducers were placed in the infusion tubing fluid path to determine the IOP by indirect means. During various maneuvers of vitrectomy including air-fluid exchange and gas-forced infusion, pressure measurements were taken simultaneously from the indwelling pressure transducer and the disposable blood pressure sensors in the infusion line. RESULTS: The directly measured IOP varied between 0 and 120 mm Hg during vitrectomy. During fluid flow, the indirectly measured IOP, calculated from the infusion line pressures, accurately corresponded with the directly measured IOP. CONCLUSIONS: Closed vitrectomy causes wide fluctuations in IOP. The IOP can be accurately measured during fluid flow with inline sensors.

Adolescent↗

PubMed1993

Intraocular pressure reduction and systemic absorption of timolol after administration of one side-coated inserts in rabbits.

The object of this study was to test whether flat, circular ophthalmic inserts releasing drug only from one side, would show improved activity parameters and reduced systemic absorption. To this purpose, uncoated and one-side coated hydroxypropylcellulose inserts containing timolol were prepared and evaluated. An acrylic copolymer (Eudragit RS) was used as coating material. Timolol release from inserts was studied both in vitro and in vivo. Timolol release in vitro from the coated inserts was much slower than from the uncoated ones, due to the smaller releasing surface area. Compared with timolol eyedrops (0.5%, 50 microliters), administration of 250 micrograms of timolol in uncoated or coated inserts produced a significantly greater hypotensive effect at 6 and 8 hr post instillation in rabbits with artificially increased intraocular pressure. The coated inserts containing 62.5 micrograms of timolol antagonised isoproterenol-induced ocular hypotension significantly more than timolol eyedrops (0.5%, 12.5 microliters) and uncoated inserts containing 62.5 micrograms of timolol. Both uncoated and coated inserts provided a significant sustaining of timolol release in tear fluid and decreased systemic peak concentrations of timolol with respect to the eyedrop control. However, one-side coated inserts failed to show significant improvements with respect to the uncoated samples.

Absorption↗

PubMed1989

Effects of intravitreal perfusion with dopamine in different concentrations on the DC electroretinogram and the standing potential of the albino rabbit eye.

The direct current electroretinogram and the standing potential were recorded from both eyes of 23 albino rabbits during intraocular perfusion of one of the eyes, which was vitrectomized, with a physiologic reference solution (PHS). PHS was then replaced by a test solution containing dopamine dissolved in PHS. The fluids were subsequently alternated (PHS-dopamine-PHS). During irrigation with 0.25-0.5 mM dopamine (11 rabbits) the c-wave amplitude was 140% higher (p less than 0.001) and during irrigation with 25 mM dopamine (6 rabbits) 85% lower (p less than 0.01) than it was during the corresponding initial perfusion with PHS. The simultaneously recorded b-wave amplitude was reduced (0.25-0.5 mM: -22%, p less than 0.001; 25 mM: -69%, p less than 0.001) and the SP level increased (0.25-0.5 mM: +2375 microV, p less than 0.01; 25 mM: +2530 microV, p less than 0.05) compared with the values obtained during the corresponding preceding irrigation with PHS. Thus the changes in the b- and c-wave amplitudes during perfusion with dopamine were dependent on the concentration of the drug. In the contralateral control eye (23 rabbits) the c-wave amplitude was 21% higher (p less than 0.001), the b-wave amplitude 14% higher (p less than 0.001) and the standing potential 1007 microV higher (p less than 0.001) during intravitreal perfusion with dopamine in the other eye than during the preceding irrigation with PHS in that eye, possibly as a result of increasing dark adaptation.

Animals↗

PubMedDate not supplied

Pneumatic retinopexy.

Pneumatic retinopexy, a term introduced by Hilton in 1985, describes a recently revised and modified operation used for primary rhegmatogenous retinal reattachment. A gas bubble is injected into the vitreous cavity and the patient positioned so that the bubble closes the retinal break, permitting resorption of subretinal fluid. A chorioretinal adhesion formed around the break secures the retina in place. The history of pneumatic retinopexy is presented as well as recent studies on the subject. Characteristics of intraocular gases are reviewed. A protocol is described for pneumatic repair of complex retinal detachments. Patient selection and surgical techniques are recommended. Pneumatic retinopexy is compared to other retinal reattachment techniques and controversial issues are discussed.

Fluorocarbons↗

PubMedDate not supplied

Localized bullous separation of Descemet's membrane after previous cataract surgery.

This paper describes four cases of localized bullous separation of Descemet's membrane that occurred from more than 1 year to 7 years after cataract surgery. In all eyes, fluid resembling a hypopyon (pseudohypopyon) filled the space created by the separation. In three cases, the fluid was white. In one of these, pathological examination of the fluid showed mostly necrotic but a few viable squamous epithelial cells. In the fourth case in which the fluid was whitish red, there were many capillaries along the edge of the separation and there was evidence of injury to the nearby epithelium. The one case with poor visual acuity improved after the fluid was removed.

Aged↗

PubMed1984

[The role of the parathalamus in covered sclerectomy].

Twenty-six eyes in which IOP had been regulated at a mean 14 mmHg by goniotrepanation were operated on for cataract after an interval of at least 4 years. On exposing the scleral flap the authors discovered gray-black funiculi on the two unsutured vertical sides, representing new fluid-permeable membranous tissue. Beneath them was a fairly small fluid-filled space, the " parathalmus " - a kind of secondary anterior chamber.

Anterior Chamber↗

PubMed2001

Ocular syphilis.

Although the annual incidence of primary and secondary syphilis has dropped to the lowest rate recorded, syphilis remains an important cause of ocular disease. Uveitis is the most common ocular manifestation of syphilis in both HIV-positive and HIV-negative patients, and the diagnosis should prompt an analysis of the cerebrospinal fluid to exclude associated neurosyphilis. Newer modalities such as enzyme immunoassays and genomic amplification using the polymerase chain reaction may prove to be useful techniques to detect Treponema pallidum in intraocular specimens. The preferred treatment for all stages of syphilis remains parenteral penicillin G, although the preparation, dose, route of administration, and duration of therapy are dictated by the stage of disease and various host factors. All patients diagnosed with ocular syphilis should be tested for HIV, because the presence of a primary genital chancre increases the risk of acquiring or transmitting HIV, and because risk factors for the two diseases are similar.

Eye Infections, Bacterial↗

PubMed1997

Heparinised intraocular infusion and bacterial contamination in cataract surgery.

BACKGROUND/AIMS: Heparin in solution reduces bacterial adhesion to intraocular lenses and a lower incidence of postoperative endophthalmitis has been reported with the use of heparin coated lenses. The safety of adding low molecular weight heparin to the infusion fluid during routine cataract surgery was investigated. Any direct antibacterial effect was looked for by culturing anterior chamber fluid samples taken at the completion of surgery. METHODS: A randomised, double blind, controlled study of 111 patients undergoing routine cataract surgery. Low molecular weight heparin at a concentration of 5 IU/ml was added to the infusion fluid in the trial patients. Samples from the anterior chamber taken at completion of surgery were cultured. Twenty nine samples of sterile infusion fluid were also cultured as further controls. RESULTS: No complications were found in either group, and no difference in observed postoperative inflammation in each group. In the heparinised group (n = 55) bacterial contamination was found in 31% of samples, compared with 27% in the no heparin group (n = 56) (no significant difference). CONCLUSIONS: There appears to be no direct antibacterial effect of heparin, and other possible mechanisms of action are discussed. Heparin avoids many of the drawbacks of traditional antibiotic prophylaxis and may have the potential to be a safe and effective addition to endophthalmitis prevention.

Aged↗

PubMed2001

[Treatment of post-traumatic cyclodialysis using by direct cyclopexy].

INTRODUCTION: We report 2 cases of posttraumatic cyclodialysis treated by direct cyclopexy. We decided to operate because of the presence of a macular and disc oedema after an ocular chronic hypotony. PATIENTS: The case was a blunt ocular trauma and the other case a perforating injury. For the latter, a cycloplegic treatment was ineffective. The ocular hypotony persisted 2 months in the first case and 2 and a half years in the second. In both cases, the hypotony was major (0mmHg) and the cyclodialysis cleft was extended to 90 degrees (in the superior temporal quadrant and the inferior nasal quadrant). A direct cyclopexy was performed with cilioscleral sutures with 10-0 monofilament. RESULTS: One patient presented a moderate and temporary postoperative hypertony. The maximal follow-up was 9 months: ocular tonus was normalized (10 and 11mmHg), the fundus aspect was improved, and visual acuity was either the same (hand movement perception) or increased from 0.1, 14 to 1.0, 2 on the Parinaud scale. DISCUSSION: The direct cyclopexy was effective in both cases. It precisely defined the cyclodialysis limits, it allowed the suprachoroïdal fluid to drain and restored the anatomic features. Moreover, it allowed treating larger cyclodialysis for which a simple laser treatment would be incomplete. On the other hand, it was invasive intraocular surgery which presented risks of hemorrhage, infection and retinal detachment. CONCLUSION: The direct cyclopexy is an advisable method in the treatment of cyclodialysis. It normalized an ocular tonus and improved of hypotonus retinopathy. However, vision remained sometimes limited because of the posttraumatic sequels are or ocular hypotony that was too lengthy.

Adult↗

PubMedDate not supplied

A brighter future for the AIDS patient.

This article explores the etiology, medical and surgical treatment, and care of the acquired immune deficiency syndrome (AIDS) patient with cytomegalovirus (CMV) retinitis. CMV retinitis is the most common intraocular infection as well as the leading cause of vision loss in people with AIDS. CMV, part of the herpesvirus group, is an opportunistic pathogen that is transmitted through body fluids. Both the human immunodeficiency virus (HIV) and the herpesvirus are factors in predisposing retinal tissue to CMV. CMV usually remains dormant in a healthy immune system. However, in people who are immunosuppressed, the virus can become active and cause infections in the GI tract, lungs, and central nervous system, as well as in the eyes.

AIDS-Related Opportunistic Infections↗

PubMed1991

Lamellar scleral resection enhances subretinal fluid absorption in eyes with choroidal congestion.

The effects of choroidal congestion and lamellar scleral resection on the absorption of subretinal fluid were studied in rabbit eyes. Small retinal detachments were induced and choroidal congestion was produced by ligating two vortex veins. Absorption time was prolonged in these eyes to roughly 138% of that in the control eyes. The choroidal congestion could be alleviated by partial thickness scleral resection, after which the absorption time was only 115% of that in untreated eyes. Our data suggest that lamellar scleral resection relieves elevated choroidal tissue pressure and helps to absorb the subretinal fluid.

Absorption↗

PubMed1998

Prevention of posterior capsule opacification with the CO2 laser.

BACKGROUND AND OBJECTIVE: Posterior capsule opacification (PCO) is a common complication after cataract extraction, despite the modern surgical techniques and lenses being used for this procedure. Its prevention challenged many investigators, because the current treatment of choice, capsulotomy with Nd:YAG laser, is associated with sight-threatening complications. In the present study, the authors investigated two approaches of preventing PCO using the CO2 laser. MATERIALS AND METHODS: A 15-W CO2 laser with a 17- or 18-gauge hollow probe was used on 20 sheep eyes and 14 rabbit eyes. Lens extraction was done by phacoemulsification. In the equatorial treatment study, the anterior chamber was filled with either air or a viscoelastic substance, and laser burns were applied to the equator of the lens capsule and to the peripheral anterior capsule to destroy the epithelial cells. In the capsulotomy study, a primary posterior capsulotomy was created by delivering 1 to 3 laser shots to the capsule behind an implanted intraocular lens (IOL). RESULTS: The CO2 laser was satisfactory in sheep eyes after filling the anterior chamber with air. In rabbit eyes, however, it was technically impractical to work with air. Using a viscoelastic material to maintain the anterior chamber, the hollow probe of the CO2 laser becomes plugged up and therefore is unable to affect the ocular tissue. However, by combining viscoelastic and air pumping, both the destruction of the lens epithelial cells and the creation of a central posterior opening behind a capsular-fixated IOL was repeatedly achieved. CONCLUSION: Using the CO2 laser for destruction of lens epithelial cells and the creation of controlled posterior capsulotomy is feasible and practical. A different design of the probe (closed gauge) is required to enable it to operate clinically in a fluid or viscoelastic environment.

Animals↗

PubMedDate not supplied

Intraocular hemorrhages: a hemostatic therapeutic approach.

Our knowledge of the local hemostatic factors capable of playing a role in certain intraocular hemorrhages is reviewed as a background to therapy with agents active in hemostasis. Common to hyphemas and subretinal hemorrhages are some conditions which are apt to disturb hemostasis and result in recurrent bleeding. They are: 1) Dilution of blood by aqueous humor or subretinal exudative fluid followed by the formation of hemostatic plugs which are prone to spontaneous lysis; 2) Contiguity of certain structures, such as the iris and the choroid, which are extremely rich in fibrinolytic activators favoring premature dissolution of the hemostatic plug and thereby recurrent bleeding; and 3) Presumptive high local concentration of fibrin degradation products (FDP), which have an anticoagulant action and would counteract hemostasis in the event of rebleeding. Based on these observations, the use of fibrinolytic inhibitors for the treatment of hyphema and subretinal hemorrhages seems warranted. Hemostatic mechanisms in intraocular hemorrhages and their treatment with various agents are discussed.

Antifibrinolytic Agents↗

PubMedDate not supplied

The nature and origin of intraocular metallic foreign bodies appearing after phacoemulsification.

In order to evaluate the nature and origin of metallic foreign bodies embedded in the iris after uneventful phacoemulsification, we aimed to produce metallic fragments by applying ultrasound power with the same phaco machine and handpiece in an experimental model in vitro. In a glass bottle, we used linear phaco power of 100% continuously for 5 min first with a new phaco tip and then with a used tip. Afterwards, the fluid in the bottle was filtered through a Millipore filter. The remains on the filter were studied by scanning electron microscopy (SEM) and microprobe. Small particles remained on the filter which was used for the new tip. Microprobe microanalysis showed that these particles were mainly titanium, the same as the phaco tip. SEM of both the new and the used tips showed small fragments on the exterior surface and lumen. Intraocular metallic foreign bodies after phacoemulsification are likely to be shaken loose from the phaco tip. Although it is mostly agreed that these fragments are well tolerated, their overall effect remains to be evaluated in the long term.

Eye Foreign Bodies↗

PubMed1984

[Intraocular penetration of ceftriaxone in man. Comparison with other beta-lactamins].

The intraocular penetration of a new antibiotic, ceftriaxon, was studied in 30 patients. Serum samples in 29 patients showed an average level of 42 micrograms/ml. Penetration into the aqueous humour flow studied in 28 patients under general anesthesia at one, two, three, four and six hours after the injection. An average level of 0,53 micrograms/ml was found which is 1,25% of average serum level. In 23 patients the dry level in tears averaged 5,75 micrograms/ml (13% of the serum level). In one case of retinal detachment the level in the subretinal fluid was 1,56 micrograms/ml. The kinetics drug secretion in tears was studied in 3 patients without anesthesia every 2 hours until the 16 th to 22 nd hours. Lower levels than those obtained under general anesthesia were obtained. This study shows that ceftriaxon has an intraocular penetration at levels above the minimal inhibitory concentrations for most commun intraocular infection.

Adult↗

PubMed1984

Intraocular argon laser photocoagulation in the management of severe proliferative vitreoretinopathy.

We surgically repaired seven eyes with severe proliferative vitreoretinopathy with intraocular argon laser photocoagulation. Five of the seven retinas were still attached six or more months postoperatively. Endolaser photocoagulation was used in conjunction with pars plana vitrectomy, periretinal membrane stripping, fluid-air exchange, and planned retinotomies. The advantages of endolaser photocoagulation include easier management of posterior retinotomies in an air-filled eye, isolation of anterior traction and retinal breaks by creating an encircling demarcation line posterior to the problem, and less manipulation of existing scleral buckling material.

Adult↗

PubMed1999

Treatment of traumatic cyclodialysis with vitrectomy, cryotherapy, and gas endotamponade.

An aphakic patient with severe chronic hypotony had an alternative treatment of a traumatic cyclodialysis cleft: a 3-port pars plana vitrectomy, cryotherapy of the cleft, and fluid-gas exchange with subsequent supine positioning. The therapeutic principle was mechanical apposition of the detached ciliary muscle to the scleral spur by the gas bubble and scar induction by cryotherapy. Intraocular pressure increased to within normal ranges, and visual acuity improved over a 15 month follow-up.

Air↗

PubMed1978

Cannabis, 1977.

Recent advances in development of immunoassay methods for marijuana constituents in body fluids provide a rapid means of detection for forensic purposes and a useful research tool for accurate quantitation of dose-response relation. Therapeutic possibilities of cannabis, such as reduction in intraocular pressure and bronchodilatation, may stimulate development of synthetic cannabinoid derivatives that meet acceptable standards of safety and effiicacy for treatment of glaucoma and asthma. Cannabis use may have harmful short- and long-term impacts on health. Potentially serious short-term effects include predisposition to angina during exercise in patients with coronary artery disease. Even in healthy subjects, marijuana smoking decreases peak exercise performance, possibly because of its chronotropic effect with achievement of maximum heart rate at reduced work loads. Although no conclusive evidence exists for long-term biologic consequences of chronic cannabis use, preliminary evidence, suggesting impairment in pulmonary function and immune responses, requires further investigation with large-scale epidemiologic studies.

Animals↗