Condensation on IOLs during fluid-air exchange.
Explore the source record for details and available documents.
Cataract Extraction↗
Biomedical subjects
B Kirchhof
Publications and source records attributed to B Kirchhof.
[Risk factors for retinal redetachment by proliferative vitreoretinopathy after episcleral surgery for pseudophakic retinal detachment].
BACKGROUND: Conventional buckling procedures in pseudophakic eyes are more often than in phakic eyes complicated by proliferative vitreoretinopathy (PVR). PATIENTS: The records of 68 patients (68 eyes) suffering from pseudophakic retina detachment between January 1988 to March 1993 were evaluated. We analysed the frequency of PVR-redetachment and possible risk-factors. RESULTS: Thirteen eyes (19%) developed PVR-redetachment after external surgery. Within this group we were not able to find a retinal break before or during surgery in 70% of patients (9 eyes), compared to 25% of patients in the group without PVR complication. CONCLUSIONS: Uncertain visualisation of the retinal break prior to and during external surgery along with persistent retinal detachment represent risk factors for PVR. Also, extended indentation and cryotherapy during frustrane hole localisation is likely to reduce absorption of subretinal fluid and increase blood-ocular-breakdown. Both factors are known to raise the risk of PVR. Whether or not these severe disadvantages of "blind buckling" can be relieved by primary vitrectomy is subject of future investigations.
Adult↗
[Pathogenesis of complicated cataract in herpetic kerato-uveitis].
BACKGROUND: Keratitis, retinitis and secondary cataract are well known complications of ocular herpes simplex infection. We report on a case of herpetic keratouveitis and cataract. Acute and inflammatory pathogenesis of cataract formation resemble a phacoanaphylactic reaction. CASE REPORT: A 15-year-old girl with recurrent herpes keratitis was referred for acute spontaneous cataract formation accompanied by iridocyclitis and hypotony. Visual acuity was decreased from 0.4 to light projection. During cataract extraction the anterior chamber was tabbed for immunological analysis. The thickened anterior lens capsule was examined by light microscopy. We found a significant local synthesis of herpes antibodies in the aqueous. Histologically the lens capsule depicted a defect and a granulomatous inflammatory infiltrate towards the basal membrane material. The specimen was not suitable to judge on eventual additional phacoanaphylaxis. After cataract extraction and systemic acyclovir and corticosteroids the keratouveitis subsided. Visual acuity improved to 0.4, but was limited by the disciform corneal scar. CONCLUSION: The granulomatous response towards lens capsule shown here, resembles the granulomatous reaction towards Descemet's membrane in advanced herpetic corneal ulcer. We speculate on the pathogenesis of the lens capsule defect as a, so far unknown, herpes-associated autoimmun response against the basal membrane material of the lens. The acuteness of cataract formation may be a consequence of contact of aqueous with lens fibres. Additional phacoanaphylaxis combined with secondary glaucoma is possible.
Acyclovir↗
Primary vitrectomy for pseudophakic retinal detachment.
AIM/BACKGROUND: Viewing the peripheral retina is the major problem in the repair of pseudophakic retinal detachments. Conventional buckling procedures in pseudophakic eyes are complicated by persistent retinal (re-) detachment and proliferative vitreoretinopathy (PVR) more often than in phakic eyes. METHODS: Primary vitrectomy was performed in 33 consecutive cases for pseudophakic retinal detachment with the help of liquid perfluorocarbons and a wide angle viewing system, following a standardised procedure. All eyes have passed the 12 month follow up examination. RESULTS: The primary reattachment rate was 94%. PVR was observed in one case (3%). Seventy nine per cent (26 eyes) regained vision of 20/50 or better, with a median visual acuity of 20/30. The most frequent complication was transient glaucoma during the early postoperative period in 48% (16 eyes) requiring carboanhydrase inhibitors. CONCLUSION: The main advantage of primary vitrectomy over conventional buckling seems to be the better intraoperative sight to the most peripheral retinal holes, controlled removal of vitreous traction, and focused endolaser coagulation. This may explain the low rate of PVR after primary vitrectomy. Also, visual results tended to be better compared with conventional surgical techniques possibly because of removed vitreous opacities, and because of a superior retinal reattachment rate as well as the reduced rate of PVR.
Adult↗
Severe congenital lagophthalmos with tarsal aplasia.
Congenital elongation of the palpebral fissure associated with large eyelids was named euryblepharon after Desmarres in 1854. In some cases the length of the lower lid margin exceeded that of the upper lid margin by more than 3 mm. The lids are lax and the elongated lid margin of the lower lid is only partially in contact with the globe. In marked cases of euryblepharon there may be an additional minor vertical shortening of the upper lid. However, the abnormalities described by Desmarres did not produce severe kerato-conjunctival xerosis. We speculate that euryblepharon as originally described is merely a mild manifestation of congenital lagophthalmos. More severe forms show additional malformations, leading to pronounced insufficiency of lid closure. We report on four patients with severe congenital lagophthalmos. The appearance differs from that of euryblepharon by the following details: (a) a symmetrical congenital retraction of both the lower and the upper lid margins; (b) a marked vertical shortening of the lids (case 1 was referred for bilateral descemetoceles); (c) tarsal aplasia; and (d) severe kerato-conjunctival xerosis after insufficient surgical treatment, leading to different degrees of disability. The surgical approach involved bilateral shortening of the lid margins and free transplantation of retroauricular skin. Stabilization of the lax lower lid margin was achieved by lyodura strips applied with medium tension and in contact with the lid margin. At 5 years after the first operation a petty horizontal shortening of the lower lids was necessary because of circumscribed trichiasis. The dura strip remained present. The long-term result as evaluated at more than 8 years following the first operation was very satisfactory.
Adult↗
Candida albicans endophthalmitis after anabolic steroid abuse.
Explore the source record for details and available documents.
Adult↗
Detection of herpes simplex virus after penetrating keratoplasty by polymerase chain reaction: correlation of clinical and laboratory findings.
BACKGROUND: The study was carried out to investigate the possible correlation of clinical findings, histopathologic features and detection of herpes simplex virus DNA in corneal buttons obtained after penetrating keratoplasty. METHODS: We examined 47 consecutive corneal buttons sent for histopathologic examination by light microscopy and using the polymerase chain reaction for the detection of HSV1 and HSV2. Twenty-one corneal buttons from eyes with bullous keratopathy served as controls. RESULTS: The 47 cases were graded from the clinical information available as unproven, suspected and clinically proven cases of herpetic keratitis. This grading did not correlate to specific histopathologic features or to the results of HSV1 DNA testing. None of the cases were positive for HSV2 DNA. CONCLUSION: HSV DNA was detected in some of the cases of clinically unsuspected herpetic keratitis. This technique of demonstrating the presence or absence of HSV in the cornea after keratoplasty is more reliable than clinical data or histopathologic findings and may be important in cases of recurrent inflammatory episodes involving grafts after keratoplasty.
Cornea↗
Posterior drainage of intraocular fluid: an experimental approach on bovine cadaver eyes.
We evaluated the posterior drainage of saline in cadaver bovine eyes using different experimental procedures. The saline perfusion via a pars plana infusion into the vitreous cavity was measured in the following 5 different groups of 20 enucleated bovine eyes: 1, control; 2, vitrectomy; 3, vitrectomy + retinectomy; 4, vitrectomy + retinectomy + removal of retinal pigment epithelium (RPE); and 5, vitrectomy + retinectomy + removal of RPE + choroidectomy. The mean values obtained for the facility of saline outflow were as follows group 1, 0.0458 microliter min-1 mmHg-1; group 2, 0.0393 microliter min-1; group 3, 0.1308 microliter min-1 mmHg-1; group 4, 0.2288 microliter min-1; and group 5, 0.9985 microliter/min-1 mmHg-1. The retina appeared to be the major barrier to fluid movement from the vitreous to the chorioid, perhaps due to the lack of extracellular space and to the tight and impervious structure of the retina. The barrier function of the retina may explain the hypotony seen after rhegmatogenous retinal detachment and the decrease in intraocular pressure observed after the removal of silicone oil in eyes that had undergone retinectomy. Our results suggest that the reduction in intraocular pressure occurring after retinectomy is attributable to the new drainage pathway.
Animals↗
[Recent vitrectomy indications].
Explore the source record for details and available documents.
Eye Injuries, Penetrating↗
Is general anaesthesia necessary to record reproducible electroretinograms in rabbits?
In toxicity testing of intraocularly applied substances the flash electroretinogram (ERG) serves as an indicator of intact or reduced retinal function in the animal. Insufficiently monitored narcosis may be a source of puzzling ERG results. We performed electroretinography in 25 dark-adapted rabbits without general anaesthesia to evaluate the reproducibility of that method. Two recordings obtained at a mean interval of 26.87 days were compared. The scotopic a- and b-waves showed the same characteristics concerning shape, amplitude and implicit time known from other publications dealing with ERG recordings in narcotised rabbits. No statistically significant difference could be found between the test and retest recordings. It could be demonstrated that narcosis is not necessary for recording of stable and reproducible scotopic ERGs in rabbits.
Anesthesia, General↗
Retinectomy lowers intraocular pressure in otherwise intractable glaucoma: preliminary results.
Surgery for glaucomas unresponsive to conventional surgical strategies has always been frustrating and puzzling. I present preliminary results achieved by partial retinectomy in nine eyes that had complete synechial closure of the chamber angle accompanied by very high intraocular pressure (IOP), debilitating pain, and poor vision. The aim of this surgical procedure was to lower IOP by rerouting aqueous humor to the absorbing compartment of the choriocapillaris through a large retinal hole. Since a retinal wound will not heal, this "filtration site" will remain open and functional. Follow up ranged from 2 to 12 months. Preoperative IOPs ranged from 38 to 70 mm Hg; final postoperative IOPs, from 2 to 50 mm Hg. IOP decreased in all of the nine patients. Phthisis developed in two eyes and hypotony in three; the latter three eyes were not phthisical. The procedure was complicated by retinal detachment in one eye. A technique for determining the optimum size of the retinectomy for specific patients remains to be developed.
Aged↗
Anterior proliferative vitreoretinopathy in trauma and complicated retinal detachment. A histopathologic study.
Anterior vitreoretinal proliferations are frequent sequelae of retinal detachment repair and severe trauma. Cellular proliferations can form membranes extending anteriorly from the peripheral retina. These membranes have the capability to contract and may lead to detachment of both the peripheral retina and, in more advanced stages, the ciliary body. Because the vitreous base and vitreous remnants are leading structures for cellular proliferation, complete removal of the anterior vitreous base in particular is important in cases of severe trauma or complicated retinal detachment. In 11 cases of anterior proliferative vitreoretinopathy examined histopathologically, we found overlying membranes and cellular infiltration of the vitreous in close correlation with the amounts of vitreous remnants present. Visualization of the peripheral retina and pars plana can rarely be accomplished in the presence of the crystalline lens or pseudophakia. Therefore, the removal of the anterior vitreous is often incomplete. To achieve complete dissection of the anterior vitreous, we remove even a clear lens during the first surgical intervention in selected cases.
Adult↗
Differential permeance of retina and retinal pigment epithelium to water: implications for retinal adhesion.
Water movement from the vitreous to the choroid would tend to maintain retinal apposition, if the retina were less permeable than the retinal pigment epithelium (RPE). We used a rabbit model, to test the relative permeability of retina and RPE to tritiated water. The retina was found less permeable than the RPE. This result suggests the presence of a hydrostatic pressure gradient across the retina which could enhance apposition of retina to the RPE.
Animals↗
Repair of outer blood-retinal barrier after severe ocular blunt trauma in rabbits.
Retinal contusion is a leading cause of visual loss in ocular blunt trauma. However, its pathogenesis remains controversial. We established a rabbit model of severe retinal contusion with energy of about 2.87 J. Typical retinal edema and sometimes subretinal hemorrhage reproducibly occurred at the posterior pole after injury. These subsided 1 week later with depigmentation in the lesion. Histopathological examination revealed severe damage of the outer layer of retina, for example, disruption of retinal pigment epithelium (RPE) and photoreceptors. Electroretinography showed a decrease in the b wave by 38-47% in amplitudes (P < 0.01) during the first 3 days and then returned, although not to normal level. To investigate the damage and repair of blood-retinal barrier (BRB), 5 ml 2% lanthanum solution (La) was injected via the common carotid artery 1-2 min before enucleation. La diffused in the interphotoreceptor space through the damaged junctions of RPE 1 h-3 days after injury. La also reached the nuclei level of photoreceptors up to 14 days after injury. Although a glial scar with scattered RPE cells attached to Bruch's membrane in the severely damage area, no La diffusion was found in the retina 4 weeks after trauma. These results showed incomplete repair of outer BRB after severe blunt trauma.
Animals↗
Corticosteroids and daunomycin in the prevention of experimental proliferative vitreoretinopathy induced by macrophages.
An experimental model of proliferative vitreoretinopathy (PVR) induced by macrophages simulates a special form of wound healing process in the eye and mimics the development of PVR from its initial stage. We used this model for the evaluation of drug efficacy in the prevention of PVR. One mg triamcinolone acetonide (TA), 10 micrograms daunomycin-liposome (DL), 5 micrograms free daunomycin (FD) and 0.1 ml saline or empty liposomes (as controls) were injected into the vitreous in four groups of animals (30 or 40 rabbit eyes each) after macrophage injection. Retinal detachment developed in 77.5% of the control eyes on day 28, compared to 13.3% of the TA-treated eyes (P < 0.01), to 33.3% of the eyes treated with DL (P < 0.01), and 50% of the FD-treated eyes (P < 0.05). TA cleared up from the vitreous within 35-63 days (average 45.5 days). The half-time of FD clearance was 145.5 min. Although DL declined rapidly during the first 2 days, there was an average of 0.64 microgram/ml daunomycin in the vitreous on day 14. Transmission electron microscopy showed that FD at a dosage of over 5 micrograms or DL over 20 micrograms was toxic to the retina and that up to 4 mg TA was nontoxic. These results suggest that steroids such as TA, given at the inflammatory stage, can effectively and safely prevent the development of PVR, and that encapsulation in liposomes of cytotoxic agents such as daunomycin can enhance drug efficacy and reduce toxicity. The time course of initiation and development of PVR is important in the selection of particular drugs.
Animals↗
[Retina/vitreous humor].
Explore the source record for details and available documents.
Diabetic Retinopathy↗
[The operative use of perfluorodecalin in severe proliferative vitreoretinopathy].
Perfluorocarbon liquids can be used as an operative hydrodynamic tool during vitreous surgery. The high specific gravity exerts a pressure on the retina to open up the retinal funnel, to displace the subretinal fluid and to stabilize the posterior retina for membrane peeling, endo-laser photocoagulation, and to release anterior traction. The authors reviewed 27 patients of a variety of severe proliferative vitreo-retinopathies (PVR) treated with the perfluorocarbon procedure, including idiopathic PVR in 9 cases, traumatic PVR in 7 cases, aphakic or pseudophakic PVR in 5 cases, intraocular inflammatory PVR in 4 cases and other forms in 2 cases. The success rate was 81.5% and the final visual acuity ranged from 0.05 to 0.5 in 50.0% of the patients that attained retinal reattachment. The retina failed to reattach in patients with rupture of the eyeball or advanced proliferative diabetic retinopathy. The surgical techniques and management of operative complications were discussed.
Adolescent↗
Growth properties of larval and adult locust neurons in primary cell culture.
We developed a cell culture system for thoracic neurons of fifth instar or adult locusts (Locusta migratoria) in order to obtain maximum visualization of cellular morphology and direct access to the neurons for electrophysiological analysis. The dissociated neurons regenerated new neurites in a serum-free defined culture medium, in which they remained viable for up to 3 weeks. Viability of the cells was confirmed by intracellular recordings demonstrating active membrane properties and action potentials. While the morphology of the cultured neurons is distinct from their in vivo counterparts, they retained some cellular surface properties and markers related to transmitter metabolism. Two factors influencing cellular morphology in vitro were identified in Locusta: 1) the presence of a primary neurite stump, and 2) membrane contacts between cells. Dissociated neurons of the locust species Schistocerca gregaria grown in a hemolymph-enriched medium showed a marked reduction in branching patterns and a tenfold increase in neurite length compared to neurons growing in a medium without hemolymph. This culture system could prove useful for identifying the action of hemolymph-derived growth factors.
Animals↗