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Biomedical subjects

V P Gabel

Publications and source records attributed to V P Gabel.

At least 19 recordsLinked to original sources
PubMed1995

[ProTon--a new portable tonometer. Initial experimental and clinical results].

To determine the accuracy of a new portable tonometer using the Mackay Marg principle (ProTon, Tomey) we measured three cadaver eyes in vitro and 196 eyes of 98 patients in vivo. The 325 manometric determined IOP values were compared to ProTon measurements in three enucleated, canulated human eyes. The correlation was r = 0.99. In a clinical study 196 eyes were measured with both the Goldmann and the ProTon tonometer. The results showed good correspondence with a correlation of r = 0.95. The statistical significance (paired t-test) was P < 0.001.

Equipment Design↗
PubMed1994

Expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) on proliferating vascular endothelial cells in diabetic epiretinal membranes.

The present study demonstrated the expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1), the proliferating status of the neovascular endothelial cells, and the activation of vascular endothelial cells bearing the two cell adhesion molecules in diabetic epiretinal membranes by using double immunofluorescence and APAAP techniques. The results showed that ICAM-1 was detected in 36 out of 40 (90%) proliferative diabetic retinopathy epiretinal membranes, VCAM-1 was found in 32 out of 40 cases (80%); in 21 out of 26 (81%) vascularised membranes the endothelial cells of the new vessels in the membranes were still in a proliferative stage (positive for proliferating endothelial cell marker EN 7/44) and, further, in 20 out of 26 cases (77%) ICAM-1 was detected on the proliferating endothelial cells and VCAM-1 was found in 21 cases (81%). The expression of cell adhesion molecules, especially ICAM-1 and VCAM-1 in diabetic epiretinal membranes suggests that cell to cell interactions may play a significant role in the development of PDR membranes. In particular, the expression of ICAM-1 and VCAM-1 on proliferating endothelial cells indicates the activation of these cells, which is the first critical step for lymphocyte/endothelial cell interactions and the initiation of immune responses. The significance of proliferating status of the neovascularisation in the membranes may be related to the clinical course and prognosis of the disease.

Cell Adhesion Molecules↗
PubMed1994

Proliferation and activation of vascular endothelial cells in epiretinal membranes from patients with proliferative diabetic retinopathy. An immunohistochemistry and clinical study.

In the present study, we investigated the status of proliferation and activation of vascular endothelial cells in epiretinal membranes from patients with proliferative diabetic retinopathy (PDR) by means of immunohistochemical techniques and compared the findings with the main clinical features of the patients. The results showed that of 21 vascularized membranes, 17 (81%) contained proliferating endothelial cells (positive for proliferating vascular endothelial cell marker EN 7/44) and 19 (90%) were positive for endothelial cell activation marker anti-VCAM-1; Furthermore, by using a double-staining technique we found that in 15 of the 17 cases (88%) the proliferating vascular endothelial cells were activated (expressing VCAM-1). Of the 18 type I diabetics, 15 (83%) contained activated proliferating endothelial cells, whereas in the 3 type II patients, only 1 membrane contained activated proliferating endothelial cells, Preoperatively, 18 patients had severe vitreous hemorrhage, among whom 15 (83%) contained proliferating endothelial cells, which were activated in 13 cases, and 16 patients had tractional retinal detachment, among whom 12 contained proliferating endothelial cells, which were activated in 11 cases. In all, 7 patients (33%) had vitreous rebleeding within 8 months postoperatively, whose membranes in 6 cases contained proliferating and activated endothelial cells. In contrast, of the 4 patients who were negative for EN 7/44, none had rebleeding, and of the 6 patients who were negative for EN 7/44 and anti-VCAM-1, only 1 had rebleeding.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

[The role of vitrectomy in the treatment of retinal detachment with macular holes].

The authors discuss the pathogenesis and the method of treatment of a retinal detachment with a macular hole basing on personal material and a review of foreign literature. Personal material consists of 11 eyes in 10 patients operated upon in the University Ophthalmic Department in Munich in the period November 1988--April 1990. In all the cases the primary method of treatment based on vitrectomy performed through the pars plana with a gas tamponade. In 4 cases a reoperation with silicon oil tamponade was necessary. Anatomical reattachment of the retina was achieved in 9 among 11 treated eyes. In 10 cases the visual acuity was 1/50 or better. Five among them showed the visual acuity at last 0.1.

Adult↗
PubMed1991

Surgical removal of massive subretinal hemorrhage associated with age-related macular degeneration.

The authors report on 11 patients with age-related macular degeneration associated with massive subretinal hemorrhage, who were treated with surgical removal of the hemorrhage and associated fibrosis. Preoperative visual acuity ranged from 20/400 to hand motions. Postoperative visual acuity ranged from 20/200 to light perception with a minimum of 3 months of follow-up. Complications included partial or total retinal detachment in four patients (36%) and cataract in four patients (36%). Four of 11 patients showed some improvement in vision (36%). All four of these patients had surgery within 1 week of the onset of severe visual loss. Although surgical removal of large subretinal hemorrhages is technically feasible, visual recovery is limited, even in uncomplicated cases, by macular degenerative changes.

Aged↗
PubMed1991

[Subretinal lavage in fresh hemorrhage in macular degeneration].

Three eyes with acute severe subretinal hemorrhages due to age-related macular degeneration were operated on by vitrectomy, retinotomy and subretinal lavage. It was possible to improve the visual acuity (VA) in case 1 from 20/500 preoperatively to 20/200 postoperatively; VA stayed the same for 16 months. In case 2 the VA was hand movements preoperatively, and postoperatively 20/200; after 18 months it was still 20/300. In case 3 VA was 20/400 preoperatively and 20/100 postoperatively; after 15 months it was 20/700. Even if this procedure cannot be recommended as routine, it can be considered in selected cases of subretinal hemorrhages no older than 1 week.

Aged↗
PubMed1990

Intravitreal silicone oil injection: complications and treatment of 415 consecutive patients.

Silicone oil injection in conjunction with pars plana vitrectomy was carried out by five surgeons in 415 consecutive patients using the same surgical equipment, the same surgical techniques and the same highly purified silicone oil (viscosity, 5000 mPa.s). Indications for silicone oil injection after vitrectomy included advanced stages of proliferative vitreoretinopathy following rhegmatogenous retinal detachment (49%), severe proliferative diabetic retinopathy (38%), and proliferative vitreoretinopathy following retinal detachment due to ocular trauma (13%). Postoperative complications were noted in a 6- to 30-month follow-up period. Cataractous changes of varying degree were seen in all phakic eyes. Silicone oil entered the anterior chamber in 6% of all phakic and pseudophakic eyes. Subretinal silicone oil was noted in 4%. Other complications associated with the use of intravitreal silicone oil included biomicroscopically visible silicone oil emulsification (0.7%), keratopathy (5.5%), glaucoma (6%), closure of the inferior iridectomy (6%), and reproliferation of epiretinal and subretinal fibrous membranes (40%). We anticipate that the physico-chemical characteristics of the highly purified silicone oil (viscosity, 5000 mPa.s) and the routine performance of an inferior iridectomy in all aphakic eyes had a positive impact on the low incidence of silicone-oil-related complications such as emulsification, keratopathy and secondary glaucoma.

Anterior Chamber↗
PubMed1990

[Does silicone oil improve the prognosis of severe proliferative diabetic retinopathy?].

We report on a series of 135 consecutive cases of pars plana vitrectomy for proliferative diabetic retinopathy (average period of observation was 13 months). BSS was used in 69 eyes and silicone oil was used in 66 eyes as a vitreous substitute, the indications for silicone oil in these cases were the presence of several retinotomies or retinectomies as well as sharply increased risk for rebleeding. Postoperatively and after a minimum follow up of 6 months (55 eyes) the two groups with BSS or silicone oil achieved comparable functional results despite the different anatomical preoperative situation. Thus 18 out of 23 eyes of the silicone oil group, originally with detached macula and visual acuity of HM or FC, achieved a visual outcome of greater than = 0.02, showing the best postoperative result. In the BSS-group, with attached macula prior to the operation and same visual acuity, this result is attained by 27 out of 35 eyes. We interpret these figures as meaning, that silicone oil in proliferative diabetic retinopathy reduces some of the problems connected with more advanced retinal changes like retinal detachment and rebleeding thereby allowing a visual outcome which corresponds to the macular condition.

Adult↗
PubMed1989

Nd:YAG laser photodisruption of hemorrhagic detachment of the internal limiting membrane.

We used a Q-switched Nd:YAG laser to create an opening in the internal limiting membrane in three eyes with hemorrhagic detachment of the internal limiting membrane. In all instances, after membranotomy blood was rapidly cleared from the preretinal space resulting in prompt improvement in visual acuity. No retinal injury was observed. Nd:YAG laser photodisruption may be useful in the treatment of some cases of subinternal limiting hemorrhages.

Adult↗
PubMed1989

Clinical observations of six cases of laser injury to the eye.

During the last decade, five patients with laser injuries were examined at the University of Munich Eye Clinic, in addition to one laser-injury patient at the University of Erlangen Eye Clinic. From a review of these cases, it is possible to gain an insight into factors that led to the eye injuries and to predict the clinical sequelae of laser retinal injury. A possible means of treatment, using an ophthalmic Q-switched Nd:YAG laser, is suggested for some types of retinal injury involving vitreal hemorrhage.

Accidents, Occupational↗
PubMed1987

Analysis of intraocularly applied silicone oils of various origins.

Complications during the intraocular use of silicone oil can be caused by two factors: first, mechanical interaction with the surrounding tissue and, second, the physiochemical properties of the oil itself. The properties of 14 oils of various origins in clinical use were investigated: 12 of the 14 oils contained various amounts of low-molecular-weight components (cyclosiloxanes and molecules with a molecular weight of less than 2,400), which are able to diffuse into the surrounding tissue and may incite toxic or inflammatory reactions. Some of the samples had a ten-fold lower volume resistivity than others, an indicator of the presence of ionic impurities, such as catalyst remnants, which may also be responsible for adverse reactions.

Chemical Phenomena↗
PubMed1987

Silicone oil with high specific gravity for intraocular use.

Silicone oil with a higher specific gravity than that of intraocular fluid or polydimethylsiloxane may have special indications in vitreoretinal surgery. Trifluorsiloxane is such a substance, and therefore its biological compatibility was investigated in rabbit eyes. It was found that this substance was clinically well tolerated within the observation time of up to 6 months, even if there was some neovascularisation from the inferior limbus. Histologically both an inflammatory response and tissue impregnation were more pronounced than with normal polydimethylsiloxane.

Animals↗
PubMed1986

[Clinical relevance of a dosage device for laser photocoagulation].

Fundus reflectometry constitutes a procedure with which dosage can be precisely regulated during the coagulation process. During retinal coagulation, for example, it is possible with this method to administer coagulations of uniform intensity regardless of variations in either the quality of the fundus image or the absorption of the pigmented structures. This can be useful for coagulation procedures which have to be confined for the most part to the pigment epithelium, as for example in the treatment of central serous retinopathy or in panretinal photocoagulation, where the functional therapeutic principle is still not clearly understood. Another area of application for reflectometric laser coagulation will be laser trabeculoplasty, in which barely detectable lesions have to be placed in the trabecular meshwork.

Computers↗