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Biomedical subjects

L Zografos

Publications and source records attributed to L Zografos.

At least 73 records · Page 4Linked to original sources
PubMed1991

In vivo phosphorus 31 magnetic resonance spectroscopy of human uveal melanomas and other intraocular tumors.

We studied the feasibility of using the surface coil probe technique for the noninvasive in vivo study of ocular tumors by phosphorus 31 magnetic resonance spectroscopy. The characteristic organophosphate metabolites of suspected uveal melanomas before proton beam irradiation were determined qualitatively by phosphorus 31 magnetic resonance spectroscopy in vivo using a three-turn surface coil. Spectra of choroidal hemangioma, osteoma, and metastasis were also obtained in vivo and compared with those of uveal melanomas. Analysis of spectra performed at 1.5 T showed significant peaks of phosphomonoesters, inorganic phosphate, phosphodiesters, phosphocreatine, and adenosine 5'-triphosphates. The unusually high concentration of phosphodiesters may be considered as a marker for uveal melanomas and other choroidal tumors. By analyzing the ratio of phosphocreatine to phosphodiesters spectral area values, we interpreted qualitatively spectra of intraocular tumors to differentiate malignant tumors from benign lesions. Nevertheless, the main limitation of interpreting the spectra was their contamination by signals from surrounding tissues.

Adult↗
PubMed1991

[Prevention of ocular complications of herpes zoster ophthalmicus by adequate treatment with acyclovir].

We compared the frequency of severe ocular complications secondary to Herpes Zoster Ophthalmicus (HZO) in 232 patients. They were divided into three groups: 1) patients without treatment (n = 164); 2) patients treated adequately (n = 48) with acyclovir (ACV; 5 x 800 mg/d orally and ophthalmic ointment 5 x /d for a minimum of 7 days, given within three days after skin eruption); and, 3) patients treated inadequately (n = 20) with ACV (only topical treatment, insufficient doses, interrupted treatment, delayed treatment). Patients with no treatment or with inadequate treatments showed the same frequency of severe ocular complications (21% (34/164) and 25% (5/20), respectively). In contrast, when adequate treatment of ACV was given complications occurred in only 4% (2/48) of cases. This study emphasizes the need for prompt (within three days after skin eruption) and adequate (5 x 800 mg/d for at least 7 days) treatment of ACV to prevent the severe complications of HZO.

Acyclovir↗
PubMed1991

[Uveal melanomas and vitreous hemorrhage. Diagnosis and treatment].

In choroidal melanoma vitreous hemorrhage can occur as initial event or as complication of conservative therapy. To understand better these relations, four groups of cases were examined: 1.) 126 choroidal melanomas which were treated conservatively with Cobalt 60 applicator from 1969 till 1984. 2.) 715 choroidal melanomas which have been treated with proton-beam from 1984 to 1989. 3.) 7 tumors or pseudotumors for which for diagnostic purposes a phosphorus 32 test was necessary. 4.) 9 choroid melanomas which had conservative treatment and where vitrectomy was realized. The multifactorial analysis gave the following results: in vitreous hemorrhages occurring before treatment the thickness of the tumor represents the significant factor. In vitreous hemorrhages which occur after conservative treatment there is in the group of cobalt applicators important irradiation of the disc, as well as the thickness of the tumor and the age of the patient in the group with proton-beam irradiation. Vitreous bleeding occurring before or after therapy does not influence the vital prognosis in a negative way. We present here a therapeutic concept in cases of vitreous bleeding in choroid melanoma which is based both on our experience and on the indications of literature.

Adult↗
PubMed1991

Choroidal metastasis and rhegmatogenous retinal detachment.

The association of a rhegmatogenous retinal detachment (RRD) with a uveal metastasis is an exceptional occurrence. In this article, the authors report the first successfully treated case (to their knowledge) of a patient with one eye in whom both the RRD and the metastasis is treated successfully. The RRD was operated on using a buckling procedure with cryopexy of the retinal break and drainage of the subretinal fluid. The metastasis, originating from an invasive canalicular carcinoma of the breast, was irradiated several days after surgery with a linear accelerator. The primary tumor was treated with systemic hormonotherapy. One and a half years after surgery, the patient is still alive. Visual acuity in the eye is 20/30, the retina is flat and no signs of tumor recurrence have been observed.

Aged↗
PubMed1991

High-dose oral acyclovir in acute herpes zoster ophthalmicus: the end of the corticosteroid era.

Systemic acyclovir (ACV), a new potent anti-herpes drug, was shown to reduce effectively the morbidity in the acute phase of herpes zoster ophthalmicus (AHZO). Using high dose oral ACV (5 X 800 mg/day) our aim in this study was: (1) to compare disease profiles in the ACV-treated group and in a group of zoster patients having had no ACV, analysed retrospectively; (2) to establish if high-dose ACV was able to prevent severe long term complications of AHZO; and (3) to determine the present role of corticosteroids in AHZO. From 1984 to 1988, 48 patients with AHZO of less than 3 days' duration were included. All patients received at least 7 days of oral ACV (5 X 800 mg/d) associated with topical ACV. Steroids were not given unless severe uveitis occurred. Follow-up was 2 years in 43 patients and 1 year in all 48 patients. Main conclusions from our study are: 1. Ocular involvement occurred in 67% of ACV-treated cases, a rate comparable to our retrospective group (59%) and to the literature (71%). However the rate of severe long term complications was minimal (4%) when compared to our non-treated retrospective group (21%). 2. Steroid treatment was not necessary in any of the ACV-treated patients. 3. ACV was well tolerated and did not have to be discontinued in any of the patients. High dose ACV and avoidance of steroids seems to eliminate the severe complications of AHZO.

Acute Disease↗
PubMed1990

Experimental study on the fractionation schedule for proton irradiation of uveal melanoma.

Greene melanoma in the anterior chamber of rabbits was irradiated by protons to find the isoeffect curve for proton irradiation fractionated into one, two, three or four doses. The isoeffect curve for tumor tissue remained constant between one- and three-dose fractionations and rose with four-dose fractionation. The isoeffect curve for normal tissue approximately followed the Ellis equation. Therefore, the optimal irradiation schedule should be in the range of three fractions because this best spares normal tissue while delivering a tumoricidal dose to the lesion. The relative reduction of the total dose from four- to one-dose fractions of intraoperative irradiation should be 20%.

Animals↗
PubMed1990

[Melanoma of the conjunctiva and its treatment].

37 cases of conjunctival melanomas treated in the University Eye Clinic of Lausanne are analysed. This total is made of 20 men and 17 women aged between 19 and 81 years with a mean age of 54.7 years. Tumors were localized in the bulbar conjunctival in 27 cases, in the palpebral conjunctival in 2 cases and were diffuse in 8 cases. Cornea was infiltrated in 19 cases. In 21 cases, the first treatment was made in our service and 16 cases were recurrences following a treatment made elsewhere. The mortality rate to 5 years was 20%. In a multivariant analysis using the COX Model, the height of the tumor was the only significant parameter (p = 0.035) for life expectancy. Recurrence of the tumor (p = 0.060) and presence of a PAM (p = 0.652) were not significant parameters. Benefits of cryocoagulation and indications for a proton beam irradiation are discussed.

Adult↗
PubMed1990

[Retinal artery occlusion: etiology and risk factors apropos of 151 cases].

A retrospective study covering 151 patients was conducted in order to determine the incidence of risk factors (arterial hypertension, diabetes mellitus, smoking, hyperlipidemia, and cardiovascular disorders) in cases of retinal artery occlusion. Occlusion of the central artery was found in 43% of the patients, occlusion of one or several branch arteries in 53%, and cilioretinal artery occlusion in 4%. A monofactorial study of risk factors produced a statistically significant value only for arterial hypertension (P = 0.01). Smoking and diabetic metabolism were not significant, and the correlation with hyperlipidemia was weak (P = 0.08). Forty-six patients were examined by continuouswave Doppler sonography: stenosis of the internal carotid artery was found in 50% of these cases. Pathologic Doppler findings were associated with an embolus in 14 cases (57%) and central artery occlusion in 9 (40%). Since retinal artery occlusion is frequently associated with carotid artery disease, systematic Doppler examination of the carotid vessels and the cardiovascular system should be performed in all patients with retinal artery occlusion.

Adult↗
PubMed1990

[Subretinal neovascularization: evolution of cicatrix of photocoagulation in the absence of recurrence].

Eleven patients successfully treated with the argon or krypton laser for macular subretinal neovascularization were followed up in order to determine the extent of long-term enlargement of the chorioretinal scars. The mean follow-up time was 51.5 months and the mean increase in choroidal scar size 46.5%. In 10 patients the scars enlarged more toward the fovea than toward the periphery (51% as opposed to 43%). The rate of enlargement per month decreased with time after treatment. Only one patient exhibited decreased visual acuity during the follow-up period, due to invasion of the foveola by the scar.

Adult↗
PubMed1990

Occurrence of uveal melanoma in contact with a chorioretinal cryocoagulation scar.

A case of a uveal melanoma arising in an eye previously treated with cryocoagulation for a horseshoe retinal tear is described. In the anterior border of the tumor, a notch, clearly fitting the curve of the chorioretinal scar was observed. Possible mechanisms which may be responsible for the local arrest of the tumor extension are discussed.

Adult↗
PubMed1990

[Long-term course of indirect traumatic ruptures of the choroid].

During the last 10 years, 46 cases of indirect choroidal tears were observed with repeated photographies and fluorescein angiographies. Patients were essentially young men with a mean age of 21.7 years. Choroidal tears were mostly single (61%), localized in the temporal part of the optic disc (63.1%), crescent shaped (77.4), and extra-foveal (96.4%). Ten of the 37 cases with a follow-up developed a neo-vascular membrane. Two of these were extra-foveal and were successfully treated with Argon Laser photocoagulation. Sub-retinal neovascular membranes as well as various other complications related to the trauma, such as macular hole, sub-retinal fibrosis and atrophic changes of the retinal pigment epithelium in the macular area, were responsible for a final visual acuity less than 0.2 in 38% of the cases. The influence of the fragility of Bruch's membrane on the number of choroidal tears was evaluated by the relation between the age of the patients and the number of tears, younger patients presenting more often single choroidal tears: the difference is nevertheless not statistically significant. A careful follow-up with repeated fluorescein angiographies is recommended for at least the 2 years following the trauma.

Adolescent↗
PubMed1989

[Irradiation treatment of choroidal hemangiomas].

Therapeutic results obtained following the treatment of 24 cases of choroidal hemangiomas (21 solitary and 3 in a Sturge-Weber syndrome) treated with 60Co applicators or an accelerated proton beam were analyzed. The observation period was less than 2 years for 4 cases, 2 to 5 years for 10 cases, 5 to 10 years for 7 cases and more than 10 years for 3 cases. Reabsorption of retinal detachment without any recurrency was obtained for all the cases. The V.A. was increased in 16 cases, did not change in 4 cases and decreased in 4 other cases. Final V.A. was 6/7.5 or more in 9 cases (37.5%), 6/60 à 6/7.5 in 6 cases (25%), and 6/60 or less in 9 cases (37.5%). None of the cases we treated presented complications induced by radiotherapy (actinic papillitis, circulatory disturbances in the macular area, or neovascular glaucoma). The comparison of the results we obtained with cases treated by photocoagulation or external radiotherapy demonstrated a slight advantage in favour of the focalized radiotherapy, which is not statistically significant because of the small number of cases included in the studies. Meanwhile, contact radiotherapy and irradiation with an accelerated proton beam seems to be a substantial alternative for the treatment of large hemangiomas and tumors invading the macula.

Adult↗
PubMed1988

Topical retinoic acid in dysplastic and metaplastic keratinization of corneoconjunctival epithelium.

We report four cases of corneoconjunctival keratinization that were successfully treated with topical retinoic acid ointment. In two cases keratinization was due to squamous metaplasia and in two others it was secondary to intraepithelial corneoconjunctival neoplasia. Treatment reversed severe keratinization in a case of drug-induced pseudopemphigoid and stabilized the disease in one of the two affected eyes without additional treatment. In a case of ocular cicatricial pemphigoid, retinoic acid was useful as an adjuvant therapy to immunosuppression, by reversing keratinization of the conjunctiva. In two cases of corneoconjunctival neoplasia, lesions regressed markedly. Long-term treatment was well tolerated in three patients. Our findings suggest that retinoic acid ointment is effective in treating severe squamous metaplasia in cicatrizing diseases of the conjunctiva. Our findings indicate further that retinoic acid seems to inhibit growth of corneoconjunctival neoplasias and thus might be useful complementary therapy in this situation.

Administration, Topical↗
PubMed1988

[Report on the conservative treatment of melanoma of the uvea at the Lausanne University Ophthalmologic Clinic].

A great number of techniques are currently available for the conservative treatment of uveal melanomas: ocular applicators emitting gamma rays 60Co, 125I) or high-energy beta rays (106Ru/106Rh), light photocoagulation, surgical excision, and accelerated proton beam irradiation. Life expectancy following conservative treatment is equal to or better than that following enucleation. This is demonstrated by nonrandomized comparative studies, and by the authors' own long-term results following the conservative treatment of melanomas by 60Co applicators: mortality due to metastases of small melanomas was 3% (V = smaller than 10 x 10 x 3 mm), with medium-size melanomas it was 12% (V = 10 x 10 x 3-15 x 15 x 5 mm), and with large melanomas 21% (V = larger than 15 x 15 x 5 mm). Accelerated proton beam irradiation of uveal melanomas is currently the method of choice for the conservative treatment of uveal melanomas. The sharp boundaries of the irradiated zone, the uniformly distributed irradiation dose, and beam-splitting are the main advantages of this technique. During the last three years, 310 cases of uveal melanoma have been treated in Switzerland with an accelerated proton beam. Of these, 214 were followed up for more than one year. Eight patients (3.9%) died of metastases. Visual acuity was identical or superior to initial visual acuity in 60.3% of the cases, while 39.6% exhibited a deterioration of vision or a functional loss. Favorable results achieved by conservative treatment of uveal melanomas considerably limited the indications for enucleation, which is now only performed in exceptional situations.

Brachytherapy↗