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Biomedical subjects

C L Dake

Publications and source records attributed to C L Dake.

At least 19 recordsLinked to original sources
PubMed1985

Ten year prospective follow-up of a glaucoma operation. The Double Flap Scheie in primary open angle glaucoma.

The results of a longterm prospective follow-up study after the 'Double Flap' Scheie filtering operation are presented. Fifty-two eyes of 47 patients with primary open angle glaucoma (POAG) were operated; after ten years 29 eyes of 24 patients could be examined. Twenty patients (43%) had died, in three follow-up was incomplete. The two and four year results have been published earlier. In the 29 eyes the mean intraocular pressure (IOP) without medical therapy rose from 15.8 mm Hg at five years to 16.3 mm Hg at ten years (not significant). Additional medical or surgical treatment was necessary in 35% of the eyes. Diurnal variation and outflow facility remained stable. During the ten years 13 eyes showed some deterioration of visual fields. Nearly all clinically important deterioration occurred within five years after the operation. Cataract progression was noticed in 45% (13 of 29); four times a lens extraction was performed (13%). Complete success of the operation, as judged by stable visual fields and IOP levels at or under 21 mm Hg without additional medical or surgical therapy was reached in 13 of 20 eyes (45%). Based on IOP alone the success rate was 62% without and 93% with additional treatment.

Aged↗
PubMed1983

Treatment of glaucoma simplex with argon laser coagulation of the scleral spur (L.S.S.C.).

Wise and Witter published in 1979 the results of argon laser treatment of glaucoma simplex. They coagulated in and just behind the trabeculum using as little energy as possible (+/- 100 coagulations, 50 mu, 1/10 sec, 80-1500 mWatt, spaced over 360 degrees). As we consider that coagulation of the trabeculum is not entirely without risk, we modified the technique by placing the lesions in the scleral spur. Up to the end of 1981, 84 eyes had been treated in 69 patients. Of 28 eyes in which treatment had taken place at least 1 year ago, the results in twenty-five were able to be analysed. The average decrease in pressure one year after treatment was 6.5-8.5 mm Hg (+/- 30% of the original value). The coefficient of outflow was measured in 10 eyes before and after treatment. This rose from an average of 0.11 (+/- 0.03) to an average of 0.18 (+/- 0.02).

Aged↗
PubMed1981

Guanethidine - adrenaline eye drops in glaucoma simplex. Pupil behaviour and response of intraocular pressure.

In the study reported here, the relation between the dilatation of the pupil and the course of intraocular pressure (IOP) is examined in open angle glaucoma patients and in glaucoma suspects after topical administration of the combination of guanethidine 3% and adrenaline 0.5% in one eye drop (GA). By treating one eye with GA and leaving the fellow eye untreated on the same day, there was a symmetrical response of IOP, independent of the mydriasis in the treated eyes. It leads to the conclusion that the mydriatic response has no influence on the course of IOP. The physiological explantation for the symmetrical course of IOP in both treated and untreated fellow eyes seems to be a mediation by the bloodstream of GA to the eye which was left untreated.

Drug Combinations↗
PubMed1980

Guanethidine--adrenaline eye drops in glaucoma simplex production and outflow of the aqueous humour during a long-term treatment.

A comparative tonographic study was performed in 10 primary open angle glaucoma patients (15 eyes) and 7 patients with suspected glaucoma (14 eyes) during a 7-months' period. The patients were treated twice daily with guanethidine 3% and adrenaline 0.5% (GA). The fall in intraocular pressure (IOP) of 44% in primary open angle glucoma patients was mainly due to an inhibition of aqueous humour production (54%; p < 0.005) and to a lesser extent an increase in outflow facility. In the suspected glaucoma patients, the fall in IOP of 43% was due to an inhibition of the aqueous rate (46%; p < 0.005) and to an increase in outflow facility (64%; p < 0.005). The increase in outflow facility during treatment was significantly different between both groups of patients. It suggests degeneration of the receptors mediating outflow mechanism in the patients with open angle glaucoma. For both groups of patients it is shown that during treatment with GA there is not only a supersensitivity for adrenaline 0.5% of the mechanisms that mediate the inhibition of the aqueous rate, but also of the mechanisms that mediate outflow facility.

Aqueous Humor↗
PubMed1980

The combination of guanethidine 1% and epinephrine 0.2% in one eye drop (GA-weak) in the treatment of glaucoma.

Thirty-one patients (58 eyes) with either primary open angle glaucoma (19 patients with 34 eyes) or suspected glaucoma (12 patients with 24 eyes) were treated for a period of 7 months with only guanethidine 1% and epinephrine 0.2% in one eyedrop (GA-weak) twice daily. The intraocular pressure (IOP) was controlled in 64% of all eyes with an average pressure decrease of 8.4 mm Hg or 31% (p < 0.005). Tonography revealed that the decrease in IOP was due both to inhibition of aqueous humour production (26%, p < 0.005) and to an increase in outflow facility (32%, p < 0.005), showing supersensitivity to inflow and outflow for epinephrine 0.2%, 8 patients were eliminated from the study due to tolerance for the drug. The side-effects were mild and did not lead to cessation of treatment. GA-weak was found to be an effective agent in the management of glaucoma. The treatment was well tolerated by the patients.

Adult↗
PubMed1980

Treatment of (recurrent) pterygium oculi by lamellar keratoplasty.

Apart from cosmetic problems, pterygium oculi can cause functional disturbances, especially when it recurs after (repeated) operative removal: diplopia and/or reduced visual acuity. The results we obtained with the treatment of these functional disturbances by various types of lamellar keratoplasty in 20 patients (22 eyes) are good.

Adult↗
PubMed1980

Timolol eye drops: bradycardia or tachycardia?

26 eyes of 14 patients--8 with primary open angle glaucoma, 6 glaucoma suspects--were treated for at least 6 months with either twice daily timolol 0.25% in both eyes or twice daily timolol 0.50% in one eye. None of the patients received concomitant local or oral drugs. Special attention was paid to tachyphylaxis and to blood pressure and pulse rate. We could detect a slight although not significant tendency to tachyphylaxis (1-2 mm Hg) after 1 week of timolol treatment. It takes at least 1-2 weeks to reach the initial I.O.P. level after withdrawal of timolol therapy. Blood pressure did not change significantly. The pulse rate showed a slight although not significant tendency to decrease (a few beats/minute), but we detected a reflex tachycardia (10 beats/minute) after withdrawal of timolol therapy which was very significant. This rebound phenomenon has not been referred to in the literature. It seems reasonable to conclude that one should take care in treating glaucoma patients with concomitant arrhythmias with timolol eye drops.

Adult↗
PubMed1980

The aqueous humor dynamics and the biphasic response in intraocular pressure induced by guanethidine and adrenaline in the glaucomatous eye.

Continuous administration of guanethidine (3%) and adrenaline (0.5%) in one eyedrop (GA) induced a biphasic response of intraocular pressure (IOP). In ten patients with primary open angle and seven glaucoma suspects treated with (GA) twice daily during a 7 month period, tonography, and tonometry were performed and the pupil diameter measured 3 and 8 h post-GA. The combined data of both groups in the hypertensive phase, showed an IOP increase of 2.8 mm Hg (P < 0.05), an unchanged coefficient of the outflow, dilated pupil (1.73 mm) (P < 0.005) and a 36% increase of aqueous humor production (P < 0.02). The specific biphasic course of IOP during treatment with GA seems to be caused by fluctuations in aqueous humor production. The increase in aqueous rate during the hypertensive phase could be related to secondary (rebound) vasodilation in the ciliary body and/or to a transient disruption of the blood-aqueous barrier induced by release of prostaglandins.

Aqueous Humor↗
PubMed1980

Maintenance therapy of glaucoma patients with guanethidine (3%) and adrenaline (0.5%) once daily.

Over a period of 4 months, 16 of 24 patients (30 of 46 eyes) with either primary open angle glaucoma (POAG) or suspected glaucoma were treated successfully with a maintenance dose of guanethidine (3%) and adrenaline (0.5%) combined in one eyedrop (GA) once daily. In the previous month the medication was given twice daily and at the end of 4 months the decrease in intraocular pressure (IOP) was 8.9 mm Hg (33%) compared to 9.9 mm Hg (37%) with twice-daily application; three of four eyes responded just as well to single-daily application as to twice daily application of GA. Once-daily treatment with GA was not successful when the average IOP in the absence of treatment was over 32 mm Hg. The advantages of once-daily application were less conjunctival hyperemia, less dilation of the pupils, less ptosis and difficulty reading, plus the advantage that the drops needed only to be applied once a day (patient compliance). The recommended regime for GA therapy in patients with an IOP of less than 32 mm Hg is application of GA twice daily for 1 month followed by a decrease in the dosage to once a day. GA can best be applied in the evening before retiring.

Drug Combinations↗
PubMed1979

Four year follow-up of a glaucoma operation. Prospective study of the double flap Scheie.

This paper presents the four-year follow-up results of a prospective study on the results of the Double Flap Scheie. The study was started in 1971 and the pre- and post-operative evaluation was carried out according to carefully selected criteria. Admitted were only open angle glaucoma patients. Diurnal IOP-curves, static perimetry, evaluation of lens and optic disc in mydriasis were included in the complete pre- and post-operative examination. In the Douible Flap Scheie a conjunctival and scleral flap are made followed by a cornea-scleral cauterization and incision after which a peripheral iridectomy is made. 51 eyes of 48 patients were operated. After 4 years 42 eyes of 37 patients could still be examined. The mean IOP was reduced from 33.0 to 17.3 mm without additional therapy. This is a mean percentage reduction of 48.5%. 75% of the mean IOP was under 21 mm; with additional therapie 91% was under 21 mm. Diurnal variation decreased from 7 to 4 mm. 48% of the eyes showed a decreased visual acuity of which 38% was caused by cataract. 52% showed visual field deterioration of which one third was attributed to cataract. In 24% the visual field deterioration was considered clinically important. There was no clear relation between IOP level and visual field deterioration.

Aged↗
PubMed1979

The combination of guanethidine 3% and adrenaline 0.5% in 1 eyedrop (GA) in glaucoma treatment.

During a 7-month period 33 patients (20 with primary open-angle glaucoma and 13 with suspected glaucoma) were treated with guanethidine 3% and adrenaline 0.5% in 1 eyedrop twice daily. The previous therapy was discontinued and the aim of the trial was to treat the patients with GA alone. There was an average decrease in intraocular pressure of 10.8 mmHg or 37.5% for the whole group (including 5 patients with additional therapy). In eyes with an average IOP in a day-curve without medication equal to or higher than 28 mmHg we found a decrease of 44.6% or 14.4 mmHg, and in eyes with an average IOP without medication between 21 and 28 mmHg a decrease of 30.4% or 7.6 mmHg. With GA alone the IOP was 3.3 to 3.9 mmHg lower than on the previous therapy (P less than 0.05); 46% of the eyes without additional therapy had all IOPs lower than 22 mmHg and 74% of the eyes had IOPs lower than 22 mmHg except 1 with a peak lower or equal to 25 mmHg 3 hours after application. This peak 3 hours after application indicates that GA has a biphasic action and was significant at the 0.5% level. Red eyes and slight ptosis were no problem for most patients. Patients found it very convenient to administer GA only twice daily.

Adult↗
PubMed1978

Metoprolol eye drops in the treatment of glaucoma. A double-blind single-dose trial of a beta1-adrenergic blocking drug.

A double-blind single-dose trial was performed on 13 patients with primary open-angle glaucoma. Metoprolol 1%, 2%, and 4% produced a median fall in IOP of 5.6, 5.4, and 6.8 mm Hg, respectively, in the treated eye. The differences in effect between the 1%, 2%, and 4% solutions were not statistically significant. There was no significant fall in IOP in the untreated eyes. There were no significant changes in blood pressure, pulse rate, or pupillary diameter. We could not detect any local objective or subjective side effects during the single-dose study. The clinical usefulness of metoprolol may be limited due to local toxic reactions after treatment with multiple doses. Furthermore, there is the problem of tachyphylaxis that could limit extended treatment with topical beta-adrenergic blocking drugs.

Adult↗
PubMed1977

Atenolol 4% eye drops and glaucoma. A double-blind short-term clinical trial of a new beta1-adrenergic blocking agent.

We studied the effect of a single dose of atenolol 4% eye drops on 21 patients with primary open-angle glaucoma during a double-blind clinical trial. We monitored intraocular pressure (IOP), blood pressure, and pulse rate. At three and six h after medication, the average reduction of IOP was 7.3 and 4.1 mm Hg, respectively, compared to the baseline readings without medication. The reduction of IOP at four h after medication was 6.3 mm Hg compared to the pretreatment value. This corresponds to an average change from the pretreatment value of 22%. Blood pressure and pulse rate did not change significantly. We observed no subjective or objective ocular side effects. The duration of the effect of a single dose of atenolol 4% eye drops is approximately six h. Atenolol 4% eye drops may become a useful agent in the medical treatment of glaucoma if a long-term effect and no ocular side effects (especially a local anesthetic effect) can be proven.

Adult↗
PubMed1977

A double-blind short-term trial of guanethidine 3% and adrenaline 0.5% combined in one eye drop.

A double-blind short-term trial was done to test the effect of guanethidine 3% - adrenaline 0.5% (G-A) in a combined eye drop in 18 patients with open-angle glaucoma and one patient with narrow-angle glaucoma. In 9 of the 19 patients we expected an IOP lowering agent. There was one false-negative result. The mean fall in IOP due to G-A was 10.1 mm Hg (range 3 to 23) and 8.7 mm Hg (range-1 to 26) 6 and 8 h after application respectively. There was no effect on IOP in the 9 eyes that received the placebo.

Clinical Trials as Topic↗