Enrico Gandolfo

Effect of Ginkgo biloba extract on preexisting visual field damage in normal tension glaucoma

OBJECTIVE To evaluate the effect of Ginkgo biloba extract (GBE) on preexisting visual field damage in patients with normal tension glaucoma (NTG). DESIGN Prospective, randomized, placebo-controlled, double-masked cross-over trial. PARTICIPANTS Twenty-seven patients with bilateral visual field damage resulting from NTG. INTERVENTION Patients received 40 mg GBE, administered orally, three times daily for 4 weeks, followed by a wash-out period of 8 weeks, then 4 weeks of placebo treatment (identical capsules filled with 40 mg fructose). Other patients underwent the same regimen, but took the placebo first and the GBE last. Visual field tests, performed at baseline and at the end of each phase of the study, were evaluated for changes. MAIN OUTCOME MEASURES Change in visual field and any ocular or systemic complications. RESULTS After GBE treatment, a significant improvement in visual fields indices was recorded: mean deviation (MD) at baseline versus MD after GBE treatment, 11.40 +/- 3.27 dB versus 8.78 +/- 2.56 dB (t = 8.86, P = 0.0001, chi-square test); corrected pattern standard deviation (CPSD) at baseline versus CPSD after GBE treatment, 10.93 +/- 2.12 dB versus 8.13 +/- 2.12 dB (t = 9.89, P = 0.0001, chi-square test). No significant changes were found in intraocular pressure, blood pressure, or heart rate after placebo or GBE treatment. Any ocular and systemic side effects were recorded for the duration of the trial. CONCLUSIONS Ginkgo biloba extract administration appears to improve preexisting visual field damage in some patients with NTG.

Color Doppler imaging of ophthalmic artery blood flow velocity: A study of repeatability and agreement

PURPOSE Color Doppler imaging (CDI) is a relatively new technique that allows quantification of blood flow velocity in orbital and ocular vasculature. Despite the numerous clinical studies that have used CDI, repeatability of this technique and agreement between observers have not been documented. METHODS The authors performed a prospective investigation of the repeatability and agreement between observers on ophthalmic artery blood flow velocity measurements in 35 patients (35 eyes). RESULTS Results on the estimated error of measurement (variability between repeated readings on the same subject) indicate good repeatability of the measurements; in fact, the measurement variances were only 5.6% for the peak systolic velocity, 11.4% for the end diastolic velocity, and 6.2% for the mean envelope velocity. The statistical analysis of repeatability showed a very narrow 95% confidence interval for both observers. The measurement of agreement between the two observers demonstrated the existence of a good concordance of the measurements taken by each observer on each subject. CONCLUSIONS Results suggest that CDI is a reliable tool for quantitative assessment of ophthalmic artery blood flow velocity.

Vigabatrin and epilepsy: lessons learned.

Summary:  Purpose: The risk factors for visual field loss attributable to vigabatrin (VAVFL) are equivocal. This multinational, prospective, observational study aimed to clarify the principal/major factors for VAVFL.

Visual field loss in patients with refractory partial epilepsy treated with vigabatrin: final results from an open-label, observational, multicentre study.

Background: Use of the antiepileptic drug vigabatrin is associated with an elevated risk of visual field loss.Objective: To determine the frequency of, and risk factors for, vigabatrin-attributed visual field loss (VAVFL) in the setting of a large-scale, multinational, prospective, observational study.Study design: A comparative, open-label, parallel-group, multicentre study.Setting: Hospital outpatient clinics at 46 centres in five countries.Patients: 734 patients with refractory partial epilepsy, divided into three groups and stratified by age (8–12 years; >12 years) and exposure to vigabatrin. Group I comprised patients treated with vigabatrin for ≥6 months. Group II comprised patients previously treated with vigabatrin for ≥6 months who had withdrawn from the drug for ≥6 months. Group III comprised patients never treated with vigabatrin. Patients underwent perimetry at either 4- or 6-month intervals, for up to 36 months. Visual field outcome was evaluated masked to drug exposure.Intervention: Perimetry.Main outcome measure: The visual field outcome at each of four analysis points: (i) at enrolment (i.e. baseline, all patients); (ii) for patients exhibiting a conclusive outcome at the initial visual field examination; (iii) for patients exhibiting at least one conclusive outcome to the visual field examinations; and (iv) at the last conclusive outcome to the visual field examinations.Results: Of the 734 patients, 524 yielded one or more conclusive visual field examinations. For Group I, the frequency of VAVFL at the last conclusive examination was 10/38 (26.3%) for those aged 8–12 years and 65/150 (43.3%) for those aged >12 years. For Group II, the respective frequencies were 7/47 (14.9%) and 37/151 (24.5%). One case resembling VAVFL was present amongst the 186 patients in Group III at the last conclusive examination. The frequency of VAVFL in Groups I and II combined was 20.0% for those aged 8–12 years and 33.9% for those aged >12 years. VAVFL was associated with duration of vigabatrin therapy (odds ratio [OR] up to 15.2; 95% CI 4.4, 51.7), mean daily dose of vigabatrin (OR up to 26.4; 95% CI 2.4, 291.7) and male gender (OR 2.51; 95% CI 1.5, 4.1). VAVFL was more frequently detected with static than with kinetic perimetry (OR up to 0.43; 95% CI 0.24, 0.75).Conclusions: Since the probability of VAVFL is positively associated with treatment duration, careful assessment of the risk-benefit ratio of continuing treatment with vigabatrin is recommended in patients currently receiving this drug. All patients continuing to receive vigabatrin should undergo visual field examination at least every 6 months for the duration of treatment. We recommend two-level (three-zone), gradient-adapted, suprathreshold static perimetry of the peripheral field together with threshold perimetry of the central field out to 30° from fixation. The frequency of ophthalmological and perimetric examinations should be increased in the presence of VAVFL.

Gonioscopic findings in patients with type 1 neurofibromatosis (Von Recklinghausen disease).

Purpose:Based on the known neurocristopathic etiology of type 1 neurofibromatosis (NF1) and the neuroectodermal embryologic derivation of the iridocorneal angle, we examined a sample of young patients affected with NF1 to see if they have evidence of underdevelopment of the angular region. Patients and Methods:We designed a case-controlled clinical study. Forty-two consecutive patients (42 eyes), 24 male and 18 female, affected with NF1 were recruited for the study. Forty-two eyes of 42 consecutive young patients (19 male and 23 female) served as a control group for the iridocorneal angle features studied. Indirect gonioscopy was performed by the means of a Goldmann lens. The intraocular pressure was measured with a Goldmann applanation tonometer. Photographs were taken of the anterior segment and of all the four quadrants of the iridocorneal angle to record the presence of abnormalities. The iridocorneal angle was graded according to the classification proposed by Spaeth. Evaluation of the angle also included the gonioscopic width of ciliary body band (CBB). Results:In this study we found that 29 of 42 eyes (69%) of the NF1 group had mild anteriorization, even if within normal limits, of the iris insertion and abundant basal iris processes. The CBB was either invisible (54.84%) or very narrow (21.4%). Three NF1 patients had bilateral juvenile congenital glaucoma. Conclusions:It seems that patients affected with NF1 often have characteristic gonioscopic findings consistent with underdevelopment of the iridocorneal angle.

Ocular hypotensive effect of sublingual administration of timolol

Purpose: A randomized clinical trial to assess ocular hypotensive effect of sublingual administration of timolol was performed. Patients and methods: Seventeen (9 male, 8 female; age range 45 to 68 years) with bilateral ocular hypertension were selected for the study. Each patient was evaluated with regard to IOP, arterial blood pressure and heart rate before and after each of the following experimental treatment: unilateral ocular administration of 20 μl of 0.5% timolol solution; sublingual administration of 20 μl of 0.5% timolol solution; unilateral ocular administration of 20 μl of saline solution (placebo); sublingual administration of 20 μl of saline solution (placebo). The sequence of the treatments and the eye topically treated were randomly chosen. At least four weeks wash-out elapsed between each experimental treatment. Results: Our results showed that sublingual administration of timolol was able to induce a bilateral significant reduction of the IOP. This reduction was not statistically different from that obtained in the eye treated with timolol. A significantly greater reduction of the IOP was obtained by sublingual timolol than in the contralateral eye after unilateral topical administration of timolol solution. No significant modification of arterial blood pressure and heart rate were evidenced after the treatment. Conclusions: Sublingual administration seems to be a new interesting way for reducing the IOP. Long term studies are required in order to test efficacy and safety of this new treatment.