Citicoline oral solution in glaucoma: is there a role in slowing disease progression?

PURPOSE: To assess the effect of citicoline on visual field rates of progression in patients with progressing glaucoma. PATIENTS AND METHODS: Forty-one patients with a diagnosis of progressing glaucoma received citicoline in oral solution for 2 years. Included were patients with a disease progression of at least -1 dB/year (at MD, mean deviation) for at least 3 years before entering the study despite controlled intraocular pressure (IOP). Patients were followed with 4 visual field examinations per year for 2 years. RESULTS: At baseline, the mean rate of progression was -1.1 (±0.7) dB/year despite the fact that the IOP had been below 18 mm Hg for at least 3 years. At study inclusion, the mean IOP was 15.5 (±2.6) mm Hg and the mean MD was -9.2 (±6.7) dB in the worst eye. Starting from the first cycle of treatment with citicoline, the mean rate of progression significantly changed to -0.15 (±0.3) dB/year at the end of the study (p = 0.01). CONCLUSIONS: This study seems to indicate that supplementation with citicoline might significantly slow down glaucomatous rates of progression.

Impaired neural conduction in crossed visual pathways in patients with ocular hypertension.

PURPOSE: To evaluate the neural conduction along crossed and uncrossed visual pathways in patients with ocular hypertension (OHT). METHODS: Fifteen patients (mean age 59.1+/-6.8 years) with OHT (IOP>22 mmHg, Humphrey 24-2 with mean deviation [MD]>-2 dB) were enrolled. They were compared to 15 age-matched controls. In OHT patients and control subjects, visual evoked potentials (VEPs) were recorded using full-field checkerboard patterns (the check subtended 15' of visual arc; contrast 80%) reversed at 2 Hz. VEP responses were simultaneously recorded in the homolateral visual cortex (HC) and in the contralateral visual cortex (CC), with respect to the stimulated eye. RESULTS: In OHT patients, VEP P100 implicit times observed in HC and CC were both significantly delayed (analysis of variance, p<0.01) when compared to those of controls, and, in particular, longer in CC than in HC. The interhemispheric differences (ID: P100 implicit time in HC - P100 implicit time in CC) were significantly higher in OHT patients than controls (-3.16+/-1.80 msec and 1.16+/-1.04 msec, respectively, p=0.001). In OHT patients we observed an MD hemifield difference (difference between nasal and temporal MD values) higher than in controls (-0.82+/-0.80 dB and 0.04+/-1.03 dB, respectively, p<0.01) and significantly correlated with the ID (r: 0.836, p<0.001). CONCLUSIONS: The observed asymmetry in the bioelectrical cortical responses and in the visual hemifield parameters suggests that crossed visual pathways could be impaired earlier than uncrossed visual pathways in OHT patients.

Comparative effects of intraocular pressure between systemic and topical carbonic anhydrase inhibitors: a clinical masked, cross-over study.

The aims of the following study were to compare the efficacy of Dorzolamide 1% eye drops with systemic Acetazolamide on the ocular pressure diurnal curve in patients with maximal medical therapy. Three ocular pressure curve were performed in glaucomatous patients, already receiving maximal medical therapy. After a baseline curve, patients were pretreated either with Dorzolamide 1% eye drops or 250 mg Acetazolamide tablets in a double-blind cross-over study. Dorzolamide 1% eye drops and 250 mg Acetazolamide tablets significantly reduced intraocular pressure (IOP) at 2 and 4 h after pretreatment. Both treatments caused a significantly additional decrease of IOP despite maximal medical therapy. Dorzolamide 1% eye drops is as effective as Acetazolamide tablets in reducing the IOP curve. Topical carbonic anhydrase inhibitors may represent an additional and safer treatment for those patients with uncontrolled medical glaucoma.

Nerve growth factor (NGF) reduces and NGF antibody exacerbates retinal damage induced in rabbit by experimental ocular hypertension.

BACKGROUND: It has been shown that intravitreal injection of NGF inhibits ganglion cell degeneration after optic nerve transection and ischemic injury. The aim of our study was to investigate the presence of NGF in aqueous humor and its involvement in retinal damage during ocular hypertension. METHODS: We used an experimental model of ocular hypertension in rabbit. Before treatment and 4, 10 and 15 days after induction of hypertension, we evaluated histological retinal damage and NGF levels in aqueous humor using an immunoenzymatic assay. Polyclonal anti-NGF antibodies were injected intravitreally into one eye of each rabbit (n = 6), and the animals were killed after 4 days of hypertension. Another group of rabbits (n = 12) was injected retro-ocularly with NGF and killed after 10 or 15 days of treatment for histologic evaluation of the retina. RESULTS: Our data show that experimental ocular hypertension in adult rabbits induces retinal damage and enhances local NGF levels. The highest NGF value was found after 4 days of intraocular hypertension: high levels persisted, though to a lesser extent, for up to 15 days. Histological examination revealed that the number of retinal ganglion cells (RGC) remained unchanged during the first 4 days but decreased at 10 days. These studies also showed that retro-ocular administration of NGF reduced RGC loss, whereas intraocular injection of NGF antibodies, which inhibited the endogenous NGF, exacerbated the retinal insult. CONCLUSION: These findings demonstrate a protective effect of NGF on RGC damaged by ocular hypertension and prompt further investigations to evaluate a possible therapeutic use of NGF to retard RGC death in humans.

Decentration of posterior chamber IOL: effects of loop material and fixation technique.

A prospective study was conducted on 90 eyes undergoing extracapsular cataract extraction and posterior chamber IOL implantation. Postoperative IOL decentration was evaluated with respect to the loop material, either polypropylene (prolene) or polymethylmethacrylate (PMMA), and the IOL fixation technique, either in the capsular sac (in-the-bag) after capsulorhexis, or in the ciliary sulcus after "can-opener" capsulotomy. More decentration was observed with IOL having polypropylene loops than with those having PMMA loops (0.80 +/- 0.735 mm versus 0.373 +/- 0.299 mm). IOL implanted in the bag showed greater decentration than those implanted in the sulcus, but the difference was not significant. Our findings confirm the recommendation to use an IOL with PMMA loops when placing the implant in the capsular sac.

Hypotensive effect of pilocarpine after argon laser trabeculoplasty.

The exact mechanism of action of argon laser trabeculoplasty (ALT) has only been presumptively proposed. There are two hypotheses of action of ALT: the first is the mechanical theory and the second is centered on the possibility of laser-induced modifications of trabecular cells. The goal of our investigation was to verify if pilocarpine determines a decrease of intraocular pressure mainly by a mechanical stretching of the meshwork; if pilocarpine could lower intraocular pressure after ALT; and thus if the mechanism of action of laser treatment could mainly be attributable to a mechanical strain of the trabecular meshwork. Twenty-one patients affected with primary open angle glaucoma had been recruited for the study. Twenty-one eyes underwent trabeculoplasty. All the patients were followed for 6 months. Statistical analysis of the data revealed that pilocarpine was not able to induce a further decrease of intraocular pressure after trabeculoplasty. Moreover, the maximum decrease of intraocular pressure induced by pilocarpine before laser treatment was not statistically different from the tensional values after ALT. The results of the present investigation suggest that the mechanism of action of trabeculoplasty is probably attributable to a mechanical stretching of the trabecular meshwork and the results show the inefficacy of pilocarpine after laser treatment in the management of glaucomatous patients.