Effects of vitamin B12 on the corneal nerve regeneration in rats.

The study was designed to investigate the effects of a new ophthalmic solution containing 0.05% vitamin B12 0.05% on corneal nerve regeneration in rats after corneal injury. Eyes of anesthetized male Wistar rats were subjected to corneal injury by removing the corneal epithelium with corneal brush (Algerbrush). After the epithelial debridement, the right eye of each animal received the instillation of one drop of the ophthalmic solution containing vitamin B12 0.05% plus taurine 0.5% and sodium hyaluronate 0.5% four time per day for 10 or 30 days. Left eyes were used as control and treated with solution containing taurine 0.5% and sodium hyaluronate 0.5% alone following the same regimen. Fluorescein staining by slit-lamp and morphological analysis was used to determine corneal wound healing. Immunohistochemistry, immunoblot and confocal microscopy were used to examine corneal re-innervation. Slit-lamp and histological analyses showed that re-epithelization of the corneas was accelerated in rats treated with vitamin B12. A clear-cut difference between the two groups of rats was seen after 10 days of treatment, whereas a near-to-complete re-epithelization was observed in both groups at 30 days. Vitamin B12 treatment had also a remarkable effect on corneal re-innervation, as shown by substantial increased in the expression of neurofilament 160 and ß-III tubulin at both 10 and 30 days. The presence of SV2A-positive nerve endings suggests the presence of synapse-like specialized structures in corneal epithelium of the eye treated with vitamin B12. Our findings suggest that vitamin B12 treatment represents a powerful strategy to accelerate not only re-epithelization but also corneal re-innervation after mechanical injury.

Randomized, double-blind, placebo-controlled clinical trial on the efficacy of 0.5% indomethacin eye drops in uveitic macular edema.

PURPOSE: The aim of the present randomized, double-blind, placebo-controlled clinical trial was to assess the efficacy and tolerability of 0.5% indomethacin (INDOM) eye drops in adult patients suffering from macular edema (ME) related to different etiology uveitis. METHODS: Forty-six eyes of 31 adult patients (20 females and 11 males) mean age 39 years, affected by inflammatory ME, were randomized to receive a dose of commercial 0.5% INDOM eye-drops four times per day (16 subjects = 23 eyes) or placebo (the vehicle of INDOM, 15 subjects = 23 eyes) during a 6-month active therapy follow-up. Study assessment at each visit included visual acuity testing (VA), slit-lamp examination, IOP evaluation, and Heidelberg Spectralis optical coherence tomography (OCT) central foveal thickness (CFT) measurement. Any variation in subjective symptoms and tolerability was also detected. RESULTS: Statistical analysis showed, from baseline to the 6-month visit, a significant reduction in CFT (P < 0.0001) and a significant improvement in VA only in the 0.5% INDOM-treated group; a global reduction of discomfort symptoms was present in both groups (P < 0.001). CONCLUSIONS: The four times per day administration of 0.5% INDOM eye drops in eyes affected with uveitic ME from different etiologies, compared with placebo, is associated with a significant reduction in ME at the 6-month follow-up visit, as measured by spectral-domain optical coherence tomography (SD-OCT). However, not all eyes showed a complete resolution of ME because of vitreoretinal traction. (https://eudract.ema.europa.eu/index.html number, EUDRACT 2011-001522-20.).

Ocular pharmacokinetics profile of different indomethacin topical formulations.

PURPOSE: This study evaluated the ocular pharmacokinetics of indomethacin following topical administration of two different formulations present in the market. METHODS: Rabbits received a multiple topical instillation (30 µL) of indomethacin ophthalmic suspension containing hydroxypropylmethylcellulose (IND-HPMC; Indom™ Alfa-Intes) or indomethacin ophthalmic solution with hydroxypropyl-ß-cyclodextrin (IND-CD; Indocollirio™ Bausch & Lomb). Aqueous humor, vitreous humor, and retina were collected from animals at fixed time intervals after dosing. Indomethacin ocular levels were measured by liquid chromatography mass spectrometry (LC-MS/MS), and the pharmacokinetic parameters--peak drug concentration (C(max)), time to peak value (T(max)), and area under the concentration-time curve between 0 and 240 min (AUC(0-240))--were determined. All of the animals were treated according to the Association for Research in Vision and Ophthalmology (ARVO) Statement for the Use of Animals in Ophthalmic and Vision Research. RESULTS: Peak concentrations of indomethacin in aqueous and vitreous were achieved within 30 min and 60 min after a single instillation of IND-HPMC and IND-CD, respectively. Retinal T(max) was 30 min and 120 min in the IND-HPMC-treated group and the IND-CD-treated group, respectively. Higher levels of indomethacin were found in retina after IND-HPMC administration compared to IND-CD (AUC(0-240) 272.9 ng/g per min vs. AUC(0-240) 73.5 ng/g/min, respectively; P<0.01). Also in the aqueous and vitreous, the drug levels were statistically higher (P<0.01) in the IND-HPMC group in comparison with the IND-CD group (AUC(0-240) 2039 ng/mL per min vs. AUC(0-240) 427.3 ng/mL per min, AUC(0-240) 53.8 ng/mL per min vs. AUC(0-240) 12.5 ng/mL per min, respectively). The highest drug levels in the ocular tissues were found following IND-HPMC administration compared with IND-CD (retina: C(max) 73.7±6.4 ng/g vs. 25.5±1.73 ng/g; aqueous: C(max) 952±6.8 ng/mL vs. 163±4.1 ng/mL; vitreous C(max) 31±3.5 ng/mL vs. 6.37±3.6 ng/mL). CONCLUSIONS: IND-HPMC treatment demonstrates a nonclinical ocular pharmacokinetic profile of indomethacin characterized by higher concentrations of drug in ocular tissues (4.7-, 4.3- and 3.7-fold higher in aqueous, vitreous, and retina, respectively) compared to the ND-CD-treated group. Taken together, these data seem to indicate that IND-HPMC formulation has good ocular distribution reaching relevant indomethacin levels in the back of the eye, and suggest that this formulation may be very useful for clinicians to manage retinal conditions.