Safety study of intravitreal and suprachoroidal Laponite clay in rabbit eyes.

PURPOSE: To study the safety and biocompatibility of Laponite clay (LAP) within an intravitreal and suprachoroidal administration in rabbit eyes. METHODS: Thirty-two New Zealand albino rabbits were divided into two experimental groups to test intravitreal (IVT group) and suprachoroidal (SCS group) administration of a 100-µl and 50-µl Laponite suspension respectively. Following injection, the eyes were monitored by ocular tonometry, slit-lamp eye examination and indirect ophthalmoscopy, at 24 h, 1, 4, 12, and 14 weeks post administration. Histological examination was also performed to determine whether any ocular pathological change had occurred. Throughout the study, LAP presence in vitreous was estimated by complexometric titration with ethylenediaminetetraacetic acid (EDTA), taking advantage of the Laponite high content of magnesium ions. RESULTS: Neither significant differences in the intraocular pressure, nor relevant ocular complications were found in the two experimental groups after LAP administration. The histology of the retina remained unchanged. LAP presence in vitreous could be indirectly confirmed by complexometric titration until 14 weeks post administration in eyes of IVT group. CONCLUSION: Laponite could be considered as a vehicle for potential clinical use in ocular drug administration, due to its proven ocular biocompatibility and its transparency in gel state.

Six month delivery of GDNF from PLGA/vitamin E biodegradable microspheres after intravitreal injection in rabbits.

Local long-term delivery of glial cell line derived neurotrophic factor (GDNF) from vitamin E/poly-lactic-co-glycolic acid microspheres (MSs) protects retinal ganglion cells in an animal model of glaucoma for up to 11weeks. However, the pharmacokinetics of GDNF after intravitreal injection of MSs is not known. We evaluated the GDNF levels after a single intravitreal injection of GDNF/VitE MSs. Biodegradable MSs were prepared by the solid-oil-in-water emulsion-solvent evaporation technique and characterized. Rabbits received a single intravitreal injection (50µL) of GDNF/VitE MSs (4%w/v; 24 right eyes; 74.85ng GDNF), blank MSs (4%w/v; 24 left eyes), and balanced salt solution (4 eyes). Two controls eyes received no injections. At 24h, 1, 4, 6, 8, 12, 18, and 24weeks after injection, the eyes were enucleated, and the intravitreal GDNF levels were quantified. Pharmacokinetic data were analysed according to non-compartmental model. Intraocular GDNF levels of 717.1±145.1pg/mL were observed at 24h for GDNF-loaded MSs, followed by a plateau (745.3±25.5pg/mL) until day 28. After that, a second plateau (17.4±3.7pg/mL) occurred from 8 to 24weeks post-injection, significantly higher than the basal levels. Eyes injected with GDNF/vitE and Blank-MSs did not show any abnormalities during the six-months follow up after administration. The single injection of GDNF/VitE MSs provided a sustained controlled release of the neurotrophic factor in a controlled fashion for up to six months.

Correction: Study of Association between Pre-Senile Cataracts and the Polymorphisms rs2228000 in XPC and rs1042522 in p53 in Spanish Population.

[This corrects the article DOI: 10.1371/journal.pone.0156317.].

Determination of Three Corticosteroids in the Biologic Matrix of Vitreous Humor by HPLC-tandem Mass Spectrometry: Method Development and Validation.

PURPOSE: To develop a simple, specific, and rapid method to determine corticosteroid concentrations in vitreous humor. METHODS: An analytical method based on high-pressure liquid chromatography-tandem mass spectrometry (HPLC-MS) with a simple extraction procedure was developed. New Zealand albino rabbits (n = 54) received a single (0.1 mL) intravitreal injection of dexamethasone (DXM, 0.1 mg), methylprednisolone (MP, 2 mg), or triamcinolone acetonide (TA, 10 mg). Eyes were enucleated and mean vitreous steroid levels were quantified at 12 h and 1, 2, 3, 7, and 14 days. RESULTS: Corticosteroids were extracted from the vitreous with acetonitrile, and TA was extracted with ethyl acetate, yielding high protein precipitation and clean solution samples. Vitreous samples were analyzed by isocratic HPLC-MS with mobile phase comprising acetonitrile and 2 mM ammonium formate buffer in water, pH 3.5. The linear range was 50-100,000 ng/g with a lower quantification limit of 45 ng/g for DXM and MP, and 50 ng/g for TA. Vitreous levels of DXM and MP were not detectable 14 days post-administration. Vitreous levels of TA were positive and stable throughout the study in both injected and control eyes. CONCLUSIONS: The HPLC-MS analytical method is an alternative to HPLC-MS/MS methods, sensitive enough for identifying and quantifying steroids in vitreous humor at a therapeutic dosage scale.

Study of association between pre-senile cataracts and rs11615 of ERCC1, rs13181 of ERCC2, and rs25487 of XRCC1 polymorphisms in a Spanish population.

BACKGROUND: The purpose of this study was to attempt to determine if the presence of certain polymorphisms in the DNA repair genes (ERCC1, ERCC2, and XRCC1) is associated with pre-senile cataract development. MATERIALS AND METHODS: We performed a retrospective study over three groups of patients. The first group with pre-senile cataract was formed by 72 patients younger than 55 years with cataract surgery. The second group with senile cataract was formed by 101 patients older than 55 years with cataract surgery. And the third group, without cataract, was formed by 42 subjects older than 55 years without lens opacities. We analyzed the presence of SNP rs11615 from ERCC1, rs13181 from ERCC2, and rs25487 from XRCC1 and the relationship between risk factors such as smoking, alcohol intake, hypertension, and diabetes. RESULTS: The comparison of the genotype distribution in ERCC1 and ERCC2 did not show any statistically significant association in any of our analyses (p > 0.05). The comparison of the genotype distribution in XRCC1 within the different groups did not show any statistically significant associations (p > 0.05), except for the comparison between the pre-senile cataract group and the group without cataract, where an increased risk of developing pre-senile cataract for the genotype Gln/Gln (p = 0.029; OR = 1.02-40.67) in recessive inheritance models was observed when adjusting for risk factors. CONCLUSIONS: Allelic variants in ERCC1 and ERCC2 are not associated with an increased risk of developing pre-senile cataract. The presence of Gln/Gln in XRCC1 in the pre-senile cataract group with regard to the group without cataract is associated with a major risk of developing pre-senile cataract.

Therapeutical Management for Ocular Rosacea.

PURPOSE: The purpose of this study is to describe a case of ocular rosacea with a very complex evolution. Rosacea is a chronic dermatological disease that may affect the ocular structures up to 6-72% of all cases. This form is often misdiagnosed, which may lead to long inflammatory processes with important visual consequences for affected patients. Therefore, an early diagnosis and an adequate treatment are important. METHODS: We report the case of a 43-year-old patient who had several relapses of what seemed an episode of acute bacterial conjunctivitis. Two weeks later, he developed a corneal ulcer with a torpid evolution including abundant intrastromal infiltrators and calcium deposits. He was diagnosed with ocular rosacea and treated with systemic doxycycline and topical protopic. RESULTS: A coating with amniotic membrane was placed in order to heal the ulcer, but a deep anterior lamellar keratoplasty to restore the patient's vision because of the corneal transparency loss was necessary. CONCLUSIONS: Ocular rosacea includes multiple ophthalmic manifestations ranging from inflammation of the eyelid margin and blepharitis to serious corneal affectations. A delayed diagnosis can result in chronic inflammatory conditions including keratinization and loss of corneal transparency, which lead to important visual sequelae for affected patients.

Study of Association between Pre-Senile Cataracts and the Polymorphisms rs2228000 in XPC and rs1042522 in p53 in Spanish Population.

PURPOSE: To determine if the presence of certain polymorphisms in the DNA repair gene XPC and the apoptosis inductor gene p53 is associated with pre-senile cataract development. METHODS: We have performed a retrospective study over three groups of patients. The group with pre-senile cataract formed by 72 patients younger than 55 with cataract surgery. The group with senile cataract formed by 101 patients older than 55 with cataract surgery. The group without cataract was formed by 42 subjects older than 55 without lens opacities. We analyzed the presence of SNP rs2228000 from XPC and rs1042522 from p53; and the relationship between risk factors such as smoking, alcohol intake, hypertension or diabetes. RESULTS: The comparison of the genotype distribution in XPC, within the different groups, did not show any statistically significant association in any of our analysis (p>0,05). The comparison of the genotype distribution in p53 within the different groups did not show any statistically significant association (p>0,05); except for the comparison between the pre-senile cataract group and the group with senile cataract where the genotype Pro/Pro (C/C) in the recessive inheritance model showed a higher risk for developing pre-senile cataract (p = 0,031; OR = 1.04-15.97). This association decreased when we performed the analysis adjusting by the studied risk factors (p = 0.056). CONCLUSIONS: Allelic variants in the gene XPC are not associated with an increased risk for developing pre-senile cataract. The presence of the genotype Pro/Pro in p53 might be associated with a major risk for developing pre-senile cataract.

Detecting Optic Atrophy in Multiple Sclerosis Patients Using New Colorimetric Analysis Software: From Idea to Application.

Neuro-ophthalmologists typically observe a temporal pallor of the optic disc in patients with multiple sclerosis. Here, we describe the emergence of an idea to quantify these optic disc color changes in multiple sclerosis patients. We recruited 12 multiple sclerosis patients with previous optic neuritis attack and obtained photographs of their optic discs. The Laguna ONhE, a new colorimetric software using hemoglobin as the reference pigment in the papilla, was used for the analysis. The papilla of these multiple sclerosis patients showed greater pallor, especially in the temporal sector. The software detected the pallor and assigned hemoglobin percentages below normal reference values. Measurements of optic disc hemoglobin levels obtained with the Laguna ONhE software program had good ability to detect optic atrophy and, consequently, axonal loss in multiple sclerosis patients. This new technology is easy to implement in routine clinical practice.