We report that eight heterozygous missense mutations in TUBB3, encoding the neuron-specific β-tubulin isotype III, result in a spectrum of human nervous system disorders we now call the TUBB3 syndromes. Each mutation causes the ocular motility disorder CFEOM3, whereas some also result in intellectual and behavioral impairments, facial paralysis, and/or later-onset axonal sensorimotor polyneuropathy. Neuroimaging reveals a spectrum of abnormalities including hypoplasia of oculomotor nerves, and dysgenesis of the corpus callosum, anterior commissure, and corticospinal tracts. A knock-in disease mouse model reveals axon guidance defects without evidence of cortical cell migration abnormalities. We show the disease-associated mutations can impair tubulin heterodimer formation in vitro, although folded mutant heterodimers can still polymerize into microtubules. Modeling each mutation in yeast tubulin demonstrates that all alter dynamic instability whereas a subset disrupts the interaction of microtubules with kinesin motors. These findings demonstrate normal TUBB3 is required for axon guidance and maintenance in mammals.

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Nutritional optic neuropathy is a cause of bilateral, symmetrical, and progressive visual impairment with loss of central visual acuity and contrast sensitivity, dyschromatopsia, and a central or centrocecal scotoma. The clinical features are not pathognomonic, since hereditary and toxic forms share similar signs and symptoms. It is becoming increasingly common due to the widespread of bariatric surgery and strict vegetarian or vegan diets, so even the scientific interest has recently increased. In particular, recent studies have focused on possible pathogenetic mechanisms, and on novel diagnostic and therapeutic strategies in order to prevent the onset, make a prompt diagnosis and an accurate nutritional supplementation, and to avoid irreversible optic nerve atrophy. Nowadays, there is clear evidence of the role of cobalamin, folic acid, thiamine, and copper, whereas further studies are needed to define the role of niacin, riboflavin, and pyridoxine. This review aims to summarize the etiology, diagnosis, and treatment of nutritional optic neuropathy, and it is addressed not only to ophthalmologists, but to all physicians who could come in contact with a patient with a possible nutritional optic neuropathy, being a fundamental multidisciplinary approach.

Treating adult amblyopes with CDP-choline has the effect of improving their VA, CS and VEPs. Changes occur in both eyes, although to different extents, and resemble those previously reported for levodopa treatment.

Background/objectives: To compare the number of eye surgical procedures performed in Italy in the 2 months following the beginning of lockdown (study period) because of COVID-19 epidemic with those performed in the two earlier months of the same year (intra-year control) and in the period of 2019 corresponding to the lockdown (inter-year control). Methods: Retrospective analysis of surgical procedures carried out at 39 Academic hospitals. A distinction was made between elective and urgent procedures. Intravitreal injections were also considered. Percentages for all surgical procedures and incidence rate ratios (IRR) for rhegmatogenous retinal detachment (RRD) events were calculated. A p value <0.05 was considered significant. Results: A total of 20,886 versus 55,259 and 56,640 patients underwent surgery during the lockdown versus intra-and inter-year control periods, respectively. During the lockdown, only 70% of patients for whom an operation/intravitreal injection was recommended, finally underwent surgery; the remaining patients did not attend because afraid of getting infected at the hospital (23%), taking public transportation (6.5%), or unavailable swabs (0.5%). Elective surgeries were reduced by 96.2% and 96.4%, urgent surgeries by 49.7% and 50.2%, and intravitreal injections by 48.5% and 48.6% in the lockdown period in comparison to intra-year and inter-year control periods, respectively. IRRs for RRDs during lockdown dropped significantly in comparison with intra- and inter-year control periods (CI: 0.65–0.80 and 0.61–0.75, respectively, p < 0.001 for both). Conclusion: This study provides a quantitative analysis of the reduction of eye surgical procedures performed in Italy because of the COVID-19 epidemic.

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PURPOSE.To investigate the immune response of human conjunctival epithelium to hyperosmolar stress. METHODS. Tear osmolarity was measured in 15 normal subjects and 25 dry eye (DE) patients; conjunctival imprint cytology samples were obtained at the nasal bulbar area. Subconfluent primary human conjunctival epithelial cells (pHCECs) and human conjunctival organ cultures (hCOCs), both cultured in iso-osmolar medium (305 mOsm/L), were exposed for 24 hours to media with progressively higher osmolarity, with or without the ion channel inhibitor ruthenium red (RuR). Human leukocyte antigen (HLA)-DR expression was evaluated by immunocytochemistry, on imprints from subjects, on primary human conjunctival epithelial cells, on formalin fixed-paraffin embedded hCOCs, and by RT-PCR. Statistical evaluation was performed by applying the unpaired Student's t test, as well as Spearman's rho and Pearson's r correlation coefficients (significance P Ͻ 0.05). RESULTS. HLA-DR expression increased in DE subjects with respect to control (% mean Ϯ SD, respectively, 46.16 Ϯ 7.2 vs. 7.48 Ϯ 1.14, P Ͻ 0.0001) and exhibited significantly high correlations with tear osmolarity values (r ϭ 0.614; P Ͻ 0.0001). In vitro experiments showed a progressive increase in HLA-DR expression as the osmolarity of the medium was increased from 6.75 Ϯ 1.16 (% mean Ϯ SD) in iso-osmolarcultured cells to 9.96 Ϯ 1.37 and 12.94 Ϯ 4.04 in cells cultured in, respectively, 350 and 400 mOsm/L (P Ͻ 0.05). A stepwise progressive increase was also found in hCOCs. Results were confirmed by RT-PCR. Ruthenium red significantly reduced HLA-DR expression in hyperosmolar-cultured cells. CONCLUSIONS. Data from complementary techniques demonstrate that extracellular hyperosmolarity induces HLA-DR overexpression in human conjunctival epithelial cells in both DE patients and in vitro cell culture models. (Invest Ophthalmol Vis Sci. 2011;52:5488 -5496)