Wallace Chamon

CD11b+GR1+ Myeloid Cells Secrete NGF and Promote Trigeminal Ganglion Neurite Growth: Implications for Corneal Nerve Regeneration

PURPOSE We characterized fluorescent bone marrow cells (YFP(+) BMCs) in the thy1-YFP mouse and determine if they promote trigeminal ganglion (TG) cell neurite growth. METHODS Excimer laser annular keratectomy was performed in thy1-YFP mice, and corneas were imaged. BMCs were harvested from femur and tibia, and the expression of surface markers on YFP(+) BMCs was analyzed by flow cytometry. The immunosuppressive action of BMCs (YFP(+) and YFP(-)) was evaluated in an allogenic mixed lymphocyte reaction (MLR). Neurotrophic action of BMCs (YFP(+) and YFP(-)) was determined in compartmental and transwell cultures of dissociated TG cells. RESULTS Following annular keratectomy, YFP(+) BMCs infiltrated the cornea. YFP(+) BMCs shared surface markers (CD11b+Gr1+Ly6C+Ly6G-F4/80(low)) with monocytic myeloid-derived suppressor cells (MDSCs), had similar morphology, and suppressed T-cell proliferation in allogenic MLR in a dose-dependent manner. YFP(+) BMCs, but not YFP(-) BMCs, significantly increased growth of TG neurites in vitro. When cultured in a transwell with TG neurites, YFP(+) BMCs expressed neurotrophins and secreted nerve growth factor (NGF) in conditioned medium. YFP(+) BMCs that infiltrated the cornea maintained their phenotype and actions (neuronal and immune). CONCLUSIONS YFP(+) BMCs in thy1-YFP mice have immunophenotypic features of MDSCs. They secrete NGF and promote neuroregeneration. Their immunosuppressive and neurotrophic actions are preserved after corneal infiltration. These findings increase our understanding of the beneficial roles played by leukocyte trafficking in the cornea and may lead to therapeutic strategies that use NGF-secreting myeloid cells to repair diseased or injured neurons.

Intrastromal epithelial accretion follows deep excimer annular keratectomy.

The purpose of this study was to evaluate corneal reepithelialization and wound healing following annular excimer keratectomy. Two sets of experiments were performed on 35 rabbit eyes. In the first set of experiments, experiment I, deep Fresnel excimer keratectomy was performed, with a 6-mm outer and 3-mm inner diameter. Animals were sacrificed at 1,5, 12, and 16 weeks, and corneas were examined by light and electron microscopy. In experiment II, the central epithelium was left intact, and superficial and deep mid-peripheral excimer annular keratectomies were performed measuring 6 mm in outer and 3 mm in inner diameter. Animals were sacrificed at 1 week, and corneas were examined by light microscopy. Following deep Fresnel excimer keratectomy (experiment I), corneas showed stromal edema in the central 3-mm zone. Intrastromal islands of epithelial cells with PAS positive basement membrane-like structures were seen histologically at 1 week. Electron microscopy showed loss of stromal collagen in areas adjacent to epithelial islands; in areas distant from the epithelial islands, the stromal collagen appeared normal. The overlying central stroma sloughed after 5 weeks. Anterior stromal scarring was observed. In experiment II (mid-peripheral annular keratectomy), intrastromal epithelial accretion was present in corneas with deep annular keratectomy but not in superficial annular keratectomy. Intrastromal epithelial accretion follows deep excimer annular keratectomy and is associated with adjacent stromal degradation.

Cyclotorsional and non-cyclotorsional components of eye rotation observed from sitting to supine position

Purpose Evaluate average cyclotorsional and non-cyclotorsional components (NCY) of eye rotation from sitting to supine, and associate average cyclotorsion to different variables. Methods Medical records of patients who underwent bilateral sequential laser refractive surgery were retrospectively evaluated. Recorded variables included the patients age, refraction, automated keratometry, pupil displacement and eye rotation from sitting to supine position. Measured iris rotation (total rotation, TR) was decomposed into two components: NCY, defined as the common rotation component of each eye of the same patient, and cyclotorsional component (CY), defined as the assumed independent eye rotation for each eye in relation to the face, so that TR=NCY+CY. Cyclotorsion ratio (CR) was calculated as CR=|CY|/|TR|, and used to correlate CY with TR for each eye. Results Data from 310 eyes of 155 patients were evaluated. TR was +1.43° ±3.41° (−8.30° to +9.20°). Average CYs and NCYs per patient were +1.43°±2.04° (−3.15± to +7.40°) and −0.28°±2.72° (−6.85° to +7.15°), respectively. TR demonstrated that 40.6% and 8.4% of patients presented bilateral excyclotorsion and incyclotorsion, respectively. When excluding NCYs, average CYs demonstrated that 74.2% of patients presented excyclotorsion and 23.9% presented incyclotorsion. CR demonstrated that TR represented from 75% to 125% of average CY in 19.68% of the eyes. TR overestimated and underestimated average CYs above these limits in 52.26% and 28.06% of the eyes, respectively. There was no statistical association between average CYs and the different variables. Discussion This study demonstrates that most of the rotations previously attributed to torsional components were probably due to NCYs, such as postural misalignments. Apparently, the amplitude of cyclotorsional movements is smaller than observed in previous reports, and could not be associated with any studied variable.

Complete depigmentation of a small aperture corneal inlay implanted for compensation of presbyopia

We describe a case of late-onset remarkable depigmentation of a small aperture corneal inlay implanted for presbyopia compensation. The patient was a participant in a clinical trial designed to evaluate the safety and efficacy of the AcuFocusTM ACU-10R160, which is a 10 µm-thick polyimide film tinted with an organic dye. Inlay implantation occurred under mechanical microkeratome Lasik flaps set for a depth of 120 µm. The patient returned to the clinic 11 years after surgery and reported loss of near-vision acuity. Clinical examination showed the complete absence of pigments in the device and the total loss of the initial effect on near vision, despite normal distance vision. Manifest refraction remained stable during the follow-up period. Scheimpflug images characterized the loss of the small aperture effect on incoming light. Confocal analysis revealed small hyper-reflective round images on the endothelium and no signs of inflammation.

Elastography Methods Applicable to the Eye

Elastography is the mapping of tissues and cells by their respective mechanical properties, such as elasticity and viscosity. Our interest primarily lies in the human eye. Combining Scanning Laser Doppler Vibrometry (SLDV) with geometrically focused mechanical vibratory excitations of the cornea, it is possible to reconstruct these mechanical properties of the cornea. Experiments were conducted on phantom corneas as well as excised donor human corneas to test feasibility and derive a method of modeling. Finite element analysis was used to recreate the phantom studies and corroborate with the experimental data. Results are in close agreement. To further expand the study, lamb eyes were used in MR Elastography studies. 3D wave reconstruction was created and elastography maps were obtained. With MR Elastography, it would be possible to noninvasively measure mechanical properties of anatomical features not visible to SLDV, such as the lens and retina. Future plans include creating a more robust finite element model, improving the SLDV method for in-vivo application, and continuing experiments with MR Elastography.

Teaching ophthalmology to the medical student: a novel approach

Globalmente, as boas instituicoes medicas de ensino cumprem paralelamente a sua vocacao para pesquisa e assistencia medica. No entanto, frequentemente, as medidas quantitativas da qualidade dessas instituicoes, ponderam preferencialmente as vocacoes paralelas em detrimento a sua missao primordial de ensino. A pesqui-sa medica e facilmente mensurada por meio de indices internacionais de impacto das publicacoes cientificas. A pesquisa patrocinada de forma publica ou privada, auxilia na construcao e manutencao de laboratorios alem de permitir a contratacao de pesquisadores e manutencao das melhores mentes nas instituicoes. A assistencia e muitas vezes uma importante fonte de recursos extraordinarios as instituicoes. O ensino, no entanto, e de dificil mensuracao e apenas consome recursos, o que nos faz questionar esse intricado raciocinio triplice. Por que ensinar? Qual o papel do ensino em um sistema que tem que lidar com a pesquisa e a assistencia medica? Os estudantes, de uma maneira geral, nao administram o tempo de atendimento de maneira eficiente, necessitam de medicos com treinamento especifico supervisionando seus atendimentos e nao tem o conhecimento ou a maturidade necessarias para a realizacao de pesquisas de maneira independente. O ensino medico e dispen-dioso por natureza e e papel de todos os envolvidos: alunos, professores e sociedade; a reavaliacao continuada da sua estrutura e dos seus processos (curriculo), considerando, principalmente, que a administracao do tempo e fundamental na elaboracao de um curriculo medico eficiente

In this issue of ABO

presented the results of a questionnaire administered to more than 600patients treated in a campaign to perform cataract surgery in Sao Paulo. The study showed a sad reality forpatients excluded from the comprehensive eye care. Almost half of all patients interviewed were unable togain access to cataract surgery before the campaign, because they have abandoned the free public service asa result of the long waiting lists or for failing to schedule their surgeries (19%), or did not have the resources toafford the costs associated with surgeries performed by health insurance or private care (29%). The costsreported by patients who had not sought public service ranged from R

New corneal findings in human T-cell lymphotropic virus type 1 infection [3] (multiple letters)

1,000 to over R

On the shoulders of giants

4,000.00. Authorsrightly emphasized in their conclusions “the need to continue to carry out community campaigns to meetpeople who would not have access to surgery by conventional means.” I also believe it is important to considerthat, despite the campaigns being indispensable at the present time the Brazilian public health, we mustkeep in mind that, ideally, access to health care should be possible for the whole population without theneed to create specific campaigns.Patients with anophthalmic cavities were evaluated in two articles