Lid Suture Research Articles

Visual experience sculpts whole-cortex spontaneous infraslow activity patterns through an Arc-dependent mechanism

Decades of work in experimental animals has established the importance of visual experience during critical periods for the development of normal sensory-evoked responses in the visual cortex. However, much less is known concerning the impact of early visual experience on the systems-level organization of spontaneous activity. Human resting-state fMRI has revealed that infraslow fluctuations in spontaneous activity are organized into stereotyped spatiotemporal patterns across the entire brain. Furthermore, the organization of spontaneous infraslow activity (ISA) is plastic in that it can be modulated by learning and experience, suggesting heightened sensitivity to change during critical periods. Here we used wide-field optical intrinsic signal imaging in mice to examine whole-cortex spontaneous ISA patterns. Using monocular or binocular visual deprivation, we examined the effects of critical period visual experience on the development of ISA correlation and latency patterns within and across cortical resting-state networks. Visual modification with monocular lid suturing reduced correlation between left and right cortices (homotopic correlation) within the visual network, but had little effect on internetwork correlation. In contrast, visual deprivation with binocular lid suturing resulted in increased visual homotopic correlation and increased anti-correlation between the visual network and several extravisual networks, suggesting cross-modal plasticity. These network-level changes were markedly attenuated in mice with genetic deletion of Arc, a gene known to be critical for activity-dependent synaptic plasticity. Taken together, our results suggest that critical period visual experience induces global changes in spontaneous ISA relationships, both within the visual network and across networks, through an Arc-dependent mechanism.

Efficacy of management of acute corneal perforation in Stevens-Johnson syndrome

Objective To observe short-term efficacy for the treatment for acute corneal perforation in patients with severe Stevens-Johnson syndrome. Methods Five eyes of 5 patients with acute corneal perforation and severe Stevens-Johnson syndrome were retrospectively studied. The clinical features, management, efficacy and complications were recorded and analyzed. Results Corneal perforation of all cases were located in the central or paracentral area of cornea. Every case received different operation according to illness needs. The operations included lamellar keratoplasty combined with anterior chamber injection of gas, corneal perforation repair associated with pedicle eyelid adhesive membrane covering combined with eyelid suture, penetrating corneoscleral transplantation with glycerol-preserved material associated with pedicled conjunctival flap covering, penetrating corneoscleral transplantation with glycerol-preserved material associated with pedicle skin flap covering through the tunnel, and penetrating corneoscleral transplantation with glycerol-preserved material combined with bridge conjunctival flap covering respectively. Followed up 6-36 months, the eyes of all the patients were preserved after operation. The vision was light perception-0.2. No complication such as corneal ulcer or corneal melting occurred. Conclusion Choosing the appropriate surgical treatment according to the patient’s condition the eye can be effectively saved. Key words: Stevens-Johnson syndrome, severe; Corneal perforation, acute; Corneal transplantation; Conjunctival flap; Skin flap, pedicle

Rapid plasticity of visually evoked responses in rat monocular visual cortex.

Sensory cortical circuits are shaped by experience during sensitive periods in development. In the primary visual cortex (V1) altered visual experience results in changes in visual responsiveness of cortical neurons. The experience-dependent refinement of the circuit in V1 is thought to rely on competitive interactions between feedforward circuits driven by the two eyes. However, recent data have provided evidence for an additional role of cortico-cortical circuits in this process. Indeed, experience-dependent changes in intracortical circuits can be induced rapidly and may result in rapid-onset functional changes. Unilateral occlusion of vision rapidly alters visual responsiveness, synaptic strength and connectivity of local circuits in the binocular region of V1 (V1b), where the inputs from the two eyes converge. In the monocular region of rodent V1 (V1m), where feedforward inputs from the ipsilateral eye are virtually absent, visual deprivation induces rapid plasticity in local circuits; however, functional changes seem to occur only after long periods of deprivation. In V1m there is currently no evidence for functional changes occurring within a time window compatible with that of local circuit plasticity. Here, we probed the visual responsiveness of neurons in rat V1m and assessed the effect of one day unilateral eye lid suture on single neuron visual responses. We report a novel form of plasticity within V1m that occurs on a timescale consistent with the earliest known changes in synaptic strength. Our data provide new insights into how sensory experience can rapidly modulate neuronal responses, even in the absence of direct competition between feedforward thalamocortical inputs.

Study on intervention mechanism of acupuncture for neuron abnormal neural coding in visual cortex area 17 of monocular deprivation rats

To investigate the electrophysiological mechanism of acupuncture for the visual cortex plasticity during the sensitive period. Fifty 2-week-old Wistar rats were randomly divided into a blank control group, a model group, an early-stage acupuncture group, a middle-stage acupuncture group and a late-stage acupuncture group, 10 rats in each group. Monocular deprivation amblyopia models were prepared in rats except those in the blank control group by unilateral eyelid suture. After successful modeling, no treatment was applied to the rats in the model group. Rats in each acupuncture group were treated with acupuncture at bilateral Jingming (BL 1), Cuanzhu (BL 2), Fengchi (GB 20) and Guangming (GB 37), started from the 3rd day, 12th day or 21st day after modeling separately, once a day, for a total of 9 d treatment. The neuronal discharge frequency and action potential inter-spike interval (ISI) in the rat visual cortex area 17 of each group were measured by multi-channel microelectrode array nerve signal technique. The discharge number of neurons in the visual cortex of the model group was significantly lower than that in the blank control group (P 0.05). The discharge number in the middle-stage acupuncture group was lower than that in the early-stage acupuncture group (P<0.05), and the discharge number of the late-stage acupuncture group was lower than that in the middle-stage acupuncture group (P<0.05). The ISI sequences of the visual cortex neurons were mainly distributed under 0.3 s in the blank control group, under 15 s in the model group, under 1 s in the early-stage acupuncture group, under 4 s in the middle-stage acupuncture group, and under 10 s in the late-stage acupuncture group, divergent in each group. The neuronal coding appears abnormality in the visual cortex area 17 of monocular deprivation rats, indicating that there is a plasticity change in the visual cortex neurons during the sensitive period. Acupuncture has a significant effect on the abnormal neural coding. The therapeutic efficacy is closely related to the stage to start the treatment. Early stage treatment in the sensitive period is the key to achieving the good efficacy.

Timing-dependent LTP and LTD in mouse primary visual cortex following different visual deprivation models.

Visual deprivation during the critical period induces long-lasting changes in cortical circuitry by adaptively modifying neuro-transmission and synaptic connectivity at synapses. Spike timing-dependent plasticity (STDP) is considered a strong candidate for experience-dependent changes. However, the visual deprivation forms that affect timing-dependent long-term potentiation(LTP) and long-term depression(LTD) remain unclear. Here, we demonstrated the temporal window changes of tLTP and tLTD, elicited by coincidental pre- and post-synaptic firing, following different modes of 6-day visual deprivation. Markedly broader temporal windows were found in robust tLTP and tLTD in the V1M of the deprived visual cortex in mice after 6-day MD and DE. The underlying mechanism for the changes seen with visual deprivation in juvenile mice using 6 days of dark exposure or monocular lid suture involves an increased fraction of NR2b-containing NMDAR and the consequent prolongation of NMDAR-mediated response duration. Moreover, a decrease in NR2A protein expression at the synapse is attributable to the reduction of the NR2A/2B ratio in the deprived cortex.

Establishment of novel therapy to reduce progression of myopia in rats with experimental myopia by fibroblast transplantation on sclera.

Myopia is one of the most common visual disorders, and is characterized by a progressive axial elongation of the eye. Several methods have been tried to reduce the progression of axial elongation and myopia, but there are still no well-accepted procedures. We hypothesized that transplantation of fibroblasts on the sclera would lead to the synthesis of collagen fibrils on the sclera and reinforce it, and reduce the degree of axial elongation of eyes with form deprivation myopia. To examine this, we developed a form deprivation myopia model in albino Wistar rats and examined the effects of human fibroblasts (hFbs) transplantation on the sclera in the progression of myopia and axial elongation. We found that the form deprivation by eyelid suture induced a myopic shift and axial elongation associated with a thinner sclera and smaller-diameter collagen fibrils in Wistar rats. We also found that the transplanted hFbs synthesized type 1 collagen fibrils on the rat sclera, and these eyes with form deprivation had significantly reduced ocular elongation and myopic shift than the eyes without hFbs transplantation. Some of the synthesized collagen fibrils migrated into the sclera and had a bundle-like appearance and a stripe-like pattern, indicating they had mature characteristics. These findings suggest that the rat sclera was reinforced by the newly synthesized collagen fibrils and the axial elongation was reduced. These results can provide important information for the development of a therapy targeting myopia in humans. Copyright © 2017 John Wiley & Sons, Ltd.

Regulation of acupuncture on NMDAR1 mRNA expression in visual cortex of monocularly-deprived rats

To explore the molecular biological mechanism of acupuncture in intervening visual deprivation. Forty-eight 2-week old Wistar rats were randomly divided into a normal group, a model group, and 6 acupuncture groups (group C1: acupuncture at the unaffected side in early stage; group C2: acupuncture at the affected side in early stage; group D1: acupuncture at the unaffected side in mid-stage; group D2: acupuncture at the affected side in mid-stage; group E1: acupuncture at the unaffected side in late stage; group E2: acupuncture at the affected side in late stage) by the random number table, 6 rats in each group. Rats in the normal group didn’t receive any interventions. The rat model of deprivation amblyopia was established by unilateral eyelid suture in the model group and each acupuncture group. After successful modeling, rats in model group didn’t receive any treatments; rats in the acupuncture groups received acupuncture intervention which began respectively on the 3rd, 12th and 21st day after modeling. Pattern visual evoked potential (P-VEP) and N-methy D-aspartatreceptor-1 (NMDAR1) mRNA expression in visual cortex area 17 were detected at the end of acupuncture intervention in each group. After the intervention, the P-VEP waveform was significantly changed, with a significantly delayed P100 value (P 0.05). P-VEP waveform is abnormal and NMDAR1 mRNA expression in visual cortex area 17 is decreased in rats with monocularly-deprived amblyopia. Acupuncture in the sensitive period can significantly regulate the abnormal P-VEP waveform and the down-regulate the NMDAR1 mRNA expression of the visual cortex of rats with monocularly-deprived amblyopia. Early treatment in the sensitive period should be the key to obtaining the curative effect.

Intervention of acupuncture on abnormal spatiotemporal pattern of visual cortex area 17 neuron in monocular deprivation amblyopia rats

To preliminarily explore the electrophysiological mechanism of acupuncture on plasticity variability of visual cortex. Fifty 14-day-old Wistar rats were randomly divided into a blank group, a model group, an early-stage acupuncture group, a middle-stage acupuncture group and a late-stage acupuncture group, 10 rats in each one. Except the blank group, the rats in the remaining groups were treated with eyelid suture to establish the model of monocular deprivation amblyopia. After model establishment, the rats in the blank group and model group were grasped without any intervention everyday. The rats in the acupuncture groups were treated with acupuncture at bilateral "Jingming" (BL 1), "Cuanzhu" (BL 2), "Fengchi" (GB 20) and "Guangming" (GB 37) on the 3rd, 12th and 21st days into model establishment. The needles were retained for 10 min, once a day for totally 9 days. After treatment, the M-NEMEA technology was applied to measure the discharge amplitude and power spectral density of visual cortex area 17 neuron of each group. Compared with the blank group, the number of discharged neuron of visual cortex area 17 was reduced, and the amplitude was significantly reduced in the model group (both P<0.05). Compared with the model group, the numbers of discharged neuron were increased, and the amplitudes were significantly increased in the early-stage acupuncture group and middle-stage acupuncture group (all P<0.05). The neuron discharge amplitude in the early-stage acupuncture group was higher than those in the middle-stage acupuncture group and late-stage acupuncture group (both P<0.05); the neuron discharge amplitude in the middle-stage acupuncture group was higher than that in the late-stage acupuncture group (P<0.05). In the 120-second time domain of acquisition, the distribution of power spectral density in the blank group was mainly between -105 dB and -100 dB; compared with the blank group, the power spectral density in the model group was increased and distributed between -132 dB and -124 dB; compared with the model group, the power spectral densities in the acupuncture groups was reduced and distributed between -115 dB and -110 dB in the early-stage acupuncture group, -120 dB and -115 dB in the middle-stage acupuncture group and -129 dB and -122 dB in the late-stage acupuncture group. There are abnormal changes of spatiotemporal pattern in visual cortex area 17 of monocular deprivation rats, but acupuncture can regulate abnormal spatiotemporal pattern of neuron. Therefore, there is developmental plasticity of visual cortex neuron in the sensitive period, and early treatment is key to superior efficacy.

Frontalis suspension surgery to treat patients with blepharospasm and eyelid opening apraxia: long-term results.

Blepharospasm may be accompanied by eyelid opening apraxia (EOA) reducing the efficacy of botulinum toxin (BT) therapy. The frontalis suspension operation (FSO) is then the only effective treatment option available. We want to report the first long-term results with FSO. We studied 15 patients with blepharospasm and EAO unresponsive to BT therapy (9 females, 6 males, age 61.9±11.5years). FSO was performed by applying 2 polytetrafluoroethylene threads (PTFE, Gore-Tex®) per eye connecting the frontalis muscle to the upper eye lid. Tension of the two carrés was set to produce a palpebral fissure width of 2-3mm. Therapy outcome was monitored by a quality-of-life questionnaire (QoL-Q) and a self-assessment calendar reviewing postoperative days 0-9 (T1), 10-89 (T2), 90-179 (T3), 180-365 (T4), and >365days (T5). Altogether, 40 FSO were performed. Postoperatively, all patients reported improved eyelid opening, 4 (27%) complete remission of symptoms. At T1, this improvement was 74.6±26.4% on the self-assessment scale, after 1year 68.2±27.5%. Throughout the observation period (T1-T5), the improvement was 71.9±25.6%. All 19 items on the QoL-Q (except for presence of involuntary eye lid closure) showed postoperative improvement. Adverse effects included circumscript upper eyelid haematomas, suture extrusion, suture granuloma, lacrimation, and infections. In all patients, BT therapy had to be continued to treat orbicularis oculi contractions. Our first long-term results demonstrate that FSO is a benign procedure producing robust and stable therapeutic effects on EOA in blepharospasm.

Maximal levator resection in unilateral congenital ptosis with poor levator function

Background/aimsSurgical treatments for the correction of congenital ptosis with poor levator function, including frontalis suspension or maximal levator resection, remain controversial. We evaluated the postoperative surgical and cosmetic outcomes after...

Overexpression of Serum Response Factor in Neurons Restores Ocular Dominance Plasticity in a Model of Fetal Alcohol Spectrum Disorders.

Deficits in neuronal plasticity underlie many neurobehavioral and cognitive problems presented in fetal alcohol spectrum disorder (FASD). Our laboratory has developed a ferret model showing that early alcohol exposure leads to a persistent disruption in ocular dominance plasticity (ODP). For instance, a few days of monocular deprivation results in a robust reduction of visual cortex neurons' responsiveness to stimulation of the deprived eye in normal animals, but not in ferrets with early alcohol exposure. Previously our laboratory demonstrated that overexpression of serum response factor (SRF) exclusively in astrocytes can improve neuronal plasticity in FASD. Here, we test whether neuronal overexpression of SRF can achieve similar effects. Ferrets received 3.5g/kg alcohol intraperitoneally (25% in saline) or saline as control every other day between postnatal day 10 to 30, which is roughly equivalent to the third trimester of human gestation. Animals were given intracortical injections of a Herpes Simplex Virus-based vector to express either green fluorescent protein or a constitutively active form of SRF in infected neurons. They were then monocularly deprived by eyelid suture for 4 to 5days after which single-unit recordings were conducted to determine whether changes in ocular dominance had occurred. Overexpression of a constitutively active form of SRF by neurons restored ODP in alcohol-treated animals. This effect was observed only in areas near the site of viral infection. Overexpression of SRF in neurons can restore plasticity in the ferret model of FASD, but only in areas near the site of infection. This contrasts with SRF overexpression in astrocytes which restored plasticity throughout the visual cortex.

Effects of monocular deprivation on the thickness of neural retina

Abstract Background: Monocular visual deprivation as a result of cataracts occurring in children who previously had normal vision may result in permanent visual deficits. However, if correction is done before the age of ten years, vision is usually restored to normal levels in the affected eye. This has been attributed to plastic changes that occur in the visual cortex, with no mention of the contribution of the retina to this plasticity. Objective: To describe the effect of monocular deprivation on the thickness of neural retina. Study design: Quasi-experimental study using a rabbit model. Materials and methods: 30 rabbits (18 experimental, 12 controls) were examined. Monocular deprivation was achieved through unilateral lid suture in the experimental animals. The rabbits were observed for three weeks. Each week, 6 experimental and 3 control animals were euthanized, their retina harvested and processed for light microscopy. In experimental animals, retina of both deprived (closed) and non-deprived (open) eyes were studied. Haematoxylin &amp; Eosin stain was used to demonstrate the layers of the retina. Photomicrographs of the retina were taken using a digital camera then entered into FIJI software for analysis. Results: In the deprived eyes, the neural retina thickness reduced by 40.5% from the baseline (p = 0.001). Compared to controls, statistically significant reduction in thickness was noted in the ganglion (p &lt; 0.001), inner nuclear (p &lt; 0.001), rod and cones (p = 0.001), outer plexiform (p = 0.008), nerve fiber (p = 0.010), and inner plexiform (p = 0.024) layers. Among the non-deprived eyes, the neural retina thickness increased by 9.8% from baseline (p = 0.075). Compared to controls, statistically significant increase in thickness was seen in the inner plexiform (p &lt; 0.001), inner nuclear (p = 0.002), and rods and cones (p = 0.007) layers. Conclusion: Monocular deprivation results in atrophy of the retina in the deprived eye. Thus, pre-retinal causes of blindness such as cataracts affects the retina and should be corrected early so as to minimize damage to the retina of the deprived eye.

Visual system plasticity in mammals: the story of monocular enucleation-induced vision loss.

The groundbreaking work of Hubel and Wiesel in the 1960’s on ocular dominance plasticity instigated many studies of the visual system of mammals, enriching our understanding of how the development of its structure and function depends on high quality visual input through both eyes. These studies have mainly employed lid suturing, dark rearing and eye patching applied to different species to reduce or impair visual input, and have created extensive knowledge on binocular vision. However, not all aspects and types of plasticity in the visual cortex have been covered in full detail. In that regard, a more drastic deprivation method like enucleation, leading to complete vision loss appears useful as it has more widespread effects on the afferent visual pathway and even on non-visual brain regions. One-eyed vision due to monocular enucleation (ME) profoundly affects the contralateral retinorecipient subcortical and cortical structures thereby creating a powerful means to investigate cortical plasticity phenomena in which binocular competition has no vote.In this review, we will present current knowledge about the specific application of ME as an experimental tool to study visual and cross-modal brain plasticity and compare early postnatal stages up into adulthood. The structural and physiological consequences of this type of extensive sensory loss as documented and studied in several animal species and human patients will be discussed. We will summarize how ME studies have been instrumental to our current understanding of the differentiation of sensory systems and how the structure and function of cortical circuits in mammals are shaped in response to such an extensive alteration in experience. In conclusion, we will highlight future perspectives and the clinical relevance of adding ME to the list of more longstanding deprivation models in visual system research.

Bridging the Gap: Theory-Based Design of a Microsurgical Skills Course for Ophthalmology Residents

Although theory-based schemes for course design are widely used in educational settings, making use of cognitive theory in the design of surgical skills courses in ophthalmology is rare. The primary aim of this study is to describe the application of instructional design, an established theory-based approach in course design, to the development of a surgical skills course for ophthalmology residents. The secondary aim of this study is to assess the educational effect of this theory-based course. A 1-day skills course was designed according to Gagné׳s events of instruction model, which was employed as a template for the instructional sequence of learning steps. Skills acquisition following the implementation of the model was measured with precourse and postcourse assessments. Moorfields Eye Hospital organized the 1-day annual intermediate surgical skills course, which was hosted at the Royal College of Ophthalmologists' microsurgical skills laboratory. A total of 20 ophthalmology residents of Moorfields Eye Hospital participated in the study. A 1-day surgical skills course was formulated according to the instructional design principles outlined. The 4 objectives of the course (corneal suturing, corneal gluing, intravitreal injections, and eyelid suturing) were addressed in a parallel fashion as to allow for multiple objectives to be processed simultaneously, in the context of the instructional design sequence. Assessments demonstrated significant improvement in skills acquisition for the 4 course objectives. Instructional design is a valuable tool for planning effective surgical training courses as it is portable, allowing its application to a wide variety of outcomes and settings, and its terminology is simple and understandable to those working in clinical education.

Effect of Monocular Deprivation on Rabbit Neural Retinal Cell Densities.

Purpose:To describe the effect of monocular deprivation on densities of neural retinal cells in rabbits.Methods:Thirty rabbits, comprised of 18 subject and 12 control animals, were included and monocular deprivation was achieved through unilateral lid suturing in all subject animals. The rabbits were observed for three weeks. At the end of each week, 6 experimental and 3 control animals were euthanized, their retinas was harvested and processed for light microscopy. Photomicrographs of the retina were taken and imported into FIJI software for analysis.Results:Neural retinal cell densities of deprived eyes were reduced along with increasing period of deprivation. The percentage of reductions were 60.9% (P < 0.001), 41.6% (P = 0.003), and 18.9% (P = 0.326) for ganglion, inner nuclear, and outer nuclear cells, respectively. In non-deprived eyes, cell densities in contrast were increased by 116% (P < 0.001), 52% (P < 0.001) and 59.6% (P < 0.001) in ganglion, inner nuclear, and outer nuclear cells, respectively.Conclusion:In this rabbit model, monocular deprivation resulted in activity-dependent changes in cell densities of the neural retina in favour of the non-deprived eye along with reduced cell densities in the deprived eye.

Binocular eyelid closure promotes anatomical but not behavioral recovery from monocular deprivation

Deprivation of patterned vision of frontal eyed mammals early in postnatal life alters structural and functional attributes of neurones in the central visual pathways, and can produce severe impairments of the vision of the deprived eye that resemble the visual loss observed in human amblyopia. A traditional approach to treatment of amblyopia has been the occlusion of the stronger fellow eye in order to force use of the weaker eye and thereby strengthen its connections in the visual cortex. Although this monocular treatment strategy can be effective at promoting recovery of visual acuity of the amblyopic eye, such binocular visual functions as stereoscopic vision often remain impaired due in part to the lack of concordant vision during the period of unilateral occlusion. The recent development of binocular approaches for treatment of amblyopia that improve the possibility for binocular interaction have achieved success in promoting visual recovery. The full and rapid recovery of visual acuity observed in amblyopic kittens placed in complete darkness is an example of a binocular treatment whose success may in part derive from a restored balance of visually-driven neural activity. In the current study we examined as an alternative to dark rearing the efficacy of binocular lid suture (BLS) to stimulate anatomical and visual recovery from a preceding amblyogenic period of monocular deprivation. In the dorsal lateral geniculate nucleus (dLGN) of monocularly deprived kittens, darkness or BLS for 10days produced a complete recovery of neurone soma size within initially deprived layers. The growth of neurone somata within initially deprived dLGN layers after darkness or BLS was accompanied by an increase in neurotrophin-4/5 labeling within these layers. Although anatomical recovery was observed in both recovery conditions, BLS failed to promote any improvement of the visual acuity of the deprived eye no matter whether it followed immediately or was delayed with respect to the prior period of monocular deprivation. Notwithstanding the lack of visual recovery with BLS, all animals in the BLS condition that were subsequently placed in darkness exhibited a substantial recovery of visual acuity in the amblyopic eye. We conclude that the balanced binocular visual input provided by BLS does not stimulate the collection of neural events necessary to support recovery from amblyopia. The complete absence of visually-driven activity that occurs with dark rearing evidently plays an important role in the recovery process.

Relationship between monocularly deprivation and amblyopia rats and visual system development

ObjectiveTo explore the changes of lateral geniculate body and visual cortex in monocular strabismus and form deprived amblyopic rat, and visual development plastic stage and visual plasticity in adult rats. MethodsA total of 60 SD rats ages 13 d were randomly divided into A, B, C three groups with 20 in each group, group A was set as the normal control group without any processing, group B was strabismus amblyopic group, using the unilateral extraocular rectus resection to establish the strabismus amblyopia model, group C was monocular form deprivation amblyopia group using unilateral eyelid edge resection + lid suture. At visual developmental early phase (P25), meta phase (P35), late phase (P45) and adult phase (P120), the lateral geniculate body and visual cortex area 17 of five rats in each group were exacted for C-fos Immunocytochemistry. Neuron morphological changes in lateral geniculate body and visual cortex was observed, the positive neurons differences of C-fos expression induced by light stimulation was measured in each group, and the condition of radiation development of P120 amblyopic adult rats was observed. ResultsIn groups B and C, C-fos positive cells were significantly lower than the control group at P25 (P<0.05), there was no statistical difference of C-fos protein positive cells between group B and group A (P>0.05), C-fos protein positive cells level of group B was significantly lower than that of group A (P<0.05). The binoculus C-fos protein positive cells level of groups B and C were significantly higher than that of control group at P35, P45 and P120 with statistically significant differences (P<0.05). ConclusionsThe increasing of C-fos expression in geniculate body and visual cortex neurons of adult amblyopia suggests the visual cortex neurons exist a certain degree of visual plasticity.

Human parallels to experimental myopia? A literature review on visual deprivation.

Raviola and Wiesel's monkey eyelid suture studies of the 1970s laid the cornerstone for the experimental myopia science undertaken since then. The aim has been to clarify the basic humoral and neuronal mechanisms behind induced myopization, its eye tissue transmitters in particular. Besides acquiring new and basic knowledge, the practical object of the research is to reduce the burden of human myopia around the world. Acquisition and cost of optical correction is one issue, but associated morbidity counts more, with its global load of myopia-associated visual loss and blindness. The object of the present PubMed literature-based review is to evaluate apparent similarities between experience from disturbed imaging in experimental laboratory science and varieties within the spectrum of childhood human myopia. So far, the main impression is that macroscopical optical deprivation appears absent in the prevalent types of human myopia, nor is myopia a regular sequel where early eye pathology has led to poor imaging and optical deprivation. Optical aberrations of a higher order are a relatively new issue in myopia research, and microstructural deprivation is only marginally dealt within the survey. Links between experimental and human myopia appear mainly occasional, and with only few examples in humans where factual parallels appear credible. Clinical and epidemiological data on refraction remain important, in particular with a view to life style and environmental factors. Such knowledge may further serve as inspiration to the laboratory research, which aims at solving the basic enigmas on a tissue level.

Transcaruncular Medial Canthal Tendon Plication with Lower Eyelid Suture Sling in Facial Nerve Palsy

Purpose: To report a technique for correcting lower eyelid punctal ectropion with an inferiorly displaced or retracted medial eyelid due to facial nerve palsy, by extending a suture sling along the pre-tarsal lower eyelid when performing transcaruncular medial canthal tendon plication.Methods: Single-centre retrospective, non-comparative review of patients with facial nerve palsy who underwent medial canthal tendon plication with lower eyelid suture sling (MCT suture sling). Outcome measures included: the presence of lower eyelid ectropion, medial eyelid height, punctal position, inferior marginal reflex distance (MRD) and inferior scleral show measured both pre-operatively and at the last follow-up visit.Results: Thirty-three patients with facial nerve palsy with a mean age of 59, underwent MCT suture sling for lagophthalmos and/or ectropion. Then, 66% (21/32) of cases had punctal ectropion pre-operatively and 9% (3/32) had punctal ectropion at the last follow-up. Medial eyelid height was deemed to improve in 66% (21/32) of cases at the last follow up visit. Follow-up was mean 13.5 months. Six (18%) patients were deemed failures due to inferior MRD and inferior scleral showing worse than pre-operative measurements.Discussion: We report a technique for incorporating a suture sling to transcaruncular-approach MCT plication when the medial canthus has retracted or descended thus requiring support and a posterior vector. It avoids rounding of the medial canthal angle that may occur with traditional medial canthoplasty. Transcaruncular MCT plication is well described. Incorporating a suture sling to potentially reduce single point-fixation cheese-wiring and early dehiscence is minimally invasive, non-excisional and repeatable.

Treatment of nonhealing corneal ulcers in 60 horses with diamond burr debridement (2010–2013)

To review the signalment, clinical characteristics, and outcome of horses with nonhealing corneal ulcers treated with diamond burr debridement (DBD); and to evaluate the role of ulcer duration, size and location, and bandage contact lens (BCL) placement on healing. From January 2012-April 2013, 60 horses were diagnosed with ulcers classified as nonhealing based on the presence of raised epithelial margins and duration of at least 7 days. Retrospective record review. Average age of included horses was 14.68 years, SD 8.17 years. There were three times as many males (45) as females (15), (χ12 = 15, P = 0.001). Forty-eight horses (80%) had nonhealing ulcers uncomplicated by associated corneal disease. In the remaining horses, associated corneal disease included esinophilic keratitis (10%), calcific band keratopathy (5%), endothelial decompensation (1.67%), habronemiasis(1.67%), and lid suture abrasion (1.67%). Average corneal ulcer duration prior to diamond burr debridement (DBD) was 29.0 days (n = 56). Ulcers occurred most commonly in the axial cornea (41%). Fifty-five of 60 horses (92%) healed with DBD. Healing time, defined as time to epithelialization following DBD, averaged 15.5 days, SD 9.32 days, and was not correlated with patient age or ulcer duration, location, or size prior to or following DBD. Healing time was significantly longer for eyes in which a BCL had been placed (n = 28, 19.0 days) than for eyes without a BCL (n = 32, 12.9 days), F(1,58) = 5.543, P = 0.02. DBD was considered a failure for five horses (8%). DBD may be an effective treatment for nonhealing corneal ulcers in horses.