Review Article

Conjunctival flaps for the treatment of advanced ocular surface disease—looking back and beyond

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Conjunctival flaps have previously proven to be effective in preserving the globe for individuals with severe ocular surface disease. Infectious keratitis, neurotrophic keratitis, nontraumatic corneal melts, descemetoceles, perforations, and corneal burns are all indications for this procedure. The flaps promote nutrition, metabolism, structure, and vascularity, as well as reduce pain, irritation, inflammation, and infection. Furthermore, patients avoid the emotional and psychological repercussions of enucleation or evisceration, while requiring fewer postoperative medications and office visits. Currently, fewer flaps are performed due to the emergence of additional therapeutic techniques, such as serum tears, bandage lenses, corneal grafting, Oxervate, amniotic membrane, and umbilical cord grafting. However, despite newer conservative medical methods, conjunctival flaps have been demonstrated to be useful and advantageous. Moreover, future technologies and approaches for globe preservation and sight restoration after prior conjunctival flaps are anticipated. Herein, we review the history, advantages, and disadvantages of various surgical techniques: Gundersen’s bipedicle flap, partial limbal advancement flap, selective pedunculated conjunctival flap with or without Tenon’s capsule, and Mekonnen’s modified inferior palpebral-bulbar conjunctival flap. The surgical pearls and recommendations offered by the innovators are also reviewed, including restrictions and potential complications. Procedures for visual rehabilitation in selective cases after conjunctival flap are reviewed as well.
Brain and Perception

AB070. Feedback improves orientation discrimination in neurotypical adults, but not in adults with autism: a pilot study

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Background: Understanding how individuals with autism spectrum disorder (ASD) learn is important for developing and implementing effective educational and behavioral interventions. Evidence suggests that individuals with ASD are relatively stronger in certain areas of perception (Simmons et al., 2009; Dakin and Frith, 2005); it therefore cannot be assumed that individuals with ASD learn using the same rules and strategies as neurotypicals (NT). Of particular interest, perceptual learning (PL) is a class of learning that is based upon changes induced by the repeated exposure and response to specific types of perceptual information. Such learning often includes feedback, indicating whether or not a response was correct during a trial within a PL task. The objectives of this study were to perform a pilot investigation of; (I) perceptual learning in adults with and without ASD using a low-level orientation discrimination task; and (II) the influence of feedback on accuracy in this task.

Methods: Eleven adults with ASD and fifteen NT adults, matched on Wechsler full-scale IQ and age (18–31 years), performed a low-level PL task. They were asked to indicate whether a grating was tilted to the left (i.e., counter-clockwise) or to the right (i.e., clockwise) relative to an oblique 45-degree reference orientation. Thresholds, defined by the minimal deviation in degrees needed to discriminate tilt orientation, were measured for each participant every 15 minutes, with each block consisting of 420 trials. To assess baseline performance, all participants completed a first block with no feedback. Participants were then randomly assigned to either feedback (NASD =6, NTD =8) or no feedback groups (NASD =5, NTD =7) and completed six subsequent testing blocks.

Results: PL was defined as the percent change in orientation discrimination threshold in each of the six testing blocks relative to baseline performance. No significant increase was found in performance as a function of testing block for any group; PL was therefore not evidenced under the conditions tested. ASD performance remained equal to that of baseline across testing blocks, whether or not trial-by-trial feedback was present. In contrast, NT performance was significantly increased when feedback was present.

Conclusions: NT individuals significantly benefited from feedback, while individuals with ASD did not. These results provide preliminary evidence for a divergent learning style in ASD and NT individuals. These pilot findings raise important questions regarding the impact of feedback during interventions, and at a more basic level, the atypical underlying perceptual and cognitive processes in individuals with ASD.

Review Article

Pathologic myopia

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Abstract: Pathologic myopia is the major cause of the loss of the best-corrected visual acuity (BCVA) worldwide, especially in East Asian countries. The loss of BCVA is caused by the development of myopic macula patchy, myopic traction macula patchy, and myopic optic neuropathy (or glaucoma). The development of such vision-threatening complications is caused by eye deformity, characterized by a formation of posterior staphyloma. The recent advance in ocular imaging has greatly facilitated the clarification of pathologies and pathogenesis of pathological myopia and myopia-related complications. These technologies include ultra-wide field fundus imaging, swept-source optical coherence tomography, and 3D MRI. In addition, the new treatments such as anti-VEGF therapies for myopic choroid all neovascularization have improved the outcome of the patients. Swept-source OCT showed that some of the lesions of myopic maculopathy were not simply chorioretinal atrophy but were Bruch’s membrane holes. Features of myopic traction maculopathy have been analyzed extensively by using OCT. The understanding the pathophysiology of complications of pathologic myopia is considered useful for better management of this blinding eye disease.

Review Article

Scleral remodelling in myopia and its manipulation: a review of recent advances in scleral strengthening and myopia control

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Abstract: The biological mechanisms of eye growth and refractive development are increasingly well characterised, a result of many careful studies that have been carried out over many years. As the outer coat of the eye, the sclera has the ultimate impact on the restraint or facilitation of eye growth, thus any changes in its biochemistry, ultrastructure, gross morphology and/or biomechanical properties are critical in refractive error development and, in particular, the development of myopia. The current review briefly revisits our basic understanding of the structure and biomechanics of the sclera and how these are regulated and modified during eye growth and myopia development. The review then applies this knowledge in considering recent advances in our understanding of how the mechanisms of scleral remodelling may be manipulated or controlled, in order to constrain eye growth and limit the development of myopia, in particular the higher degrees of myopia that lead to vision loss and blindness. In doing so, the review specifically considers recent approaches to the strengthening of the sclera, through collagen cross-linking, scleral transplantation, implantation or injection of biomaterials, or the direct therapeutic targeting and manipulation of the biochemical mechanisms known to be involved in myopia development. These latest approaches to the control of scleral changes in myopia are, where possible, placed in the context of our understanding of scleral biology, in order to bring a more complete understanding of current and future therapeutic interventions in myopia, and their consequences.

Review Article

Conjunctival flaps for the treatment of advanced ocular surface disease—looking back and beyond

:-
 
 Conjunctival flaps have previously proven to be effective in preserving the globe for individuals with severe ocular surface disease. Infectious keratitis, neurotrophic keratitis, nontraumatic corneal melts, descemetoceles, perforations, and corneal burns are all indications for this procedure. The flaps promote nutrition, metabolism, structure, and vascularity, as well as reduce pain, irritation, inflammation, and infection. Furthermore, patients avoid the emotional and psychological repercussions of enucleation or evisceration, while requiring fewer postoperative medications and office visits. Currently, fewer flaps are performed due to the emergence of additional therapeutic techniques, such as serum tears, bandage lenses, corneal grafting, Oxervate, amniotic membrane, and umbilical cord grafting. However, despite newer conservative medical methods, conjunctival flaps have been demonstrated to be useful and advantageous. Moreover, future technologies and approaches for globe preservation and sight restoration after prior conjunctival flaps are anticipated. Herein, we review the history, advantages, and disadvantages of various surgical techniques: Gundersen’s bipedicle flap, partial limbal advancement flap, selective pedunculated conjunctival flap with or without Tenon’s capsule, and Mekonnen’s modified inferior palpebral-bulbar conjunctival flap. The surgical pearls and recommendations offered by the innovators are also reviewed, including restrictions and potential complications. Procedures for visual rehabilitation in selective cases after conjunctival flap are reviewed as well.
其他期刊
  • 眼科学报

    主管:中华人民共和国教育部
    主办:中山大学
    承办:中山大学中山眼科中心
    主编:林浩添
    主管:中华人民共和国教育部
    主办:中山大学
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  • Eye Science

    主管:中华人民共和国教育部
    主办:中山大学
    承办:中山大学中山眼科中心
    主编:林浩添
    主管:中华人民共和国教育部
    主办:中山大学
    浏览
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