Original Article

Short-term observation of management of sclera patch grafts used in the scleral defects

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Background: To explore the safety and effectiveness of Sclera patch grafts in the management of scleral defects.

Methods: This is a retrospective uncontrolled study. Medical records were retrospectively reviewed for 8 eyes of 8 patients with sclera patch grafts. Two patients had necrotizing scleritis, 2 patients had scleral melting/perforation secondary to thermal burns, 4 patients had scleral staphyloma secondary to surgery. Sclera was reconstructed with allogenic sclera patch grafts, 6 in 8 patients combined autologous conjunctival pedicle flap, 1 patient combined partial medial rectus translocation, 1 patient combined autologous pedicle tenon graft, simultaneously. Treatment outcomes were evaluated using structural integrity, best corrected visual acuity (BCVA), scleritis remission, sclera rejection and melt, and ocular symptoms.

Results: Eight patients were reviewed. In all of these cases, satisfactory anatomic and functional outcomes were achieved. In the at least half a year follow-up, the BCVA of all the eight patients were no worse than that of preoperative. No eye pain, foreign body sensation and other discomforts showed in all the patients, except one woman, who showed sclera rejection and melt 1 month postoperative. In addition, one patient showed high intraocular pressure (28 mmHg), which can be controlled by a kind of medicine.

Conclusions: In this series, sclera patch grafts is an effective method for management scleral defects in the at least half a year following-up. Attention should be paid to the sclera patch rejection and melt post operatively.

Original Article

Simplified pupilloplasty technique through a corneal paracentesis to manage small iris coloboma or traumatic iris defect

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Background: To report a new simplified surgical technique to manage small iris coloboma or traumatic iris defect.

Methods: A new surgical technique in which simplified pupilloplasty technique through only a clear corneal paracentesis to manage the iris coloboma or traumatic iris defect within the 120° range was designed. A retrospective revision of the medical records of patients treated with this technique between the years 2013 and 2016 was made. Six eyes of six patients with iris coloboma or traumatic iris defect treated with this new technique were included.

Results: All the operated eyes quickly recovered with central round pupil, negligible complications, inessential symptoms of photophobia and glare, and mild inflammation after a median follow-up time of 22 months (range: 6–34 months).

Conclusions: The simplified pupilloplasty technique presented here could be a good alternative for the management of small iris coloboma or traumatic iris defect.

Original Article

A virtual model of the retina based on histological data as a tool for evaluation of the visual fields

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Background: To settle the fundamentals of a numerical procedure that relates retinal ganglion-cell density and threshold sensitivity in the visual field. The sensitivity of a generated retina and visual pathways to virtual stimuli are simulated, and the conditions required to reproduce glaucoma-type defects both in the optic-nerve head (ONH) and visual fields are explored.

Methods: A definition of selected structural elements of the optic pathways is a requisite to a translation of clinical knowledge to computer programs for visual field exploration. The program is able to generate a database of normalized visual fields. The relationship between the number of extant receptive fields and threshold sensitivity is plotted for background sensitivity and corresponding automated perimetry. A solution in two planes to the 3D distribution of axons in the ONH is proposed. Visual fields with induced damage in the optic disc are comparable in pattern and quantity to glaucomatous records.

Results: The two-level simulation of the ONH facilitates the analysis of optic-cup/retinal defects. We can generate the virtual optic pathways tailored to the age and morphology of the patient’s eye, and it is possible to reproduce glaucomatous damage by “reverse engineering” engineering. The virtual cortical model renders a quantitative relationship between visual defect and neural damage.

Conclusions: A two-level computing of the retina/optic nerve facilitates the analysis of neuroretinal defects and can be incorporated to automatic perimeters to facilitate visual field analysis.

Original Article
Editorial
Original Article
Original Article

Combined pars plana vitrectomy and suture less scleral fixation of foldable intraocular lens: single surgery visual rehabilitation of dislocated lens/intraocular lens

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Background: To evaluate efficacy and safety of combined pars plana vitrectomy (PPV) and scleral fixated intraocular lens (SFIOL) surgery as a single procedure.

Methods: Retrospective interventional case series done at a tertiary eye care center in Northern India. Eleven patients who underwent combined PPV and SFIOL surgery were included and analyzed retrospectively.

Results: Mean age of the patients was 43.36±15.12 years (range, 22–64 years). Eight were male. Mean baseline best corrected visual acuity (BCVA) was 0.78±0.63 logMAR units while the mean post-operative BCVA at 6 months follow-up was 0.37±0.29 logMAR units, the visual gain being statistically significant (P=0.021). None of the patients had a drop in BCVA with nine patients having final BCVA better than 0.48 logMAR units. Choroidal detachment (CD) was the only notable complication, seen in three patients. Other complications included two cases of intraoperative retinal breaks, a case each of reversible corneal edema, ocular hypertension and cystoid macular edema.

Conclusions: Combined PPV and SFIOL is an efficacious procedure for managing IOL/lens dislocation and aphakia in a single surgery. There may be short-term reversible complications with no impact on final visual gain.

Theme 4: OMICS

AB015. The relationship between copy number variations and high myopia in Chinese: a case-control study

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Abstract: As a complex disease, myopia is the most common eye disease worldwide. Many myopia susceptibility genes or variants have been successfully identified in the past years by genome-wide genetic association studies (GWAS), which focus mainly on the single-nucleotide polymorphisms. Little attention has been paid to examine the role of copy number variations (CNVs) in refractive error and myopia. This study adopted a systematic strategy to investigate the role of CNVs in high myopia. In the discovery phase, a pilot GWAS suggests putative CNVs for follow-up. Multiplex ligation-dependent probe amplification was then used to quantify the copy number of 89 CNV segments in 737 case-control samples in the second phase and then 24 top-ranking CNVs in a second group of 1,029 case-control samples in the final validation phase. This validation phase identified 22 significant CNVs. Further work is needed to examine the role of these few CNVs in myopia development.

Theme 3: Emerging Technologies

AB011. A collagen-alginate-based cell-encapsulation intraocular implant for retinal disease therapy

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Abstract: Encapsulated-cell therapy (ECT) is an attractive approach for continuously delivering freshly synthesized therapeutics to treat sight-threatening posterior eye diseases, circumventing repeated invasive intravitreal injections and improving local drug availability clinically. Composite collagen-alginate (CAC) scaffold in ECT contains an interpenetrating network that integrates the physical and biological merits of its constituents, including biocompatibility, mild gelling properties and availability. An injectable CAC system that supported the growth of HEK293 cells with sustainable glial-derived neurotrophic factor (GDNF) delivery has been developed. Continuous GDNF delivery was detected in culture and in healthy rat eyes for at least 14 days. The gels were well tolerated with no host tissue attachment and contained living cell colonies. Most importantly, gel implantation in dystrophic Royal College of Surgeons rat eyes for 28 days retained photoreceptors while those gels containing higher initial cell number yielded better photoreceptor rescue effect. This rescue effect is clinically relevant as photoreceptor death is a common pathology in many retinal diseases. Moreover, since cells including autologous cells can be genetically engineered to secrete various therapeutic agents, CAC gel offers a flexible system design and is a potential treatment option for other chronic neurodegenerative diseases.

Theme 3: Emerging Technologies

AB009. Regenerative medicine—stem cell delivery for retinal disease

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Abstract: Vision loss in retinal disease is often secondary to neural cell loss. Neural loss of any type including that of the retina has always been considered irreversible as these cells rarely retain the ability to regenerate. The recent identification of stable stem cell sources and the advances in stem cell technology have transformed this area of research science into an important area of strong therapeutic possibility. These sources include human embryonic stem cells (hESC), induced pleuripotent stem cell sources (iPS) as well as adult sources. The main advantage of using a stem cell source is that there is an infinite capacity to reproduce and therefore an infinite capacity to produce cells, including neural cells for transplantation. The challenge more recently has been to transform these stem cells into differentiated cells that are useful for transplantation in disease. In terms of the retina, hESC have been successfully developed into retinal pigment epithelial cells. These cells have been characterised as identical to native human RPE cells structurally, functionally and biochemically. Previous studies of macular translocation and RPE/choroidal transplantation have shown that vision loss from AMD can be reversed. Early animal studies show that the transplanted HESC RPE survive and can prevent vision loss in animal models of disease. Initial hESC based RPE transplantation trials using suspension cultures were successful in demonstrating safety of the cells in the context of disease and sub-retinal delivery. More recently, we have carried out the first 2 transplantations of sheets of hESC based RPE on a coated artificial Bruch’s membrane, in the London Project’s RPE transplantation trial, with promising results. As well as RPE— Bruch’s transplantation I will also briefly discuss the recent advances in neuro-retinal and vascular reconstructions using stem cells.

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  • 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
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