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.
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.
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.
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.
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.
Abstract: Dopamine is known as a key molecule in retinal signaling pathways regulating visually guided eye growth, as evidenced by reduced retinal dopamine levels in various species when experimental myopia is generated. However, in C57BL/6 mice our recent work demonstrated that neither retinal dopamine levels, retinal tyrosine hydroxylase (rate-limiting enzyme in dopamine synthesis) levels, nor dopaminergic amacrine cell density/morphology, were altered during the development of form-deprivation myopia (FDM). These results suggest that retinal dopamine is unlikely associated with FDM development in this mouse strain. The role of dopamine in refractive development was further explored in this mouse strain when retinal dopamine levels were reduced by intravitreal injections of 6-OHDA, a neurotoxin that specifically destroys dopaminergic neurons. The dose was so chosen that retinal dopamine levels were reduced, but no significant changes in electroretinographic responses were detected. 6-OHDA induced significant myopic shifts in refraction in a dose-dependent manner, suggesting the involvement of dopamine in normal refractive development. Biometric measurements of ocular dimensions revealed that 6-OHDA resulted in a shorter axial length and a steeper cornea, while form-deprivation led to a longer axial length without changing the corneal radius of curvature. These results strongly suggest that in addition to the dopamine-independent mechanism, a dopamine-dependent mechanism works for refractive development. We have obtained evidence, suggesting that the dopamine-independent mechanism might be related to intrinsically photosensitive retinal ganglion cells (ipRGCs). Firstly, selective ablation of ipRGCs with an immunotoxin resulted in myopic shifts in refraction. Secondly, form-deprivation induced less myopic shifts in animals with ipRGC ablation.
