OBJECTIVE: The study aimed to construct a new retinal tack design with high retention forces to prevent spontaneous disentanglement in cases of complicated retinal surgery.
METHODS: Six new forms for the peak of a retinal tack were developed using computer-aided design (CAD); then a prototype was produced for each model. Finally, standardised design testing was conducted using human (ex vivo) sclera by logging 15 consecutive measurements for each model.
RESULTS: Seven different models underwent pull-out testing (six new models and the original tack model), but two tack models (Model 4, Model 5) failed to penetrate the human tissue. The highest pull-out forces (median) were measured for Model 3, followed by Model 6, Model 2 and Model 1. The original Heimann tack (Model H) was found to have the lowest retention forces.
CONCLUSIONS: The different tack designs altered the penetration and holding forces. The retention forces of the proposed peak design led to a significant increase in the retention forces that were more than twice as high as those in the original Heimann Model.

BACKGROUND: Giant retinal tear is usually challenging among retinal detachment with recurrent rate up to 45%. Here we presented a case of giant retinal tear being treated by microincision vitrectomy and retinal tacks fixation.
METHODS: A 53-year-old male presented to our hospital with blurred vision of his right eye for one week with floaters and obscured sensation over nasal visual field. Ocular examination showed a 120 degree giant tear with large inverted flap and retinal detachment of his right eye. The BCVA was only naming digit. Under the impression of giant retinal tear with retinal detachment, 23-gauge pars plana vitrectomy were performed using Constellation high speed vitrectomy system and Topcon non-contact wide angle viewing system. During surgery, the vitreous was removed and perfluorocarbon liquids (PFCL) was injected to help unfolding the large inverted retinal flap. Three retinal tacks were applied to help fixating the large inverted retinal flap. Then, fluid-gas exchange, endolaser photocoagulation and intraocular silicone oil tamponade were performed as well. Initial reattachment of his right retina was achieved and his best corrected visual acuity improved to 0.3 of his right eye postoperatively. There was no recurrent retinal detachment during follow up period of 19 months.
CONCLUSIONS: Primary microincision vitrectomy using wide-angle viewing system with intraoperative perfluorocarbon liquids (PFCL) assistant, retinal tacks fixation and intraocular silicone oil tamponade appears to be safe and feasible for managing giant retinal tear with retinal detachment.

Several different approaches for restoring sight in subjects who are blind due to outer retinal degeneration are currently under investigation, including stem cell therapy, gene therapy, and visual prostheses. Although many different types of visual prostheses have shown promise, to date, the Argus II Epiretinal Prosthesis System, developed in a clinical setting over the course of 10 years, is the world\'s first and only retinal prosthesis that has been approved by the United States Food and Drug Administration (FDA) and has been given the CE-Mark for sale within the European Economic Area (EEA). The incidence of serious adverse events from Argus II implantation decreased over time after minor changes in the implant design and improvements in the surgical steps used for the procedure had been made. In order to further decrease the scleral incision-related complications and enhance the assessment of the tack position and the contact between the array and the inner macular surface, we used an ophthalmic endoscope during the regular course of Argus II implantation surgery in 2 patients with late-stage retinitis pigmentosa in an attempt to improve the anatomical and functional outcomes.

BACKGROUND: The Argus II retinal prosthesis may improve visual function in patients with severe vision loss from retinitis pigmentosa. Optimal centration of the electrode array over the macula is important to achieve optimal visual results. Argus tack malrotation is a novel entity that may be encountered during placement, especially in patients with posterior staphyloma.
METHODS: Retrospective case review.
RESULTS: During tacking of the electronics array a clockwise rotation occurred resulting in malposition. We hypothesize this was secondary to undue rotation or posterior pressure applied during tack insertion in conjunction with placement over a previously unrecognized posterior staphyloma. Intraoperative optical coherence tomography, because of the cross-sectional images provided, was helpful in visualizing the distance between the electronics array and the retina, which was difficult to assess using the surgical microscope alone. Repositioning was achieved by adjusting the tack without removal. The patient experienced an improvement in vision as a result of the surgery.
CONCLUSIONS: Malrotation may occur when tacking the Argus II prosthesis, and the presence of a posterior staphyloma may increase this risk. It is important to differentiate malrotation from tack misplacement - the former may be addressed with array unrotation or partial tack withdrawal and the latter may require tack removal and reinsertion. Also, intraoperative optical coherence tomography may be helpful in characterizing electronics array position during surgery.