Novel transscleral sutureless subretinal fluid drainage using a 25-gauge trocar-cannula with a self-closing valve in patients with advanced Coats disease

A novel approach for 25-gauge transconjunctival sutureless vitrectomy to evaluate vitreous substitutes in rabbits

AIM

To improve the standard three-port vitrectomy for establishing and evaluating an endotamponade model in rabbits.

METHODS

Three ports were prepared near the third eyelid of rabbits, and the infusion port was placed at the inferior nasal quadrant with the inserted cannula linking with a self-designed handheld rigid infusion catheter. All right eyes of rabbits underwent a modified 25-gauge vitrectomy and were subsequently filled with balanced salt solution, silicone oil, and eight-arm polyethylene glycols (8-arm PEGs) hydrogel separately for comparison. Ophthalmic examinations were performed regularly to record the changes after the surgery.

RESULTS

Successful vitrectomy was achieved among 44 chinchilla rabbits. The mean operation time was 4.51±1.25min. Four eyes (9.1%) presented limited lens touch and two eyes (4.5%) showed retinal touch during surgery. Incision leakage was found in three eyes (6.8%) after surgery. There was no endophthalmitis, hemorrhage, or retinal detachment during the observation period and ophthalmic examinations after the implantation of vitreous substitutes.

CONCLUSION

The modified technique of the standard vitrectomy applied in the endotamponade model in rabbits shows excellent safety and practicality.

Novel Surgical Pathway for Controlled Access to the Subretinal Space: A Case Series

Purpose

We report a case series demonstrating a novel technique to access the subretinal space through a trans-scleral approach.

Methods

This was a prospective, interventional case series. All 25 cases underwent three-port vitrectomy using CONSTELLATION Vision System (Alcon. Laboratories, Inc., Fort Worth, TX) and NGENUITY 3D Visualization System. In all cases a fourth 25G valved cannula was inserted posteriorly in the vitreous cavity to secure a controlled access to the subretinal space. This route was used to remove subretinal fibrosis, drain subretinal fluid, and inject vital dye to identify an occult retinal break in some cases.

Results

In 23 of 25 cases, the retina remained attached postoperatively after a single surgery, and vision improvement was observed. In two cases, the retina was attached after an additional procedure. Although mild subretinal hemorrhage was seen in three cases, no other major complication was observed.

Conclusions

Access to the subretinal space by a posteriorly placed fourth valved cannula is safe and helps in subretinal fibrosis removal and drainage of subretinal fluid and can be useful in complicated retinal detachments.

Translational Relevance

This case series uses knowledge acquired from developing small gauge microincision instruments for pars plana vitrectomy to present a novel clinical application applicable to difficult, complex retinal surgeries.