This article is more than 5 years old. Information may no longer be current.
Modified capsular tension ring injector minimizes risks
The traditional method using forceps involves a risk of rupturing the capsular bag or misplacing the ring into the sulcus or vitreous cavity.
Click Here to Manage Email Alerts
A modified injector reduces risks associated with the insertion of capsular tension rings in eyes with lax zonules, according to a report.
“Inserting a CTR with two instruments is quite difficult, especially for a beginner surgeon,” corresponding author Anca Cristina Dogaroiu, MD, told Ocular Surgery News. “When a CTR is implanted using the classic maneuver, there is a very high risk of intraoperative complications including the implantation of the CTR into the sulcus or, worse, into the vitreous cavity.”
This classic approach can create an obstructed view and uncontrolled maneuvering of the ring’s free end, which may result in intraoperative complications during insertion, according to the report, published in the European Journal of Ophthalmology.
“With our injector, it is more safe,” Dogaroiu said. “We have full control of the CTR during the entire period of implantation.”
Modified technique
The modified injector comprises a metal anchoring element attached to the free end of the tube on which the second eyelet of a standard CTR is fixed.
An angular stainless steel rod with a length of 3.33 mm and a diameter of 0.45 mm is attached to the free end of the standard injector tube. The free segment forms an angle of about 40° with the axis of the tube. At 0.57 mm from the distal end of the rod, an anchoring stainless steel element with a height of 0.65 mm and a diameter of 0.25 mm, slightly inclined toward the distal end of the injector tube, is attached.
When the CTR is loaded into the injector, the first eyelet of the CTR is attached to the hook on the extended arm, so that releasing the spring-loaded plunger under force from the tension ring pulls the CTR into the injector. The other eyelet is fixed to the anchoring element attached to the angular rod.
An ophthalmic viscoelastic device is injected into the anterior chamber and capsular bag. The piston of the injector operates so that the CTR emerges slowly. The CTR forms a loop that extends in a circular fashion with a stable point on the eyelet fixed on the anchoring element. This reduces the risk of capsular bag rupture or vitreous placement of the CTR.
Improved visualization
The CTR eyelets are visible when the piston is compressed; one is fixed on the anchoring element and one is on the hook. The eyelets are released with intraocular forceps or a spatula inserted through a side port, and the injector is removed from the eye.
“When the forceps are used for implantation, the first eyelet can’t be seen; therefore, it can get tangled with the bag or other cortex material,” Dogaroiu said. “This technique is easier because at the end of pushing the piston of the injector, you see both eyelets. And with the help of intraocular forceps, each eyelet can be easily placed into the bag, so there is no risk for damaging the rhexis and the CTR is placed in the proper location, into the capsular bag.”
Unlike standard injection methods in which the free end of the CTR can disrupt the zonular fibers when entering the capsular bag, the modified injector allows controlled circular expansion of the loop with the free end of the ring fixed to the anchoring element, according to the report.
The modified CTR injector was used in performing cataract surgery in 50 adults with lax zonules. The device reduced the duration and complexity of CTR injection; no intraoperative incidents or postoperative complications were reported.
“The key point, in significant lax zonules and zonular dehiscences, is that we found the possibility to implant a CTR easier, faster and without surgical complications,” Dogaroiu said. – by Matt Hasson
- Reference:
- Tataru CP, et al. Eur J Ophthalmol. 2016;doi:10.5301/ejo.5000613.
- For more information:
- Anca Cristina Dogaroiu, MD, can be reached at Clinical Hospital of Ophthalmological Emergencies, Piata Al. Lahovari 1, Sect. 1, Bucharest, Romania; email: ancapuscasumd@gmail.com.
Disclosure: Dogaroiu reports no relevant financial disclosures.