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A new device for pupil enlargement: Bhattacharjee’s ring

Session Details

Session Title: Complex Cases and Surgery

Session Date/Time: Monday 07/10/2013 | 14:30-16:00

Paper Time: 14:45

Venue: Forum (Ground Floor)

First Author: : S.Bhattacharjee INDIA

Co Author(s): :                  

Abstract Details

Purpose:

To evaluate performance of Pupil Dilating Devices with a new design having Notches and Flanges.

Setting:

Nayan Eye Associates, Kolkata, India.

Methods:

The pupil dilating device uses a novel concept of notches at the corners to engage the pupillary margin. It has a closed ring design, is entirely in a single plane and is made of a strand of thermally treated 4-0 Nylon. Ends are butt joined with cyanoacrylate adhesive. Square and the Hexagon designs are available in 6 and 7 mm sizes. The device is inserted into the anterior chamber through a 1.5 to 2.2 mm incision under topical anesthesia. Using a 23G forceps, opposite flanges are tucked under the iris one after another. As a flange is tucked under the iris, the two notches at the ends of the flange engage the pupillary margin. To remove the device, a 23G forceps is used through a side port to disengage two adjacent notches while the flange is held with another 23G forceps and gently pulled out through the clear corneal incision. Ease of device insertion, engagement and removal were recorded. Pupil & iris trauma were noted. Dilated pupil was measured from side to side and corner to corner. Capsulorhexis size was recorded. Stability of the device, any difficulty in movement of phaco probe or side port instruments, ease of IOL injection and complications were recorded. Floppiness of the Iris was graded.

Results:

22 eyes with non dilating pupil underwent Phaco surgery using the new pupil dilating device by a single surgeon. Moderately dilating pupils with history of IFIS during the other eye surgery, were also included. 1.5 to 2.2 mm clear corneal phaco incisions were used. Two 20 G (0.9 mm) side port incisions were used in all eyes. A 6 mm ring was used in eyes with 11 mm or less white to white corneal diameter. The Square design was used in 10 eyes (6 mm in 3 and 7 mm in 7 eyes) and the 7 mm Hexagon design in 12 eyes. Satisfactory pupillary dilatation was achieved in all eyes. Average capsulorhexis size was 5.2 mm. There was no snagging of the incision at insertion or removal of the device. The device did not obstruct movement of instruments even in eyes with shallow AC. Iris floppiness was restricted by the flanges lying anterior to the Iris. A small Irido dialysis with hyphema occurred in one eye due to the pupillary margin being held by the forceps inadvertently during removal. All eyes, except for one, which had a sphincter tear, had round pupils at the end of surgery and postoperatively.

Conclusions:

The novel concept of notches at the corners to engage the pupillary margin eliminates the disadvantages associated with the Malyugin ring. The notches, flanges & the entire device being in a single plane, there is no snagging of the incision unlike the Malyugin ring which has a two plane structure at the corners and snags the incision. With the Malyugin ring, using a top view, it is difficult to precisely align the gap at the side of the helical loop to the pupillary margin. With deformation of the ring, the gap in the Malyugin helical loop can narrow or widen, causing unpredictable crushing or slipping out of the pupil margin. This did not occur with the notches. 4-0 Nylon (0.16 mm) used in this new device has greater flexibility and resilience and better bend recovery compared to the 5-0 Polypropylene used in Malyugin rings. The notches straighten as they pass through the incision and can be easily inserted through 1.5 mm incisions. None of the existing devices can achieve that. The initial results of the new pupil dilating device with notches and flanges, suggest that they are safe and efficient. However, a better delivery system needs to be developed.

Financial Interest:

NONE