This week I am sharing a scientific video. It shows various techniques for restoring vision in cases with partial corneal opacification without the use of allograft corneal tissue. These techniques avoid the use of donor corneas and the complications associated with use of allograft corneal tissue.
Continuing with the theme of iris repair techniques from the last post, this week I share a case of traumatic mydriasis.
A 52 year old man, sustained blunt trauma to his left eye. He was diagnosed with traumatic cataract and mydriasis. Subsequently, he underwent phacoemulsification along with PC IOL implantation (5.25mm PMMA IOL). He had 6/6 BCVA following surgery , but complained of debilitating glare. At this point he was referred for management of traumatic mydriasis.
On examination (Fig. 1), it was found that the pupil size was 8.0×7.8 mm along with exposed optic
edges. Further, a superior decentration of 1.5 mm of the IOL exposed the inferior optic–haptic junction (Fig. 2). These two factors( exposed optic edge and inferior optic-haptic junction) appeared to be the contributing causes of glare. Hence, a pupil-size reduction surgery was planned in the inferior area to cover the exposed edge of the IOL.
Surgical Technique
A 2.75-mm clear corneal tunnel incision was made superiorly, followed by 2 opposing stab incisions at 4 and 8 o’clock made with a 15-degree blade. The anterior chamber (AC) was filled with high-viscosity viscoelastic: Healon GV. Sinskey hook was used to mobilize the iris prior to suturing to ensure there were no posterior synechia. A 10-0 polypropylene suture with straight needles was used. A 20-G pick forceps was used to provide countertraction to the iris for the passage of straight needles. After taking bites of iris at 8 and 4 o’clock, the needle was exited out of the AC with the help of 26-G guide needle through the second side port at 4 o’clock position . Several centimeters of suture were pulled through the AC. A Sinskey hook was used to engage the suture between the distal iris and the site
where it exits the cornea. It was then withdrawn, retrieving a loop of suture through the incision. The externalized suture loop was oriented adjacent to the original strand, untwisting any polypropylene within the incision neck so as to achieve a parallel orientation of the sutures . The trailing end of the suture was passed down through the loop twice, always directing the passes back toward the cornea and then over itself. Each free end of the polypropylene suture was cinched, gently drawing the 2 iris surfaces together with the initial slipknot. The distal suture loop was again retrieved and externalized. The trailing end was passed up through the similarly oriented loop and under itself. The free suture ends were cinched gently,completing the locking knot. The ends of the suture were
trimmed and removed with a 20-G horizontal scissors.
Postoperatively, there was a reduction of pupil size from 8.0×7.8 mm to 5.5 mm (Fig 3). The patient’s complaint of glare was relieved and the glare acuity was 20/40 at 6 months follow-up.
What I learnt from This Case
Achieving 6/6 BCVA following cataract surgery may enthuse the cataract surgeon but the patient may still be miserable.
All cases with traumatic mydriasis may not need repair. Such a repair may be considered if the visual symptoms of the patient can be correlated with the physical findings.
This week I am pulling out a case from about 7 years back.
An 18 year old man presented with traumatic iridodialysis and underlying zonular dialysis with cataract (Fig. 1).
The patient was planned for iridodialysis repair along with phacoemulsification and IOL implantation. The cataract was removed without much difficulty. Subsequently, iris was repaired using prolene suture as shown in the video. A 3-piece foldable IOL was placed in the sulcus, without any bag fixation (remember, this is circa 2006). The IOL appeared quite stable on the table, and even sustained the pressure of viscoelastic removal without getting decentered.
Post operatively, the iris repair showed good outcome with only a mild distortion of the pupil. However, the IOL subluxated soon after.This was then treated with IOL explanation and scleral fixation of a PMMA IOL. Finally, the patient had a good overall outcome with a well centered IOL, adequately covered iris defect and BCVA improving to 6/6 (-0.5 DS) (Fig. 2) .
What I learnt from this Case
In cases with zonular dialysis >90 degrees, sulcus placement of IOL might appear stable on the table, but may not hold during the post operative period. These cases require some type of capsular bag/IOL fixation.
