RUPTURE REMEDY

A well-centred single-piece intraocular lens (IOL), securely positioned in the capsular bag, is possible in eyes with posterior capsule ruptures, provided the tear is not too big, the anterior hyaloid face is intact and the surgeon acts promptly and appropriately, according to Brian Little FRCS, FRCOphth, of Moorfields Eye Hospital, London, UK.

“One of the problems that we often have is a tendency towards denial whenever something like this happens, and that delays making the right decision and taking action,” he told the 20th ESCRS Winter Meeting in Athens, Greece.

Once there is a tear in the bag, continuing with phacoemulsification will only exacerbate the problem and enlarge the tear, he said. Enlarging the tear not only makes the capsular fixation of a single-piece lens less possible, it also further increases the risk of rupture of the anterior hyaloid face and vitreous loss.

DISASTROUS COMPLICATIONS

Vitreous loss increases the risk of several potentially disastrous complications, including suprachoroidal haemorrhage, cystoid macular oedema, endophthalmitis, glaucoma and retinal detachment. In fact, a recent publication from a UK national dataset showed that vitreous loss increased the risk of retinal detachment 40-fold.

Dr Little noted that, when the tear occurs during the early part of the procedure, often too little of the posterior capsule remains to support a single-piece IOL. However, the prospects of good capsular support are improved when the posterior capsule tear occurs later in the procedure.

In these cases, a reasoned, stepwise approach will result in a postoperative situation almost identical to that which would have occurred if there had been no capsular rupture, Dr Little said.

He noted that in all such cases it is essential to tamponade the posterior capsule in order to prevent further enlargement of the tear by pushing back the anterior hyaloid face. This is best achieved by maintaining irrigation whilst removing the second instrument from the side port, and then inserting the ophthalmic viscosurgical device (OVD) cannula. The OVD is steadily injected as the irrigation is simultaneously turned off, thereby maintaining tamponade of the posterior capsule. Turning off or removing the irrigation from the eye without OVD exchange will cause the anterior chamber to decompress, allowing the vitreous to push forward, resulting in the rupture of the anterior hyaloid and vitreous prolapse.

A controlled posterior capsulorhexis can then be performed using forceps, taking the existing tear and circularising it. The anterior and posterior leaflets of the bag can then be maximally separated with more OVDs and a single-piece IOL safely inserted into the bag, he explained.

Brian Little: brian.little@moorfields.nhs.uk