[Yag-Nd posterior capsulotomy.When? Where? How?].

PURPOSE: To answer a few elementary questions raised when confronted with the patient with aftercataract: Which are the indications and counter indications of the posterior capsulotomy? How can be evaluated the degree of PCO (posterior capsule opacification)? Which are the ideal size and location of the capsular opening? Is it mandatory to dilate the pupil? What energies are to be used? Which would be the recommended follow-up pattern? METHOD: This paper is a retrospective analysis of the 956 posterior capsulotomies performed between January 2001 and December 2002 at Bucharest Eye Hospital, Ophthalmology III Clinic, Nd:Yag laser surgery department. RESULTS: The best outcome is obtained with the fewest complications when the following conditions are met: the capsulotomy is performed no sooner than 6 months postoperatively; the capsular opening is small--2 mm in diameter--but perfectly aligned relative to the pupil and the IOL (sometimes this is difficult to achieve and the surgeon must always bare in mind the geometry of the posterior chamber and the parallax effect); laser pulses have low energy and are posteriorly defocused; when energy higher than 2 mJ is employed, the capsulotomy is performed by applying punctures in a circular pattern instead of a crosslike rectilinear pattern (in the case of IOL pitting, the visual axis is spared). CONCLUSION: The Nd:Yag photodisruptive laser offers a swift, safe and elegant method for dealing with a common and disturbing complication of the modern cataract surgery, the posterior capsule opacification. The results are often spectacular from the patient's point of view, but one should not neglect the risks related to the posterior capsulotomy.