Optical coherence tomography for an in-vivo study of posterior-capsule-opacification types and their influence on the total-pulse energy required for Nd:YAG capsulotomy: a case series.
BACKGROUND
Posterior capsule opacification (PCO) is the most common post-operative complication associated with cataract surgery and is mostly treated with Nd:YAG laser capsulotomy. Here, we demonstrate the use of high-resolution spectral-domain optical coherence tomography (OCT) as a technique for PCO analysis. Additionally, we evaluate the influence of PCO types and the distance between the intraocular lens (IOL) and the posterior capsule (PC), i.e., the IOL/PC distance, on the total-pulse energy required for the Nd:YAG laser posterior capsulotomy.


METHODS
47 eyes with PCO scheduled for the Nd:YAG procedure were examined and divided into four categories: fibrosis, pearl, mixed type and late-postoperative capsular bag distension syndrome. Using custom-made computer software for OCT image analysis, the IOL/PC distances in two dimensions were measured. The IOL/PC distances were compared with those of a control group of 15 eyes without PCO. The influence of the different PCO types and the IOL/PC distance on the total-pulse energy required for the Nd:YAG procedure was analyzed.


RESULTS
The total-pulse energy required for a laser capsulotomy differs significantly between PCO types (p = 0.005, Kruskal-Wallis test). The highest energy was required for the fibrosis PCO type, followed by mixed, pearl and late-postoperative capsular bag distension syndrome. The IOL/PC distance also significantly influenced the total-pulse energy required for laser capsulotomy (p = 0.028, linear regression). Lower total-pulse energy was expected for a larger IOL/PC distance.


CONCLUSIONS
Our study indicates that the PCO types and the IOL/PC distance influence the total-pulse energy required for Nd:YAG capsulotomy. The presented OCT method has the potential to become an additional tool for PCO characterization. Our results are important for a better understanding of the photodisruptive mechanisms in Nd:YAG capsulotomy.
Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1525 Ljubljana, Slovenia. gregor.hawlina@gmail.com.
Gregor
G
Hawlina
Darko
D
Perovšek
Brigita
B
Drnovšek-Olup
Janez
J
MoŽina
Peter
P
Gregorčič
D000368:Aged; D000369:Aged, 80 and over; D058442:Capsule Opacification / Q000145:classification / Q000175:diagnosis* / Q000601:surgery; D005260:Female; D006801:Humans; D053844:Lasers, Solid-State / Q000627:therapeutic use*; D019654:Lens Implantation, Intraocular; D008297:Male; D008875:Middle Aged; D018918:Phacoemulsification; D057852:Posterior Capsule of the Lens / Q000473:pathology*; D064727:Posterior Capsulotomy / Q000379:methods*; D011446:Prospective Studies; D041623:Tomography, Optical Coherence / Q000379:methods*