N. Hirnschall et al.
Influencing factors for morphological changes of Elschnig pearls after Nd:YAG capsulotomy
Nino Hirnschall 1, 2, Thomas Neumayer 3, Michael Georgopoulos 3, Oliver Findl 1, 2
1 VIROS Institute, Hanusch Hospital, Vienna, Austria2 Moorfields Eye Hospital, London, UK3 Department of Ophthalmology, AKH, Vienna, Austria
Financial disclosure: none
N. Hirnschall et al.
Aim
To assess the influence of the following factors on Elschnig pearls and the YAG-opening:
• Nd:YAG capsulotomy settings:– number of shots– YAG-Energy– total Energy
• Morphological changes:– number of newly appearing pearls– size and shape changes of Elschnig pearls
N. Hirnschall et al.
Methods
• Design: prospective observational study
• Patients with pronounced regeneratory posterior capsule opacification (rPCO) were included in a continuous cohort
• Five digital retroillumination images were taken 10 minutes before YAG-capsulotomy, and 10 minutes, 1 week, 2 weeks and 1year after YAG-capsulotomy in a standardized fashion by two experienced examiners.
PreY
AG
1w 2w
PostY
AG
Nd:YAG-capsulotomy
1a
N. Hirnschall et al.
Methods
• Analysis: all image-series were analyzed with a dedicated image analysis software that allows tracing of single Elschnig pearls from image to image
N. Hirnschall et al.
• Alltogether 2452 pearls in 20 eyes of 19 patients were observed.
• In the first week after Nd:YAG-capsulotomy 6 new pearls appeared per eye (range: 0-18) with a mean size of 3000µm2 (range: 4000 – 9000).
Results
1 year after YAG
One year after Nd:YAG-capsulotomy pearl formations at the capsulotomy margin were found in 84% of eyes (mean: 3.9 pearls per eye, range: 0-17).
pearl formation at the capsulotomy margin
N. Hirnschall et al.
Results• Mean laser energy level of 1.5mJ was used for the YAG-
capsulotomy (range: 1.1mJ to 2.4mJ)
• No correlation between the laser settings and morphological changes of Elschnig pearls, or the YAG-opening
Correlation of YAG energy and changes of the YAG-opening
3210Changes of the YAG opening1 week after Nd:YAG capsulotomy
400
300
200
100
0
Tot
al N
d:Y
AG
ene
rgy
r= 0.29
mm2
mJ
N. Hirnschall et al.
11x increase in size 3x stable (±5%) 6x decrease in size
20 YAG-openings:
1 week 2 weeks 1 year
%
Change of the YAG-opening in the first year after Nd:YAG capsulotomy
N. Hirnschall et al.
Early pearls - prognostic factor
r = 0.834, p < 0.05
Num
ber
of a
ppea
ring
pear
ls
n = 20 eyes
Number of pearl strings per eye after 1 year
The correlation between number of appearing pearls in the first week after capsulotomy and pearl formations at the capsulotomy-margin one year later was high.
N. Hirnschall et al.
Conclusion
The appearance of new pearls in the first week after Nd:YAG-capsulotomy seems to be a prognostic factor for the long-term outcome concerning number of pearl formations at the capsulotomy margin. Pearl strings can cause glare, impede peripheral retinal examination and may necessitate secondary enlargement of the capsulotomy opening.