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.

Example: Decrease (6 cases)

2 weeks after YAG 1 year after YAG

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.

N. Hirnschall et al.