Comparative Analysis of Optical Versus Immersion Biometry in Silicone-Oil-Filled Eyes
Narrative Responses:
Purpose
To analyze biometry results in post vitrectomized silicon oil filled eyes underwent phacoemulsification.
Methods
Retrospective study of 105 silicon filled eyes who underwent phacoemulsification & silicon oil removal from Jan 2011-Dec 2012. The mean absolute postoperative refractive errors were analyzed with respect to preoperative AL, biometry method and type of retinal surgery done.
Results
The mean preoperative axial length (AL) was 24.52+2.78 mm. For AL<24mm: Mean absolute postoperative refractive error (MAE): Optical biometry group (OBG)=1.71D; Immersion group(IG)= 2.39D, (P=0.202). For AL >24 mm, OBG=2.30D and IG = 3.84D, (P=0.037); MAE in OBG=1.99D and IG=3.18D, (P=0.012). MAE for scleral buckling with vitrectomy group in OBG=2.08D; IG=3.58D, (P=0.031); Vitrectomy alone group: OBG=1.85D; IG=2.46D, (P=0.215). AL (>24) in BUC/PPV group was highly significant than PPV groups (P=0.007). Absolute refractive error in OBG was <1D in 43.4%, 1-2D in 24.1% and >2 D in 32.5% and 13.6%, 36.4 % and 50.0% respectively in IG.
Conclusion
Optical biometry had scored better over immersion in all groups especially in eyes with axial length >24 mm and in buckle vitrectomy group. Optical biometry is reliable and accurate than A-scan immersion biometry in silicon filled eyes.