Meridional differences in internal dimensions of the anterior segment in human eyes evaluated with 2 imaging systems.
OBJECTIVE
To evaluate meridional differences in angle-to-angle (A-A) and sulcus-to-sulcus (S-S) dimensions in human eyes using very high frequency ultrasound (VHF US) and anterior segment optical coherence tomography (AS-OCT).


METHODS
John A. Moran Eye Center, University of Utah, USA; Berlin Eye Research Institute, Germany; Quattroelle Centri Oftalmochirurgici, Italy.


METHODS
Human autopsy eyes were fixated to special eye holders and had anterior segment scanning using 50 MHz ultrasound (Artemis, Ultralink) (20 eyes) and AS-OCT (SL-OCT, Heidelberg Engineering) (24 eyes). Seventy-three eyes (58 patients) also had anterior segment scanning using the same systems (Artemis, 50 eyes; SL-OCT, 23 eyes). Four meridians were evaluated in each eye. The A-A dimensions were measured by VHF US and AS-OCT. The S-S dimensions were also measured by VHF US. Statistical analyses were done with the Huynh-Feldt test.


RESULTS
In the autopsy-eye study, the differences in A-A and S-S dimensions between the 4 meridians in eyes analyzed with VHF US were statistically significant (P=.002 and P=.009, respectively). The differences in A-A dimensions in eyes analyzed with the AS-OCT were also significant (P=.005). The same findings were observed in the clinical study (VHF US, P=.001 for A-A and P<.001 for S-S; AS-OCT, P<.001 for A-A).


CONCLUSIONS
This study suggests that the internal geometry of the anterior segment of human eyes does not constitute a circle. This may have significant relevance for the accurate sizing of phakic intraocular lenses.
John A. Moran Eye Center, University of Utah, Salt Lake City, Utah 84132, USA. liliana.werner@hsc.utah.edu
Liliana
L
Werner
Carlo
C
Lovisolo
Jesse
J
Chew
Manfred
M
Tetz
Matthias
M
Müller
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000869:Anterior Eye Segment / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D001699:Biometry / Q000379:methods; D001837:Body Weights and Measures; D002387:Cataract Extraction; D005260:Female; D006801:Humans; D019654:Lens Implantation, Intraocular / Q000379:methods; D008297:Male; D033401:Microscopy, Acoustic / Q000379:methods*; D008872:Microwaves; D008875:Middle Aged; D054120:Phakic Intraocular Lenses; D041623:Tomography, Optical Coherence / Q000379:methods*