Clinical Study
Ultrasound Biomicroscopy Comparison of Ab Interno and
Ab Externo Intraocular Lens Scleral Fixation
Lie Horiguchi,
1
Patricia Novita Garcia,
1,2
Gustavo Ricci Malavazzi,
1,2
Norma Allemann,
2
and Rachel L. R. Gomes
2,3
1
Department of Ophthalmology, Irmandade da Santa Casa de Miseric´ ordia de S˜ ao Paulo, S˜ ao Paulo, SP, Brazil
2
Department of Ophthalmology, Federal University of S˜ ao Paulo, S˜ ao Paulo, SP, Brazil
3
Hospital de Olhos Paulista, Rua Ab´ılio Soares 218, 04005-000 S˜ ao Paulo, SP, Brazil
Correspondence should be addressed to Rachel L. R. Gomes; rachelgomes@novais.md
Received 22 March 2016; Revised 1 May 2016; Accepted 4 May 2016
Academic Editor: Sang Beom Han
Copyright © 2016 Lie Horiguchi et al. is is an open access article distributed under the Creative Commons Attribution License,
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Purpose. To compare ab interno and ab externo scleral fixation of posterior chamber intraocular lenses (PCIOL) using ultrasound
biomicroscopy (UBM). Methods. Randomized patients underwent ab externo or ab interno scleral fixation of a PCIOL. Ultrasound
biomicroscopy was performed 3 to 6 months postoperatively, to determine PCIOL centration, IOL distance to the iris at 12, 3, 6, and
9 hours, and haptics placement in relation to the ciliary sulcus. Results. Fiſteen patients were enrolled in the study. e ab externo
technique was used in 7 eyes (46.6%) and the ab interno in 8 eyes (53.3%). In the ab externo technique, 14 haptics were located: 4
(28.57%) in the ciliary sulcus; 2 (14.28%) anterior to the sulcus; and 8 (57.14%) posterior to the sulcus, 6 in the ciliary body and 2
posterior to the ciliary body. In the ab interno group, 4 haptics (25.0%) were in the ciliary sulcus, 2 (12.50%) anterior to the sulcus,
and 10 (75.0%) posterior to the sulcus, 4 in the ciliary body and 6 posterior to the ciliary body. Conclusions. Ab externo and ab
interno scleral fixation techniques presented similar results in haptic placement. Ab externo technique presented higher vertical tilt
when compared to the ab interno.
1. Introduction
Capsular bag is the standard of care for posterior chamber
intraocular lens (IOL) placement. However, if the capsular
support is absent, many techniques can be used to fixate the
lens. Ab interno and ab externo are trans scleral suture tech-
niques described to fixate a posterior chamber intraocular
lens (PCIOL) [1–3]. Nevertheless, other techniques to fixate
an IOL have been described, such as the no-suture technique
that places the IOL haptic inside a scleral tunnel [4–6].
e aim of fixation is to position the haptics in the ciliary
sulcus; however, these procedures are performed without
direct visualization of the path of the needle.
Direct view techniques, guided by endoscopic probe,
have greater rate of success in lens centration and correct
haptic position [7, 8]. is technique is considered the
gold standard; however, it requires particular equipment and
specific training.
Ultrasound biomicroscopy (UBM) is an effective method
to study the anterior segment and haptics placement behind
the iris [9]. In this study we compared ab interno and
ab externo techniques to evaluate both haptics position in
relation to ciliary sulcus and the IOL distance from iris plane
determining vertical and horizontal tilt using UBM.
2. Methods
is study was approved by the Santa Casa de S˜ ao Paulo
Ethics Committee. Patients scheduled for IOL implantation
were randomly assigned to participate in one of the groups.
Scleral fixation was performed aſter a complete ophthalmic
examination. Surgery was scheduled according to patient’s
intraocular inflammation status. Patients with any sign of
active inflammation or best-corrected visual acuity worse
than 20/40 during the recruitment timeframe were excluded
from this study. In one group, the IOL was fixated using
Hindawi Publishing Corporation
Journal of Ophthalmology
Volume 2016, Article ID 9375091, 5 pages
http://dx.doi.org/10.1155/2016/9375091