Article Text
ABSTRACT
A radial tear of the anterior capsule can occur either as a primary tear-out during capsulorrhexis or as a secondary event during phaco. Endocapsular surgery in this situation is hazardous and the risk of posterior propagation of the tear is significantly increased by performing hydrodissection. We describe an alternative technique of endocapsular phacoemulsification without primary hydrodissection. The risk of tear propagation is reduced whilst at the same time auto-hydrodissection of the cortico-capsular connections occurs, enabling rotation and removal of the nucleus. This simple modification of conventional phacoemulsification reduces the risk of posterior extension in cases of radial anterior capsular tear and allows the relatively safe completion of endocapsular phacoemulsification.
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Supplementary materials
Video Report
Endocapsular Phacoemulsification without Hydrodissection: an effective technique for cataract surgery following anterior capsular tear
Romesh I Angunawela, Brian LittleDepartment of Ophthalmology, Royal Free Hospital, London, NW3 2QG, UK
Correspondence: Mr Brian Little,
Email: brianlittle{at}blueyonder.co.uk Consultant Ophthalmologist, Royal Free Hospital, London, NW3 2QG, UK.Date of acceptance: 27 January 2008
Figure: Capsular tear out during capsulorrhexis. The blue arrow shows the tear extending posteriorly. Video: This segment shows the technique of phacoemulsification without hydrodissection in the situation of a radial capsular tear out during capsulorrhexis. The technique and key points described in the text minimise the likelihood of posterior tear extension.
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Introduction
Continuous curvilinear capsulorhexis facilitates safer, controlled endocapsular phacoemulsification, whilst also providing optimal and stable positioning of the intraocular lens (IOL). A radial tear of the anterior capsule can occur during the capsulorhexis or later on and if the use of previously described rhexis rescue techniques is unsuccessful then surgery has to continue in the presence of a compromised rhexis.1,2 The peripheral extension of an anterior capsule tear to the equatorial capsule and beyond carries the risk of vitreous loss, posterior lens dislocation, and restricted options for intraocular lens placement.3
All current endocapsular phaco techniques require free rotation of the crystalline lens within the bag, which is achieved by the use of cortical cleaving hydrodissection. The principle of hydrodissection is that a bolus of fluid is injected behind the nucleus which is pushed forwards due to the intentionally induced lenticulo-capsular block. The nucleus is then balloted backwards with resultant anterior propagation of a sub-capsular fluid wave to break the anterior cortico-capsular connections. In the presence of a compromised rhexis this internal pressurisation of the bag causes considerable expansile stress on the apex of any tear and leads to its peripheral and posterior propagation with predictable consequences. These forces are evident in the situation of a posterior capsular 'blow-out' occurring during hydrodissection even in the presence of an intact capsulorhexis.
We describe a straightforward modified technique for continuing with endocapsular phaco under these circumstances but without hydrodissection. It is simple to perform and we have used it for over three years and found it to be relatively safe and effective for dealing successfully with this hazardous complication.
Surgical technique
In this case an irretrievable primary radial tear-out occurred during capsulorhexis (figure 1). In order to minimise the risk of propagating the tear peripherally it is important that fastidious attention is paid to maintaining a deep and stable anterior chamber throughout the procedure. There are two techniques that greatly assist in achieving this. The first is to use continuous irrigation throughout both phacoemulsification and irrigation and aspiration (IA). The second is to use Viscoelastic-BSS (OVD-BSS) exchange when removing irrigation from the eye. This involves simultaneously filling the chamber with an ophthalmic viscosurgical device (OVD) via a side port just as the irrigation is switched off, but while the phaco or irrigating instrument is still occluding the wound to prevent leakage. The instrument can then be safely removed without chamber collapse. This is particularly important after phacoemulsification is complete and the capsular bag is empty.
It is important that no initial hydrodissection is performed. Instead the lens is gradually emulsified and slowly 'bowled out' (see video). We avoid cracking the nucleus in order to decrease any outward expansile forces that are required to separate the fragments. We try to reduce lens manipulation so that radial and rotational forces are kept to an absolute minimum. Slow and shallow sculpting strokes are used together with gentle fluidics.
As the central nucleus is progressively debulked, the horizontal fluid outflow from the coaxial irrigation sleeve is naturally directed towards the subcapsular plane and usually results in spontaneous hydrodissection of the outer epinucleus and cortex from the surrounding capsule. This shell can then be removed by phaco-aspiration. If the bowl remains adherent to the capsule it can now be safely mobilised using gentle hydrodissection as the wave of BSS tends to follow the line of least resistance, which is to collapse the bowl inwards rather than expand the bag outwards.
The residual cortex is then aspirated using bimanual IA and, as a precaution, the area that involves the tear is left until last. We prefer bimanual IA as this avoids the manipulation required for adequate aspiration using coaxial IA which may place additional stresses on the capsule. Aspiration of the torn anterior capsular flap should be avoided. Cortex that is adherent to the area of the tear is aspirated last and a final OVD-BSS exchange is performed prior to lens implantation.
The lens can then be introduced into the bag or the sulcus depending upon surgeon preference, IOL characteristics and local conditions. In our experience it is usually possible to implant an IOL within the capsular bag and to place the haptics perpendicular to the tear. A relieving incision diametrically opposite the tear using Ong scissors may reduce asymmetric capsule contraction and possible future lens decentration.
Finally, the remaining viscoelastic is aspirated as gently as possible. Particular care is needed when a cohesive viscoelastic is present because this can all too easily be rapidly aspirated en bloc. The post-occlusion surge that may follow causes sudden chamber decompression and posterior propagation of the tear with dislocation of the IOL into the vitreous.
Conclusion
An anterior capsular tear can result in a dropped nucleus with potentially sight-threatening complications. Hydrodissection is particularly likely to cause peripheral and posterior extension of such a tear. We offer a simple and effective approach to endocapsular phacoemulsification in this situation that avoids hydrodissection and which, in our experience, minimises the risk of posterior tear propagation thereby improving surgical outcomes.
The key points of this technique are:
- Fastidious attention to chamber stability and tamponade throughout the surgery. Use of continuous irrigation and OVD-BSS exchange when removing the irrigating instrument
- No primary hydrodissection
- Avoid cracking the lens
- Bowl out the lens using gentle sculpting
- The residual lens bowl often 'auto hydrodissects' due to irrigating fluid flow beneath the anterior capsule
- Aspirate the remaining cortex
- Position the IOL within the capsular bag or sulcus
- Avoid aspirating residual viscoelastic from behind the intraocular lens
Conflict of Interest Statement
No funding was acquired. This technique has not previously been presented. None of the authors has a financial or proprietary interest in the material presented.
References
- Little BC, Smith JH, Packer M. Little capsulorhexis tear-out rescue. J Cataract Refract Surg 2006; 32(9):1420-1422.
- Osher RH, Falzoni W, Osher JM. Our phacoemulsification technique. In: Burrato L, Werner L, Zanini M, Apple DJ, editors. Phacoemulsification Principle and Techniques, 2 edn. Slack, 2003:355-362.
- Assia EI, Apple DJ, Tsai JC, Morgan RC. Mechanism of radial tear formation and extension after anterior capsulectomy. Ophthalmology 1991; 98(4):432-437.
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