Clinical and Experimental Ophthalmology (2002) 30, 386–387

Letter to the Editor ________________________________

Letter to the Editor

Trypan blue assisted phacoemulsification by residents in training

We would like to report the usefulness of trypan blue dye(VisionBlue, DORC, Drunen, Netherlands) for capsularstaining in phacoemulsification for immature cataractremoval performed by trainee residents. Trainee surgeonsoften find difficulty in performing the capsulorhexis (CCC)due to the failure of visualization of the tearing edge of theanterior capsule because of poor red reflex in mature cata-racts and disruption of the cortical matter in immaturecataracts.

Data were collected prospectively on the first 60 dye-assisted phacoemulsification surgeries done by four third-year residents (15 eyes each) for the first time on clinicalsubjects at our centre from April 2001 to July 2001. Thethird-year resident trainees practised phacoemulsification inan experimental laboratory on at least 20 goat eyes aftermastering the steps of CCC and hydrodissection duringextracapsular cataract surgery on a similar number. Further,they had assisted a senior surgeon in the phacoemulsifica-tion and foldable intraocular lens implantation in at least 25eyes.

All surgeries were performed under peribulbar anaesthe-sia and supervised by an experienced phacoemulsificationsurgeon (RBV). A clear corneal tunnel was made with a3.2-mm diamond knife and a stab incision at the 2 o’clockposition with a microvitreoretinal knife. Sterile air wasinjected into the anterior chamber through the side portusing a 27-gauze cannula on a 2.0 cc syringe followed by0.1 mL of 0.1% trypan blue under the air bubble over theanterior capsule. The anterior chamber was washed with abalanced salt solution after waiting for a period of 10 s. TheCCC was performed under Healon GV (Pharmacia &Upjohn, Kalamazoo, MI, USA) after initiating the nick witha bent 26G needle and completing it with an Utrata’scapsulorhexis forceps. Following hydroprocedures, phaco-emulsification was done by stop and chop manoeuvre on aventuri-pump-based machine (Protégé, Baush & Lomb,Surrey, UK). After automated irrigation aspiration of thecortical matter a foldable intraocular lens (Acrysof, AlconLaboratories, Fortworth, TX, USA) was implanted.

All cases were completed successfully without any majorcomplications. Staining of the side port and the woundoccurred in all eyes intraoperatively. The dye delineated theone case of anterior capsular fibrosis and hence this area wasencompassed in the capsulorhexis. The anterior capsule wasdamaged with the cannula in one eye while injecting theviscoelastic. Peripheral extension of the capsulorhexis

occurred in two eyes and a small capsulorhexis requiringenlargement occurred in two eyes. The step that requiredexpert intervention most frequently was subincisional cortexaspiration (n = 12). No evidence of posterior capsule tear orvitreous loss was noted in any of the 60 eyes, although twoeyes had zonular dialysis (<90 degrees). The dye stainedzonules were visible in one of these cases. All eyes achieveda best-corrected visual acuity of 6/12 or better at the firstweek follow up.

DISCUSSION

Dye enhanced cataract surgery has been found to be usefulin mature cataracts1 and in learning the various critical stepsof phacoemulsification in a wet laboratory setting.2 Thestaining of the anterior capsule with the dye has beenadvocated under an air bubble or by an intracameral subcap-sular injection. Staining under the air bubble provides aquick homogenous staining of the anterior capsule so thatthe blue stained rim, namely the unexcised, peripheralportion of the anterior capsule, is clearly distinguished fromthe grey lenticular mass underlying the excised centralportion of the capsule. The CCC margin is visualizedthroughout the procedure and the stained peripheral ante-rior capsule rim aids in emulsification of the fragments as thedye also stains the peripheral part of the anterior capsule.Thus, the proper positioning of the depth of the chopper tipis visualized and any inadvertent ripping of the CCC isprevented.

Additional advantages include staining of the side port,unmasking of the anterior capsular fibrosis and staining ofthe zonules. The novice surgeon can visualize the side portat all times during the surgery, which aids the timely intro-duction of second instruments, such as a chopper or asinskey. The intraocular tissues were identified better incases where supervisory intervention was required such assubincisional cortex removal, when a rhexis flap extendedtowards the periphery and in the event of a small rhexisneeding enlargement. Vitreous loss for this series of 60 eyeswas 0% compared with the usual resident rate of2.9–14.7%.3,4

Namrata Sharma MD, Prashant Bhartiya MD, Rajesh SinhaMD and Rasik B Vajpayee MB BS MS

Dr Rajendra Prasad Centre for Ophthalmic Sciences, All India Instituteof Medical Sciences, New Delhi, India

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REFERENCES

1. Melles GRJ, de Waard PWT, Pameyer JH, Beekhuis WH.Trypan blue capsule staining to visualize the capsulorhexis incataract surgery. J. Cataract Refract. Surg. 1999; 25: 7–9.

2. Werner I, Pandey SK, Escobar-Gomez M et al. Dye enhancedcataract surgery. Part 2: learning critical steps of phacoemulsi-fication. J. Cataract Refract. Surg. 2000; 26: 1060–65.

3. Straatsma BR, Meyer KT, Bastek JV, Lightfoot DO. Posteriorchamber intraocular implantation by ophthalmology residents.

A prospective study of cataract surgery. Ophthalmology 1983;90: 327–35.

4. Allinson RW, Metrikin DC, Fante RG. Incidence of vitreousloss among third year residents performing phacoemulsifica-tion. Ophthalmology 1992; 99: 726–30.

5. Allinson RW, Palmer ML, Fante R, Stanko M. Vitreous lossduring phacoemulsification by residents. Ophthalmology 1992;99: 1181.