Second instrument use during Phacoemulsification – does it really protect the posterior capsule?

1. Second instrument use during Phacoemulsification – does it really protect the posterior capsule? James Tee Ameet Shah Brian Little Royal Free Hospital, London, United Kingdom Authors have no financial interest

2. Does a second instrument protect from posterior capsule aspiration? • Common practice to place a second instrument between posterior capsule and nuclear fragment during phacoemulsification • Intuitively provides added protection against capsular aspiration by the phaco tip • In our experience the posterior capsule can easily wrap around a second instrument and still be aspirated by the phaco tip

3. Leakage from second instrument use Leakage occurring as a result of incision gape

4. Incisional Leakage in Coaxial Phacoemulsification • Significant fluid loss occurs with routine second instrument use compared with no second instrument (176 ml vs 75 ml) ✪ • Leakage destabilises chamber • Risk of posterior capsule aspiration increases with capsular fluctuation • Logically this risk is reduced if segment removal is performed without a second instrument • Liyanage S, Wong C, Angunawela R, Little BC. Incisional leakage causing chamber instability • in coaxial phacoemulsification. J Cataract Refract Surg (accepted Jan 2009 JCRS-08-634R1)

5. Purpose of Study • But is the second instrument being used optimally whilst it is routinely placed in the eye during segment removal? • We undertook an observational analysis of the actual use of the second instrument during segment removal phase of phacoemulsification

6. Methods • 54 consecutive video recordings of cases performed by 5 surgeons were randomly allocated to 2 residents for analysis • The 5 surgeons were unaware of study purpose, each used own technique which involved intraocular second instrument use during the entire duration of segment removal phase • Sub-sample of cases reviewed by senior author to check for inter-observer variability

7. Parameters measured • Total time (taken from commencement of segment removal until aspiration of last nuclear segment) • Second instrument idle time (when held stationary or performing non-purposeful movements which did not involve touching nuclear fragments) • Statistical analysis performed using MedCalc Software Version 9.6.4.0 for subgroup analysis

8. Results Statistically significant idle time difference between consultants and residents. Two tail probability value as calculated with Mann-Whitney test, p =0.0008

9. Idle time (no subgroup analysis) Count Idle time [%]

10. Idle time (subgroup analysis) Count Idle time [%]

11. Conclusion • Second instrument used sparingly to re-crack and reposition nuclear segments • Hence cracking quadrants completely prior to segment removal can greatly reduce need for second instrument during this time • The second instrument can be inserted and removed when necessary instead of being left lying idle in the eye

12. Conclusion • We suggest that phaco is safer performed without the routine intraocular presence of a second instrument during segment removal, i.e. remove it when not using it • Sideport leakage is significantly reduced • Chamber stability is enhanced • Posterior capsule fluctuation less likely hence the chances of posterior capsule aspiration by the phaco tip is reduced