Outcomes of resident-performed phacoemulsification cataract extraction complicated by vitreous loss

1. Outcomes of resident-performed phacoemulsification cataract extraction complicated by vitreous loss Gowri Pachigolla, M.D., Steven Verity, M.D., Preston H. Blomquist, M.D. April 2008 The University of Texas Southwestern Medical Center at Dallas, TX

2. Introduction • Over 2.5 million cataract extractions are performed per year in the US • 97% of cataract extraction are performed using phacoemulsification techniques • Accidental vitreous loss has been associated with CME, glaucoma, retinal detachment, endophthalmitis, vitreous hemorrhage, IOL dislocation, corneal endothelial decompensation and retinal vascular occlusions • Nevertheless most patients (67-97%), even in training centers, achieve at least BCVA 20/40 Leaming DV. Practice styles and preferences of ASCRS members--2003 survey. J Cataract Refract Surg 2004; 30:892-900

3. Introduction • Most comparative studies in the past have found that outcomes after posterior capsular rupture or vitreous loss are significantly worse than after uncomplicated cases • However, one study by Nishi demonstrated equivalent outcomes in several measures including VA, incidence of post-operative complications and endothelial cell loss • More recently with phacoemulsification becoming the predominant technique for CE, a few studies have shown that in cases of vitreous loss, ECCE fare worse Nishi O. Vitreous loss in posterior chamber lens implantation. J Cataract Refract Surg 1987; 13:424-7. Chan FM, et al. Short-term outcomes in eyes with posterior capsule rupture during cataract surgery. J Cataract Refract Surg 2003; 29:537-41. Blomquist PH, et al. Visual outcomes after vitreous loss during cataract surgery performed by residents. J Cataract Refract Surg 2002; 28:847-52. Ah-Fat FG, et al. Vitreous loss during conversion from conventional extracapsular cataract extraction to phacoemulsification. J Cataract Refract Surg 1998; 24: 801–805.

4. Purpose & Methods • To compare clinical outcomes after resident-performed phacoemulsification complicated by vitreous loss and uncomplicated control cases • Retrospective comparative study of all consecutive patients undergoing planned phacoemulsification from April 2005 to March 2006 at Parkland Memorial Hospital • Exclusions: <4 weeks of followup, combined procedures, planned ECCE, h/o ruptured globe, dislocated native lens

5. Results • 525 consecutive patients were identified • 127 excluded • inadequate follow-up (67) • combined surgical procedure (29) • unavailable operative report (13) • primary ECCE (5) • cases performed by fellows (4) • unavailable medical charts (3) • history of ruptured globe (2) • dislocated native lens (1) • 4 aborted cases. 1 rescheduled within study time and included in the data analysis. • A total of 398 patients were included in the study

6. Results • 3 groups: • Controls (366 eyes) No vitreous loss 2. Vitreous loss group (23 eyes) Completion of CE with phacoemulsification 3. Conversion group (9 eyes) Conversion to ECCE/ICCE regardless of vitreous loss

7. Demographics Mean follow up time was less for the Vitreous loss group. Unplanned operative incidents Numbers in parenthesis are percentages

8. Operative procedures and IOL Types Most eyes in the Control group had IOLs placed within the bag, while Sulcus and ACIOLs were more commonly placed in the Vitreous Loss and Conversion groups respectively.

9. Preoperative lenticular characteristics Having at lease one preoperative lenticular pathology was more common in the Conversion group than in the Control group. Numbers in parenthesis are percentages * P = 0.006, versus Control group (z-test)

10. Late complications Both the Vitreous Loss and Conversion groups were more often complicated by at least one late adverse event, while CME occurred more frequently in the Conversion group only. Only one of the endophthalmitis cases was culture-positive. Numbers in parenthesis are percentages * P < 0.001, versus Control group (z-test) + P = 0.002 for Vitreous loss and Conversion groups versus Controls (z-test)

11. Visual outcomes Mean logMAR BCVA (Snellen equivalent) Postop BCVA was not significantly worse in the Vitreous Loss group compared to Controls, with both groups having approximately 20/30 vision. Alternately, postop BCVA in the Conversion group was significantly worse than in Controls with a VA of about 20/70 in the Conversion group. * P < 0.05, versus Control group (ANOVA on ranks) + P >= 0.05, versus Control group (ANOVA on ranks) ~ P < 0.05, versus Control group (ANOVA on ranks) Percentage of eyes with postoperative BCVA 20/40 or better * P = < 0.001, versus Control group (z-test) Postoperative BCVA excludes 57 patients in the Control group and 2 in the Vitreous loss group with preexisting ocular disease accounting for BCVA < 20/40

12. Conclusion • In the past, comparative studies evaluating clinical outcomes after CE complicated by vitreous loss have included ECCE. Given the more complicated postop course and variable VA outcomes after complicated and uncomplicated ECCE, the current study chose to separate these patients. • The study is limited by its small sample size and limited follow up time; however, it does conclude that although, vitreous loss after resident-performed phacoemulsification more often results in late complications, visual outcome is not significantly worse as long as complications do not result in conversion to EC/ICCE. • Careful surgical planning and anticipation of conversion to ECCE may improve outcomes.