1. Effects of the “Pop & Prechop” Supracapsular Phacoemulsification Technique on Endothelial Cell Counts and Corneal Clarity
Brandon Rodriguez, MD
Michael Klufas, MD
Christopher E. Starr, MD, FACS
Department of Ophthalmology
Weill Cornell Medical College
New York-Presbyterian Hospital
New York, NY 10021
The authors have no financial interests in any of the topics/products mentioned

2. Purpose
To determine the effects of a novel supracapsular phacoemulsification technique, “Pop & Prechop,” on corneal endothelial cell counts (ECC) and corneal clarity

3. Methods
Prospective data was collected on 24 patients at Weill Cornell Medical College
Each patient underwent phacoemulsification with the “Pop & Prechop” technique
Preoperative and 1 month postoperative confocal microscopy measurements were taken
Corneal clarity was measured preoperatively, day 1, week 1 and month 1 postoperatively
0 = no edema
0.5 = trace edema
1-4 = grading of Descemet’s fold

4. Surgical Technique
Soft-shell anterior chamber fill for endothelial protection
After creating a 5.0 to 5.75 mm capsulorhexis, hydrodissection is performed tangentially via the main wound. Pushing gently down on the peripheral nucleus with the cannula enables the lens to tilt or prolapse (‘Pop’) out of the capsular bag
Viscoelastic is then injected behind the nucleus to protect the posterior capsule and keep the prolapsed nucleus upright

5. Surgical technique
A cyclodialysis spatula is then introduced through one paracentesis and is placed behind the lens
A chopper is introduced through the opposite paracentesis or the main wound and placed in front of the lens

6. Surgical Technique
Via a scissoring maneuver at the iris plane, the nucleus is easily cracked into two halves (“Prechop”)
Further chopping into quadrants and smaller pieces is also possible
Care is taken to minimize zonular stress and corneal endothelial trauma

7. Surgical Technique
Once adequately prechopped, supracapsular phacoemulsification is carried out at the iris plane or in the anterior chamber, away from the posterior capsule
Since the nucleus has been divided mechanically, less ultrasound energy is needed for disassembly and emulsification

8. Results N=24, all surgeries performed by trainees (fellow/resident)
Mean preoperative ECC = 2473 cells/mm2
Mean postoperative ECC at 1 month = 2354 cells/mm2
Mean reduction of 4.8%
Previous published literature of “in-the-bag” techniques (divide & conquer etc.)
Mean reduction of 4 to 8% at 1 month

9. Results
No statistically significant difference with ECC loss and axial length (AL)
AL <23 mm = loss of 150 cells/mm2
AL >23 mm = loss of 104 cells/mm2
p value = 0.356
Mean corneal clarity scores:
Day 1 = 1.02
Week 1 = 0.15
Month 1 = 0.0
100% of corneas were clear by 1 month
There were no intra-operative or postoperative complications
Post-op day #1, 20/20 vision & clear cornea

10. Conclusion
“Pop & Prechop,” a novel modification of supracapsular phacoemulsification, is a safe alternative to in-the-bag techniques such as “Divide & Conquer”
Compared to published data, endothelial cell loss is comparable among the different techniques, even when performed by trainee surgeons
Longer term follow-up is needed to fully evaluate the impact on the cornea

11. References
RRA Bourne, DC Minassian, et al. Effect of Cataract Surgery on the Corneal Endothelium. Ophthalmology. 2004; 111:
WM Bourne , LR Nelson, et al. Continued endothelial cell loss ten years after lens implantation. Ophthalmology. 1994; 101:
TJ Liesegang, WM Bourne, et al. Short and long-term endothelial cell loss associated with cataract extraction and intraocular lens implantation. Am J Ophthalmol. 1984; 97: 32-9.
B Lundberg, M Jonsson, et al. Postoperative Corneal Swelling Correlates Strongly to Corneal Endothelial Cell Loss After Phacoemulsification Cataract Surgery. Am J Ophthalmol. 2005; 139:
T Walkow, N Anders, et al. Endothelial cell loss after phacoemulsification: relation to preoperative and intraoperative parameters. J Cat Refract Surg. 2000; 26:
TP Werblin. Long-term endothelial cell loss following phacoemulsification: model for evaluating endothelial damage after intraocular surgery. Refract Corneal Surg. 1993; 9: