EC Ophthalmology

Purpose: We investigated the long-term effects of cataract surgery by the eight-chop technique on intraocular pressure (IOP) in cataract patients.

Methods: The patients were classified into three groups (Grade II, III, and IV) according to the lens hardness. The operative time, phaco time, aspiration time, cumulative dissipated energy, and volume of fluid used were measured intraoperatively. The best-corrected visual acuity and corneal endothelial cell density were measured. The IOP was monitored for 5 years. Based on the preoperative IOP, eyes were classified into two groups for analysis: IOP > 15 mmHg and < 15 mmHg.

Results: The operative time in grades II, III, and IV were 4.63 ± 0.88 min, 5.48 ± 1.52 min, and 7.77 ± 1.47 min, respectively. The rate of corneal endothelial cell density loss was 1.9 ± 8.3% at 19 weeks. Postoperatively, the IOPs at 1 year were 12.6 ± 2.4 mmHg, 13.2 ± 2.3 mmHg, and 11.7 ± 2.2 mmHg, and at 5 years were 13.1 ± 2.5 mmHg, 12.0 ± 2.0 mmHg, and 12.0 ± 0.6 mmHg, in Grades II, III, and IV, respectively. In patients with a preoperative IOP < 15 mmHg, the IOP remained significantly lower even after 5 years of surgery.

Conclusion: The eight-chop technique can lower the IOP and this effect persists for 5 years. This procedure is short and is associated with a minimal reduction in corneal endothelial cell density. Thus, this technique is very effective in lowering IOP in patients with cataracts.

 Keywords: Cataract Surgery; Phacoemulsification; Corneal Endothelial Cell; Intraocular Pressure; Eight-Chop Technique

1. Elgin U., et al. “Early postoperative effects of cataract surgery on anterior segment parameters in primary open-angle glaucoma and pseudoexfoliation glaucoma". Turkish Journal of Ophthalmology3 (2016): 95-98.
2. Majstruk L., et al. “Long term effect of phacoemulsification on intraocular pressure in patients with medically controlled primary open-angle glaucoma". BMC Ophthalmology1 (2019): 149.
3. Liu CJ., et al. “Determinants of long-term intraocular pressure after phacoemulsification in primary angle-closure glaucoma". Journal of Glaucoma9 (2011): 566-570.
4. Tian T., et al. “The effect of phacoemulsification plus goniosynechialysis in acute and chronic angle closure patients with extensive goniosynechiae". BMC Ophthalmology1 (2019): 65.
5. Damji KF., et al. “Intraocular pressure following phacoemulsification in patients with and without exfoliation syndrome: a 2 year prospective study". British Journal of Ophthalmology8 (2006): 1014-1018.
6. Wirbelauer C., et al. “Intraocular pressure in nonglaucomatous eyes with pseudoexfoliation syndrome after cataract surgery". Ophthalmic Surgery, Lasers and Imaging Retina6 (1998): 466-471.
7. Shingleton BJ., et al. “Long-term changes in intraocular pressure after clear corneal phacoemulsification: normal patients versus glaucoma suspect and glaucoma patients". Journal of Cataract and Refractive Surgery7 (1999): 885-890.
8. Irak-Dersu I., et al. “Intraocular pressure change after temporal clear corneal phacoemulsification in normal eyes". Acta Ophthalmologica1 (2010): 131-134.
9. Sato T. "Efficacy and safety of the eight-chop technique in phacoemulsification for cataract patients". Journal of Cataract and Refractive Surgery5 (2023): 479-484.
10. Sato T. "Effects of the eight-chop technique in phacoemulsification on intraocular pressure in patients with primary open-angle glaucoma and controls". EC Ophthalmology8 (2023): 1-11.
11. Akahoshi T. "Phaco prechop”. Phaco Chop and Advanced Phaco Techniques. Editions. Chang DF. Thorofare: SLACK Incorporated (2013): 55-76.
12. Emery JM. "Kelman phacoemulsification; patient selection”. Extracapsular Cataract Surgery. Editions. Emery JM and Mclyntyre DJ. St Louis: CV Mosby (1983): 95-100.
13. Miyata K., et al. “Efficacy and safety of the soft-shell technique in cases with a hard lens nucleus". Journal of Cataract and Refractive Surgery9 (2002): 1546-1550.
14. Poley BJ., et al. “Long-term effects of phacoemulsification with intraocular lens implantation in normotensive and ocular hypertensive eyes". Journal of Cataract and Refractive Surgery5 (2008): 735-742.
15. Sato M., et al. “Soft-shell technique using Viscoat and Healon 5: a prospective, randomized comparison between a dispersive-viscoadaptive and a dispersive-cohesive soft-shell technique". Acta Ophthalmologica1 (2008): 65-70.
16. Igarashi T., et al. “Effects of hydrogen in prevention of corneal endothelial damage during phacoemulsification: a prospective randomized clinical trial”. American Journal of Ophthalmology (2019): 10-17.
17. Abdelmotaal H., et al. “Comparison of the phaco chop and drill-and-crack techniques for phacoemulsification of hard cataracts: A fellow eye study". Acta Ophthalmology3 (2021): e378-e386.
18. Helvacioglu F., et al. “Outcomes of torsional microcoaxial phacoemulsification performed by 12-degree and 22-degree bent tips". Journal of Cataract and Refractive Surgery8 (2013): 1219-1225.
19. Upadhyay S., et al. “Comparative evaluation of modified crater (endonucleation) chop and conventional crater chop techniques during phacoemulsification of hard nuclear cataracts: a randomized study". Indian Journal of Ophthalmology3 (2022): 794-798.
20. Park J., et al. “Comparison of phaco-chop, divide-and-conquer, and stop-and-chop phaco techniques in microincision coaxial cataract surgery". Journal of Cataract and Refractive Surgery10 (2013): 1463-1469.
21. Shingleton BJ., et al. “Three and five year changes in intraocular pressures after clear corneal phacoemulsification in open angle glaucoma patients, glaucoma suspects, and normal patients". Journal of Glaucoma6 (2006): 494-498.
22. Alvarado J., et al. “Trabecular meshwork cellularity in primary open-angle glaucoma and nonglaucomatous normals". Ophthalmology6 (1984): 564-579.
23. Grierson I and Howes RC. “Age-related depletion of the cell population in the human trabecular meshwork”. Eye (1987): 204-210.
24. Babizhayev MA and Brodskaya MW. "Fibronectin detection in drainage outflow system of human eyes in ageing and progression of open-angle glaucoma". Mechanisms of Ageing and Development2 (1989): 145-157.
25. Floyd BB., et al. “Fibronectin in human trabecular drainage channels". Investigative Ophthalmology and Visual Science6 (1985): 797-804.
26. Sato T and Roy S. "Effect of high glucose on fibronectin expression and cell proliferation in trabecular meshwork cells". Investigative Ophthalmology and Visual Science1 (2002): 170-175.
27. Lütjen-Drecoll E. "Structural factors influencing outflow facility and its changeability under drugs. A study in Macaca arctoides". Investigative Ophthalmology and Visual Science4 (1973): 280-294.
28. Ellingsen BA and Grant WM. "Trabeculotomy and sinusotomy in enucleated human eyes". Investigative Ophthalmology1 (1972): 21-28.
29. Murphy CG., et al. “Juxtacanalicular tissue in pigmentary and primary open angle glaucoma. The hydrodynamic role of pigment and other constituents". Archives of Ophthalmology12 (1992): 1779-1785.
30. Hamard P., et al. “Confocal microscopic examination of trabecular meshwork removed during ab externo trabeculectomy". British Journal of Ophthalmology9 (2002): 1046-1052.
31. Rohen JW., et al. “Ultrastructure of the trabecular meshwork in untreated cases of primary open-angle glaucoma (POAG)". Experimental Eye Research6 (1993): 683-692.
32. Rohen JW., et al. “The relation between the ciliary muscle and the trabecular meshwork and its importance for the effect of miotics on aqueous outflow resistance. A study in two contrasting monkey species, Macaca irus and Cercopithecus aethiops". Albrecht Von Graefe's Archive Klin Experimental Ophthalmology1 (1967): 23-47.
33. Jimenez-Roman J., et al. “Effect of phacoemulsification on intraocular pressure in patients with primary open angle glaucoma and pseudoexfoliation glaucoma". International Journal of Ophthalmology9 (2017): 1374-1378.
34. Salimi A., et al. “Matched cohort study of cataract surgery with and without trabecular microbypass stent implantation in primary angle-closure glaucoma”. American Journal of Ophthalmology (2021): 310-320.
35. Hayashi K., et al. “Effect of cataract surgery on intraocular pressure control in glaucoma patients". Journal of Cataract and Refractive Surgery11 (2001): 1779-1786.
36. Iancu R and Corbu C. "Intraocular pressure after phacoemulsification in patients with uncontrolled primary open angle glaucoma". JML Journal of Medicine and Life1 (2014): 11-16.
37. Falck A., et al. “A four-year prospective study on intraocular pressure in relation to phacoemulsification cataract surgery". Acta Ophthalmologica7 (2011): 614-616.