This article is more than 5 years old. Information may no longer be current.

Changing paradigms: Evolving therapeutic management in the refractive cataract era

Add topic to email alerts

Receive an email when new articles are posted on

Please provide your email address to receive an email when new articles are posted on .

Subscribe

Added to email alerts

You've successfully added to your alerts. You will receive an email when new content is published.

Click Here to Manage Email Alerts

You've successfully added to your alerts. You will receive an email when new content is published.

Click Here to Manage Email Alerts

Back to Healio

We were unable to process your request. Please try again later. If you continue to have this issue please contact customerservice@slackinc.com.

Back to Healio

The presbyopic IOL market is the largest growing patient population in general ophthalmology. There are more than 90 million baby boomers in the United States. By 2011, a quarter of the population will be older than 40, and 50,000 people will turn 50 every day until 2015.¹ These statistics are true in Western and Eastern Europe, as well.

The old paradigm of successful cataract surgery has changed. In the past, successful cataract surgery meant the patient would still have to wear glasses for intermediate and near vision. The new paradigm of successful cataract surgery is 20/20 uncorrected distance vision, near and intermediate vision with a multifocal lens implant and greatly reduced or eliminated dependence on glasses.

The paradigm shift is driven by technology. The ophthalmologists’ armamentarium includes a refractive multifocal acrylic IOL that features balance view optics; an apodized diffractive IOL, with a single-piece and three-piece acrylic design; and an accommodating IOL. Ophthalmologists need to complement these refractive IOL technologies with evolutions in therapeutic use.

Endophthalmitis

The incidence of endophthalmitis following cataract surgery is increasing. Looking at Medicare data from 1994 to 2001, the incidence of endophthalmitis following cataract surgery was 0.25%.² It was previously estimated much lower, at 0.07% to 0.2%. Various theories exist as to the cause of this increase, such as evolving antibiotic resistance, trends toward self-sealing clear corneal incisions and increased instances of wound leaks due to clear corneal incisions. Risk factors for postsurgical endophthalmitis include incision leak, surgical complications and not starting an antibiotic the day of surgery (Figure 1).³

A widespread resistance to older antibiotics and fourth-generation fluoroquinolones has been demonstrated. In a paper presented at the 2006 annual meeting of the Association for Research in Vision and Ophthalmology, methicillin-resistant Staphylococcus aureus endophthalmitis isolates exhibited statistically significant reduced sensitivities to older-generation fluoroquinolones ocufloxacin and ciprofloxacin and the fourth-generation fluoroquinolones moxifloxacin and gatifloxacin.⁴ Additional studies indicate widespread resistance to older antibiotics as well.⁵

The mode of postsurgical endophthalmic inoculation has also been studied.^6,7 Particles travel from the corneal surface into all incisions, and are visible for up to three-quarters of the wound length; however, IOP variation causes incisions to gape after clear corneal incisions, resulting in a surface fluid influx that penetrates the anterior chamber and can result in postsurgical endophthalmitis infection.^6,7

Ophthalmologists will need to take a multifactorial approach to preventing endophthalmitis. To treat lid disease, it is necessary to sterilize the eye and manage the wound properly. In practice, ophthalmologists should focus on sterilizing the surface and killing organisms before they enter the eye. A study conducted by Speaker and Menikoff showed that the organisms causing endophthalmitis are from the patients’ own flora and that sterilizing the surface using povidone-iodine was one of the most effective techniques of preventing endophthalmitis (Figure 2).⁸

Additionally, ophthalmologists should prevent the introduction of isolates postoperatively as well by taking steps to avoid wound leakage and by continuing antibiotic therapy with topical dosing until the wound is healed. A study conducted by Moshirfar reviewed 20,000 cataract cases from the University of Utah.⁹ All of the cases were managed postoperatively with fourth-generation fluoroquinolones, both moxifloxacin and gatifloxacin. Of the 20,000 patients, 14 developed endophthalmitis at a rate of 0.07%. An interesting aspect of the study was that the average time to presentation was 9.3 days. Six of the 14 cases of endophthalmitis occurred after the antibiotic was stopped. Many ophthalmologists use antibiotics for 1 week, but this study supports the idea of using antibiotics for as long as 2 weeks postoperatively.⁹

CME

Ophthalmologists no longer view CME as a large cystic macula and instead see small macular changes as CME. —Y. Ralph Chu, MD

Although studies suggest the amount of cystoid macular edema (CME) has increased, it is possible that the rate has not increased but that technology is better and helps ophthalmologists detect subtler levels of CME. Studies show that angiographic and subclinical CME rates are 9% to 19%, not the previously reported 1% to 2%.^10-12

A recent study by Lobo examined retinal leakage in low-risk patients at 3, 6, 12 and 30 weeks.¹³ At 3 weeks, optical coherence tomography found 98% of patients presented with vessel leakage. As time progressed, the rate of vessel leakage did not drop as quickly as some ophthalmologists might expect. At 6 weeks, 41% of patients had increased retinal thickness, even with good Snellen acuity. The study showed that, with low-risk patients, ophthalmologists may be missing some of the subtle findings in terms of quality of vision.

Ophthalmologists no longer view CME as a large cystic macula and instead see small macular changes as CME. Improved diagnostic techniques have also allowed ophthalmologists the opportunity to note smaller macular changes (Figure 3).

A study by Wittpenn compared ketorolac vs. ketorolac plus a corticosteroid.¹⁴ The results of the study showed ketorolac with a corticosteroid reduced the incidence of CME and macular thickening, and that there was a correlation between macular thickening and visual outcomes (Figure 4).¹⁴

Retinal thickening can have an impact on visual outcomes, with 10 µm of thickening showing a significant break in terms of quality of vision. Patients could have 20/20 vision but be unhappy due to retinal thickening. If the patient was implanted with an IOL, contrast sensitivity is further lost with retinal thickening. Using combination therapy — a nonsteroidal anti-inflammatory drug with a steroid — will maximize patient outcomes.

Conclusion

Advances in technology have made this an exciting time for cataract surgery. Therapeutic decisions have to evolve along with surgical technology to work synergistically to improve quality of vision and patient outcomes. Improvements in IOL technology including presbyopia correction as well as advances in phacoemulsification with torsional, elliptical or microincisional technology continue to increase patient and surgeon expectations.

References

1. The age explosion: Baby boomers and beyond. Harvard Generations Policy Journal. Winter 2004.
2. West ES, Behrens A, McDonnell PJ, et al. The incidence of endophthalmitis after cataract surgery among the U.S. Medicare population increased between 1994 and 2001. Ophthalmology. 2005;112:1388-1394.
3. Wallin T, Parker J, Jin Y, et al. Cohort study of 27 cases of endophthalmitis at a single institution. J Cataract Refract Surg. 2005;31:735-741.
4. Major JC Jr., Flynn HW Jr., Miller D, et al. Antibiotic sensitivities and visual acuity outcomes in endophthalmitis caused by methicillin-sensitive (MSSA) versus methicillin-resistant (MRSA ) Staphylococcus aureus. Poster 5282/B697. Presented at: Annual Meeting of the Association for Research in Vision and Ophthalmology; May 4, 2006; Fort Lauderdale, Fla.
5. Miño de Kaspar H, Koss MJ, He L, et al. Antibiotic susceptibility of preoperative normal conjunctival bacteria. Am J Ophthalmol. 2005;139:730-733.
6. McDonnell PJ, Taban M, Sarayba M, et al. Dynamic morphology of clear corneal cataract incisions. Ophthalmology. 2003;110:2342-2348.
7. Taban M, Rao B, Reznik J, et al. Dynamic morphology of sutureless cataract wounds — effect of incision angle and location. Surv Ophthalmol. 2004;49(Suppl):S62-72.
8. Speaker MG, Menikoff JA. Prophylaxis of endophthalmitis with topical povidone-iodine. Ophthalmology. 1991;98:1769-1775.
9. Moshirfar M, Feiz V, Vitale AT, et al. Endophthalmitis after uncomplicated cataract surgery with the use of fourth-generation fluoroquinolones: A retrospective observational case series. Ophthalmology. 2006;31:2624-2629.
10. Ray S, D’Amico DJ. Pseudophakic cystoid macular edema. Semin Ophthalmol. 2002;17:167-180.
11. Ursell PG, Spalton DJ, Whitcup SM, Nussenblatt RB. Cystoid macular edema after phacoemulsification: Relationship to blood-aqueous barrier damage and visual acuity. J Cataract Refract Surg. 1999;25:1492-1497.
12. Mentes J, Erakgun T, Afrashi F, Kerci G. Incidence of cystoid macular edema after uncomplicated phacoemulsification. Ophthalmologica. 2003;217:408-412.
13. Lobo CL, Faria PM, Soares MA, et al. Macular alterations after small-incision cataract surgery. J Cataract Refract Surg. 2004;30:752-760.
14. Wittpenn JR, Silverstein S, Heier J, et al. A randomized, masked comparison of topical ketorolac 0.4% plus steroid vs. steroid alone in low-risk cataract surgery patients. Am J Ophthalmol. In press.