Prevention of cystoid macular edema after cataract surgery in diabetic patients : Journal of Cataract & Refractive Surgery

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From the editor

Prevention of cystoid macular edema after cataract surgery in diabetic patients

Kohnen, Thomas MD, PhD, FEBO

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Journal of Cataract & Refractive Surgery 44(7):p 795-796, July 2018. | DOI: 10.1016/j.jcrs.2018.06.021
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“A wise man proportions his belief to the evidence.”

—David Hume, Section X, An Enquiry Concerning Human Understanding

Last November, the associate editor of the JCRS, Sathish Srinivasan, wrote an editorial on cataract surgery in patients with diabetes, highlighting the lack of well-designed randomized clinical trials to evaluate the various treatment strategies.1 In the editorial, he brought the recent results of the ESCRS-sponsored PREvention of Macular EDema after cataract surgery (PREMED) study to our readers’ attention. As the study is now finished and part 2 published in this issue of JCRS (page 836), I would like to draw your attention to, in my opinion, this important landmark article in cataract surgery. The PREMED study was conceived in 2012 in 12 sites across Europe to provide the foundations on which to create evidence-based clinical guidelines to prevent cystoid macular edema (CME) after cataract surgery in diabetic and nondiabetic patients.2 As you know, cataract is the leading cause of treatable and preventable blindness,2 and while modern cataract surgery has come a long way in being able to effectively treat cataracts, CME continues to be one of the most prevalent complications leading to poor postoperative visual acuity after uneventful surgery, especially in the diabetic population where incidence rates are higher.3

Cystoid macular edema, also known as the Irvine-Gass syndrome, remains an important cause of suboptimum visual acuity after cataract surgery.4,5 Cystoid macular edema is characterized by the accumulation of fluid in the macula (central retina) due to leakage from capillaries. While the cause of CME after cataract surgery has not been conclusively determined, surgical trauma with an inflammation response, removal of the crystalline lens, the breakdown of the blood–retina barrier, and anterior–posterior and tangential forces of the posterior vitreous membrane are likely causes. In particular, inflammation, considered a possible cause of acute CME defined as edema of fewer than 4 months duration, often gets better spontaneously.6 The higher incidence level of this postoperative complication in patients with diabetes makes it a particular issue for this group given the increasing rates of diabetes worldwide coupled with their higher and earlier incidence rates of cataract formation.1,7

The treatment protocol adopted to manage CME is an area that has attracted much controversy with a lack of clear evidence on which to base a clinical decision.3 The intraoperative and postoperative medication protocols are not clearly defined. Topical steroids as well as intravitreal antivascular endothelial growth factor and steroids have been tried. However, recently there was a shift in understanding, particularly within the European community, toward the use of topical nonsteroidal antiinflammatory drugs (NSAIDs) based on the evidence published by the Cochrane Collaboration6,8 and European-based research, although none provided a definitive answer.9,10 In general, many recommended the use of a topical NSAID before and after surgery with the caveat that the literature did not allow an exact regimen to be determined.11

This lack of clarity led to ESCRS identifying the need to create the basis for evidence-based guidelines for the treatment of CME after cataract surgery, which in turn led to the PREMED study. Headed by Rudy Nuijts and Laura Wielders and funded by ESCRS, it is the first international multicenter randomized controlled clinical trial specifically designed to answer questions relating to the prevention of CME after cataract surgery. As head of one of the 12 clinical centers involved in the study, I am pleased to announce the publication of the second part of the PREMED study in this issue of JCRS (page 836). The research compares the efficacy of perioperative treatment strategies with the aim of reducing the risk of developing CME after uncomplicated cataract surgery in diabetic patients.

The 213 diabetic patients taking part in the study received standard phacoemulsification for cataract and placement of an intraocular lens. Intraoperative and postoperative antibiotics were administered following local protocols. The participants were randomly placed into 3 groups of receiving at the end of cataract surgery: a single subconjunctival injection of 40 mg triamcinolone acetonide, an intravitreal injection with 1.25 mg bevacizumab, or a combination of both. Follow-up occurred over 12 weeks postoperatively and the outcomes were clear.

Wielders et al. conclude that incidences of CME in patients with diabetes can be significantly reduced with the use of a single subconjunctival injection of 40 mg triamcinolone acetonide. However, they caution against a one-size-fits-all strategy, as the risk of developing increased intraocular pressure remains at a level that requires surgeons to carefully balance the risk of CME occurring against other postoperative complications in the treatment decision. Furthermore, they found that the intravitreal injection with 1.25 mg bevacizumab has no effect on postoperative macular thickness, macular volume, and visual acuity, which is an important finding for those who still use this pharmacological regime.

I believe the publication of this data is of considerable importance to the ophthalmic community. The outcomes of this and related studies will provide the much sought after data that will allow our community to develop evidence-based guidelines that will enable further reduction in the risk factor. This is particularly true for patients with diabetes where the incidence rate of CME as a postoperative complication is considerably higher and where, if current trends continue, we as surgeons will face the potential of on a regular basis.


1. Srinivasan S. Cataract surgery in patients with diabetes. [editorial] J Cataract Refract Surg. 43, 2017, p. 1369-1370, Available at: Accessed 13-6-2018
2. Wielders LHP, Schouten JSAG, Winkens B, van den Biggelaar FJHM, Veldhuizen CA, Findl O, Murta JCN, Goslings WRO, Tassignon M-J, Joosse MV, Henry YP, Rulo AHF, Güell JL, Amon M, Kohnen T, Nuijts RMMA., on behalf of the ESCRS PREMED Study Group. European multicenter trial of the prevention of cystoid macular edema after cataract surgery in nondiabetics: ESCRS PREMED study report 1. J Cataract Refract Surg. 2018;44:429-439.
3. Kim SJ, Schoenberger SD, Thorne JE, Ehlers JP, Yeh S, Bakri SJ. (2015). Topical nonsteroidal anti-inflammatory drugs and cataract surgery; a report by the American Academy of Ophthalmology (Ophthalmic Technology Assessment). Ophthalmology, 122, 2159-2168, Available at: Accessed 13-6-2018
4. Gass JDM, Norton EWD. Cystoid macular edema and papilledema following cataract extraction; a fluorescein funduscopic and angiographic study. Arch Ophthalmol. 1966;76:646-661.
5. Irvine SR. A newly defined vitreous syndrome following cataract surgery; interpreted according to recent concepts of the structure of the vitreous; the Seventh Francis I. Proctor Lecture. Am J Ophthalmol. 1953;36:599-619.
6. Sivaprasad S, Bunce C, Crosby-Nwaobi R. Non-steroidal anti-inflammatory agents for treating cystoid macular oedema following cataract surgery. Cochrane Database Syst Rev. 2, 2012, CD004239, Abstract available at: Accessed 13-6-2018
7. Lim LL, Morrison JL, Constantinou M, Rogers S, Sandhu SS, Wickremasinghe SS, Kawasaki R, Al-Qureshi S. (2016). Diabetic macular edema at the time of cataract surgery trial: A prospective, randomized clinical trial of intravitreous bevacizumab versus triamcinolone in patients with diabetic macular oedema at the time of cataract surgery – preliminary 6 month results. Clin Exp Ophthalmol, 44, 233-242, Available at: Accessed 13-6-2018
8. Lim BX, Lim CHL, Lim DK, Evans JR, Bunce C, Wormald R. Prophylactic non-steroidal anti-inflammatory drugs for the prevention of macular oedema after cataract surgery. Cochrane Database Syst Rev. 11, 2016, CD006683, Available at: Accessed 13-6-2018
9. Kessel L, Tendal B, Jφrgensen KJ, Erngaard D, Flesner P, Lundgaard Andresen J, Hjortdal J. (2014). Post-cataract prevention of inflammation and macula edema by steroid and nonsteroidal anti-inflammatory eye drops; a systematic review. Ophthalmology, 121, 1915-1924, Available at: Accessed 13-6-2018
10. Sheppard JD. (2016). Topical bromfenac for prevention and treatment of cystoid macular edema following cataract surgery: a review. Clin Ophthalmol, 10, 2099-2111, Available at: Accessed 13-6-2018
11. Royal College of Ophthalmologists. Cataract Surgery Guidelines. September 2010. 2010, Scientific Department, The Royal College of Ophthalmologists, London, UK, Available at: Accessed 13-6-2018
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