Incidence of CME
Cataract surgery is one of the most common causes of CME. There is a lack of uniform definition of and diagnostic criteria for pseudophakic CME; its reported incidence ranges from approximately 1% to over 30% following extracapsular cataract extraction. The incidence of clinically relevant pseudophakic CME, which is usually defined as reduced vision in the presence of petaloid CME on fluorescein angiography, is 1%–2% in the absence of additional risk factors. Thus, most cases of pseudophakic CME are mild and asymptomatic; in other words, OCT or fluorescein angiography demonstrates CME, but the patient’s visual acuity is unaffected. The peak incidence occurs 6–10 weeks postoperatively, with spontaneous resolution occurring clinically in approximately 95% of uncomplicated cases, usually within 6 months. More severe CME may result in permanent vision loss. Many factors affect the incidence of CME. The presence of predisposing disease, as mentioned in the section Etiologies of CME, is an important factor. Factors affecting the incidence and severity of CME after intraocular surgery, particularly cataract surgery, include the degree of postoperative inflammation and the presence or absence of surgical complications such as vitreous loss or iris prolapse. For further discussion of CME, see BCSC Section 11, Lens and Cataract.
Figure 7-7 Pseudophakic cystoid macular edema (CME). A, Color fundus photograph of an optic nerve head and macula 3 months after complex cataract surgery. A small incidental grayish-yellow adult vitelliform dystrophy lesion is present in the subfoveal region (circled). B, A midphase fluorescein angiography image demonstrates cystic hyperfluorescence, with a classic petaloid pattern. As is typical in eyes with pseudophakic CME, there is mild hyperfluorescence of the nasal portion of the optic nerve head. C, OCT shows cystic retinal thickening and a subfoveal vitelliform lesion. D, Following 8 weeks of topical steroidal and nonsteroidal anti-inflammatory therapy, OCT shows that the CME has fully resolved.
(Courtesy of Brian Leonard, MD.)
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.