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Diagnosis and Treatment of CNV in Myopic Macular Degeneration

Diagnosis and Treatment of CNV in Myopic Macular Degeneration

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Diagnosis and Treatment of CNV in Myopic

by matthew e. raecker, md, dong-wouk park, md, and andreas k. lauer, md edited by sharon fekrat, md, and ingrid u. scott, md, mph

egenerative —also 1A 1B known as pathologic myopia—is defined as a of greater than –6.00 D with an axial Dlength of more than 26 mm. Although myopia is a common disorder, with a prevalence of between 11 and 36 per- cent in developed countries, degenera- tive myopia is relatively uncommon. The condition accounts for 27 to 33 percent of the myopic population and corresponds to rates of 1.7 to 2.1 per- 1C 1D cent in the overall population.1 It is re- ported to be the seventh leading cause of blindness in the United States and Europe1 and the leading cause of blind- ness in Japan.2 Because as many as 10 percent of eyes with degenerative myopia may develop choroidal (CNV), it is important for ophthal- mologists to recognize this condition and to understand that management of myopic CNV differs from that of CNV CLINICAL CLUES. This set of images is from a 55-year-old Asian woman with due to age-related macular degenera- pathologic myopia. (1A ,1B) Color fundus and red-free photos reveal lacquer tion (AMD). This will be particularly cracks (blue arrowheads). The displays tilting and temporal flattening, true as globalization continues, even there is a posterior staphyloma, and macular hemorrhage (thin white arrow) is though regional variations in preva- present near the lacquer cracks. (1C) Early image shows lence rates for pathologic myopia are choroidal fluorescence blocked by hemorrhage with faint hyperfluorescence likely to continue. (white arrow). (1D) In the later angiographic image, increased central hyperfluo- rescence with leakage is observed, consistent with CNV. Also note overall greater Clinical Features transmission of scleral staining due to thinning of and . The characteristic clinical appearance of the posterior pole in the myopic with readily visible choroidal vessels Pathologic studies indicate that a pos- fundus is caused by stretching of the and . terior staphyloma is present in as many ocular layers as axial length increases. Variable findings. Fundus mani- as 35 percent of eyes, although this Classically, attenuation and absence of festations vary by patient; for instance, is frequently underestimated during the retinal pigment epithelium (RPE) the disc displays tilting and temporal clinical examinations.3 Histopatho-

casey eye institute eye casey correspond to a peripapillary crescent flattening in 37.7 percent of these eyes. logic studies demonstrate that retinal

eyenet 35 Ophthalmic Pearls degeneration is present in 11.4 percent 2A it difficult to discern CNV leakage in of highly myopic eyes; over time, areas the late angiographic images. of atrophy can coalesce and result in Nonneovascular angiographic fea- (GA). tures in the prearterial phase of the Lacquer cracks representing rup- myopic fundus include more visible tures in Bruch’s membrane occur in detail of choroidal vessels due to thin- 4.2 percent of eyes with an axial length ning of the overlying RPE. During 2B of greater than 26.5 mm and are most FA, an overall decrease in is commonly found within staphyloma- seen as a result of increased reflection tous areas of the posterior pole (Figs. from the underlying sclera, as well as 1A, 1B). Macular or foveal retinos- a transmission defect in the early and chisis may also be present in highly mid phases and staining of sclera in myopic eyes, particularly in staphylo- the late phases. Areas of retinal atro- matous areas.1 RESPONSE. (2A) SD-OCT images of phy may appear as well-defined patch- the same patient demonstrate foveal es of transmission defect with clearly CNV and Risk of Progression and CNV (white arrow). discernible choroidal vessels. Staining CNV. Choroidal neovascularization (2B) After a single treatment with of the sclera is readily noticeable in is frequently associated with lacquer intravitreal , the CNV these atrophic areas. FA can be help- cracks or areas of RPE atrophy. CNV regressed in the course of a month. ful in detecting lacquer cracks, which has been reported to affect up to 10 to As of the most recent follow-up (two appear as hyperfluorescent streaks of 15 percent of eyes with an axial length years after the ), she has not transmission defect in the early and greater than 26.5 mm and is a major developed new or recurrent CNV. transit phases.1 cause of vision loss among patients OCT. Spectral-domain optical with myopic degeneration. during an average follow-up of 11.8 coherence tomography (SD-OCT) is Although patients may be asymp- years.2 an essential tool in the evaluation of tomatic if CNV is located outside the In another study, 27 eyes with myo- myopic CNV, which may appear as central macula, symptoms of new- pic CNV were followed for at least 10 a hyperreflective lesion with fuzzy onset , scotomata, years. At the initial visit, 19 of the eyes borders at the RPE, central ellipsoid, and/or decreased vision are typical had vision better than 20/200. This and external limiting membrane (Fig. when CNV occurs centrally. Often, decreased significantly, with 24 of the 2A). Unless subretinal hemorrhage is CNV is self-limited and becomes con- eyes having vision worse than 20/200 present, the remainder of the overlying fined by migration of RPE cells. The at the five-year mark, and 26 of the retina may be only minimally elevated resultant hyperpigmented spot, visual- eyes having vision worse than 20/200 or thickened. Intraretinal fluid, sub- ized on examination, has been termed at the 10-year mark. The cause of vi- retinal fluid, or an RPE detachment Fuchs’ spot.1 sion loss was attributed to progressive may be present, but often these find- The clinical course of CNV as- chorioretinal atrophy surrounding ings are minimal or absent.5 sociated with degenerative myopia is previous sites of CNV.4 different from that of CNV associated Management with AMD. This difference is impor- Diagnosis Treatment of degenerative myopia has tant for the clinician to keep in mind FA. (FA) may shifted significantly over the last two when evaluating, treating, and coun- be useful in detecting myopic CNV decades. seling patients with myopic macular (Figs. 1C, 1D). Hyperfluorescence, Laser. Although laser photocoagu- degeneration. often with a hypofluorescent rim of lation has been used for the treatment Progression. The natural progres- pigmentation, is seen in early images. of CNV related to myopic macular sion of degenerative myopia has been In late angiographic images, leakage degeneration, it has fallen from favor documented in several studies. For may be subtle and is characterized by in the last 15 years. Initially, while sig- instance, in a study that followed 806 blurring of the pigmented rim. nificant benefit was seen two years af- eyes with axial lengths greater than Although myopic CNV typically ter treatment, the benefit was lost after 26.5 mm or refractive error greater does not leak to the same degree as five years; and high rates of recurrent than –8.00 D for an average of 12.7 CNV in AMD, leakage may be more CNV were noted in treatment groups.6 years, the researchers observed pro- pronounced in elderly myopic patients. In many cases, recurrent CNV arose at gression of myopic fundus changes in Often, a rim of subretinal hemorrhage the margins of previous areas of pho- 40.6 percent of eyes. accompanies the development of myo- tocoagulation, suggesting that photo­ Moreover, 82 of 91 eyes (90.1 per- pic CNV. In such cases, the hyperfluo- thermal disruption of the RPE and cent) that presented with CNV dem- rescence due to leakage by CNV may Bruch’s membrane may stimulate the onstrated progressive macular atrophy be blocked by the hemorrhage, making development of CNV in some patients.

36 april 2015 Ophthalmic Pearls

In addition, new lacquer cracks have aware of intravitreal anti-VEGF ther- been reported after photocoagulation, apy for neovascular AMD, they may and this may predispose patients to fear a long course of numerous injec- Write for us! recurrent CNV. tions. However, current data indicate Finally, expansion of the chorio- that treatment of myopic CNV may retinal photocoagulation scar has been differ from that of AMD in that fewer noted in nearly all highly myopic eyes intravitreal injections appear to be that undergo photocoagulation. Laser needed (see “Frequency of Intravitreal Got Pearls? scar expansion may develop quickly Injections” at www.eyenet.org). Share your knowledge with your and be strikingly broad, and it may Follow-up. Ongoing monitoring by colleagues! Ophthalmic Pearls expand to involve the fovea and cause an ophthalmologist continues to be an articles provide a literature re- significant vision loss. important aspect of management, as view and offer helpful tips on PDT. Because of the complications recurrent CNV and chorioretinal atro- disease management or proce- associated with laser photocoagula- phy may develop. n dures in widespread use. tion, (PDT) emerged as a treatment for myopic 1 Ryan SJ et al. Retina. 5th edition. Philadel- Are you a resident? CNV. The utility of PDT was sup- phia: Elsevier; 2012:1115-1133. Authorship of an Ophthalmic ported by the in Photo- 2 Hayashi K et al. . 2010; Pearls will satisfy the RRC dynamic Therapy (VIP) study, which 117(8):1595-1611. requirements for resident evaluated patients with subfoveal CNV 3 Grossniklaus HE, Green WR. Retina. scholarly activity. due to pathologic myopia. The primary 1992;12(2):127-133. outcome of the study was the propor- 4 Yoshida T et al. Ophthalmology. 2003; tion of eyes that lost fewer than 8 let- 110(7):1297-1305. 1 5 Introini U et al. Eye (Lond). 2012;26(7): ters of during two years 2 of treatment. In this study, 64 percent 976-982. of treated eyes lost fewer than 8 letters, 6 Soubrane G et al. Bull Soc Ophtalmol Fr. 3 compared with 49 percent of eyes in 1986;86(3):269-272. the placebo group.7 7 Blinder KJ et al. Ophthalmology. 2003; With regard to longer-term results, 110(4):667-673. 4 a retrospective study of 43 eyes that 8 Giansanti F et al. Retina. 2012;32(8):1547- had been treated with PDT found that 1552. visual acuity was stable during the first 9 Oishi A et al. Graefes Arch Clin Exp Oph- 5 year but tended to worsen during the thalmol. 2013;251(1):1-7. second year and thereafter, reaching a loss of nearly 3 lines at seven years. Dr. Raecker is a fellow in ophthalmology at How to write an opHtHalmic Macular chorioretinal atrophy devel- the Department of Ophthalmology and Visual pearls article oped in 83 percent of the patients at Sciences at the University of Iowa, Iowa City. 1. Come up with a topic, and e- the five-year mark.8 Dr. Park is a resident in ophthalmology, and mail Peggy Denny (pdenny@aao. Anti-VEGF agents. Over the last Dr. Lauer is professor of ophthalmology, vice- org) to clear it before writing. decade, intravitreal anti-VEGF therapy chair for education, residency program direc- 2. Medical students, residents, has emerged as a promising treatment tor, and chief of the Vitreoretinal Division; and fellows: Team up with a modality for myopic CNV. Typical both are at the Casey Eye Institute at Oregon faculty member who can provide response includes resolution of retinal Health & Science University, in Portland, pearls from experience. fluid and regression of the subretinal Ore. Financial disclosure: The authors report 3. Send at least one photo or fuzzy lesion as visualized on SD-OCT4 no related financial interests. This article was illustration. (Fig. 2B). supported by unrestricted departmental fund- 4. Use subheadings to help Short-term results with anti-VEGF ing from Research to Prevent Blindness in New readers easily navigate your therapy are encouraging. However, as York and the Ophthalmology Resident Educa- 1,500-word article. this treatment modality is relatively tion Fund at Casey Eye Institute. The funding 5. Keep references to five or new, long-term results regarding its organizations had no role in the design or con- fewer, if possible. effectiveness and its effects on visual duct of this article. acuity are needed.9 Moreover, the clini- cian should be aware that this repre- MORE ONLINE. For a discussion EXTRA SubmiSSionS sents an off-label use of these medica- of intravitreal injections of anti- E-mail your manuscript and art tions. VEGF agents, see the Web Extra that accom- to [email protected]. If patients with myopic CNV are panies this article at www.eyenet.org.

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