Laser Photocoagulation Of Extrafoveal Choroidal Neovascularization Research Articles

Long-term follow-up of choroidal neovascularization secondary to angioid streaks: case series and literature review

BackgroundThe purpose of this paper is to report the clinical course of choroidal neovascularization (CNV) secondary to angioid streaks and the outcomes in response to different treatment modalities.MethodsThis was a case series of two consecutive patients (four eyes) with CNV secondary to angioid streaks. Visual acuity, ophthalmological examination, color photographs, fluorescein angiography, and optical coherence tomography were used to assess the outcomes of treatment.ResultsTwo eyes were treated with photodynamic therapy for subfoveal choroidal neovascular membrane, one eye underwent thermal laser photocoagulation for extrafoveal CNV followed by intravitreal bevacizumab for subfoveal CNV, and one eye underwent intravitreal bevacizumab for subfoveal CNV. The follow-up period was 4–6 years. The final visual acuities of all eyes were 20/300 or worse with large submacular fibrosis.ConclusionCNV secondary to angioid streaks in these two patients had a poor prognosis despite undergoing different types of treatment. Poor outcome was likely related to frequent recurrence and newly developed CNV, which remained a clinical concern in these cases.

Treatment of Exudative Age-related Macular Degeneration

I. Prophylactic Treatment We followed 75 eyes contralateral to eyes with exudative age-related macular degeneration (AMD), using indocyanine green angiography (IA), for more than one year. Hyperfluorescent areas in the late phase of IA were seen in 19 eyes at the initial examination, and in 25 eyes during follow-up. Exudative AMD developed in 9 of the 25 eyes. Using timetable analysis, we estimated that 11% of these 27 eyes developed AMD within one year and 55% within three years. The hyperfluorescent areas seen on IA appeared to be latent choroidal neovascularization (CNV) under the retinal pigment epithelium. We propose that photocoagulation aimed at hyperfluorescent areas should be considered in such cases. We performed prophylactic laser photocoagulation in 21 eyes, which were then followed up for at least six months. These eyes all had 10 or more serous drusen within 1,500 μm of the fovea and did not show hyperfluorescence, suggesting latent CNV in the late phase of IA. The majority or a small fraction of the serous drusen disappeared in 48% and 18% of the 21 eyes, respectively. CNV appeared adjacent to the laser scar in one eye (5%). Judging from these results, it is important to establish a method of definitively abolishing drusen and preventing the development of CNV. II. Treatment of CNV Of 229 eyes which showed occult CNV in fluorescein angiography (FA), 124 eyes (54%) showed classic CNV outside the fovea on IA. One hundred and two of the 124 eyes (45%) underwent laser photocoagulation. We evaluated indocyanine green guided laser photocoagulation of extrafoveal CNV in 139 eyes. The success rate was 81% at 3 months after laser photocoagulation. This was estimated using timetable analyses to have decreased to 78% at one year and 71% at three years. Eighty percent of successfully treated eyes showed maintained or improved visual acuity. These results did not differ significantly from those obtained with laser photocoagulation based on FA findings. When classic CNV is not detected on FA, IA is indicated and if classic CNV is detected outside the fovea, photocoagulation should be performed aggressively. We compared the histological findings of removed subfoveal CNV with the IA findings prior to removal. IA findings of CNV before removal were divided into four types. Types I and II showed numerous vascular lumina in von Willebrand factor staining. Prominent proliferation in types I and II was demonstrated with Ki-67. Vascular endothelial growth factor (VEGF) showed strong staining in types I, II and III. Therefore, CNV in eyes with types I, II and III, and especially type I, requires urgent treatment. We compared visual outcomes one year after treatment between 52 eyes that underwent removal and 56 eyes that underwent laser photocoagulation of subfoveal CNV. When CNV size was one disc diameter or less, mean visual acuity, the percentage of eyes with improved vision and with a visual acuity of 0.1 or more, was significantly greater in operated eyes than in coagulated eyes. Removal is therefore superior to photocoagulation in subfoveal CNV of one disc diameter or less in size. We evaluated preoperative factors influencing the best corrected visual acuity at least six months after removal of subfoveal CNV in 67 eyes. Factors influencing the best corrected visual acuity were IA findings, feeder vessel ingrowth sites and CNV sizes. Good indications for removal included types I, II and III IA findings, extra foveal location feeder vessel ingrowth sites, and small CNV. III. Low Vision Care We performed reading tests using the MN read J chart for 90 eyes with the scar stage of CNV. Reading speed profiles of the 90 eyes were classified into two groups: 48 eyes showing a plateau with a relatively constant reading rate at the maximum level; and 42 eyes showing steadily increasing reading rate without a plateau. Eyes without a plateau had worse visual acuity, worse reading acuity, and slower reading speed. We evaluated newspaper reading performance by comparing conventional versus new methods based on the critical print size of the MN read J chart. Magnification power based on the critical print size were similar to those finally chosen as the best aid by the patients. On the other hand, magnification power was lower when conventional methods were used. The critical print size of the MN Read J chart appears to be valuable for determining low vision aids which facilitate reading by AMD patients.

RECURRENT CHOROIDAL NEOVASCULARIZATION AFTER LASER PHOTOCOAGULATION IN SORSBYʼS FUNDUS DYSTROPHY

Patients with autosomal dominant Sorsby's fundus dystrophy are at high risk of severe visual loss due to choroidal neovascularization (CNV) during the fourth or fifth decade of life. To assess the efficacy of argon laser photocoagulation for extrafoveal well-defined CNV, we analyzed retrospectively the clinical course in 10 eyes of 7 patients who had Sorsby's fundus dystrophy with CNV 200 microns to 2,500 microns from the center of the foveal avascular zone, and who subsequently underwent laser photocoagulation. All treated eyes developed severe visual loss as a consequence of recurrent or persistent CNV occurring on the foveal side of the treatment scar, which extended under the fovea. The average time until occurrence of angiographically documented CNV after initial treatment was 8.1 +/- 8.9 weeks, but ranged from 2 weeks to 32 weeks. Retreatment for persistent or recurrent extrafoveal CNV was performed in 5 eyes, but CNV recurred in all 5. Results of this study suggest that the risk of persistence or recurrence of CNV after laser photocoagulation for extrafoveal CNV is unusually high in patients with Sorsby's fundus dystrophy, and that this treatment is ineffective in preventing severe visual loss in such patients.

Five-Year Follow-up of Fellow Eyes of Patients With Age-Related Macular Degeneration and Unilateral Extrafoveal Choroidal Neovascularization

To assess the visual prognosis of patients with age-related macular degeneration and unilateral extrafoveal choroidal neovascularization (CNV), and to determine the risk of CNV developing in fellow eyes that were initially unaffected. Five-year prospective follow-up study of fellow eyes of 228 patients enrolled in a randomized clinical trial of laser photocoagulation of extrafoveal CNV. Visual acuity was measured and macular photographs were taken at 6-month intervals. Five-year change in visual acuity of fellow eyes from baseline, incidence of legal blindness (visual acuity of < or = 20/200 in the better eye), and cumulative incidence of CNV in fellow eyes free of neovascular maculopathy at the time of study enrollment. Photographically documented CNV developed in 33 (26%) of 128 fellow eyes that were initially free of neovascular maculopathy, and was associated with poor visual acuity at the end of the 5-year follow-up period. Among 67 patients who had bilateral neovascular maculopathy initially and were examined 5 years later, 33 (49%) were legally blind compared with 13 (12%) of 106 patients who had unilateral neovascular maculopathy initially. In all 13 of the latter group, CNV had developed in the fellow eye. Patients with age-related macular degeneration and CNV in one eye are at high risk of legal blindness within 5 years, and, thus, should be followed up carefully to ensure that laser treatment can be applied to CNV in either eye whenever it is likely to improve the visual prognosis.