Results
The management of MNV/CNV secondary to IRDs is discussed under the heading of different diseases. The terms MNV and CNV have both been used interchangeably to denote neovascularisation in the macula. Genotyping results have not been consistently available in published cases but have been included where available (online supplemental table).
Autosomal recessive bestrophinopathy
Madhusudhan et al and Hussain et al have described cases of CNV treated with three 4-weekly intravitreal ranibizumab and bevacizumab, respectively.5 6 They both reported improvement in VA with no recurrence of CNV during the follow-up period of 1–2 years. However, the case presented by Madhusudhan et al had persistent cystoid macular oedema (CMO), which is a hallmark of autosomal recessive bestrophinopathy (ARB) that fluctuated during the follow-up period.5 Iannaccone et al also showed success with serial intravitreal bevacizumab over 2 years with most of the improvement in VA occurring after three injections.7 Moreira et al described an 8-year-old female who successfully underwent bilateral vitrectomies and surgical excision of the CNV (prior to photodynamic therapy (PDT)/antivascular endothelial growth factor (VEGF) availability) with improvement in VA.8 Ten years later, the optical coherence tomography (OCT) scans showed macular schisis in both eyes for which she had four intravitreal anti-VEGF injections and a 6-month course of dorzolamide eye-drops without success. Therefore, she underwent sequential vitrectomies with removal of the internal limiting membrane and C3F8 gas in both eyes that improved her VA. There was mild recurrence of the intraretinal cystic spaces 2–3 months postsurgery, however, these remained stable with stable VA at 1 year.8
Best dystrophy
MNV in Best dystrophy, diagnosed on OCT angiography (OCTA), has been reported to have a high prevalence of up to 35%.9 MNV has been variably described as being both exudative and non-exudative in different stages of Best dystrophy and can occur in earlier stages such as vitelliform and pseudohypopyon stages, and not necessarily as a late complication.9
PDT has been shown to be successful in the treatment of CNV in numerous case reports.10–14 These patients have had 1–3 applications of PDT with no recurrences of CNV over a follow-up period ranging from 2 to 8.75 years. Interestingly, some cases have shown delayed improvement in VA over time, although with scarring.10 12 Nóbrega et al reported a case where PDT alone was unsuccessful initially, however, VA improved with combined PDT and intravitreal triamcinolone and, remained stable with no recurrence at 14 months.15 Argon laser photocoagulation has also been reported to be successful in one case with no recurrences over 1 year.16
Moreover, a single intravitreal injection of ranibizumab has improved VA with resolution of CNV and no recurrences over a follow-up period of 4 months to 3 years.17–20 Batioglu et al also showed similar results when treated with three 4-weekly injections of intravitreal ranibizumab.21 Another study described a patient with type 2 CNV who had clinical features and genetically proven Best disease, however, with a normal electro-oculogram.22 There was minimal improvement in VA with two 4-weekly intravitreal ranibizumab injections and no active CNV (clinically) at 3 years. This patient already had developed subfoveal fibrosis pretreatment. Subbiah et al reported the outcomes of children aged 5–8 years who were treated with intravitreal ranibizumab.23 They reported resolution of CNV with no recurrences in two patients treated with 0.5 mg of intravitreal ranibizumab followed up to 1 and 3 years. However, there were recurrences of the CNV at 1 year in two other patients treated with 0.25 mg of intravitreal ranibizumab. One of these cases had transient anterior chamber inflammation that was successfully treated with a 1-week course of topical steroids. Good visual and anatomical outcomes at 1 month was also described using a combined approach with a single intravitreal injection of ranibizumab and PDT.24 Recurrence at 8 months was treated with a single intravitreal injection of ranibizumab and vision with a fairly stable VA at 4 years (0.2 at 1 month and 0.3 at 4 years).
There are multiple reports that demonstrated successful treatment with 1–4 injections of intravitreal bevacizumab with improved VA, resolution of CNV and no recurrences from 0.5 to 8 years after the last treatment.4 25–32 However, poor functional and anatomical response to two 4-weekly intravitreal bevacizumab was reported in one study, with persistence of the CNV.25 Khan et al presented the functional outcomes of 14 eyes of 12 patients (11 Best dystrophy and 1 ARB) with a median follow-up period of 2.8 years (0.8–6 years).33 Seven eyes were treated with intravitreal bevacizumab (1.25 mg/0.05 mL; single injection in 4 cases and, 2, 3 and 10 injections in 1 case each) and 7 eyes were observed. The median gain in VA was greater in the treated versus observed group (0.46 vs 0.17 decimalised units of Snellen, p<0.05).33 Cakir et al presented a 11-year-old female who was treated with combined intravitreal bevacizumab (1.25 mg) and triamcinolone acetonide.4 The authors reported an improvement in VA at 1 month and shrinkage of CNV at 2 months post treatment with no recurrence at 6 months on fluorescein angiography (FA). The hypothesis was that triamcinolone potentiated the anti-angiogenic effect of bevacizumab reducing the need for repeated injections, decreases vascular permeability and reduces inflammation.4
Bietti crystalline dystrophy
Hua et al treated a patient with a single intravitreal bevacizumab which lead to regression of CNV at 1 month but recurred at 3 months.34 However, other authors have described cases where patients were treated with three 4-weekly bevacizumab and ranibizumab with subsequent improvement in VA and no recurrences over a follow-up period that ranged from 4 to 12 months.35–38
Choroideremia
MNV is rarely reported in choroideremia, in affected males and in female carriers. Spontaneous resolution is known, and MNV may go undiagnosed as visual symptoms and signs of exudation are minimal. Treatment with intravitreal bevacizumab39 40 and ranibizumab41 have shown to either maintain or improve VA.
Doyne honeycomb retinal dystrophy (Malattia Leventinese and EFEMP1 retinal dystrophy or autosomal dominant drusen)
This condition is characterised by extensive drusen and can be complicated by MNV in advanced stages, which has been successfully treated with intravitreal bevacizumab,42 except one case where the VA continued to reduce despite anatomical improvement.40
Enhanced S-cone syndrome
MNV has been reported in 14 of 93 (15.1%) patients with enhanced S-cone syndrome in a group of patients from Saudi Arabia, all of whom subsequently developed subretinal fibrosis.43 Of the 10 patients who had genetic testing, all of them had mutations in the NR2E3 gene. Three patients were treated with intravitreal bevacizumab, all of whom developed fibrotic lesions at the macula with no improvement to vision.43 In contrast, other studies have shown improvements in VA with intravitreal bevacizumab44 and ranibizumab,45 latter with no recurrence at 7 years. Type 3 MNV showing retinochoroidal anastomoses has been described in three eyes of two patients with enhanced S-cone syndrome; one eye was successfully treated with a course of intravitreal bevacizumab.46
Gyrate atrophy
There are isolated case reports of treatment with bevacizumab and ranibizumab in MNV associated with gyrate atrophy where both the MNV and VA stabilised promptly with a single injection and a course of three 4-weekly injections, respectively.47 48
North Carolina macular dystrophy
Bakall et al successfully treated a patient with reduced vision and retinal fluid on OCT, although no convincing evidence of a CNV on FA with intravitreal bevacizumab.49 Other studies reported using intravitreal ranibizumab50 and bevacizumab,51 although details of the outcome of injections were not clear in the literature.
Oliver McFarlane syndrome
Although more than 30 cases of Oliver McFarlane syndrome have been published, only 1 case that was complicated by CNV has been reported in a 10-year-old female who was treated with a single intravitreal bevacizumab injection and then a single intravitreal ranibizumab injection for recurrence 2 years later.52 In this case, VA continued to be stable 6 years after the initial diagnosis.
Pattern macular dystrophy
Pattern macular dystrophy (PMD) represents a rare group of disorders with generally a favourable prognosis, unless complicated by MNV which in one case series was suspected in 50% of patients.53 Parodi et al described a prospective series of 13 eyes with MNV associated with reticular pattern dystrophy, treated with PDT with more than 50% of their patients losing more than 15 letters at 3 years, concluding that alternative therapies need to be explored.54
Parodi et al prospectively assessed patients with PMD (10 with reticular dystrophy and 2 patients with adult-onset foveomacular vitelliform dystrophy (AOFVD)) associated with subfoveal CNV who were treated with three 4-weekly intravitreal bevacizumab 1.25 mg and then on a pro-re-nata (prn) basis.55 The mean VA was 0.73±0.34 logMAR at baseline and 0.45±0.23 logMAR at 24 months, with only one patient losing one line compared with baseline vision. Moreover, nine patients only required the loading doses to reach stabilisation of CNV that was confirmed on FA and OCT. Other three patients required up to eight further injections in the follow-up period.55
PMD has also been successfully treated with intravitreal ranibizumab.56–59 One of these cases were initially treated with three 4-weekly intravitreal bevacizumab injections and then laser photocoagulation before being given a single intravitreal ranibizumab injection. The VA improved from 20/50 to 20/30 at 1 month and 20/20 at 8 months after the injection with regression of the CNV. However, she required two more injections of ranibizumab due to reduction in VA to 20/40 over the next 6 months and VA improved to 20/25.56 Lee et al described two patients in the same family with PMD simulating fundus flavimaculatus (FFM) with secondary CNV who had C213W mutation in the PRPH2 gene60 who were with intravitreal anti-VEGF injections (bevacizumab, ranibizumab and aflibercept) on a prn basis.
Mimoun et al treated 20 patients (24 eyes) with occult CNV secondary to AOFVD with three 4-weekly intravitreal ranibizumab and then on a prn basis as per predetermined criteria over 12 months.61 Mean number of intravitreal ranibizumab given was 4.5±1.29 at final visit. The VA improved (≥3 lines) in 25% of patients, did not change in 62.5% and worsened (≥3 lines) in 12.5% of patients. Of the three patients who had worsened VA, one developed macular atrophy and the other two patients had persistence of a serous retinal detachment without evidence of active CNV. Overall, the mean VA did not change significantly over the follow-up period (0.37±0.2 logMAR vs 0.30±0.25 logMAR, p=0.115).61 Similarly, another study showed the mean VA to improve from 0.36±0.1 at baseline to 0.56±0.1 (p=0.038) with improvement of the metamorphopsia in six female patients with occult CNV as diagnosed on FA who were treated with three 4-weekly intravitreal ranibizumab injections.62
Retinitis pigmentosa
The prevalence of MNV in retinitis pigmentosa (RP) is variable among studies, with an Italian retrospective study looking at 176 eyes with RP reporting MNV prevalence to be 1.7%.63 Cheng et al reported successful treatment of CNV with PDT in two patients with improvement in VA and no recurrence during the follow-up period of up to 2 years.64 CNV has also been treated successfully with intravitreal bevacizumab3 65 66 and ranibizumab67 68 with stable or improved VA and resolution of CNV although with fibrosis in some cases. However, VA failed to improve in one case (56-year-old female) despite being treated with 34 intravitreal injections over 6 years (bevacizumab, pegaptanib, ranibizumab and aflibercept).69
Sorsby fundus dystrophy
Studies have shown argon laser photocoagulation70 and PDT71–74 for CNV secondary to Sorsby fundus dystrophy to be ineffective, necessitating anti-VEGF therapy. However, one case reported successful treatment of an extrafoveal classic CNV treated with PDT at months 0, 3, 6 and 12 (due to fresh leakage on FA) with a small subretinal scar and improved VA from 6/36 to 6/12 (maintained for 1 year).75
CNV has been managed successfully with both intravitreal bevacizumab71 74 76–78 and ranibizumab,72 73 79 although majority of the studies reported recurrences requiring multiple injections. Tsokolas et al suggested that a treat and extend protocol was more effective compared with a pro re nata protocol in reducing recurrence of CNV.74 Prager et al presented a case where the patient was managed with three 2-weekly intravenous bevacizumab injections (patient refused PDT and intravitreal treatments).80 VA improved with one episode of recurrence requiring one additional treatment at 7 months. There were no serious ocular or systemic side effects.80 A systematic review by Baston et al reviewed 31 cases that were treated with intravitreal anti-VEGF injections with a mean follow-up of 54 months.81 Treatment was given between 0 and 9 months following the onset of CNV, with an average of 5.4 months (not reported in 8 cases). They concluded that better functional outcomes are observed when treated immediately after the onset of CNV compared with delayed treatment.
Combined treatment with PDT and intravitreal triamcinolone has also shown promising results.82 83 Kapoor et al treated their patient with a single intravitreal bevacizumab injection initially, however, this patient required multiple injections thereafter for recurrences and developed bevacizumab-related intraocular inflammation after the eighth injection (36). The patient was subsequently treated with a combination of PDT, intravitreal dexamethasone (200 μg in 0.05 mL) and intravitreal bevacizumab, the latter two medications being continued long term. At 7 years, VA (20/50) was worse than at initial presentation (20/30), with normal intraocular pressure, cataract and, macular scarring and atrophy.84 Atan et al successfully managed their patient with multiple courses of oral and sub-Tenon’s injections of steroids for recurrent CNV that was initially presumed to be secondary to punctate inner choroidopathy, however, later confirmed as Sorsby fundus dystrophy on genetic analysis.85
Stargardt disease and fundus FFM
FFM is a late-onset phenotypically similar condition to Stargardt disease (SD) CNV associated with SD has required repeated PDT for either persistent leakage or recurrences on FA.64 86 87 Querques et al reported a patient with SD and CNV who was successfully treated with three consecutive monthly intravitreal injections of ranibizumab and no recurrence at 6 months.88 Battaglia Parodi et al presented a prospective case series involving three patients who were treated with ranibizumab injections on a prn regimen and followed up for 24 months (4-weekly clinical examination with OCT and 3-monthly FA).89 A mean of 11 (9–14) injections were required over the 24 months, with only one patient showing reactivation at the end of this period. Mean VA improved from 0.47±0.06 logMAR at baseline to 0.90±0.17 at 24 months. Over the follow-up period, the area of RPE atrophy enlarged in all three cases with development of outer retinal tubulations, which is may be explained by the natural history of this condition.89
Two cases of MNV in FFM were treated successfully with a single application of PDT and showed no signs of recurrence over 9–21 months.90 91 However, 2–3 applications of PDT were required in two other published cases, due to persistent leakage on FA, with improved VA.90 CNV secondary to FFM was also managed successfully with a single intravitreal ranibizumab injection in one patient who had no recurrence at 10 months92 and, in another patient who required a second injection for recurrence at 3 months and remained stable at 9 months.93 Quijano et al managed their patient with FFM with a course of three 4-weekly injections of ranibizumab and showed improved VA, resolution of the CNV with scarring with no recurrence 6 months after the last treatment.94 Roy et al presented a patient with CNV and choroiditis on a background of FFM.95 The patient had a full uveitic workup that did not show any positive associations. There was an improvement in VA, resolution of the inflammation and the CNV with a tapering course of oral steroids and three 4-weekly intravitreal bevacizumab injections. The authors stated that the inflammatory component may have been a random association or indeed suggests a role of inflammatory pathways in Stargardt-like diseases.95 In another case of FFM, three 3-monthly intravitreal injections of aflibercept in combination with PDT showed resolution of CNV with scarring, but no significant improvement in the VA.96