Corticosteroids as an antiangiogenic agent for histoplasmosis-related subfoveal choroidal neovascularization

Use of Adjunctive Corticosteroid With Antivascular Endothelial Growth Factor Agents in the Treatment of Choroidal Neovascular Membrane Associated With Presumed Ocular Histoplasmosis

Purpose: To evaluate the impact of combination treatment of antivascular endothelial growth factor (anti-VEGF) intravitreal injections and corticosteroids in patients with choroidal neovascularization (CNV) secondary to presumed ocular histoplasmosis syndrome (POHS). Methods: A retrospective multicenter study was conducted in a cohort from Illinois and Missouri. Patients were identified over an 8-year period, and data were evaluated over a 1-year study window commencing with treatment initiation. Group 1 included patients treated with intravitreal injections of anti-VEGF, and group 2 included those who received intravitreal injections of anti-VEGF and adjuvant corticosteroids. Optical coherence tomography (OCT) measurements and increases in Early Treatment Diabetic Retinopathy Study (ETDRS) letter score were compared between each group. Results: Using the method of last visit carried forward, the visual acuity (VA) in group 2 was 6.42 ETDRS letters better than the VA in group 1 at the final assessment. Patients in group 2 had a mean ETDRS letter gain of 21.50 (P = .06) from the initial baseline vision. The average amount of decrease in OCT central subfield thickness compared with baseline was lower in group 1 (80.9 ± 129.8 µm) vs group 2 (102.8 ± 90.40 µm) at the 1-year follow-up visit (P = .25). Conclusions: Approved treatment of CNV secondary to POHS is limited. Adjuvant corticosteroid treatment in patients with CNV secondary to POHS may provide better long-term vision and OCT outcomes than anti-VEGF alone and may offer an additional therapy option for these patients.

Long-Term Analysis of Clinical Features and Treatment Outcomes of Inflammatory Choroidal Neovascularization

PURPOSE

To investigate the long-term clinical features and treatment outcomes of patients with inflammatory choroidal neovascularization (CNV) treated with intravitreal anti-vascular endothelial growth factor (anti-VEGF).

DESIGN

Retrospective, interventional, consecutive case series.

METHODS

Sixty-five eyes of 65 patients with inflammatory CNV treated with anti-VEGF injections and followed up at least 12 months were included. Retrospective chart review was conducted at a single tertiary referral center.

RESULTS

Study participants were followed up for 60.6 ± 42.8 (range, 16-160) months. Mean age was 33.4 ± 10.8 years, and mean refractive error was -3.94 ± 1.35 D in spherical equivalent. Final best-corrected visual acuity (BCVA) was 0.21 ± 0.20 logMAR after treatment. Patients were treated with bevacizumab (76.9%), ranibizumab (4.6%), aflibercept (3.1%), and drug combinations (15.4%). Systemic corticosteroid or immunosuppressant use was not correlated with visual outcome, required number of anti-VEGF injections, and recurrence. Commonly occurring optical coherence tomography (OCT) features included ellipsoid zone disruption, choroidal hypertransmission, retinal pigment epithelium atrophy or absence (RPEA), intraretinal hyperreflective foci (HRF), choroidal vessel engorgement, focal choroidal excavation, and irregular vascular loops (on OCT angiography). RPEA after treatment (β = 0.238, P = .036) and BCVA (β = 0.267, P = .029) showed significant correlation with final BCVA. A total of 28 patients (43.1%) experienced recurrence; intraretinal HRF after treatment was the single risk factor for recurrence (odds ratio = 2.712, P = .031).

CONCLUSIONS

Inflammatory CNV recurrence showed higher rates over time after anti-VEGF treatment than previously reported, even though the overall visual outcome was good. Baseline BCVA and RPEA after treatment are significant predictors for visual outcome. Intraretinal HRF after anti-VEGF treatment suggests the potential risk of recurrence.

Bronchial angiogenesis in horses with severe asthma and its response to corticosteroids

Background

Severe asthma in horses is characterized by structural changes that thicken the lower airway wall, a change that is only partially reversible by current treatments. Increased vascularization contributes to the thickening of the bronchial wall in humans with asthma and is considered a potential new therapeutic target.

Objective

To determine the presence of angiogenesis in the bronchi of severely asthmatic horses, and if present, to evaluate its reversibility by treatment with corticosteroids.

Animals

Study 1: Bronchial samples from asthmatic horses in exacerbation (7), in remission (7), and aged‐matched healthy horses. Study 2: Endobronchial biopsy samples from asthmatic horses in exacerbation (6) and healthy horses (6) before and after treatment with dexamethasone.

Methods

Blinded, randomized controlled study. Immunohistochemistry was performed using collagen IV as a marker for vascular basement membranes. Number of vessels, vascular area, and mean vessel size in the bronchial lamina propria were measured by histomorphometry. Reversibility of vascular changes in Study 2 was assessed after 2 weeks of treatment with dexamethasone.

Results

The number of vessels and vascular area were increased in the airway walls of asthmatic horses in exacerbation (P = .01 and P = .02, respectively) and in remission (P = .02 and P = .04, respectively) when compared to controls. In Study 2, the differences observed between groups disappeared after 2 weeks of treatment with corticosteroids because of the increased number of vessels in healthy horses.

Conclusions and Clinical Importance

Angiogenesis contributes to thickening of the airway wall in asthmatic horses and was not reversed by a 2‐week treatment with corticosteroids.

MANAGEMENT OF NEOVASCULAR OCULAR HISTOPLASMOSIS: Past and Present

PURPOSE

To review the wide variety of treatment modalities available for choroidal neovascularization secondary to the presumed ocular histoplasmosis syndrome.

METHODS

A literature search was performed to review the multitude of studies conducted to investigate the efficacy and safety of treatment modalities available for choroidal neovascularization secondary to the presumed ocular histoplasmosis syndrome.

RESULTS

Each treatment modality is reviewed, with the studies summarized and presented to support or refute the method of treatment. Two case reports are presented to demonstrate the treatment regimens.

CONCLUSION

This is a comprehensive review of the treatment modalities available to address choroidal neovascularization secondary to the presumed ocular histoplasmosis syndrome. Investigators will continue to strive toward higher efficacy and safety with future innovations in the field.

An update on inflammatory choroidal neovascularization: epidemiology, multimodal imaging, and management

Inflammatory choroidal neovascular membranes are challenging to diagnose and manage. A number of uveitic entities may be complicated by the development of choroidal neovascularization leading to a decrease in central visual acuity. In conditions such as punctate inner choroidopathy, development of choroidal neovascularization is extremely common and must be suspected in all cases. On the other hand, in patients with conditions such as serpiginous choroiditis, and multifocal choroiditis, it may be difficult to differentiate between inflammatory choroiditis lesions and choroidal neovascularization. Multimodal imaging analysis, including the recently introduced technology of optical coherence tomography angiography, greatly aid in the diagnosis and management of inflammatory choroidal neovascularization. Management of these neovascular membranes consists of anti-vascular growth factor agents, with or without concomitant anti-inflammatory and/or corticosteroid therapy.

INFLAMMATORY CHOROIDAL NEOVASCULAR MEMBRANE: Long-Term Visual and Anatomical Outcomes After Intravitreal Anti-vascular Endothelial Growth Factor Therapy

PURPOSE

To assess the long-term visual and anatomical outcomes after intravitreal anti-vascular endothelial growth factor therapy for inflammatory choroidal neovascular membrane (CNVM).

METHODS

Retrospective case series of 15 consecutive cases of newly diagnosed inflammatory CNVM who were treated with intravitreal bevacizumab or ranibizumab injections.

RESULTS

The study included 8 women and 7 men with mean age at presentation with CNVM of 40.53 ± 17.46 years (range, 11-70 years), and mean follow-up duration after anti-vascular endothelial growth factor therapy was 20.53 ± 14.53 months (range, 6-48 months). All eyes had classic CNVM confirmed by fluorescein angiography, most commonly located in the peripapillary area (8 eyes, 53.3%), followed by juxtafoveal (4 eyes, 26.7%), and subfoveal location (3 eyes, 20%). All CNVMs showed complete resolution with mean 2.6 ± 1.2 injections per eye. Preinjection mean best-corrected visual acuity of logarithm of minimum angle of resolution 0.79 ± 0.76 (approximate Snellen equivalent 20/123) and mean central macular thickness of 435.9 ± 190.2 μm improved significantly to mean best-corrected visual acuity of logarithm of minimum angle of resolution 0.46 ± 0.43 (approximate Snellen equivalent 20/58) and mean central macular thickness of 262.13 ± 108.70 μm (P value 0.02 and <0.0001, respectively) at the final visit. Recurrence was seen in 26.7% eyes (4/15), all of which regressed with single injection. Only complication noted was subretinal fibrosis in one eye (6.7%).

CONCLUSION

For inflammatory CNVM, in addition to immunosuppression in cases with active inflammation, anti-vascular endothelial growth factor therapy seems as a very effective treatment modality resulting in significant visual improvement and foveal flattening. Incidence of major complications is rare, and the recurrence rate seems low.

Idiopathic Acute Exudative Polymorphous Vitelliform Maculopathy: Clinical Spectrum and Multimodal Imaging Characteristics

PURPOSE

To describe clinical findings in patients with acute exudative polymorphous vitelliform maculopathy (AEPVM).

DESIGN

Retrospective, observational, multicenter case series review.

PARTICIPANTS

Consecutive patients diagnosed with idiopathic AEPVM.

METHODS

Review of clinical charts, multimodal imaging, electrophysiologic findings, and genetic findings in previously unpublished patients and review of the literature.

MAIN OUTCOME MEASURES

Clinical features of idiopathic AEPVM and differential diagnosis.

RESULTS

Eighteen patients (age range, 21-74 years) with typical features of AEPVM, including initial localized, serous detachments followed by the development of characteristic yellow-white deposits in the vitelliform space. Over time, this hyperautofluorescent material gravitated within the larger lesions, resulting in typical curvilinear deposits characteristic of later stages. Symptoms and clinical findings lasted from weeks to several years. Some patients showed previously undescribed features such as fluorescein-negative intraretinal cystic changes, choroidal neovascularization, serous retinal elevations mimicking retinal folds, increased choroidal thickness, lack of rapid visual recovery, and recurrence years after complete resolution of initial manifestations.

CONCLUSIONS

Acute exudative polymorphous vitelliform maculopathy can present with a more variable natural course than previously described. Paraneoplastic retinopathy and autosomal recessive bestrophinopathy closely resemble AEPVM, necessitating medical and hereditary evaluation to exclude these clinical possibilities. This series of patients with AEPVM expands the clinical spectrum of the disorder, including demographics, clinical manifestations, imaging features, natural course, and visual prognosis.

Vision Preservation in Eyes of Polypoidal Choroidal Vasculopathy with Low-Dose Intravitreal Triamcinolone Acetonide

PURPOSE

To evaluate the efficacy and adverse effects of using low-dose intravitreal triamcinolone acetonide (IVTA) to preserve vision in polypoidal choroidal vasculopathy (PCV) eyes.

METHODS

This retrospective chart review study examined 8 eyes of 7 PCV patients, for whom verteporfin photodynamic therapy (vPDT) or antivascular endothelial growth factor (VEGF) therapy was not affordable/available and also with intolerable risk because of underlying cardiovascular and/or cerebrovascular ischemia. Low-dose IVTA (1 mg/0.025 mL) monotherapy was administered and repeated every 4 weeks if intraretinal edema or subretinal fluid persisted.

RESULTS

The median follow-up time was 26.4 months. Three eyes (3/8) maintained their initial best-corrected visual acuity and 4 eyes (4/8) exhibited improvement, whereas 1 eye (1/8) sustained some loss. The mean injection number per month was 0.7 for the first 6 months, after which it decreased to 0.4. In regard to adverse effects, intraocular pressure (IOP) of more than 21 mmHg was noted as persisting for a few weeks in 4 eyes and that of more than 30 mmHg was noted once in 1 eye. The increased IOP was adequately controlled by using IOP-lowering agents. Two initially phakic eyes each underwent cataract surgery in the 12th and 14th months after treatment.

CONCLUSIONS

Low-dose IVTA therapy may be valuable for preserving the vision of PCV patients, while vPDT or anti-VEGF is not affordable/available or of those with underlying diseases for whom anti-VEGF therapy is with intolerable risk.

Choroidal Neovascularization Associated With Birdshot Chorioretinopathy

BACKGROUND AND OBJECTIVE

Patients with birdshot chorioretinopathy (BCR) may develop visual compromise due to choroidal neovascularization (CNV), and few series address management strategies in the anti-vascular endothelial growth factor (VEGF) era. The purpose of this study was to describe the clinical outcomes of combination anti-VEGF and immunosuppressive therapy for CNV associated with BCR.

PATIENTS AND METHODS

Retrospective, interventional case series. Patients with BCR from two tertiary uveitis and retina practices were reviewed. Patients with CNV in association with BCR were identified and reviewed in detail. Clinical features, treatments utilized (ie, anti-VEGF injections, immunosuppressive therapy), and functional and structural outcomes over long-term follow-up were recorded. Outcomes measured included Snellen visual acuity, spectral-domain optical coherence tomography macular thickness during treatment, number and type of anti-VEGF injections, the need for initiation or escalation of immunosuppression, and incidence of CNV in macula-involved versus macula-sparing BCR.

RESULTS

Four of 36 BCR patients were diagnosed with choroidal neovascularization (11%). Identification of CNV in all patients prompted treatment with intravitreal anti-VEGF injections and an increase or initiation of local or systemic immunosuppression. Mean Snellen visual acuity improved from 20/60 to 20/30 at final follow-up (P = .02). Mean central subfield thickness improved from 443 μ to 254 μ (P = .04). CNV in association with BCR occurred at a rate of 0.11 events per patient-year (95% CI, 0.02-0.31) in macula-involved BCR versus zero events/patient-year in macula-spared BCR (95% CI, 0-0.058; P = .009).

CONCLUSION

Anti-VEGF therapy was effective for the treatment of CNV in BCR patients. A combination of systemic or local immunosuppression and anti-VEGF therapy may be useful in the management of CNV associated with BCR. [Ophthalmic Surg Lasers Imaging Retina. 2016;47:450-457.].

Treatment of CNV secondary to presumed ocular histoplasmosis with intravitreal aflibercept 2.0 mg injection

OBJECTIVE

To assess the efficacy and safety of intravitreal aflibercept injection in the treatment of CNV secondary to presumed ocular histoplasmosis syndrome (POHS).

PURPOSE

To assess safety of intravitreal aflibercept for the treatment of CNV secondary to presumed ocular histoplasmosis syndrome.

METHODS

Masked, open-label, prospective study. Five subjects will receive 2.0 mg aflibercept injection every 8 weeks with 3 initial monthly doses over a 12 month period.

RESULTS

No adverse systemic or ocular were reported. At month six, the mean visual acuity improved by 7.8 ETDRS letters, mean central subfoveal thickness decreased by 38.8 microns and mean OCT volume decreased by 0.076 mm3 . At month twelve, the mean visual acuity improved by 12.4 ETDRS letters, mean central subfoveal thickness decreased by 34.6 microns and mean OCT volume decreased by 0.576 mm3.

CONCLUSION

The use of intravitreal 2.0 mg aflibercept injection for the treatment of CNV secondary to presumed ocular histoplasmosis syndrome yielded no systemic or ocular adverse events and produced improvement in visual acuity and reduction of OCT thickness and volume.

Inflammatory choroidal neovascular membrane in posterior uveitis-pathogenesis and treatment

Choroidal neovascular membrane (CNVM) formation is a well-documented sight-threatening complication of posterior segment intraocular inflammation (PSII). The aim of this article is to review the basic and clinical science literature on the pathogenesis of CNVM formation in PSII and to present results of a case series. We searched the literature using the mesh terms- inflammation, CNVM, age-related macular degeneration, immunosuppression, photodynamic therapy, steroids, vascular endothelial growth factors and posterior uveitis. Additionally, we evaluated the visual outcome of and clinical response to our standard treatment protocol involving a combination treatment for young patients with inflammatory CNVM. The development of CNVM in PSII is promulgated by infiltrating myeloid cells as well as choroidal and retinal myeloid cell activation, subsequent vascular endothelial growth factors, cytokine and chemokine production and complement activation acting in consort to mediate angiogenic responses. No clear standard of care currently exists for the treatment of inflammatory CNVM and various combinations have been tried. Using our combination treatment, visual acuity improved in four, stabilized in one and worsened in four patients. Though significant advances have occurred in the understanding of the pathogenesis and management of this condition, optimizing therapeutic regimens will require further well-constructed prospective cohort series.

Bevacizumab in inflammatory eye disease

PURPOSE

To report the effect of intravitreal bevacizumab (Avastin; Genentech Inc, South San Francisco, California, USA) on visual acuity and macular thickness in patients with inflammatory choroidal neovascularization (CNV) or cystoid macular edema (CME).

DESIGN

Retrospective, noncomparative, interventional case series.

METHODS

Each eye received 1.25 mg of intravitreal bevacizumab at baseline. Follow-up examinations were scheduled at 1- to 2-month intervals, with additional injections at the discretion of the physician. Comprehensive evaluations, including Snellen best-corrected visual acuity (BVCA) and optical coherence tomography measurements, were performed at each visit. Main outcome measures were BCVA and central subfield thickness (CST), as measured by optical coherence tomography.

RESULTS

Thirty-four eyes of 30 patients with inflammatory CNV (n = 21 eyes of 19 patients; 9 male, 10 female) or CME (n = 13 eyes of 11 patients; 4 male, 7 female) were identified. Median ages were 52 years (range, 7 to 83) and 67 years (range, 17 to 83) for the CNV and CME groups, respectively. The median length of follow-up for CNV eyes was 7 months (range, 1 to 28) while the median follow-up for CME eyes was 13 months (range, 1 to 20). Both groups received a median of two injections (range, 1 to 9 for CNV and 1 to 4 for CME). For eyes with CNV, BCVA improved significantly at follow-up month 1, but was not different from baseline thereafter; CST remained unchanged throughout follow-up. For eyes with CME, neither BCVA nor CST changed significantly over the course of follow-up.

CONCLUSIONS

Bevacizumab appears to stabilize BCVA and CST for eyes with inflammatory CNV or CME.

Intravitreal bevacizumab for uveitic choroidal neovascularization

PURPOSE

To report 5 cases of inflammatory choroidal neovascularization (CNV) that were treated with intravitreal bevacizumab.

METHODS

Six eyes of 5 patients with uveitic CNV were treated with 2.5 mg/0.1 mL of intravitreal bevacizumab. Main outcome measures were the changes in BCVA and reduction in the size of the CNV.

RESULTS

The mean follow-up time was 15.3 months. The mean intravitreal injections administered were 2.7. All patients showed a reduction in the size of the CNV with improvement in BCVA in 60% of cases at the last follow-up.

CONCLUSION

Intravitreal bevacizumab may provide an additional strategy in the management of inflammatory CNV.

Triamcinolone acetonide in ocular therapeutics

Triamcinolone acetonide has been effectively used in ocular therapeutics for over 50 years. Its use has increased dramatically in recent years for periocular and intraocular treatment of retinal vasculature disease and uveitis. This comprehensive review discusses the pharmacokinetics of triamcinolone acetonide and summarizes its uses in a number of diseases, both intraocular and extraocular. It discusses side effects and their management. Finally, it discusses the controversy over its use.

Intravitreal bevacizumab as initial treatment for choroidal neovascularization associated with presumed ocular histoplasmosis syndrome

PURPOSE

To report a case of juxtafoveal choroidal neovascularization in a patient with presumed ocular histoplasmosis syndrome (POHS) who was treated with intravitreal injection of bevacizumab (Avastin) as initial treatment.

METHODS

A 23-year-old woman with POHS presented with sudden dimness of vision and metamorphopsia in the right eye. The patient was examined with ophthalmoscopy, fluorescein angiography, and optical coherence tomography (OCT).

RESULTS

Fundus examination, fluorescein angiography, and OCT of the right eye revealed a juxtafoveal choroidal neovascularization. Intravitreal injection of bevacizumab was performed with a postoperative improvement of visual acuity and resolution of the distortion.

CONCLUSIONS

This case report describes a case of juxtafoveal choroidal neovascularization associated with POHS that responded remarkably well to intravitreal injection of bevacizumab.

Periocular Triamcinolone and Photodynamic Therapy for Subfoveal Choroidal Neovascularization in Age-Related Macular Degeneration

PURPOSE

To evaluate fluorescein angiographic and visual acuity (VA) outcomes from patients enrolled in a trial of a single periocular corticosteroid injection immediately before photodynamic therapy (PDT) versus PDT alone for subfoveal choroidal neovascularization secondary to age-related macular degeneration (AMD).

DESIGN

Randomized 2-center clinical trial.

PARTICIPANTS

Sixty-seven subjects with AMD, subfoveal choroidal neovascularization, and best-corrected VA of 20/20 to 20/320 in the study eye who had received no more than 1 prior PDT treatment.

METHODS

Subjects were randomized to receive PDT alone (no corticosteroid) or a single periocular corticosteroid injection given via the posterior superior sub-Tenon's capsule route before PDT (corticosteroid) and assessed 1, 3, and 6 months after enrollment. Best-corrected VA and intraocular pressure (IOP) measurements were taken during each examination. Color photographs and fluorescein angiograms were taken at baseline and 3 and 6 months.

MAIN OUTCOME MEASURE

Presence or absence of fluorescein leakage from choroidal neovascularization 3 months after randomization.

RESULTS

Between the 34 participants randomized to periocular corticosteroid and 33 to no corticosteroid, baseline features appeared balanced. Thirty-three corticosteroid participants and 30 no corticosteroid participants returned for the 3-month follow-up, at which time 56 had fluorescein leakage. Proportions of participants with leakage at 3 months for the 2 treatment groups did not statistically significantly differ; 94% of the corticosteroid group and 90% of the no corticosteroid group had fluorescein leakage at 3 months (P = 0.66). Mean VAs at 3 months after enrollment were 20/100 and 20/125 in the corticosteroid and no corticosteroid groups, respectively, decreasing on average 1.5 and 0.9 lines from baseline (P = 0.50). Adverse events included IOP > 21 mmHg in 7 corticosteroid participants (21%) and 1 (3%) no corticosteroid participant (P<0.05) and ptosis of the study eyelid in 1 (3%) corticosteroid participant.

CONCLUSIONS

In contrast to previously reported uncontrolled studies and 1 controlled study, this trial did not find a reduction in the amount of fluorescein leakage 3 months after a single periocular injection of corticosteroid and PDT compared with PDT alone.

Combination therapy for the treatment of ocular neovascularization

The growth of inappropriately regulated, leaky blood vessels is a prominent component of several debilitating eye diseases, such as age-related macular degeneration (AMD), proliferative diabetic retinopathy (PDR), and retinopathy of prematurity (ROP). New pharmacological therapies that target vascular endothelial growth factor-A (VEGF-A) have significantly enhanced the treatment of AMD by limiting the progression of the disease, and in some cases, by improving vision. Although anti-VEGF therapy will undoubtedly prove valuable in the treatment of other neovascular diseases of the eye, improvements with this type of therapy are still required. At present, anti-VEGF therapy requires intravitreal injection and a relatively frequent dosing regimen (4-6 weeks). Furthermore, in experimental models of neovascularization, anti-VEGF treatment becomes less effective at blocking vessel growth and at regressing vessels as the neovascularization develops over time. As such, the use of anti-VEGF therapy in late-stage AMD may be limited. An important strategy for improved treatment of neovascular diseases of the eye could be combination therapy. Combination therapy of anti-VEGF drugs with established treatments, such as photodynamic therapy with verteporfin (PDT-V), or with newly-developed drugs targeting specific kinases, presents opportunities for increased efficacy and improved therapeutic outcome. In this review, we evaluate the opportunities for combination therapy for the treatment of neovascular diseases of the eye.

Preventing reactivation of ocular histoplasmosis: Guidance for patients at risk

BACKGROUND

Ocular histoplasmosis syndrome (OHS), a significant cause of vision loss in young and middle-aged adults, is associated with the fungus Histoplasma capsulatum (Hc). There is considerable evidence that recurrent reactivation of perimacular ocular histoplasmosis lesions is an important cause of disease progression and that vision loss is at least, in part, a consequence of host sensitivity to fungal antigen.

METHODS

The etiology and pathogenesis of OHS is reviewed and specific recommendations are made for patients with OHS that may decrease the risk of reactivation of ocular histoplasmosis lesions and slow disease progression.

CONCLUSION

Patients with perimacular chorioretinal scars secondary to OHS should be informed by the clinician that they are at risk for vision loss; they should be told the symptoms of choroidal neovascularization and how to self-monitor their vision with an Amsler grid. We recommend they also be instructed on how to decrease their risk of reinfection by Hc. Aggressive treatment of dermatomycoses, onychomycosis, vaginal candidiasis, and other chronic fungal infections may decrease the risk of reactivation of ocular lesions. Patients with OHS who are considering LASIK surgery should be informed that the procedure may trigger choroidal neovascularization.

Outcomes after combination photodynamic therapy and immunosuppression for inflammatory subfoveal choroidal neovascularisation

AIM

To report the visual and angiographic outcomes after combination photodynamic therapy (PDT) and immunosuppression for inflammatory subfoveal choroidal neovascularisation (CNV).

METHODS

Retrospective review of six consecutive patients, five female and one male, aged 23-40 years with active subfoveal CNV secondary to posterior uveitis. Patients received either intravitreal triamcinolone or systemic immunosuppression (mycophenolate mofetil, tacrolimus) and PDT. Five patients had intravitreal triamcinolone injections and two patients were on systemic immunosuppression; all patients underwent PDT (mean two treatments). Visual acuity was measured on a 2 metre ETDRS chart and fluorescein angiograms were performed at each visit.

RESULTS

Median follow up was 15 months (range 10-31). Vision improved by a median of 13 letters in five patients and remained stable (+/-1 letter) in one patient. Median visual acuity improved from 20/160 at presentation to 20/40 at latest follow up (p=0.03). There was a reduction in clinical exudation and cessation of angiographic leakage in all six patients. All interventions were well tolerated.

CONCLUSION

Combination PDT and immunosuppression may be a useful therapeutic option for young patients with active inflammatory subfoveal CNV.

New and classic insights into presumed ocular histoplasmosis syndrome and its treatment

PURPOSE OF REVIEW

Presumed ocular histoplasmosis syndrome classically presents with atrophic choroidal scars, which are thought to progress into choroidal neovascularization in a small proportion of patients. The pathophysiology of the disease, including its underlying etiology, continues to be controversial and subject to ongoing research. Even more important is the controversy that surrounds the optimal treatment for choroidal neovascularization in patients with presumed ocular histoplasmosis, in particular that of subfoveal localization.

RECENT DEVELOPMENTS

Intense efforts oriented toward defining the most beneficial therapeutic modality have resulted in some well-designed, large studies that evaluated submacular surgery, photodynamic therapies, and anti-angiogenic therapies, as well as small pilot studies exploring new therapeutic approaches for choroidal neovascularization.

SUMMARY

Important results obtained by these studies were recently made public, and the conclusions that may be drawn from them, as well as an update on findings concerning presumed ocular histoplasmosis etiology, epidemiology, and pathophysiology are presented in this report.

Interferon alpha-2a treatment for serpiginous choroiditis

PURPOSE

To describe the management and long-term outcome of patients with serpiginous choroiditis (SPC) treated with interferon (IFN) alpha-2a.

DESIGN

Prospective, non-comparative case series.

PARTICIPANTS

Five patients (8 eyes) with active vision-threatening SPC, who failed to respond and/or presented with side effects to the combination of steroid-cyclosporin-A or chlorambucil, at a tertiary care referral center.

INTERVENTION

The patients were treated with IFN alpha-2a (4,500,000 IU, 3 times a week for the first 3 months, followed by once a week for the next 3 months). Prednisone was also given initially, then tapered and discontinued.

MAIN OUTCOME MEASURES

Visual acuity, control of inflammation, duration of drug-free disease remission, and side effects of IFN alpha-2a therapy.

RESULTS

Argon laser photocoagulation (ALP) was applied in three eyes with extrafoveal choroidal neovascular membrane (CNM). All active lesions, including complicating subfoveal CNM in one eye, resolved within six months. The patients had no recurrences and recovered (4 out of 8; 50%) or maintained (4 out of 8; 50%) useful vision during the 16-48-month follow-up. Except for flu-like symptoms at the beginning of the therapy, no noticeable adverse reaction was observed.

CONCLUSIONS

IFN alpha-2a seems to be a novel treatment option for SPC. In the five patients (8 eyes) with SPC, who were intolerant or unresponsive to the combination of steroid-cyclosporin-A or chlorambucil, IFN alpha-2a treatment prevented recurrences and stabilized the lesions during the long-term follow-up (16-48 months). These promising results support the use of this mode of therapy in controlled clinical trials.

Future pharmacological treatment options for nonexudative and exudative age-related macular degeneration

Age-related macular degeneration (AMD) is the leading cause of irreversible vision loss in the industrialised world. Within the past decade, researchers have introduced many promising prevention and treatment options in an attempt to minimise the central vision loss imparted from AMD. Based on large-scale, randomised, prospective, placebo-controlled trials, a specially formulated combination of the antioxidants vitamin C, vitamin E, beta-carotene, copper and zinc is the only proven means of AMD prophylaxis. Thermal laser photocoagulation and photodynamic therapy with verteporfin are the only standard treatment options. However, efficacy is limited and treatment is only applicable to a minority of AMD patients. Thus, alternative pharmacological interventions are in all phases of clinical development. Researchers are guardedly optimistic that these advances may change the entire approach to AMD management in the near future. This review article will detail the currently accepted treatment options, as well as describe several of the more promising investigational pharmacological approaches to AMD.

MICROBIOLOGIC STUDIES OF MULTIPLE-DOSE CONTAINERS OF TRIAMCINOLONE ACETONIDE AND LIDOCAINE HYDROCHLORIDE

PURPOSE

Reports of high endophthalmitis rates following intravitreal triamcinolone acetonide (TA) injection have raised concerns about safety. One possible risk factor is the use of multiple-dose containers. The purpose of this study was to determine whether there is a substantial risk of contamination of multiple-dose containers.

METHODS

Microbiologic Challenge Study: Suspensions of a known quantity of several microorganisms were placed in samples of TA to determine whether the preservative, benzyl alcohol 0.99%, is rapidly bacteriocidal. Simulated Clinical Use Study: After ten days of simulated clinical use of multiple-dose containers of TA and lidocaine hydrochloride 4%, samples were cultured. Additionally, samples from lidocaine containers in actual clinical use were cultured.

RESULTS

Microbiologic Challenge Study: Four of five challenge organisms demonstrated moderate growth, even after 24 hours of exposure to the benzyl alcohol preservative. Simulated Clinical Use Study: Simulated clinical use of multiple-dose containers of TA and lidocaine did not result in contamination, nor did actual clinical use of multiple-dose lidocaine containers.

CONCLUSIONS

No culture-proven contamination of multiple-dose containers in simulated or actual clinical use was found. However, TA suspension is capable of harboring viable bacterial and fungal pathogens. The use of multiple-dose containers of triamcinolone for intravitreal injections is therefore discouraged.

Visual improvement following trans-Tenon’s retrobulbar triamcinolone acetonide infusion for polypoidal choroidal vasculopathy

PURPOSE

To report a case of polypoidal choroidal vasculopathy (PCV) that was successfully treated by sub-Tenon's infusion of triamcinolone acetonide (TA).

METHODS

A 56-year-old Japanese man had PCV in his left eye with vision of 20/32. Fluorescein angiography demonstrated a hyper-fluorescent spot, and indocyanine green angiography showed marked leakage of dye from the polypoidal vessel. Optical coherence tomography showed anterior protrusion of highly reflective layers and subretinal fluid.

RESULTS

The patient underwent trans-Tenon's retrobulbar infusion of 12 mg TA. Subsequently, the reddish-orange lesion decreased in size and elevation with complete resolution of the serous retinal detachment, and visual acuity improved to 20/20. Visual acuity remained good through a 15-month follow-up during which the patient was free of endophthalmitis and elevated intraocular pressure.

CONCLUSIONS

Trans-Tenon's retrobulbar TA infusion is potentially effective in treating PCV.

Photodynamic therapy for inflammatory choroidal neovascularisation unresponsive to immunosuppression

AIM

To report on visual and angiographic outcomes of a consecutive series of patients with inflammatory choroidal neovascular membranes (CNV) unresponsive to systemic immunosuppression treated with photodynamic therapy (PDT).

METHODS

The medical records of six consecutive patients with inflammatory CNVs that failed to respond to systemic immunosuppression and that later underwent PDT were retrospectively reviewed. Patient demographics, visual acuity, and fluorescein angiographic findings were evaluated.

RESULTS

There were five females and one male with a mean age of 40.8 years (range 35-58 years). Four patients had clinical features consistent with punctate inner choroidopathy and two with presumed ocular histoplasmosis. In all cases clinical signs of CNV activity, including subretinal fluid, subretinal blood, hard exudates, and/or recent decrease in visual acuity were present prior to PDT. All patients had been treated with high dose systemic immunosuppressants, which failed to induce regression of the CNV and/or to improve vision. The CNVs were subfoveal in five patients and juxtafoveal in one; all were classified as predominantly classic. Following PDT an improvement in vision occurred in all cases (median improvement of 18 letters, range 3-42 letters). At last follow up, signs of decreased activity in the CNV were detected in all cases. Patients were followed for a median of 10 months (range 9-20 months).

CONCLUSION

PDT appears to be a useful option in the management of patients with inflammatory CNVs unresponsive to immunosuppressive therapies.

Photodynamic therapy of subfoveal and juxtafoveal choroidal neovascularization in ocular histoplasmosis syndrome: a retrospective case series

PURPOSE

To evaluate the safety and effect on visual acuity of photodynamic therapy (PDT) with verteporfin in patients with subfoveal and juxtafoveal choroidal neovascular membranes from ocular histoplasmosis syndrome (OHS).

METHODS

Retrospective case series. The visual outcome of 11 patients with subfoveal (n = 6) and juxtafoveal (n = 5) choroidal neovascularization treated with PDT was reviewed. At 1 to 3 months of follow-up, retreatment with PDT was performed if angiography showed leakage.

RESULTS

Within the subfoveal group, 3 patients (50%) had improved vision (two or more lines better than initial vision), 2 patients (33.3%) had no change in vision (within 1 line), and 1 (16.7%) lost four lines of vision. At last follow-up, 3 patients (50%) had vision between 20/20 and 20/40 compared with only 1 patient (16.6%) at the initial visit. Mean follow-up was 13.7 months. Within the juxtafoveal group, 3 patients (60%) had improved vision, 1 patient (20%) had no change in vision, and 1 patient (20%) lost nine lines of vision. At last follow-up, 3 of 5 patients (60%) had vision between 20/20 and 20/40 compared with 2 patients (40%) at the initial visit. Mean follow-up was 10.2 months. No significant adverse effects were reported.

CONCLUSION

PDT is a safe and promising option for patients with OHS with choroidal neovascularization that is subfoveal or juxtafoveal.

Corticosteroids in posterior segment disease: an update on new delivery systems and new indications

PURPOSE OF REVIEW

Corticosteroids are traditionally used for inflammatory disorders because of their ability to diminish neutrophil transmigration, limit access to sites of inflammation, and decrease cytokine production. More recently, however, investigators have focused on the angiostatic and antipermeability properties of corticosteroids for posterior segment diseases such as age-related macular degeneration (AMD), diabetic retinopathy, and macular edema. Both new angiostatic and traditional corticosteroids are currently undergoing evaluation as new delivery techniques such as intravitreal injection and intraocular sustained-release devices facilitate high local angiostatic and antipermeability concentrations while minimizing extraocular toxicity. The purpose of this review is to discuss recent work concerning both the mechanism and effectiveness of these newer treatments.

RECENT FINDINGS

Steroids may exert a beneficial effect in AMD-related choroidal neovascular membranes (CNVM) through inhibition of CNVM-promoting macrophages and direct inhibition of angiogenic growth factors. They may also alter extracellular matrix turnover and inhibit matrix metalloproteinases involved in CNVM formation. Intravitreal steroid injections potently inhibit experimental CNVM in primates and rats and have shown promise in some early human pilot trials. In proliferative diabetic retinopathy, steroids may directly inhibit growth factors such as vascular endothelial derived growth factor and inhibit leukocytes that play an important role in early microvascular alterations. Intravitreal steroid injections inhibit experimental preretinal neovascularization in pigs and rats, and rubeosis in some early human studies. In addition, the effect of steroids on vascular permeability has led to their use for macular edema from many causes such as diabetes and venous occlusive disease.

SUMMARY

The use of steroids to treat a number of retinal diseases is gaining wide spread acceptance. The apparent short-term success must be balanced by the fact that the long-term safety and efficacy have yet to be determined for any of these approaches. A number of large randomized prospective clinical trials of steroid compounds and new delivery systems are currently under way for AMD, diabetic retinopathy, uveitis, and other retinovascular diseases, and hopefully these studies will provide guidance about the use of these new modalities.

Pharmacologic therapy for diabetic retinopathy

Diabetic retinopathy remains one of the major causes of acquired blindness in developed nations. This is true despite the development of laser treatment, which can prevent blindness in the majority of those who develop macular oedema (ME) or proliferative diabetic retinopathy (PDR). ME is manifest by retinal vascular leakage and thickening of the retina. The hallmark of PDR is neovascularisation (NV)--abnormal angiogenesis that may ultimately cause severe vitreous cavity bleeding and/or retinal detachment. Pharmacologic therapy aimed specifically at preventing vascular leakage and NV would be a welcome addition to the armamentarium. PDR and ME could be prevented by improved metabolic control or by pharmacologically blunting the biochemical consequences of hyperglycaemia (e.g., with aldose reductase inhibitors, inhibitors of non-enzymatic glycation or by protein kinase C [PKC] inhibition). The angiogenesis in PDR could be treated via growth factor (e.g., vascular endothelial growth factor [VEGF], insulin like growth factor-1 [IGF-1]) blockade, integrin (e.g., alpha-v beta-3) blockade, extracellular matrix alteration (e.g., with steroid compounds) or interference with intracellular signal transduction pathways (e.g., PKC and mitogen activated protein kinase [MAPK] pathway proteins). Some of these antiangiogenic agents may also prove useful for treating or preventing ME. Numerous potentially useful antiangiogenic compounds are in development; two drugs are presently in clinical trials for treatment of the preproliferative stage of PDR, while two are in clinical trials for treatment of ME.

Current and Future Treatment Options for Nonexudative and Exudative Age-Related Macular Degeneration

Age-related macular degeneration (AMD) is the leading cause of irreversible visual loss in the industrialised world. Although relatively simple to diagnose through direct visualisation augmented with rapid sequence fluorescein angiography, treatment has presented a far greater challenge because the true aetiology of AMD is largely unknown. Within the past decade, researchers have introduced many new, potentially promising treatment and prevention options in an attempt to minimise the damage imparted from AMD. They capitalise on many of the theoretical and known factors contributing to AMD progression. A high-dose of an orally administered combination of the antioxidants ascorbic acid (vitamin C), tocopherol (vitamin E) and beta-carotene, in addition to copper and zinc, is the only widely accepted preventive therapy. Thermal laser photocoagulation and verteporfin photodynamic therapy are the only standard treatment options available based on large scale, randomised, prospective, placebo-controlled trials; however, efficacy is limited and only a minority of patients who present with AMD are eligible for these treatments. Many other preventive and treatment options are in all phases of clinical studies and expected to change the entire approach to AMD management in the near future. For example, alternative antioxidants, drusen ablation, apheresis and HMG-CoA reductase inhibitors have shown promise in some studies by preventing or slowing the progression of certain forms of AMD. In addition, alternative photodynamic therapies, low-intensity laser, antiangiogenic medications, radiation treatment and surgery have demonstrated the ability, albeit to differing degrees, to inhibit or possibly even reverse the severe vision loss often associated with AMD characterised by choroidal neovascularisation.

Possible Benefits of Triamcinolone-Assisted Pars Plana Vitrectomy for Retinal Diseases

PURPOSE

To study the advantages and complications of triamcinolone acetonide (TA)-assisted pars plana vitrectomy (PPV) for various retinal diseases.

METHODS

This report is an interventional case series and nonrandomized study. One hundred seventy-seven eyes from 158 patients underwent PPV with or without TA. Group TA(+) consisted of 94 eyes and group TA(-) consisted of 83 eyes. The improvement in vision and postoperative complications were prospectively studied.

RESULTS

Sixty-two percent of the eyes in group TA(+) and 49% of the eyes in group TA(-) had improved vision after surgery (P = 0.34). Twelve eyes in group TA(+) and 12 eyes in group TA(-) had an intraocular pressure higher than 21 mmHg after the operation, with no statistically significant difference (P = 0.63). Four eyes with proliferative diabetic retinopathy in group TA(+) and five eyes with proliferative diabetic retinopathy in group TA(-) needed an additional filtering surgery. Group TA(+) (five eyes) had a lower incidence (P = 0.041) of reoperation caused by preretinal fibrous membrane formation than group TA(-) (13 eyes). No apparent corneal disorder or infectious signs were found in any eyes.

CONCLUSIONS

Triamcinolone acetonide-assisted PPV appears to be potentially useful to reduce the incidence of reoperation owing to preretinal fibrosis with no serious complications.

Intravitreal triamcinolone for choroidal neovascularization in ocular histoplasmosis syndrome

PURPOSE

To report the effects of intravitreal triamcinolone acetonide injections for subfoveal and juxtafoveal choroidal neovascularization (CNV) in ocular histoplasmosis syndrome.

METHODS

In a retrospective analysis, the proportion of eyes that gained >or=5 or lost >or=5 and >or=15 Early Treatment of Diabetic Retinopathy Study (ETDRS) letters, best-corrected visual acuity using ETDRS letter score (VA), greatest linear dimension (GLD), and treatment side effects were assessed.

RESULTS

Ten patients (five subfoveal, five juxtafoveal CNV; median follow-up: 17 months; range, 6-41 months) were evaluated. Thirty percent gained >or=5 letters, 20% lost 5 to 14 letters, and 50% maintained stable VA. Overall, mean VA and GLD remained stable. Side effects were transient intraocular pressure elevation and mild cataract development.

CONCLUSIONS

Intravitreal triamcinolone acetonide for CNV resulting from OHS was found to be relatively safe and showed good visual outcome for both subfoveal and juxtafoveal CNV. Further studies are warranted to evaluate this treatment.

Choroidal neovascular membrane inhibition in a laser treated rat model with intraocular sustained release triamcinolone acetonide microimplants

AIM

To determine if intravitreal microimplants containing triamcinolone acetonide (TAAC) inhibit experimental fibrovascular proliferation (FVP) induced by laser trauma in a rat as a model of choroidal neovascular membranes (CNVMs).

METHODS

20 anaesthetised male Brown Norway rats received a series of eight krypton red laser lesions per eye (647 nm, 0.05 s, 50 micro m, 150 mW). Three types of sterilised TAAC microimplant designs were evaluated: implant A consisting of 8.62% TAAC/20% polyvinyl alcohol (PVA) matrix (by dry weight); implant B consisting of 3.62% TAAC/20% PVA matrix; and implant C consisting of a dual 8.62% TAAC/20% PVA matrix design combined with a central core (0.5 mm) of compressed TAAC to extend the implant release time. For each animal studied, one eye received one of the three aforementioned TAAC implant designs, while the fellow eye received a control implant consisting of PVA but without TAAC. The animals were sacrificed at day 35 and ocular tissues were processed for histological analysis. Serial histological specimens were methodically assessed in a masked fashion to analyse each laser lesion for the presence or absence of FVP; maximum FVP thickness for each lesion was measured from the choriocapillaris.

RESULTS

All three types of TAAC implants inhibited FVP relative to controls in a statistically significant fashion. In the eyes that received implant A (n = 8), the mean thickness of the recovered lesions (n = 36) measured 32 (SD 22) micro m, compared to 52 (30) micro m (p <0.005) for the recovered lesions (n = 40) from the fellow control eyes. In the eyes that received implant B (n = 6), the mean thickness of the recovered lesions (n = 31) measured 28 (15) micro m, compared to 50 (29) micro m (p <0.001) for the lesions (n = 19) recovered from the fellow control eyes. In the eyes that received implant C (n = 6), the mean thickness of the recovered lesions (n = 21) measured 39 (24) micro m, compared to 65 (30) micro m (p <0.001) for the lesions (n = 39) recovered from the fellow control eyes.

CONCLUSIONS

All three of the tested TAAC microimplant designs produced potent inhibition of FVP in a rat model of CNVMs. There were no differences in inhibition of FVP between the three different types of implants evaluated. This study provides evidence that: (1) corroborates previous investigations that propose TAAC as a potential treatment for CNVMs in humans, and (2) demonstrates TAAC can be effectively delivered via long acting sustained release intraocular microimplants. It should be noted, however, that the FVP observed in this rat laser trauma may not reflect the CNVM observed in human with exudative age related macular degeneration (AMD).

Effect of squalamine on iris neovascularization in monkeys

PURPOSE

To investigate the effect of squalamine, an antiangiogenic aminosterol, in an experimental model of iris neovascularization.

METHODS

Iris neovascularization was created in cynomolgus monkeys by occluding retinal veins with an argon laser and inducing persistent hypotony with a central corneal suture. Twenty-four eyes were treated in three groups. In Group 1, four eyes were injected intravitreally with 3 microg/0.1 mL squalamine and four eyes with balanced saline solution (controls) immediately after vein occlusion (day 1); injections were repeated every 3 days for 3 weeks. In Group 2, 1 mg/kg squalamine was administered with intravenous infusion in dextrose 5% in four animals; four control animals received only dextrose. Infusions began on day 1 and were repeated every 3 days for 3 weeks. In Group 3, after development of iris neovascularization on day 7, 1 mg/kg squalamine was injected systemically in four animals; four control animals received dextrose 5%. Monkeys were examined by slit-lamp biomicroscopy and underwent color photography and fluorescein angiography.

RESULTS

Group 1: All eyes, treated and control, developed intense and persistent rubeosis iridis. Group 2: Two of the four treated eyes in this group developed minimal iris neovascularization; the other two had no iris neovascularization. All four control eyes developed intense, persistent iris neovascularization. Group 3: All eyes developed extensive rubeosis iridis; iris neovascularization regressed in all four treated eyes after squalamine injections. Two of four treated eyes retained minimal iris neovascularization; two showed complete regression of rubeosis iridis. Rubeosis iridis completely regressed in two of the four control eyes; the remaining two control eyes had intense, persistent iris neovascularization.

CONCLUSIONS

Intravitreally injected squalamine did not affect the development of iris neovascularization; however, systemic squalamine injection inhibited the development of iris neovascularization and caused partial regression of new vessels in a primate model.

Pathologic myopia: where are we now?

PURPOSE

To describe current concepts and available treatments for pathologic myopia.

DESIGN

Review of experimental and clinical studies.

METHODS

The demography, natural history, medical and surgical treatments for choroidal neovascular membrane, vitreoretinal interface disorders and future strategies for pathologic myopia are reviewed.

RESULTS

Several medical and surgical modalities are currently available to treat various complications of pathologic myopia. Macular translocation appears to stabilize or improve visual function in many eyes with choroidal neovascularization.

CONCLUSION

Newer strategies are emerging to better ameliorate or prevent the complications of pathologic myopia.

Photodynamic therapy of subfoveal choroidal neovascularization with verteporfin in the ocular histoplasmosis syndrome: one-year results of an uncontrolled, prospective case series

OBJECTIVE

To evaluate the safety and effect on visual acuity of photodynamic therapy with verteporfin (Visudyne, Novartis AG) in patients with subfoveal choroidal neovascularization (CNV) secondary to the ocular histoplasmosis syndrome (OHS).

DESIGN

Open-label, three-center, noncomparative prospective case series.

PARTICIPANTS

OHS patients with subfoveal CNV lesions no larger than 5400 micro m in greatest linear dimension (GLD) with classic or occult CNV extending under the geometric center of the foveal avascular zone and best-corrected visual acuity letter score of 73 to 34 (approximate Snellen equivalent 20/40-20/200).

METHODS

Twenty-six patients received verteporfin (6 mg/m(2)) infused IV over 10 minutes. Fifteen minutes after the start of infusion, a laser light at 689 nm delivered 50 J/cm(2) at an intensity of 600 mW/cm(2) over 83 seconds using a spot size with a diameter 1000 micro m larger than the GLD of the lesion. At 3-month follow-up examinations, retreatment with the same regimen was applied if angiography showed fluorescein leakage. Safety assessments were also made.

MAIN OUTCOME MEASURES

Visual function measurements were the changes from baseline in visual acuity and contrast sensitivity scores and the proportion of patients who, based on best-corrected visual acuity scores, (1) gained 7 or more letters, (2) lost 8 or more letters, and (3) lost 15 or more letters.

RESULTS

One patient was omitted from the study at the month 3 examination for not meeting the visual acuity eligibility requirements at baseline. By the month 12 examination, but excluding any retreatment at that visit, patients had received an average of 2.9 treatments of a maximum of 4 possible treatments. The month 12 median improvement from baseline in visual acuity of the remaining 25 patients was 7 letters, and median contrast sensitivity improved by 2 letters. Median visual acuity improvement was also 7 letters when three patients, who failed to meet all photographic eligibility requirements at baseline, were excluded. At the month 12 examination, 14 (56%) patients gained 7 or more letters of visual acuity from baseline, whereas 4 (16%) patients lost 8 or more letters, of which 2 (8%) lost 15 or more letters. No serious systemic or ocular adverse events were reported.

CONCLUSIONS

Median visual acuity improved after verteporfin therapy for at least 1 year in a small uncontrolled prospective case series of patients with subfoveal CNV caused by OHS. Verteporfin therapy seemed to be safe and well tolerated in these patients. Two-year data from this study will provide important, additional information on the safety and effect of verteporfin therapy for the treatment of subfoveal CNV secondary to OHS.

Presumed ocular histoplasmosis syndrome: update on epidemiology, pathogenesis, and photodynamic, antiangiogenic, and surgical therapies

Presumed ocular histoplasmosis involves the classic triad of discrete atrophic choroidal scars in the macula or midperiphery known as histo spots, peripapillary atrophy, and choroidal neovascularization, which leads to severe loss of central vision. The histo spots from which the choroidal neovascularization develop do not show active inflammation but do represent focal defects in Bruch membrane that could facilitate development of choroidal neovascularization. The macular photocoagulation studies unequivocally show the benefit of photocoagulation compared with observation in reducing the risk of vision loss in patients with presumed ocular histoplasmosis, well defined extrafoveal or juxtafoveal choroidal neovascularization, and choroidal neovascularization in the peripapillary area. However, laser treatment itself causes an absolute scotoma correlating with the site of the laser photocoagulation scar, and subfoveal choroidal neovascularization is not amenable to laser photocoagulation because this would cause a blinding central scotoma. Consequently, other treatments have been sought. The Verteporfin in Ocular Histoplasmosis study evaluated photodynamic therapy for subfoveal choroidal neovascularization caused by presumed ocular histoplasmosis and demonstrated stabilization of the choroidal neovascularization and visual acuity benefit. In addition to photodynamic therapy, antiangiogenic compounds are being developed for choroidal neovascularization caused by age-related macular degeneration, and these agents will likely be of benefit in presumed ocular histoplasmosis associated choroidal neovascularization. Finally, submacular surgery for the removal of subfoveal choroidal neovascularization has promising results. The results of these research efforts will produce more effective therapeutic approaches in the future.

Immunological and aetiological aspects of macular degeneration

Aetiological and immunological aspects of AMD, a leading cause of blindness in Western countries, have been reviewed. Developmental studies suggest that anatomical features unique to the fovea result in a critical relationship between metabolic demand and blood supply at the macula, which is maintained throughout life. Recent studies show a sufficient degree of consistency in the link between smoking and both dry and wet AMD to regard it as causative. Dry AMD is considered to be the natural endstage of the disease; epidemiological and morphological studies point to choroidal vascular atrophy as the causative event and it is suggested that signals associated with acute vascular compromise lead to the development of subretinal neovascularisation. The relationship between sub-pigment epithelial deposits, including basal laminar deposit, and the pathogenesis of AMD is examined. Much of the literature is consistent with a choroidal origin for the constituents of drusen. The blood-retinal barrier preserves the physiological environment of the neural retina and limits inflammatory responses. The factors, including cytokines, adhesion molecules and the presence of resident immunocompetent cells (microglia), which determine the immune status of the retina are considered. Historical descriptions of the involvement of inflammatory cells are provided, evidence implicating inflammation in the pathogenesis of AMD involving macrophages, giant cells and microglia has been derived from observations of human and animal subretinal neovascular lesions. The role of humoral factors such as anti-retinal autoantibodies and acute phase proteins together with clinical observations has been surveyed. Taken together these data demonstrate the involvement of both cellular and humoral immunity in the pathogenesis of AMD. It remains to be determined to what degree the influence of immunity is causative or contributory in both wet and dry AMD, however, the use of anti-inflammatory agents to ameliorate the condition further indicates the existence of an inflammatory component.

Anti-angiogenic therapy of proliferative diabetic retinopathy

Proliferative diabetic retinopathy (PDR) remains one of the major causes of acquired blindness in developed nations. This is true despite the development of laser treatment, which can prevent blindness in the majority of those who develop this complication. The hallmark of PDR is neovascularisation (NV), abnormal angiogenesis that may ultimately cause severe vitreous cavity bleeding and/or retinal detachment. Pharmacologic therapy aimed at preventing NV, as an adjunct to laser treatment, or as an alternative to laser treatment, would be a welcome addition to the armamentarium. PDR could be prevented by improved metabolic control or by pharmacologically blunting the biochemical consequences of hyperglycaemia (e.g., with aldose reductase inhibitors, inhibitors of non-enzymatic glycation or by protein kinase C (PKC) inhibition). The angiogenesis in PDR could be treated via growth factor (e.g., vascular endothelial growth factor (VEGF), insulin like growth factor-1) blockade, integrin (e.g., alpha-v beta-3) blockade or extracellular matrix alteration (e.g., with steroid compounds), or interference with intracellular signal transduction pathways (e.g., PKC and mitogen activated protein kinase pathway proteins). Numerous potentially useful anti-angiogenic compounds are in development, but two drugs are presently in clinical trials for the treatment of the preproliferative stage of PDR.