Submacular surgery trials randomized pilot trial of laser photocoagulation versus surgery for recurrent choroidal neovascularization secondary to age-related macular degeneration: I. Ophthalmic outcomes submacular surgery trials pilot study report number 1

The Next Generation of Molecular and Cellular Therapeutics for Inherited Retinal Disease

Inherited retinal degenerations (IRDs) are a diverse group of conditions that are often characterized by the loss of photoreceptors and blindness. Recent innovations in molecular biology and genomics have allowed us to identify the causative defects behind these dystrophies and to design therapeutics that target specific mechanisms of retinal disease. Recently, the FDA approved the first in vivo gene therapy for one of these hereditary blinding conditions. Current clinical trials are exploring new therapies that could provide treatment for a growing number of retinal dystrophies. While the field has had early success with gene augmentation strategies for treating retinal disease based on loss-of-function mutations, many novel approaches hold the promise of offering therapies that span the full spectrum of causative mutations and mechanisms. Here, we provide a comprehensive review of the approaches currently in development including a discussion of retinal neuroprotection, gene therapies (gene augmentation, gene editing, RNA modification, optogenetics), and regenerative stem or precursor cell-based therapies. Our review focuses on technologies that are being developed for clinical translation or are in active clinical trials and discusses the advantages and limitations for each approach.

Ab-interno surgical technique for the implantation of a wireless subretinal prosthesis in mini-pigs

We sought to describe the surgical techniques required in the ab-interno method to implant subretinal prostheses in mini-pigs and suggest tips to facilitate optimal outcomes. During vitrectomy, the use of valved trocar cannulas was essential to stabilize the detached retina and implanted chip. As a first step in retinal detachment, a 23-gauge cannula with very small amount of viscoelastic material was used to establish the retinal hole and promote retinal detachment. Then, balanced salt solution was applied to increase the retinal detachment and diathermy was used to make opening for subretinal prosthesis. For easy positioning of the subretinal prosthesis, a curved laser probe was adopted when handling the subretinal prosthesis under the retina. After surgery, the sclerotomy sites were tightly sutured to prevent silicone oil leakage. Without special equipment, such as a 41-gauge tip, retinal detachment could be induced easily, while the prosthesis was also successfully inserted and manipulated under the retina without an iatrogenic retinal tear. Two weeks after the operation, the oil fully occupied the intraocular volume without leakage. The subretinal prosthesis remained stable without complication. Understanding the principle of the ab-interno method and considering several tips for improving surgical access may help to enhance surgical success rates of subretinal prostheses implantation.

Ranibizumab plus fufang xueshuantong capsule versus ranibizumab alone for exudative age-related macular degeneration

Objective

To compare the efficacy of ranibizumab plus fufang xueshuantong capsule (cFXST) with the efficacy of ranibizumab alone in treatment of exudative age-related macular degeneration.

Methods

This prospective, randomized, controlled, pilot study included 38 eyes from 38 patients with exudative age-related macular degeneration (AMD) that were randomly allocated into two cohorts of 19 eyes each: ranibizumab (C_r) and ranibizumab plus cFXST (C_fr). All patients received three monthly injections of ranibizumab. Patients in C_fr also received daily oral supplementation of cFXST. Best corrected visual acuity (BCVA) and thickness of the choroidal neovascularization-pigment epithelial detachment (CNV-PED) complex (measured by optical coherence tomography) were recorded at baseline and at 1 and 3 months after the first intravitreal injection of ranibizumab.

Results

In the C_fr, the CNV-PED complex thickness was reduced by 31.7% and 36.1% at 1 and 3 months, respectively; these reductions were significantly greater than the 19.7% and 24.2% reductions in the C_r. BCVA improvement was significantly greater in the C_fr than in the C_r after 3 months; the proportion of patients with functional response was also greater in the C_fr than in the C_r (16/16 vs. 8/17).

Conclusion

Oral cFXST increases the efficacy of short-term ranibizumab treatment for exudative AMD.

Is subretinal surgery feasible for a non-responsive juxtafoveal type 2 choroidal neovascular membrane?

Purpose

To describe the long-term outcome of a patient with multifocal choroiditis, who underwent surgical removal of a type 2 choroidal neovascular membrane employing 23 G pars plana vitrectomy.

Observations

A 50-year-old man was treated with 3 monthly intravitreal bevacizumab injections, but despite treatment, visual acuity continued to worsen from 20/40 to 20/100, and bleeding was not receding. A minimal invasive pars plana vitrectomy was performed for surgical removal of the neovascular complex without any complicating incident. Subsequent visual acuity was 20/25 for more than eleven years.

Conclusions and Importance

Surgical removal of choroidal neovascular membranes employing minimal invasive surgery in addition to anti-VEGF therapy, and OCT evaluation can be a viable approach for selected cases of juxtafoveal type 2 CNV.

Prospective Evaluation of Patients With X-Linked Retinoschisis During 18 Months

Purpose

Prospective evaluation of patients with X-linked retinoschisis (XLRS).

Methods

Fifty-six males XLRS patients, age ≥7 years, had retinal structure and function tests performed every 6 months during an 18-month period.

Results

Best corrected visual acuity (BCVA) was abnormal (mean ± SD logMAR 0.57 ± 0.32 OD and 0.50 ± 0.27 OS), with weak correlation between visual acuity and age (R = -0.24, P = 0.0095). Mean cyst cavity volume (CCV) determined on optical coherence tomography showed weak correlation with age (R = -0.33, P = 0.0009) and no correlation with visual acuity. Subjects had modest reduction in mean kinetic and static perimetry results, reduced b-wave amplitude on electroretinography, abnormal reading speed results, and decreased visual function quality of life scores. Contrast sensitivity results were normal in 85 of 99 eyes tested. Most subjects had no meaningful change in BCVA during follow-up. Subjects who started carbonic anhydrase inhibitor (CAI) treatment at enrollment had improved BCVA (mean ± SD change 3.15 ± 7.8 ETDRS letters, with increase of ≥15 ETDRS letters at 8 of 110 visits [in 3 subjects]). There were no significant changes in other parameters tested.

Conclusions

Structural and functional results were stable during the 18-month follow-up period. Some patients starting CAI treatment at the baseline visit showed improvement in BCVA that was not correlated with changes in CCV. Natural history data such as these will be important for comparisons to the changes in measures of retinal structure and function following gene replacement therapy in patients with XLRS.

Removal of choroidal neovascular membrane in a case of macular hole after anti-VEGF therapy for age-related macular degeneration

Purpose

The formation of macular hole after receiving anti-vascular endothelial growth factor (anti-VEGF) therapy is rare. We report a case of macular hole that occurred after intravitreal injection of an anti-VEGF agent for age-related macular degeneration (AMD) in a patient, who underwent vitrectomy combined with choroidal neovascularization (CNV) removal.

Observations

A 64-year-old female with AMD affecting her right eye received an intravitreal injection of an anti-VEGF agent. After treatment, we identified a full thickness macular hole (MH) that was associated with the rapid resolution of the macular edema and contraction of the CNV. After performing vitrectomy combined with CNV removal, the MH closed and her visual acuity improved. Examination of the removed CNV revealed a network of microvessels devoid of pericytes.

Conclusions and importance

The present findings suggest that rapid resolution of macular edema and contraction of the CNV and/or mild increase in the vitreous traction after anti-VEGF therapy could potentially cause MH. CNV removal via the MH may be an acceptable procedure, if the MH remains open, the CNV is of the classic type, and it spares a central portion of the fovea.

Tissue plasminogen activator-assisted vitrectomy for submacular hemorrhage due to age-related macular degeneration

Purpose:

The purpose of this study was to evaluate the treatment efficacy of vitrectomy combined with subretinal recombinant tissue plasminogen activator (r-tPA) and factors affecting visual improvement in patients with submacular hemorrhage (SMH) due to neovascular age-related macular degeneration (nAMD).

Materials and Methods:

Medical records of 17 consecutive patients diagnosed with SMH secondary to nAMD were retrospectively reviewed. The initial surgical procedure involved a 23-gauge transconjunctival vitrectomy, subretinal r-tPA application through a self-sealing inferior retinotomy, and sulfur hexafluoride gas for tamponade in all patients. The duration, size, and thickness of the hemorrhage and the pre- and post-operative visual acuity (VA) using a Snellen chart were recorded. VA was converted to logMAR for statistical analysis.

Results:

The average duration and size of the SMH were 12.8 ± 18.2 days and 8.6 ± 5.3 disc areas, respectively. The mean follow-up time was 16.9 ± 4.7 months. A statistically significant visual improvement was found when comparing initial VA with postoperative best-corrected VA (BCVA) and final BCVA (Wilcoxon rank test, P ≤ 0.01). There was no significant correlation between the size of the hemorrhage and postoperative BCVA and final BCVA (Spearman's rho test). There was no statistically significant correlation between the initial VA and postoperative BCVA and final BCVA (Spearman's rho test). There was no significant correlation between the duration of hemorrhage and postoperative BCVA and final BCVA (Spearman's rho test). The preoperative thickness of hemorrhage (747.5 ± 30 μm) was not correlated with postoperative BCVA or final BCVA (Pearson's test).

Conclusions:

Vitrectomy combined with subretinal r-tPA injection and gas tamponade is an effective surgical intervention to preserve VA in selected patients with apparent SMH.

Stem Cell-Based Therapy for Diseases of the Retinal Pigment Epithelium: From Bench to Bedside

Age-related macular degeneration (AMD) represents a leading cause of blindness in the elderly, and Stargardt's macular dystrophy (SMD) is the most common form of juvenile-onset macular degeneration. Dry AMD and SMD share an underlying pathophysiology, namely dysfunction and ultimately loss of the retinal pigment epithelium (RPE), suggesting that RPE transplantation may offer a potential treatment strategy for both patient populations. Stem cells have emerged as a promising source of replacement RPE. During the past 15 years, extraordinary strides have been made in the identification, characterization, and differentiation of stem cells. Recently, this large body of basic science and preclinical research has been translated to patient care with the publication of results from Phase 1/2 trials demonstrating safety of transplantation of human embryonic stem cell (hESC)-derived RPE into patients with AMD and SMD. While significant challenges remain before dry AMD and SMD become treatable diseases, the goal has become more tangible.

Time trends in personnel certification and turnover in the Collaborative Ocular Melanoma Study

Background The purpose of this analysis was to examine and quantify the coordinating center workload in regard to certification and turnover of clinical personnel who participated in the Collaborative Ocular Melanoma Study (COMS).

Methods The COMS was a set of multicenter, multidisciplinary randomized clinical trials conducted to evaluate radiotherapy for initial treatment of choroidal melanoma, a primary eye cancer. Patients were screened, enrolled, treated, and followed for mortality and clinical outcomes at 43 clinical centers in the United States and Canada, beginning late in 1986. Clinical centers were added to the COMS during three calendar periods. Training and certification of clinical personnel was performed by five resource centers and coordinated at the COMS coordinating center. A personnel database was maintained at the coordinating center for tracking certification progress, recertification, transfers and resignations. Certification records were analyzed for the period 1986 through 1998 when patient accrual and treatment were completed.

Results Clinical personnel (929 individuals) were certified for one or more of nine distinct roles in the COMS, resulting in 1342 certifications; 26% were certified for two or more positions. The total number certified for each role ranged from 114 to 208. Certifications per year ranged from 260 in 1987 to 35 in 1997. The certification workload at the coordinating center rose following addition of each group of new clinical centers. It also increased in 1995 as a result of recertification of current personnel mandated by the external data monitoring committee.

Conclusions This analysis documented that training and certification were continuing tasks, and not limited to initiation of the study. Resignations and reassignments of certified personnel were responsible for 642 decertifications.

Clinical Trials in Retinal Dystrophies

Research development is burgeoning for genetic and cellular therapy for retinal dystrophies. These dystrophies are the focus of many research efforts due to the unique biology and accessibility of the eye, the transformative advances in ocular imaging technology that allows for in vivo monitoring, and the potential benefit people would gain from success in the field – the gift of renewed sight. Progress in the field has revealed the immense complexity of retinal dystrophies and the challenges faced by researchers in the development of this technology. This study reviews the current trials and advancements in genetic and cellular therapy in the treatment of retinal dystrophies and also discusses the current and potential future challenges.

Polypoidal Choroidal Vasculopathy in Asians

Age related macular degeneration (AMD) in Asians has been suggested to differ from their Western counterparts in terms of epidemiology, pathogenesis, clinical presentation and treatment. In particular, polypoidal choroidal vasculopathy (PCV) appears to be the predominant subtype of exudative AMD in Asian populations, in contrast to choroidal neovascularization secondary to AMD (CNV-AMD) in Western populations. Epidemiological data on PCV has been largely limited to hospital-based studies and there are currently no data on the incidence of PCV. Similarities and differences in risk factor profile between PCV and CNV-AMD point to some shared pathogenic mechanisms but also differential underlying mechanisms leading to the development of each phenotype. Serum biomarkers such as CRP, homocysteine and matrix metalloproteinases suggest underlying inflammation, atherosclerosis and deranged extracellular matrix metabolism as possible pathogenic mechanisms. In addition, recent advances in genome sequencing have revealed differences in genetic determinants of each subtype. While the standard of care for CNV-AMD is anti-vascular endothelial growth factor (VEGF) therapy, photodynamic therapy (PDT) has been the mainstay of treatment for PCV, although long-term visual prognosis remains unsatisfactory. The optimal treatment for PCV requires further clarification, particularly with different types of anti-VEGF agents and possible benefits of reduced fluence PDT.

Correlation of platelet activating factor and age-related macular degeneration

OBJECTIVE

To investigate the role of Platelet Activating Factor (PAF) in the pathogenesis and development of Age-Related Macular Degeneration (ARMD).

RESEARCH DESIGN AND METHODS

Fifty six patients with ARMD (24 patients with dry ARMD and 32 patients with wet ARMD) and 25 age-matched control participants underwent ophthalmological examination, including visual acuity measurement and evaluation of the retina. The participants were classified into three groups according to their retinal status, based on indirect fundoscopy, Optical Coherence Tomography and fluorescein angiography findings. In order to evaluate the concentrations of PAF in serum, blood samples were collected from all participants and were analyzed with ELISA technique.

RESULTS

The concentrations of PAF differed significantly according to macular lesions and were found to be lower in patients with ARMD than control participants.

CONCLUSIONS

PAF levels are decreased along with the severity of ARMD. Understanding the role of PAF in pathogenesis of ARMD could be the impetus for the development of new therapies field of treatment of ARMD or even other retinal diseases.

United Kingdom National Ophthalmology Database Study of Vitreoretinal Surgery: report 1; case mix, complications, and cataract

AIM

To report the vitreoretinal (VR) surgical case mix in the United Kingdom, the intraoperative complication rate of pars plana vitrectomy (PPV), and the incidence of post-vitrectomy cataract extraction.

METHODS

Participating hospitals prospectively collected ophthalmic data using a single electronic medical record system, with automatic extraction of anonymised data to a national database. This study included the subset of 11618 VR operations undertaken on 9619 eyes, of 8741 patients, over 8 years, from 27 sites. Surgical data included the indication for surgery, all procedure elements, and whether or not an intraoperative complication occurred. Post-vitrectomy cataract data were also analysed. The main outcome measures were a description of the indications for surgery, intraoperative PPV complication rate, and percentage of eyes undergoing post-vitrectomy cataract surgery (PVCS).

RESULTS

The most common indications for VR intervention were retinal breaks and rhegmatogenous retinal detachment (48.5%), macular hole (9.8%), epiretinal membrane (9.6%), and diabetic eye disease (7.3%). Overall, 7.8% of PPVs had at least one intraoperative complication-the most common were iatrogenic retinal breaks (3.2%), and lens touch (1.2-1.6% of phakic eyes). PVCS occurred in 50.2, 68.7, and 74.0% of eyes at 1, 2, and 3 years, respectively.

CONCLUSION

VR surgery is undertaken for a wide range of conditions, but a small number of diagnoses encompass the majority of cases. Intraoperative PPV complications are not uncommon, and post-vitrectomy cataract is to be expected in most phakic eyes.

Intervisit variability of visual parameters in Leber congenital amaurosis caused by RPE65 mutations

PURPOSE

To determine the intervisit variability of kinetic visual fields and visual acuity in patients with Leber congenital amaurosis (LCA) caused by mutations in the RPE65 (Retinal Pigment Epithelium-specific protein 65kDa) gene.

METHODS

RPE65-LCA patients (n = 20; ages 11-40 years) were studied on at least two visits separated by fewer than 120 days using Goldmann visual field (GVF) and ETDRS visual acuity (VA) in a retrospective review. GVFs were quantified by computing the spherical coordinates of their vertices and calculating the solid angle subtended, and reported in normalized solid-angle units (nsu) as a percentage of average normal field extent. Repeatability coefficients were calculated using 95% confidence intervals on log(10)-converted variables.

RESULTS

Visual field extents in RPE65-LCA spanned a wide range from 4 to 95 nsu. The repeatability coefficient was 0.248 (log(10)nsu), suggesting cutoffs for significant change (in nsu) of +77% for improvement and -44% for worsening. VA in RPE65-LCA ranged from logMAR = 0.14 to 1.96 (20/40 to 20/1250). The repeatability coefficient was 0.170 (logMAR) (±8.5 ETDRS letters). Comparisons with published studies of ungenotyped retinitis pigmentosa showed that the RPE65-LCA patients had higher variability in kinetic field extent. VA variability in RPE65-LCA fell within reported results for retinitis pigmentosa.

CONCLUSIONS

Variability data for GVF and VA are provided to permit interpretation of the significance of increases and decreases of these functional outcomes in ongoing and planned clinical trials of therapy for LCA caused by RPE65 mutations.

Treatment of age-related macular degeneration: focus on ranibizumab

Ranibizumab, a humanized antigen-binding fragment (Fab) that binds all isoforms of VEGF-A, significantly slows down loss of vision and causes significant visual improvement in many patients with choroidal neovascularization (CNV) due to exudative age-related macular degeneration (AMD). These benefits of intravitreal ranibizumab apply to all angiographic subtypes of neovascular AMD and across all lesion sizes when the drug is injected at monthly intervals as shown in two pivotal phase III trials (ANCHOR and MARINA). The results from the PrONTO study suggest that less frequent treatment with ranibizumab through a variable dosing regimen dependent on optical coherence tomography (OCT) findings is a treatment option that results in comparably favorable visual outcomes. Currently, it is unclear whether combination therapy of ranibizumab with photodynamic therapy (PDT) provides any significant advantage over ranibizumab monotherapy (FOCUS trial); however, the combination of PDT and ranibizumab may decrease the need for frequent retreatment. This question will be addressed in the SUMMIT trial. Therapy with ranibizumab is generally very well tolerated with a low rate of seriously adverse ocular events or systemic side-effects. The advent of vascular endothelial growth factor (VEGF) inhibitors has revolutionized the therapy of neovascular AMD. Ranibizumab at the moment appears to be the most effective approved treatment for neovascular AMD.

Neovascular age-related macular degeneration: opportunities for development of first-in-class biopharmaceuticals

Age-related macular degeneration (AMD) is a condition that may cause blindness. The prevalence of the disease in the Western world is estimated at 1-2% of the population. Over the past decade, treatment of neovascular AMD has been shifting from destruction of newly formed blood vessels towards inhibitors that silence the vascular endothelial growth factor (VEGF) pathway. Such agents are often first-in-class biopharmaceuticals that benefit from the fact that they can be locally administered in an immune-privileged environment with slow clearance. These new VEGF pathway inhibitors have improved therapeutic effects over conventional treatment and have promoted the identification of novel targets for inhibition of AMD angiogenesis. This review describes the rationale behind the shift from conventional to current treatment options and discusses investigational, most notably biopharmaceutical, drugs that are in clinical trials. It also provides possible points for improvement of these treatments, specifically regarding their delivery.

Potential bias in ophthalmic pharmaceutical clinical trials

To make clinicians aware of potential sources of error in ophthalmic pharmaceutical clinical trials that can lead to erroneous interpretation of results, a critical review of the study design of various pharmaceutical ophthalmic clinical trials was completed. Discrepancies as a result of study shortcomings may explain observed differences between reported ophthalmic trial data and observed clinical results.

Temperature Distribution During ICG-Dye-Enhanced Laser Photocoagulation of Feeder Vessels in Treatment of AMD-Related Choroidal Neovascularization

Laser photocoagulation of the feeder vessels of age-related macula degeneration-related choroidal neovascularization (CNV) membranes is a compelling treatment modality, one important reason being that the treatment site is removed from the fovea in cases of sub- or juxtafoveal CNV. To enhance the energy absorption in a target feeder vessel, an indocyanine green dye bolus is injected intravenously, and the 805nm wavelength diode laser beam is applied when the dye bolus transits the feeder vessel; this tends to reduce concomitant damage to adjacent tissue. A 3D theoretical simulation, using the Pennes bioheat equation, was performed to study the temperature distribution in the choroidal feeder vessel and its vicinity during laser photocoagulation. The results indicate that temperature elevation in the target feeder vessel increases by 20% in dye-enhanced photocoagulation, compared to just photocoagulation alone. The dye bolus not only increases the laser energy absorption in the feeder vessel but also shifts the epicenter of maximum temperature away from the sensitive sensory retina and retinal pigment epithelial layers and toward the feeder vessel. Two dominant factors in temperature elevation of the feeder vessel are location of the feeder vessel and blood flow velocity through it. Feeder vessel temperature elevation becomes smaller as distance between it and the choriocapillaris layer increases. The cooling effect of blood flow through the feeder vessel can reduce the temperature elevation by up to 21% of the maximum that could be produced. Calculations were also performed to examine the effect of the size of the laser spot. To achieve the same temperature elevation in the feeder vessel when the laser spot diameter is doubled, the laser power level has to be increased by only 60%. In addition, our results have suggested that more studies are needed to measure the constants in the Arrhenius integral for assessing thermal damage in various tissues.

Surgical treatment of age-related macular degeneration: will there be a role in the future?

Surgical treatment has been shown to be able to improve vision that is lost as a result of age-related macular degeneration. Surgery is complex, such that improvement has always to be weighed against risk of complications. The availability of Ranibizumab and Bevacizumab is set to dramatically alter our management options. Surgical treatment will have a limited role to play in the next few years.

Transplantation of the RPE in AMD

The retinal pigment epithelium (RPE) maintains retinal function as the metabolic gatekeeper between photoreceptors (PRs) and the choriocapillaries. The RPE and Bruch's membrane (BM) suffer cumulative damage over lifetime, which is thought to induce age-related macular degeneration (AMD) in susceptible individuals. Unlike palliative pharmacologic treatments, replacement of the RPE has a curative potential for AMD. This article reviews mechanisms leading to RPE dysfunction in aging and AMD, laboratory studies on RPE transplantation, and surgical techniques used in AMD patients. Future strategies using ex vivo steps prior to transplantation, BM prosthetics, and stem cell applications are discussed. The functional peculiarity of the macular region, epigenetic phenomena leading to an age-related shift in protein expression, along with the accumulation of lipofuscin may affect the metabolism in the central RPE. Thickening of BM with age decreases its hydraulic conductivity. Drusen are deposits of extracellular material and formed in part by activation of the alternative complement pathway in individuals carrying a mutant allele of complement factor H. AMD likely represents an umbrella term for a disease entity with multifactorial etiology and manifestations. Presently, a slow progressing (dry) non-neovascular atrophic form and a rapidly blinding neovascular (wet) form are discerned. No therapy is currently available for the former, while RPE transplantation and promising (albeit non-causal) anti-angiogenic therapies are available for the latter. The potential of RPE transplantation was demonstrated in animal models. Rejection of allogeneic homologous transplants in patients focused further studies on autologous sources. In vitro studies elucidated cell adhesion and wound healing mechanisms on aged human BM. Currently, autologous RPE, harvested from the midperiphery, is being transplanted as a cell suspension or a patch of RPE and choroid in AMD patients. These techniques have been evaluated from several groups. Autologous RPE transplants may have the disadvantage of carrying the same genetic information that may have led to AMD manifestation. An intermittent culturing step would allow for in vitro therapy of the RPE, its rejuvenation and prosthesis of BM to improve the success RPE transplants. Recent advances in stem cell biology when combined with lessons learned from studies of RPE transplantation are intriguing future therapeutic modalities for AMD patients.

The end of submacular surgery for age-related macular degeneration? A meta-analysis

BACKGROUND

The aim of this meta-analysis was to summarize and to discuss the results of the four main submacular surgical procedures for age-related macular degeneration (AMD) as reported in the literature through 2004 and to compare them to the Submacular Surgery Trials (SST) data.

METHODS

The existing data in the literature on submacular surgery for AMD from 1992 to 2004 were evaluated. The main outcomes were proportion of patients with two or more lines of improvement in visual acuity (VA) and proportion with two or more lines of deterioration in VA after surgery.

RESULTS

Eighty-eight studies including 1,915 cases met the inclusion criteria. Estimates for the treatment outcome within the four groups of treatment based on a logistic regression model gave comparable results for removal of choroidal neovascularization (CNV) (improvement of VA 28%, deterioration of VA 25%), macular translocation (improvement of VA 31%, deterioration of VA 27%), and for transplantation of pigment epithelium (improvement of VA 22%, deterioration of VA 21%). Estimates for removal of subretinal hemorrhage were significantly different (improvement of VA 62%, deterioration of VA 13%).

CONCLUSIONS

Selected case series showed superior results of VA compared to the SST. The question of whether this is due to selection bias that seems inevitable when dealing with medium-sized nonrandomized case series or due to better results in single centers cannot be answered. In our opinion there still seem to be indications for submacular surgery such as in patients with AMD with low preoperative VA due to large hemorrhagic or fibrotic membranes or nonresponders to photodynamic therapy (PDT).

Pathogénie des lésions de la dégénérescence maculaire liée à l’âge à un stade avancé

To summarize the evidence that exists concerning the pathogenesis of lesions in late age-related macular disease (AMD), we reviewed both experimental evidence and clinical observations that address these problems. There is good evidence that choroidal neovascularization is due to a change in the balance of growth factors derived from the retinal pigment epithelial basolateral plasma membrane domain (RPE). Retinal angiomatous proliferation may also have a similar pathogenesis involving the apical domain. Detachment of the RPE is likely to be a consequence of increased resistance of Bruch's membrane to water flow due to deposition of lipids. Geographic atrophy is preceded by accumulation of autofluorescent material in the RPE and possible causal relationships between the two have been demonstrated. There is increasing understanding concerning the sequence of events that lead to those lesions causing loss of central vision in AMD. Therapeutic approaches that address the underlying mechanisms are more likely to succeed than current treatment options. Such an approach has already been initiated in the management of choroidal neovascularization.

SUBRETINAL SURGERY FOR PERIPAPILLARY SUBRETINAL NEOVASCULAR MEMBRANES

PURPOSE

To report the results of surgical removal of extrafoveal peripapillary subretinal neovascular membranes (PSRNVMs) for elderly patients in whom visual acuity was threatened or affected by subretinal fluid, subretinal hemorrhage, subretinal exudate, or PSRNVM growth toward the fovea.

METHODS

Retrospective review of six eyes of six patients undergoing subretinal surgical removal of PSRNVMs via pars plana vitrectomy.

RESULTS

PSRNVMs were successfully removed in six eyes of six patients with initial preservation of foveal function. The preoperative Snellen visual acuity ranged from 20/40 to counting fingers, and the best postoperative visual acuity ranged from 20/25 to 20/40. The final visual acuity with a mean follow-up of 3 years (range, 6-63 months) was stable or improved in 83% (5 eyes) of cases, ranging from 20/25 to 20/80. Early recurrence of PSRNVM was noted only in 1 eye (17%) at 1 month after surgery and was successfully treated with laser photocoagulation. Late recurrence of choroidal neovascularization developed after 3 years in two eyes. Cataract developed in three of four phakic eyes.

CONCLUSION

PSRNVMs sparing the central fovea in elderly patients can be successfully removed surgically with initial preservation of foveal function and with a low rate of early recurrence.

Surgical management of age-related macular degeneration

The development of increasingly refined vitreoretinal surgical techniques has resulted in a variety of surgical procedures for age-related macular degeneration (AMD). These have included submacular surgery with removal of choroidal neovascular membranes and subretinal blood, intraoperative lysis of feeder vessels, pneumatic displacement of subretinal blood and macular translocation surgery. The goals of these procedures have been to improve upon the poor natural history of exudative AMD and restore useful central vision. This article reviews the varied approaches, results and complications of the surgical management of AMD.

Evaluation of the traveling vision examiner program in the submacular surgery trials pilot study

PURPOSE

To describe methods and results and to assess the value of a Traveling Vision Examiner (TVE) Program designed to provide masked vision measurements by expert vision examiners who were independent of, and traveled to, local clinical centers.

METHODS

The Submacular Surgery Trials (SST) Pilot Study was conducted to refine the design and methods for a set of multicenter, randomized clinical trials to evaluate submacular surgery in patients with subfoveal choroidal neovascularization (CNV) due to age-related macular degeneration (AMD) or ocular histoplasmosis (OHS), or idiopathic CNV in which the primary study outcome would be change in 2-year best-corrected vision from baseline. As part of the SST Pilot Study, the feasibility and value of a TVE Program was assessed. The goal of the program was to obtain unbiased vision measurements, according to a standard protocol, of best-corrected visual acuity, reading speed, and contrast threshold, of each patient at 2 and 4 years after enrollment.

RESULTS

Eighty-three visits by TVEs were made to 16 centers participating in the SST Pilot Study; 239 patients had at least one masked vision examination. Comparison of pairs of vision measurements of the traveling vision examiners and local vision examiners for 71 patients made on the same day showed good agreement overall (intraclass correlation coefficient > or = 0.81).

CONCLUSIONS

The proposed TVE Program was judged to be a feasible and useful method of providing standardized, unbiased, masked vision measurements. This approach was incorporated into the larger clinical trials conducted by the SST Research Group.

Changes in lesion size after submacular surgery for subfoveal choroidal neovascularization in the submacular surgery trials pilot study

PURPOSE

To compare the size of subfoveal lesions based on photographic documentation before and after submacular surgery of choroidal neovascularization (CNV) lesions.

METHODS

Subfoveal lesion sizes at baseline and month 3 follow-up visits for patients assigned to surgery in the Submacular Surgery Trials (SST) Pilot Study were assessed categorically using Macular Photocoagulation Study (MPS) disc area (DA) circles. The Submacular Surgery Trials Pilot Study groups reviewed were as follows: Group N (age-related macular degeneration [AMD]; lesion <50% blood; classic CNV present; size < or =9 MPS DAs); Group R (AMD; prior nonfoveal laser; classic CNV present; size < or =9 MPS DAs); Group B (AMD; lesion > or =50% blood); and Group H (ocular histoplasmosis syndrome or idiopathic; classic CNV present; size < or =9 MPS DAs).

RESULTS

Postoperative month 3 lesion size was at least 1 size category smaller than the preoperative lesion size in 6% (4/66) of Group N, 0 (0/31) of Group R, 6% (2/34) of Group H, and 45% (18/40) of Group B eyes. In Group H eyes, there was no size change in 50% (17/34), and enlargement was found in 44% (15/34). For eyes in Groups N and R, approximately one third remained stable (20/66, 30% and 12/31, 39%, respectively), whereas two thirds enlarged by at least 1 category (42/66, 64% and 19/31, 61%, respectively).

CONCLUSIONS

The change in lesion size after submacular surgery was variable, with a tendency for Group H lesions to remain the same size or larger, Group B lesions to measure smaller, and Group N and Group R lesions to be larger.

Longterm results in surgical removal of subfoveal choroidal neovascularization in age-related macular degeneration

PURPOSE

This study aimed to analyse visual outcome, surgical complications and recurrence rates 3 years after removal of subretinal choroidal neovascularization (CNV) in patients with age-related macular degeneration (AMD).

METHODS

The study involved a retrospective analysis of 50 eyes of 50 patients who underwent surgical removal of CNV in AMD between February 1996 and June 1998. The minimum follow-up period was 36 months. Improvement or worsening of visual acuity (VA) was defined as a change of more than two lines.

RESULTS

The mean reduction in VA was 2.2 +/- 6.9 lines. Visual acuity improved in 12 eyes, remained stable in 16 eyes and worsened in 22 eyes. Recurrence of CNV occurred in three eyes.

CONCLUSION

After surgical excision of age-related subfoveal CNV, VA improved or stabilized in a large group of patients. Considering the development of VA and the low recurrence rate, surgical treatment seems to be beneficial compared to the natural course of CNV over a longterm follow-up of more than 3 years.

Surgical removal vs observation for subfoveal choroidal neovascularization, either associated with the ocular histoplasmosis syndrome or idiopathic: I. Ophthalmic findings from a randomized clinical trial: Submacular Surgery Trials (SST) Group H Trial: SST Report No. 9

OBJECTIVE

To present visual acuity findings and related outcomes from eyes of patients enrolled in a randomized trial conducted by the Submacular Surgery Trials (SST) Research Group (SST Group H Trial) to compare surgical removal vs observation of subfoveal choroidal neovascular lesions that were either idiopathic or associated with ocular histoplasmosis.

METHODS

Eligible patients 18 years or older had subfoveal choroidal neovascularization (new or recurrent) that included a classic component on fluorescein angiography and best-corrected visual acuity of 20/50 to 20/800 in 1 eye ("study eye"). Patients were examined 3, 6, 12, and 24 months after enrollment to assess study outcomes and adverse events. Best-corrected visual acuity was measured by a masked examiner at the 24-month examination. A successful outcome was defined a priori as 24-month visual acuity better or no more than 1 line (7 letters) worse than at baseline.

RESULTS

Among 225 patients enrolled (median visual acuity 20/100), 113 study eyes were assigned to observation and 112 to surgery. Forty-six percent of the eyes in the observation arm and 55% in the surgery arm had a successful outcome (success ratio, 1.18; 95% confidence interval, 0.89-1.56). Median visual acuity at the 24-month examination was 20/250 among eyes in the observation arm and 20/160 for eyes in the surgery arm. The prespecified subgroup of eyes with visual acuity worse than 20/100 at baseline (n = 92) had more successes with surgery; 31 (76%) of 41 eyes in the surgery arm vs 20 (50%) of 40 eyes in the observation arm examined at 24 months (success ratio, 1.53; 95% confidence interval, 1.08-2.16). Five (4%) of 111 eyes in the surgery arm subsequently had a rhegmatogenous retinal detachment. Twenty-seven (24%) of 112 initially phakic eyes in the surgery arm (none in the observation arm) had cataract surgery during follow-up, all among patients older than 50 years. Recurrent choroidal neovascularization developed by the 24-month examination in 58% of surgically treated eyes.

CONCLUSIONS

Overall, findings supported no benefit or a smaller benefit to surgery than the trial was designed to detect. Findings support consideration of surgery for eyes with subfoveal choroidal neovascularization and best-corrected visual acuity worse than 20/100 that meet other eligibility criteria for the SST Group H Trial. Other factors that may influence the treatment decision include the risks of retinal detachment, cataract among older patients, and recurrent choroidal neovascularization and the possibility that additional treatment will be required after submacular surgery.

Surgery for subfoveal choroidal neovascularization in age-related macular degeneration: ophthalmic findings: SST report no. 11

PURPOSE

To present visual acuity (VA) and related findings from patients enrolled in one of the Submacular Surgery Trials (SST) evaluating surgical removal versus observation of subfoveal choroidal neovascularization secondary to age-related macular degeneration (SST Group N Trial).

DESIGN

Randomized clinical trial.

PARTICIPANTS

Eligible patients had age-related macular degeneration with subfoveal choroidal neovascularization, some with a classic pattern on fluorescein angiography, and best-corrected VA (BCVA) of 20/100 to 20/800 in one eye (study eye) that had received no treatment in the macula. Any contiguous blood had to account for <50% of the total area occupied by the subfoveal lesion (maximum size, 9.0 disc areas [22.9 mm2]).

METHODS

Randomization was stratified by VA and by clinical center. All patients were scheduled for study examinations at 3, 6, 12, and 24 months after enrollment for assessment of study outcomes.

MAIN OUTCOME MEASURE

A successful outcome was defined a priori to be either improvement of BCVA or VA no more than 1 line (7 letters) worse than baseline at the 24-month examination.

RESULTS

Of 454 patients enrolled, 228 study eyes were assigned to observation and 226 to surgery. The percentages of eyes that had successful outcomes were similar in the 2 arms: 44% assigned to observation and 41% assigned to surgery. Median VA losses from baseline to the 24-month examination were 2.1 lines (10.5 letters) in the observation arm and 2.0 lines (10 letters) in the surgery arm. Median VA declined from 20/100 at baseline to 20/400 at 24 months in both arms. No subgroup of patients was identified in which submacular surgery led to better VA outcomes. In the surgery arm, 55 (39%) of 142 initially phakic eyes had cataract surgery by the 24-month examination, compared with 6 (5%) of 133 eyes in the observation arm. Rhegmatogenous retinal detachment occurred in 12 surgery eyes (5%) and 1 observation eye.

CONCLUSIONS

Submacular surgery, as performed in this clinical trial, did not improve or preserve VA for 24 months in more eyes than observation and is not recommended for patients with similar lesions. This article contains additional online-only material available at http://www.ophsource.com/periodicals/ophtha.

Clinical trial performance of community- vs university-based practices in the submacular surgery trials (SST): SST report no. 2

OBJECTIVE

To compare the performance of community- vs university-based clinical centers in 3 multicenter randomized clinical trials of intraocular surgery.

METHODS

Each Submacular Surgery Trials clinical center was classified as a university-based center, if the contract to perform as a center was signed by a university official, or as a community-based center. The 2 groups of centers were compared on performance, assessed cumulatively by the Submacular Surgery Trials Quality Assurance and Monitoring Subcommittee.

OUTCOME MEASURES

Patient accrual, completion of scheduled examinations, completion of masked vision examinations 2 years after enrollment (the designated primary study end point evaluation time), timeliness of submission of retinal photographs required by protocol to the Photograph Reading Center, completion of health- and vision-related quality-of-life interviews, and timeliness of submission of the primary outcome data to the Coordinating Center after completion of the examination.

RESULTS

Almost all centers performed at a very high (good) level, although there was a trend for some community-based centers to be at the lower end of most distributions.

CONCLUSIONS

Most community- and university-based centers performed well in these multicenter clinical trials. Monitoring performance and periodically providing feedback to clinical center investigators may encourage excellent performance in areas critical to the success of clinical trials, regardless of whether the center is community or university based.

Subfoveal hemorrhage after verteporfin photodynamic therapy in treatment of choroidal neovascularization

BACKGROUND

To identify the frequency of new subfoveal hemorrhage and its impact on visual acuity 2 weeks following verteporfin photodynamic therapy (PDT) in the treatment of predominantly classic subfoveal choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD).

METHODS

Retrospective, noncomparative, consecutive, interventional case series. At a tertiary retinal referral center, 104 eyes of 97 consecutive patients with predominantly classic subfoveal CNV were treated by PDT. Morphological outcomes include new subfoveal hemorrhage assessed on the photo review (pretreatment, 2 and 12 weeks after PDT). Visual acuity outcomes include moderate (3-5 ETDRS lines) and severe (6 and more ETDRS lines) loss of visual acuity at 2 weeks after PDT.

RESULTS

In this study, 104 eyes of 97 patients were analyzed. CNV in all eyes was secondary to AMD. New subfoveal hemorrhage was found in 22% (23/104) of the eyes 2 weeks following PDT. 17.4% (4/23) of the eyes with new subfoveal hemorrhage had moderate or severe loss of visual acuity. In such eyes the 12-week examination revealed considerable resorption of the new subfoveal hemorrhage with some improvement of visual acuity.

CONCLUSIONS

In 3.8% of the eyes that underwent PDT for predominantly classic subfoveal CNV secondary to AMD, new subfoveal hemorrhage may result in moderate or severe loss of visual acuity within 2 weeks. In all eyes with new subfoveal hemorrhage, considerable resorption of the hemorrhage and some improvement of the visual acuity were seen at 12 weeks. Candidates for PDT should be informed about the low risk of this complication.

massive peripapillary subretinal neovascularization: an indication for submacular surgery

PURPOSE

To describe the course and outcome of three consecutive patients with massive peripapillary subretinal neovascularization secondary to ocular histoplasmosis syndrome managed with submacular surgery.

METHODS

Three eyes of three consecutive patients with progressive and massive peripapillary subretinal neovascularization secondary to ocular histoplasmosis syndrome were treated with submacular surgery and followed up for a mean of 41 months (range, 11-59 months). The main outcomes were surgical complications, visual acuity, and subretinal membrane recurrence.

RESULTS

Visual acuity improved in each patient from counting fingers, 20/25, and 20/400 preoperatively to 20/50, 20/20, and 20/20, respectively, at the last follow-up visit. With respect to complications, Patient 3 was found to have an operculated retinal tear approximately 1 month postoperatively, which was successfully treated with argon laser retinopexy. There were no cases of visually significant cataract, rhegmatogenous retinal detachment, or recurrent choroidal neovascularization in any of the operated eyes during the period of follow-up.

CONCLUSIONS

Submacular surgery proved safe and beneficial in this small series of young patients with massive peripapillary subretinal neovascularization secondary to ocular histoplasmosis syndrome and should be considered in this relatively uncommon clinical presentation.

Pathogenesis of lesions in late age-related macular disease

PURPOSE

To review the evidence that exists concerning the pathogenesis of lesions in late age-related macular disease (AMD).

DESIGN

Review of the literature.

METHODS

A review of both experimental evidence and clinical observations that address these problems.

RESULTS

There is good evidence that choroidal neovascularization (CNV) is due to a change in the balance of growth factors derived from the retinal pigment epithelial basolateral plasma membrane domain (retinal pigment epithelium). Retinal angiomatous proliferation may also have a similar pathogenesis involving the apical domain. Detachment of the retinal pigment epithelium is likely to be a consequence of increased resistance of the Bruch membrane to water flow due to deposition of lipids. Geographic atrophy is preceded by accumulation of autofluorescent material in the retinal pigment epithelium and possible causal relationships between the two have been demonstrated.

CONCLUSION

There is increasing understanding concerning the sequence of events that lead to those lesions causing loss of central vision in AMD. Therapeutic approaches that address the underlying mechanisms are more likely to succeed than current treatment options. Such an approach has already been initiated in the management of choroidal neovascularization.

Radiotherapy for recurrent choroidal neovascularisation complicating age related macular degeneration

AIMS

To report the safety and visual outcome data of external beam irradiation for recurrent choroidal neovascularisation complicating age related macular degeneration.

METHODS

Eighteen consecutive eyes received external beam irradiation with seven fractions of 2 Gy (total dose 14 Gy). The next 16 consecutive eyes received external beam irradiation with five fractions of 3 Gy (total dose 15 Gy). Main outcome measure was change in visual acuity. Secondary outcome variables were contrast sensitivity and fundus photographic/fluorescein angiographic progression.

RESULTS

The 3 Gy fraction group lost fewer lines of distance visual acuity at the three and six month follow up. At one year follow up, this difference was not maintained with 2 Gy fraction and 3 Gy fraction eyes. At one year follow up a decrease in visual acuity of three or more lines (moderate visual loss) occurred in 58% of 2 Gy and 42% of 3 Gy fraction eyes (p<0.36). At one year follow up a decrease in visual acuity of six or more lines (severe visual loss) occurred in 41% of 2 Gy eyes and 17% of 3 Gy eyes (p<0.23). At three months follow up, 3 Gy eyes were less likely (0%) than 2 Gy eyes (47%) to show moderate visual loss (p<0.003). However, Kaplan Meier curves estimate a significantly lower rate of severe visual loss in the 3 Gy group (p = 0.02). There were no significant differences in contrast sensitivity loss or fluorescein angiographic stabilisation rates. No evidence of radiation toxicity was observed.

CONCLUSION

Our results are consistent with trends for a palliative benefit with higher fraction sizes and doses. The radiobiologic differences between low and high fraction size groups in this study are modest and correlate with the modest and short term difference in visual outcomes. These trends support further investigation of radiotherapy using fraction sizes of 4 Gy or higher.

Current concepts and recent advances in the management of age-related macular degeneration

BACKGROUND

Age-related macular degeneration (AMD) is the leading cause of visual impairment and blindness in the Western World in those aged 65 and older. At present, several treatment modalities are utilised and several more are undergoing investigation in an attempt to retard the occurrence and progression of this devastating condition.

AIMS

To provide the non-ophthalmologist with an understanding of the current treatment options available to patients suffering from all variants of AMD.

METHODS

Medline and Embase search.

RESULTS

Several treatment modalities have been investigated and utilised in the treatment of all variants of this condition. While promising results have been reported, no treatment is ideal.

CONCLUSION

While no curative treatment for this condition currently exists, early recognition and treatment, if indicated, have been shown to reduce the risk of severe vision loss in patients with this condition.

Responsiveness of the National Eye Institute Visual Function Questionnaire to changes in visual acuity: findings in patients with subfoveal choroidal neovascularization--SST Report No. 1

BACKGROUND

The National Eye Institute Visual Function Questionnaire (NEI-VFQ) measures vision-targeted quality of life, but it is unclear whether it is sensitive to changes within individuals over time.

OBJECTIVE

To determine the responsiveness of the NEI-VFQ to "within-individual" changes in visual acuity in patients who had subfoveal choroidal neovascularization in at least one eye secondary to age-related macular degeneration, ocular histoplasmosis syndrome, or idiopathic causes, and who participated in randomized trials of submacular surgery.

METHODS

Trained telephone interviewers administered the NEI-VFQ as part of annual follow-up data collection for pilot trials and larger clinical trials of submacular surgery. Best-corrected visual acuity was measured by local vision examiners at 12 months after enrollment and, typically, by central "traveling" vision examiners at 24 months after enrollment. Changes in visual acuity and NEI-VFQ scores from 12 to 24 months were analyzed using linear regression methods.

RESULTS

Two-hundred eighteen patients had both interviews and visual acuity measurements at 12 and 24 months after enrollment. Changes in the overall NEI-VFQ score and in 9 of the subscales (near activities, dependency, driving, role difficulties, distance activities, mental health, general vision, peripheral vision, and social functioning) were related to changes in visual acuity of the better-seeing eye based on linear regression analysis (P<.05). In our analysis, a 3-line decrease in the visual acuity of the better-seeing eye was associated with 3.6- to 16.2-point decreases in the overall NEI-VFQ score and 9 subscale scores.

CONCLUSIONS

Most of the NEI-VFQ subscales were responsive to changes in the visual acuity of the better-seeing eye over a 12-month interval in this patient population. Thus, the NEI-VFQ can be used to measure change in vision-targeted quality of life over time to augment clinical measurements of visual acuity.

Age-related macular degeneration: epidemiology and optimal treatment

Age-related macular degeneration (AMD) is a common macular disease affecting elderly people in the Western world. It is characterised by the appearance of drusen in the macula, accompanied by choroidal neovascularisation (CNV) or geographic atrophy. The disease is more common in Caucasian individuals than in pigmented races. In predominantly Caucasian populations, the age-standardised prevalence of AMD in at least one eye is 7760 cases per million. The age-standardised cumulated 1-year incidence of AMD in at least one eye is 1051 cases per million individuals. AMD is the most important single cause of blindness among Caucasian individuals in developed countries. Blindness resulting from AMD rarely occurs before age 70, and most cases occur after age 80. The age-standardised 1-year incidence of legal blindness resulting from AMD is 212 cases per million. Two-thirds of AMD cases have CNV (exudative cases); the remainder has only geographic atrophy. In cross-sectional population-based studies about 45% of eyes with AMD have visual acuity reduced to 20/200 or worse. This is true both for exudative AMD and pure geographic atrophy. Age and genetic predisposition are known risk factors for AMD. Smoking is probably also a risk factor. Preventive strategies using macular laser photocoagulation are under investigation, but their efficacy in preventing visual loss is as yet unproven. There is no treatment with proven efficacy for geographic atrophy. Optimal treatment for exudative AMD requires a fluorescein angiographic study and a physician capable of interpreting it. For CNV not involving the foveal centre, the only evidence-based treatment is laser photocoagulation. For AMD cases with subfoveal CNV, good visual acuity, and predominantly classic fluorescence pattern on fluorescein angiography, photodynamic therapy with verteporfin is the treatment of choice. Photodynamic therapy is also effective in eyes with pure occult CNV and evidence of recent disease progression. For new subfoveal CNV with poor vision and recurrent CNV, laser photocoagulation can be considered.

Radiotherapy for subfoveal choroidal neovascularization in age-related macular degeneration: a randomized clinical trial

PURPOSE

To report results of 18-month follow up of external beam radiation therapy with photons for subfoveal classic or occult choroidal neovascularization (CNV) in age-related macular degeneration (ARMD).

DESIGN

Randomized clinical trial.

METHODS

A total of 161 patients with subfoveal CNV in ARMD were recruited in a prospective double-masked study. The posterior pole of the afflicted eye was given 1 Gy (4 x 0.25 Gy) in the control group and 8 Gy (4 x 2 Gy) or 16 Gy (4 x 4 Gy) in the treatment groups. At the time of treatment, and 6, 12, and 18 months post treatment, best-corrected visual acuity (BCVA), reading ability, and CNV size were measured.

RESULTS

At the completion of the study 150 (93.2%), 139 (86.3%), and 137 (85.1%) patients were followed for 6, 12, and 18 months, respectively. The mean number of lines lost in the BCVA was -1.69, -2.2, and -3.23 in the 1 Gy group; -0.94, -1.25, and -1.73 in the 8 Gy group; -0.51, -0.67, and -1.93 in the 16 Gy group. The difference was significant after 12 months (P =.016 for 8 Gy vs. 1 Gy; P =.006 for 16 Gy vs. 1 Gy), and 18 months (P =.011 for 8 Gy vs. 1 Gy; P =.05 for 16 Gy vs. 1 Gy). The patients with classic CNV, or with an initial distance visual acuity >or=20/100, benefited more from treatment. A significant difference was not found between control group and treatment groups in the reading ability and in the CNV size. No radiation-associated side effects were reported thus far.

CONCLUSION

The number of lines lost in the BCVA was less in the 8 Gy and 16 Gy treatment groups than in the control group during the complete follow up examination. Radiation therapy with 8 Gy and 16 Gy, without showing any difference in efficacy, resulted in a near stabilization of the BCVA in patients with subfoveal classic or occult CNV in ARMD. Further studies are necessary to determine the significance of repeated radiotherapy series with a dose of 8 Gy to improve the effect on the CNV size and thereby to prolong stabilization of distance visual acuity.

Limited macular translocation with scleral retraction suture

BACKGROUND/AIMS

Macular translocation with scleral imbrication is a new technique for treating subfoveal choroidal neovascular membranes (CNV). This procedure shortens the sclera but may result in a minimal decrease in the internal circumference of the globe and limits the amount of foveal displacement. The authors propose a new scleral retraction suture aimed at decreasing the internal circumference of the globe in an effort to increase foveal displacement.

METHODS

Using a cadaver model, they compared the amount of scleral shortening using a standard scleral imbrication technique and a modified three suture scleral retraction technique. Sections of the globes were digitised and specialised software was used to estimate the amount of scleral shortening. Three patients with subfoveal choroidal neovascularisation underwent limited macular translocation using pars plana vitrectomy and macular detachment with the modified scleral suture technique. The main outcome measures were visual acuity, foveal displacement, and complications.

RESULTS

In the cadaver model, the scleral retraction suture resulted in a flatter internal scleral fold compared to the standard suture technique and created approximately 890 microm of effective scleral shortening. In the patients who underwent macular translocation and laser photocoagulation of the CNV, visual acuity improved in two patients and worsened in one patient. The range of foveal displacement was 1400-2400 microm.

CONCLUSION

The foveal displacements achieved in this limited study compared to median displacement previously published using standard suture techniques demonstrates that the scleral retraction suture technique may be a useful adjunct to limited macular translocation. The advantage of this type of suture in conjunction with translocation may depend on the effective scleral shortening offered by this retraction suture.

Early attachment of uncultured retinal pigment epithelium from aged donors onto Bruch's membrane explants

Retinal pigment epithelium (RPE) transplantation might replace cells lost as a consequence of choroidal neovascular membrane excision in patients with age-related macular degeneration (AMD). Autologous transplantation of RPE cells harvested from a peripheral biopsy may overcome problems of immune rejection. To study the feasibility of autologous RPE cell transplantation, the authors examined the attachment of freshly harvested RPE cells from aged donors onto Bruch's membrane explants, debrided to (1) remove or (2) preserve the RPE basement membrane. Human retinal pigment epithelial sheets were harvested from adult donor eyes (N = 12, mean age 79.00 +/- 9.40 years) and, following incubation in collagenase, were mechanically fragmented into microaggregates. Microaggregates (approximately 120 000 cells) were seeded onto the paired explants (7 mm diameter) and incubated for 20 min, 1, 4, or 24 hr at 37 degrees C. The percent coverage of the debrided surface by microaggregates was determined by sampling the center of the explants with scanning electron microscopy. RPE microaggregate attachment to Bruch's membrane was significantly greater at all time points analysed in samples with intact basement membrane versus those with an exposed inner collagenous layer. Coverage of debridements retaining intact RPE basement membrane was 1.83 +/- 1.10% at 20 min, 3.54 +/- 2.14% at 1 hr, and 8.68 +/- 2.63% at 4 hr. Coverage of debridements lacking basement membrane was 0.10 +/- 0.04% at 20 min, 0.39 +/- 0.25% at 1 hr, and 0.63 +/- 0.42% at 4 hr. Based on their morphologic appearance, many cells were dying as early as 1 hr following seeding. To increase surface coverage, the authors seeded four times the above number of cells and incubated the specimens for 1 hr. Coverage on explants lacking RPE basement membrane showed no increase in the number of cells attached to the inner collagenous layer. There was a significant approximately three-fold increase in the number of cells attached in the presence of basement membrane. These results indicate that if RPE cells from aged human donors are used for transplantation, some modification of the Bruch's membrane surface or the cells must be considered for cell attachment and eventual cell survival.

Uptake dynamics and retinal tolerance of phosphorothioate oligonucleotide and its direct delivery into the site of choroidal neovascularization through subretinal administration in the rat

This study aimed to investigate uptake dynamics and retinal tolerance of phosphorothioate oligonucleotides (PS-oligos) following subretinal injection. A fluorescent-labeled PS-oligo (FL-oligo) with random sequence was administered into the subretinal space of rat by transsclera-choroid-retinal pigment epithelium (RPE) injection at doses of 0.129, 1.29, and 12.9 microg in 2.0 microl solution. The uptake dynamics were evaluated by fundus fluorescent photography in real time and by fluorescence microscopy using flat mounts and cryosections. Immunophenotyping for CD4+, CD8+ cytotoxic lymphocytes, and CD68+ macrophages was performed to assess cellular infiltration in the retina. In addition, the FL-oligo was injected subretinally in a rat model of choroidal neovascularization (CNV) for direct delivery into the site of CNV. Subretinal administration of FL-oligo resulted in both dose-dependent and time-dependent distribution in the retina, where it accessed the RPE and all layers of the neuroretina. CD4+, CD8+ cytotoxic lymphocytes, and CD68+ macrophages were observed at the site of needle penetration. However, in areas far from the injection site where the FL-oligo appeared strongly, cellular infiltration was absent, and the retinal morphology was preserved very well. The FL-oligo was successfully delivered into the site of intense laser photocoagulation. It was predominantly localized to the RPE, macrophages, and some choroid cells and remained detectable for at least 56 days after injection. Our results demonstrate for the first time that subretinal injection efficiently introduced PS-oligo into the RPE and neuroretina with an acceptable level of safety. Subretinal administration of antiangiogenic oligonucleotides may hold great potential for the treatment of CNV.

Foveal translocation with scleral imbrication in patients with myopic neovascular maculopathy

PURPOSE

To report our surgical results of foveal translocation with scleral imbrication in patients with myopic neovascular maculopathy.

DESIGN

Noncomparative, interventional, consecutive case series.

METHODS

Ten eyes of 10 myopic patients with subfoveal neovascular membranes that had undergone foveal translocation with scleral imbrication were recruited for this retrospective study. Inclusion criteria were myopia 6.0 diopters or greater in refractive error (or axial length 26.5 mm or longer), subfoveal choroidal neovascularization, and preoperative best-corrected visual acuity of 20/100 or worse. None of these eyes had undergone prior laser photocoagulation or submacular surgery. The main outcome measures were surgical complications and postoperative visual function.

RESULTS

Postoperatively, visual acuity had improved more than 3 lines in the logarithm of minimum angle of resolution (logMAR) measurement in all eyes. The mean preoperative, postoperative best, and final visual acuity were 0.12, 0.59, and 0.51, respectively. Of the 10 eyes, six achieved a postoperative final visual acuity of 20/40 or better. The mean postoperative foveal displacement was 0.78 disk diameter (range, 0.3--1.3 disk diameter). Two patients underwent a reoperation because of insufficient foveal displacement. Furthermore, one of these two patients required a third operation to reduce an excessive retinal fold involving the fovea induced by the second surgery. Of the 10 patients, two noted transient diplopia. This complaint, however, resolved over time as suppression developed. Although unintentional iatrogenic retinal tears formed intraoperatively in two eyes, these were successfully treated without serious complications. Postoperatively, mild retinal pigment epithelial changes were observed in all cases, but none led to significant deterioration of visual acuity during the follow-up period. All patients but one were followed for a minimum of 6 months.

CONCLUSIONS

In eyes with myopic neovascular maculopathy, foveal translocation with scleral imbrication may be useful in improving visual acuity. Further refinements in surgical technique and assessment of the long-term complications will be needed to make this procedure safer and more useful.

Surgical removal of subfoveal choroidal neovascularization: visual outcome and prognostic value of fluorescein angiography and optical coherence tomography

PURPOSE

To study the functional results of macular surgery and determine pre-operative features associated with better final visual outcome.

METHODS

Forty-two consecutive patients underwent surgical removal of subfoveal choroidal neovascularization (CNV), related to age-related macular degeneration (AMD) in 8 eyes, degenerative myopia in 14 eyes, multifocal choroiditis (MFC) in 10 eyes, idiopathic CNV in 6 eyes and other etiologies in 4 eyes. Mean age was 49 years. Pre-operative visual acuity (VA) was 20/200 or less in 30 eyes (71.4%) and never better than 20/40. Fluorescein angiography was analyzed before and after surgery. Pre-operative optical coherence tomographs (OCT) were studied in a masked fashion. Mean follow-up was 12 months (range 4-48 months).

RESULTS

Final VA was 20/200 or less in 25 eyes (60%). According to the CNV etiology, the percentage were 87.5%, 80%, 57.1% and 20% respectively in eyes with AMD, MFC, high myopia, and idiopathic or other diseases. Post-operative VA improved in 21 eyes (50%) but subsequently declined in 7% by the final examination. Patients younger than 50 years had better functional results (p=0.006). Lack of retinal pigment epithelium (RPE) changes on pre-operative angiography was correlated with good visual outcome (p<0.001). The OCT study confirmed some features already described and showed some different CNVpatterns: above and usually separated from the RPE, below and not separated from the RPE, and ungradable. Eyes with the first OCT pattern had the best visual outcome. Main complications included 4 (10%) retinal detachments and 9 (21%) recurrences. OCT was also useful to confirm CNV recurrences post-operatively.

CONCLUSIONS

CNV surgical excision results vary depending on the underlying disease, the RPE and choriocapillaris function, and the features observed on pre-operative OCT images.