Transscleral Approach Research Articles

Impact of illumination spectrum and eye pigmentation on image quality from a fundus camera using transscleral illumination.

.Significance: The use of the transscleral illumination approach has the potential to simplify the optical design of fundus cameras. In particular, this approach could allow the use of smaller and cheaper cameras that are easier to use by non-specialists, thereby facilitating a wider spread of eye disease screening programs.Aim: Our aim was to investigate the suitability of transscleral illumination in a fundus camera system. In particular, we explored the impact of the illumination spectrum and the eye pigmentation on the quality of the image. These factors have never been systematically investigated before in the literature on transscleral illumination.Approach: A fundus camera was constructed using transscleral illumination. We studied the influence of eye pigmentation and choice of illumination spectra on the image quality for a group of 10 individuals with varied skin pigmentation, ranging from pale white (North-European) to darkest brown (African). The influence of the light source spectrum on the image quality was assessed using wavelength filters.Results: There was a difference of a factor of 100 in the signal level of retinal images between individuals with low and high skin pigmentation. The image contrast was highest using illumination wavelengths of 500 to 600 nm. The illumination level can be adjusted to obtain high-quality images for highly pigmented eyes while keeping the system eye-safe.Conclusions: We have demonstrated that a fundus camera with transscleral illumination can provide high-quality images. However, the variations observed in scleral and retinal pigmentation in a practical setting require a system that must be able to adapt illumination and/or exposure to the individual patient.

Design of a navigational catheter system for the targeted delivery of therapeutics within the suprachoroidal space

Diseases of the posterior segment of the eye are common causes of blindness and can be difficult to treat due to their location. Recently, there has been increased interest in the use of the suprachoroidal space to deliver therapeutics to the posterior segment. This space is accessible through a trans-scleral approach and blunt dissection of the adjacent scleral and choroidal tissues. However, despite recent commercial interest, there are few tools designed specifically to provide targeted delivery of therapeutics to a localised region within the suprachoroidal space. Therefore, we designed and prototyped a novel navigational catheter system for the targeted delivery of payloads within the suprachoroidal space. The system consists of a customised catheter tip designed to minimise blunt dissection stresses on neighbouring tissues, a mechanism for controlled catheter navigation, and a method for targeted delivery of large payloads. A customised in vitro model of the eye was also designed to visually demonstrate the capability of the catheter system to controllably navigate within the suprachoroidal space and deliver a targeted payload. This system can enable the delivery of large therapeutic payloads to the eye for the treatment of posterior eye diseases, thereby impacting the development and availability of vision-saving treatments.

Surgical Technique, Indications, and Outcomes of BIOM-Assisted Transvitreal Biopsy for Uveal Melanoma.

Controversy exists regarding the best method for biopsy of uveal melanoma. We describe our transvitreal technique and evaluate the safety of this technique as well as the efficacy for obtaining sample for prognostic genetic profiling. Description of surgical technique and retrospective case series. Medical records for uveal melanoma patients who underwent transvitreal biopsy using our described technique were analyzed for tumor size, location, primary treatment, method of biopsy, and any complications thereof. Characteristics of tumors that underwent transvitreal biopsy were noted including tumor size, location, or presence of subretinal fluid, to see whether these affected surgeon preference for biopsy modality. A cohort of contemporaneous uveal melanoma patients who underwent biopsy through a transscleral technique served as a comparator group for these patient, tumor, and complication factors. A total of 27 patients aged 27.2 to 88.6 years (mean 64.8) underwent transvitreal biopsy using our described technique between 2013 and 2016. There were 15 small, 10 medium, and 2 large tumors at diagnosis with the majority (n = 17) posterior to the equator. Intraoperative complications included a clot or small trickle of blood at the biopsy site in 20 (74.1%) of patients, small localized subretinal hemorrhage in 8 (29.6%), small vitreous hemorrhage in 4 (14.8%), and small transient choroidal detachments in 1 patient (3.6%). When subretinal hemorrhage occurred, it was almost always into a pre-existing pocket of subretinal fluid ( P = 0.0093). However, the presence of subretinal fluid was not associated with the decision to proceed with any biopsy ( P = 0.36) or transvitreal biopsy specifically ( P = 1.00). By 3 months, subretinal and/or vitreous hemorrhage resolved in essentially all cases. There were no cases of iatrogenic retinal detachment or extraocular tumor spread over a mean follow-up of 41.7 (range: 20-62.1) months. Adequate tissue for gene expression profiling was obtained from each biopsy. The comparator group of patients undergoing transscleral biopsy including 21 uveal melanomas in 20 patients (one eye had two melanomas). Transvitreal biopsies were more common in patients with small (n = 15; P < 0.0001), posterior (n = 17; P < 0.0001) tumors, compared with patients who underwent transscleral biopsy during the same period. This technique can be used for small or posterior tumors or for small anterior tumors where a transscleral approach would risk tumor perforation. Complications were minor, transient, and self-limited. Biopsy yields for molecular prognosis were adequate in all cases. The presence of subretinal fluid may be considered a relative contraindication because it may lead to subretinal hemorrhage in the fluid pocket but did not dissuade us from using this transvitreal technique for patients who would benefit from it.

Surgical Retrieval of an Intraocular Needle Following Intravitreal Bevacizumab Injection

Purpose: The purpose of this case report is to describe a case of iatrogenic intraocular foreign body due to a fractured 30-gauge needle following intravitreal injection of bevacizumab. Methods: A case report is presented. Results: The patient presented with a 30-gauge needle in the vitreous cavity after receiving an intravitreal injection of bevacizumab for diabetic macular edema. Bilateral eye shields were placed to reduce movement of the foreign body and decrease the risk of injury to the lens or retina. The needle was successfully removed via a combination of 23-gauge pars plana vitrectomy and removal of the foreign body via a transscleral approach through the initial injection site. Visual acuity improved to 20/25 2 months after surgery. Conclusions: We present the successful preoperative management and surgical removal of a needle fragment from the vitreous cavity after the needle fractured during intravitreal injection.

Ultrahigh Resolution Mouse Optical Coherence Tomography to Aid Intraocular Injection in Retinal Gene Therapy Research.

HR-SD-OCT is utilized to monitor the progression of photoreceptor degeneration in live mouse models, assess the delivery of therapeutic agents into the subretinal space, and to evaluate toxicity and efficacy in vivo. HR-SD-OCT uses near infrared light (800-880 nm) and has optics specifically designed for the unique optics of the mouse eye with sub-2-micron axial resolution. Transgenic mouse models of outer retinal (photoreceptor) degeneration and controls were imaged to assess the disease progression. Pulled glass microneedles were used to deliver sub retinal injections of adeno-associated virus (AAV) or nanoparticles (NP) via a trans-scleral and trans-choroidal approach. Careful positioning of the needle into the subretinal space was required prior to a calibrated pressure injection, which delivers fluid into the sub retinal space. Real time subretinal surgery was conducted on our retinal imaging system (RIS). HR-SD-OCT demonstrated progressive uniform retinal degeneration due to expression of a toxic mutant human mutant rhodopsin (P347S) (RHOP347S) transgene in mice. HR-SD-OCT allows rigorous quantification of all the retinal layers. Outer nuclear layer (ONL) thickness and photoreceptor outer segment length (OSL) measurements correlate with photoreceptor vitality, degeneration, or rescue. The RIS delivery system allows real-time visualization of subretinal injections in neonatal (~P10-14) or adult mice, and HR-SD-OCT immediately determines success of delivery and maps areal extent. HR-SD-OCT is a powerful tool that can evaluate the success of subretinal surgery in mice, in addition to measuring vitality of photoreceptors in vivo. HR-SD-OCT can also be used to identify uniform animal cohorts to evaluate the extent of retinal degeneration, toxicity, and therapeutic rescue in preclinical gene therapy research studies.

Fine-Needle Aspiration Biopsy for Molecular Genomic Classification: Evaluation of Transscleral vs Transvitreal Biopsy

Purpose: To evaluate the transvitreal and transscleral fine-needle aspiration biopsy (FNAB) approach for molecular classification with gene-expression profiling (GEP) of uveal melanoma. Methods: Institutional review board–approved single-surgeon retrospective analysis of a consecutive case series of all patients undergoing FNAB using a 25-gauge-needle multipass approach for GEP analysis of uveal melanoma between 2012 and 2016. All FNAB specimens were processed for uveal melanoma diagnostic testing using a standard processing approach, and all testing was completed at a single laboratory (Castle Biosciences, Inc.). Results: Three hundred fifty-three eyes (353 patients) were included. Transvitreal biopsies were performed in 216 eyes (216/353, 61.2%), whereas transscleral biopsies were performed in 137 eyes (137/353, 38.8%). Twenty biopsies exhibited multiple gene failure (20/353, 5.6%). Excessive fluid biopsy volume was the primary association with reported multiple gene failure, occurring in 10 of 20 eyes (50%). FNAB performed via the transvitreal approach was significantly more likely to have an excessive volume report compared with transscleral biopsy (18/216, 8.3% vs 1/137, 0.7%; P &lt; .001). Conclusions: FNAB performed via a transscleral or transvitreal multipass approach utilizing a 25-gauge needle achieves molecular classification in 95% of all patients undergoing treatment for presumed uveal melanoma independent of tumor size. Complications related to FNAB using these techniques are rare and may be associated with the presentation of the uveal melanoma.

Allogeneic iPSC-Derived RPE Cell Graft Failure Following Transplantation Into the Subretinal Space in Nonhuman Primates

PurposeTo characterize the intraocular immune response following transplantation of iPS-derived allogeneic RPE cells into the subretinal space of non–immune-suppressed rhesus macaques.MethodsGFP-labeled allogeneic iPS-derived RPE cells were transplanted into the subretinal space of one eye (n = 6), and into the contralateral eye 1 day to 4 weeks later, using a two-stage transretinal and transscleral approach. Retinas were examined pre- and post-surgery by color fundus photography, fundus autofluorescence, and optical coherence tomography (OCT) imaging. Animals were euthanized between 2 hours and 7 weeks following transplantation. T-cell (CD3), B-cell (CD20), and microglial (Iba1) responses were assessed immunohistochemically.ResultsCells were delivered into the subretinal space in all eyes without leakage into the vitreous. Transplanted RPE cells were clearly visible at 4 days after surgery but were no longer detectable by 3 weeks. In localized areas within the bleb containing transplanted cells, T- and B-cell infiltrates and microglia were observed in the subretinal space and underlying choroid. A T-cell response predominated at 4 days, but converted to a B-cell response at 3 weeks. By 7 weeks, few infiltrates or microglia remained. Host RPE and choroid were disrupted in the immediate vicinity of the graft, with fibrosis in the subretinal space.ConclusionsEngraftment of allogeneic RPE cells failed following transplantation into the subretinal space of rhesus macaques, likely due to rejection by the immune system. These data underscore the need for autologous cell sources and/or confirmation of adequate immune suppression to ensure survival of transplanted RPE cells.

Choroidal Melanoma Resection.

Uveal melanoma is the most common intraocular malignant tumor, with the choroid being the most common site. Management of choroidal melanoma has evolved greatly over the past years. In the past, the conventional method of treatment was enucleation of the affected eye with a debate regarding the effect of enucleation to promote or prevent metastasis. However, nowadays, there are many therapeutic options available including plaque radiotherapy, proton beam radiotherapy, argon laser photocoagulation, transpupillary thermotherapy, stereotactic radiotherapy using gamma knife, enucleation, and surgical resection of the tumor whether through transscleral approach “Exoresection” or less commonly through internal resection approach “Endoresection.” The indications and complications of each technique are reviewed. Although radiotherapy is the primary treatment of choroidal melanoma in most ocular oncology centers, it is used as an adjuvant therapy in combination with surgical resection. Preoperative stereotactic radiotherapy before endoresection and brachytherapy to the surgical bed in both exo and endoresection can effectively decrease the recurrence rate. In this article, we will focus on surgical resection of choroidal melanoma whether endoresection or exoresection. We collected data published in indexed journals and related books.

SUBRETINAL CELL-BASED THERAPY: An Analysis of Surgical Variables to Increase Cell Survival.

To develop a novel surgical approach to provide consistent delivery of cell suspension into the subretinal space without cell leakage into the vitreous. Cell viability was assessed following mock injections to determine the optimal size cannula for delivery of the cells. A pars plana without vitrectomy approach was used to create a subretinal bleb with balanced salt solution using a 41-gauge cannula. GFP-labeled retinal pigment epithelium cells were injected through transretinal (n = 8) and transscleral (n = 16) injection approaches. Optical coherence tomography, fundus photography and autofluorescence, and histological analysis were used to evaluate surgical success. The 30-gauge cannula yielded the highest recovery of cells with highest viability. The transretinal approach consistently resulted in transplanted cells in the vitreous, with some cells coming to rest on the inner limiting membrane. Conversely, the transscleral approach resulted in transplantation of cells into the subretinal space in 100% of cases. Histological analysis confirmed these results. We have developed a novel surgical approach that resulted in encapsulation of transplanted cells into the subretinal space with a 100% success rate. This approach will provide a useful tool for further cell transplantation study and may provide an approach for clinical application of delivering cells to the subretinal space.

Xeno-Free and Defined Human Embryonic Stem Cell-Derived Retinal Pigment Epithelial Cells Functionally Integrate in a Large-Eyed Preclinical Model.

SummaryHuman embryonic stem cell (hESC)-derived retinal pigment epithelial (RPE) cells could replace lost tissue in geographic atrophy (GA) but efficacy has yet to be demonstrated in a large-eyed model. Also, production of hESC-RPE has not yet been achieved in a xeno-free and defined manner, which is critical for clinical compliance and reduced immunogenicity. Here we describe an effective differentiation methodology using human laminin-521 matrix with xeno-free and defined medium. Differentiated cells exhibited characteristics of native RPE including morphology, pigmentation, marker expression, monolayer integrity, and polarization together with phagocytic activity. Furthermore, we established a large-eyed GA model that allowed in vivo imaging of hESC-RPE and host retina. Cells transplanted in suspension showed long-term integration and formed polarized monolayers exhibiting phagocytic and photoreceptor rescue capacity. We have developed a xeno-free and defined hESC-RPE differentiation method and present evidence of functional integration of clinically compliant hESC-RPE in a large-eyed disease model.

Fine-needle aspiration biopsy of uveal melanoma: outcomes and complications

PurposeTo report outcomes and complications of fine-needle aspiration biopsy (FNAB) of uveal melanoma performed for diagnostic and prognostic purposes.MethodsProspective interventional case series of 150 consecutive patients with a clinical diagnosis...

Survival and Migration of Pre-induced Adult Human Peripheral Blood Mononuclear Cells in Retinal Degeneration Slow (rds) Mice Three Months After Subretinal Transplantation

Introduction: Retinitis pigmentosa (RP), an inherited disease characterized by progressive loss of photoreceptors and retinal pigment epithelium, is a leading genetic cause of blindness. Cell transplantation to replace lost photoreceptors is a potential therapeutic strategy, but technical limitations have prevented clinical application. Adult human peripheral blood mononuclear cells (hPBMCs) may be an ideal cell source for such therapies. This study examined the survival and migration of pre-induced hPBMCs three months after subretinal transplantation in the retinal degeneration slow (rds) mouse model of RP. Materials and Methods: Freshly isolated adult hPBMCs were pre-induced by co-culture with neonatal Sprague-Dawley (SD) rat retinal tissue for 4 days in neural stem cell medium. Pre-induced cells were labeled with CM-DiI for tracing and injected into the right subretinal space of rds mice by the trans-scleral approach. After two and three months, right eyes were harvested and transplanted cell survival and migration examined in frozen sections and whole mountretinas. Immunofluorescence in whole-mount retinas was used to detect the expression of human neuronal and photorece ptorsprotein markers by transplanted cells. Results: Pre-induced adult hPBMCs could survive in vivo and migrate to various parts of the retina. After two and three months, transplanted cells were observed in the ciliary body, retinal outer nuclear layer, inner nuclear layer, ganglion cell layer, optic papilla, and within the optic nerve. The neuronal and photoreceptor markers CD90/Thy1, MAP-2, nestin, and rhodopsin were expressed by subpopulations of CM-DiI-positive cells three months after subretinal transplantation. Conclusion: Pre-induced adult hPBMCs survived for at least three months after subretinal transplantation, migrated throughout the retina, and expressed human protein markers. These results suggest that hPBMCs could be used for cell replacement therapy to treat retinal degenerative diseases.

Pre-induced adult human peripheral blood mononuclear cells migrate widely into the degenerative retinas of rd1 mice

Background aimsRecent advances in stem cell research have raised the possibility of stem cells repairing or replacing retinal photoreceptor cells that are either dysfunctional or lost in many retinal diseases. Various types of stem cells have been used to replace retinal photoreceptor cells. Recently, peripheral blood stem cells, a small proportion of pluripotent stem cells, have been reported to mainly exist in the peripheral blood mononuclear cells (PBMCs). MethodsIn this study, the effects of pre-induced adult human PBMCs (hPBMCs) on the degenerative retinas of rd1 mice were investigated. Freshly isolated adult hPBMCs were pre-induced with the use of the conditioned medium of rat retinas for 4 days and were then labeled with chloromethyl-benzamidodialkylcarbocyanine (CM-DiI) and then transplanted into the subretinal space of the right eye of rd1 mice through a trans-scleral approach. The right eyes were collected 30 days after transplantation. The survival and migration of the transplanted cells in host retinas were investigated by whole-mount retinas, retinal frozen sections and immunofluorescent staining. ResultsAfter subretinal transplantation, pre-induced hPBMCs were able to survive and widely migrate into the retinas of rd1 mice. A few CM-DiI–labeled cells migrated into the inner nuclear layer and the retinal ganglion cell layer. Some transplanted cells in the subretinal space of rd1 host mice expressed the human photoreceptor–specific marker rhodopsin. ConclusionsThis study suggests that pre-induced hPBMCs may be a potential cell source of cell replacement therapy for retinal degenerative diseases.

Transscleral Sustained Vasohibin-1 Delivery by a Novel Device Suppressed Experimentally-Induced Choroidal Neovascularization

We established a sustained vasohibin-1 (a 42-kDa protein), delivery device by a novel method using photopolymerization of a mixture of polyethylene glycol dimethacrylate, triethylene glycol dimethacrylate, and collagen microparticles. We evaluated its effects in a model of rat laser-induced choroidal neovascularization (CNV) using a transscleral approach. We used variable concentrations of vasohibin-1 in the devices, and used an enzyme-linked immunosorbent assay and Western blotting to measure the released vasohibin-1 (0.31 nM/day when using the 10 μM vasohibin-1 delivery device [10VDD]). The released vasohibin-1 showed suppression activity comparable to native effects when evaluated using endothelial tube formation. We also used pelletized vasohibin-1 and fluorescein isothiocyanate-labeled 40 kDa dextran as controls. Strong fluorescein staining was observed on the sclera when the device was used for drug delivery, whereas pellet use produced strong staining in the conjunctiva and surrounding tissue, but not on the sclera. Vasohibin-1 was found in the sclera, choroid, retinal pigment epithelium (RPE), and neural retina after device implantation. Stronger immunoreactivity at the RPE and ganglion cell layers was observed than in other retinal regions. Significantly lower fluorescein angiography (FA) scores and smaller CNV areas in the flat mounts of RPE-choroid-sclera were observed for the 10VDD, VDD (1 μM vasohibin-1 delivery device), and vasohibin-1 intravitreal direct injection (0.24 μM) groups when compared to the pellet, non-vasohibin-1 delivery device, and intravitreal vehicle injection groups. Choroidal neovascularization can be treated with transscleral sustained protein delivery using our novel device. We offer a safer sustained protein release for treatment of retinal disease using the transscleral approach.

Ocular cysticercosis in a 32-year-old man in Abuja: ultrasonic features as an aid in diagnosis

We report the case of a 32-year-old man suffering from intraocular cysticercosis, with special emphasis on the use of B-scan ultrasound in the diagnosis and management of the condition. An 8000 B-Scan Scanmate was used to obtain the ultrasound images. The patient had worked on a pig farm a few years before presentation. He presented with shadows seen in the right eye. Binocular indirect ophthalmoscopy revealed that he had a choroidal detachment in the right eye inferotemporally. B-scan ultrasound revealed a subretinal subchoroidal cyst with a thick wall containing well defined intracystic echogenic entities representing scolices, and an associated retinal detachment. These findings appear to be pathognomonic. Excision of the cyst through a trans-scleral approach revealed a yellowish serous fluid, with scolices of cysticercus later confirmed histologically. B-scan ultrasound is extremely useful in the diagnosis of ocular cysticercosis and the findings can be pathognomonic.

Transscleral Drainage of Subretinal/Suprachoroidal Silicone Oil

Silicone oil migration into the subretinal space following vitreoretinal surgery may occur in complex cases of retinal detachment with proliferative vitreoretinopathy. This complication prevents achievement of the primary goal (ie, to attach the retina) and fails to provide the internal tamponade, leading to a permanent decrease in visual acuity. Successful and complete removal of the subretinal oil is a challenge. Internal drainage as described earlier in the literature advocates a large relaxing retinotomy. The authors describe two similar cases, one with retinal detachment secondary to type II iridochoroidal coloboma wherein the oil had passed into the subretinal space and the other with diabetes mellitus and retinal detachment with oil in the suprachoroidal space. In both cases, silicone oil was removed successfully through a transscleral approach. The transscleral approach for removal of subretinal/suprachoroidal oil appears to be relatively safe, less time-consuming, and effective.

Endozyklophotokoagulation bei der Behandlung des Glaukoms

Cyclophotocoagulation is the standard cyclodestructive procedure for treating patients with refractory glaucoma. In addition to transscleral cyclophotocoagulation, endoscopically controlled cyclophotocoagulation (ECPC) is a relatively new method, introduced in the 1990s. Its clinical and technical background is outlined in this article. ECPC allows direct visualization of the ciliary body and better control of the applied laser energy. Therefore, ECPC has been described as being more effective and safer than the transscleral approach. Our own retrospective ECPC data, however, do not indicate that this method can sufficiently decrease intraocular pressure. The indication for the invasive procedure of endoscopic cyclophotocoagulation is therefore questionable.

Incidence of vitreoretinal complications following cyclophotocoagulation

Dear Editor, We present our data on the risk of vitreoretinal complications after cyclophotocoagulation (CPC). In CPC, the ciliary epithelium is coagulated typically by a transscleral approach [1]. There is intense discussion about uncontrollable hypotonia with the risk of phthisis bulbi as a severe complication of CPC [2, 3]. Little is known about retinal complications of the procedure that are possibly related to a post-operative prostaglandin burst [4, 5]. Our hypothesis is that CPC leads to vitreoretinal complications such as macula edema or epiretinal gliosis. We have retrospectively evaluated 850 consecutive patients who underwent transscleral contact CPC with a diode laser (810 nm) between March 2004 and June 2008, for severe vitreoretinal complications requiring vitreoretinal surgery. The electronic patient files were reviewed for the analysis. In the 850 patients, a total of 1,693 CPC treatments were performed. Of these patients, 20 (2.4% of the patients, 1.2% of the treatments) had to undergo surgery for vitreoretinal conditions after CPC treatment. The diagnoses that led to vitreoretinal surgery were: epiretinal membranes and vitreofoveal traction (12 cases), retinal detachment (four), macular edema (one), choroidal neovascularization (one), endophthalmitis (one) and vitreous haze (one). Age and gender were apparently not risk factors for severe vitreoretinal complications after CPC. The mean age of the 850 patients was 67.5±2.0 years, and in the vitreoretinal complications group 66.4±13.5 years. The male:female ratio was 382:468 (0.816) compared to 8:12 (0.667) respectively. The mean number of CPC treatments applied to all the patients was 2.0±1.4, and to the patients with vitreoretinal complications 1.8±1.1. The average time between the last CPC and the vitreoretinal surgery was 336±39 days. To obtain an indication of whether the number of CPCs influences the risk of severe vitreoretinal complications, a subgroup analysis was done. Table 1 shows the incidence of vitreoretinal surgery for each subgroup. The coefficient of correlation between percentage of vitreoretinal surgery after CPC and total amount of patients in this subgroup was 0.25 (p=0.68). Thus, the number of CPCs does not seem to impact the risk for severe vitreoretinal complications. We carefully reviewed the medical history of each patient who had to undergo vitreoretinal surgery, to determine whether there were other possible reasons for vitreoretinal issues. Without exception, each patient had a history of multiple previous surgeries, and presented with complex combinations of ocular diseases. All had undergone one or more of the following operations: cataract extraction (13 cases), YAG capsulotomy (one), secondary lens implantation (one), deep scelerctomy (eight), YAG goniopuncture (three), trabeculectomy (two), retinal lasercoagulation (four), retinal cryocoagulation (one), or argon laser trabeculoplasty (two). Indications for CPC were: primary open-angle glaucoma (14), PEX-glaucoma (two), traumatic glaucoma (one), neovascular glaucoma (one) and congenital glaucoma (two). In addition to the reasons for Graefes Arch Clin Exp Ophthalmol (2009) 247:1565–1566 DOI 10.1007/s00417-009-1115-5

Inhibition of Nuclear Translocation of Apoptosis-Inducing Factor Is an Essential Mechanism of the Neuroprotective Activity of Pigment Epithelium-Derived Factor in a Rat Model of Retinal Degeneration

Photoreceptor apoptosis is a critical process of retinal degeneration in retinitis pigmentosa (RP), a group of retinal degenerative diseases that result from rod and cone photoreceptor cell death and represent a major cause of adult blindness. We previously demonstrated the efficient prevention of photoreceptor apoptosis by intraocular gene transfer of pigment epithelium-derived factor (PEDF) in animal models of RP; however, the underlying mechanism of the neuroprotective activity of PEDF remains elusive. In this study, we show that an apoptosis-inducing factor (AIF)-related pathway is an essential target of PEDF-mediated neuroprotection. PEDF rescued serum starvation-induced apoptosis, which is mediated by AIF but not by caspases, of R28 cells derived from the rat retina by preventing translocation of AIF into the nucleus. Nuclear translocation of AIF was also observed in the apoptotic photoreceptors of Royal College of Surgeons rats, a well-known animal model of RP that carries a mutation of the Mertk gene. Lentivirus-mediated retinal gene transfer of PEDF prevented the nuclear translocation of AIF in vivo, resulting in the inhibition of the apoptotic loss of their photoreceptors in association with up-regulated Bcl-2 expression, which mediates the mitochondrial release of AIF. These findings clearly demonstrate that AIF is an essential executioner of photoreceptor apoptosis in inherited retinal degeneration and provide a therapeutic rationale for PEDF-mediated neuroprotective gene therapy for individuals with RP.

Small Choroidal Melanoma with Chromosome 3 Monosomy on Fine-Needle Aspiration Biopsy

To evaluate the presence of chromosome 3 monosomy in small choroidal melanoma using fine-needle aspiration biopsy (FNAB). Noncomparative case series. Fifty-six patients with small choroidal melanoma measuring 3 mm or less in thickness who were undergoing plaque radiotherapy. Fine-needle aspiration biopsy was used at the time of plaque radiotherapy to sample tumor cells using a 27-gauge long needle via an indirect transvitreal approach into the tumor apex for postequatorial tumors or a 30-gauge short needle via a direct transscleral approach into the tumor base for preequatorial tumors. Chromosome 3 monosomy in small choroidal melanoma. The median tumor thickness was 2.6 mm. Monosomy 3 was found in 15 (27%) cases and disomy 3 was found in 32 (57%) cases. In 9 (16%) cases, genomic DNA yield was insufficient for genetic analysis. Fine-needle aspiration biopsy with a 27-gauge needle transvitreal approach provided quantity sufficient for genetic testing in 31 (97%) of 32 cases versus 16 (67%) of 24 cases sampled with a 30-gauge transscleral technique. Compared with disomy 3 tumors, monosomy 3 tumors were statistically more likely to occur in older patients (P = 0.040). Monosomy 3 (versus disomy 3) tumors showed thickness of more than 2 mm in 100% (vs. 84%), subretinal fluid in 87% (vs. 94%), symptoms in 40% (vs. 56%), orange pigment in 93% (vs. 81%), and margin of 3 mm or less to the optic disc in 20% (vs. 50%). There was no statistical difference between monosomy 3 and disomy 3 tumors in the presence or number of these clinical factors. However, small choroidal melanomas with monosomy 3 mutation were more likely to have had documented growth (63%) compared with those with disomy 3 (25%; P = 0.025; odds ratio, 5.00). Using FNAB at the time of plaque radiotherapy, monosomy 3 was found in approximately 27% of small choroidal melanomas, more often in older patients and tumors with documented growth. Transvitreal biopsy into the tumor apex provided better yield compared with transscleral biopsy into the tumor base.