Strabismus management in retinoblastoma survivors.

PURPOSE: To report the result of strabismus surgery in eye-salvaged retinoblastoma (Rb) patients. METHODS: A retrospective case series including 18 patients with Rb and strabismus who underwent strabismus surgery after completing tumor treatment by a single pediatric ophthalmologist. RESULTS: A total of 18 patients (10 females and 8 males) were included with a mean age of 13.3 ± 3.0 (range, 2-39) months at the time tumor presentation and 6.0 ± 1.5 (range, 4-9) years at the time of strabismus surgery. Ten (56%) patients had unilateral and 8(44%) had bilateral involvement and the most common worse eye tumor's group was D (n = 11), C (n = 4), B (n = 2) and E (n = 1). Macula was involved by the tumors in 12 (67%) patients. The tumors were managed by intravenous chemotherapy (n = 8, 47%), intra-arterial chemotherapy (n = 7, 41%) and both (n = 3, 17%). After complete treatment, the average time to strabismus surgery was 29.9 ± 20.5 (range, 12-84) months. Except for one, visual acuity was equal or less than 1.0 logMAR (≤ 20/200) in the affected eye. Seven (39%) patients had exotropia, 11(61%) had esotropia (P = 0.346) and vertical deviation was found in 8 (48%) cases. The angle of deviation was 42.0 ± 10.4 (range, 30-60) prism diopter (PD) for esotropic and 35.7 ± 7.9 (range, 25-50) PD for exotropic patients (P = 0.32) that after surgery significantly decreased to 8.5 ± 5.3 PD in esotropic cases and 5.9 ± 6.7 PD in exotropic cases (P < 0.001). The mean follow-up after surgery was 15.2 ± 2.0 (range, 10-24) months, in which, 3 (17%) patients needed a second surgery. CONCLUSION: Strabismus surgery in treated Rb is safe and results of the surgeries are acceptable and close to the general population. There was not associated with tumor recurrence or metastasis.

Uveal melanoma in the Iranian population: two decades of patient management in a tertiary eye center.

BACKGROUND: To assess the characteristics and outcomes of uveal melanoma management at a tertiary center in the Middle East. METHODS: A study on 164 patients with uveal melanoma was conducted by reviewing the available medical records, ultrasound, and pathology report results. Age at diagnosis, tumor location and size, treatment mode, visual outcome, metastasis, mortality, and survival were studied. RESULTS: The mean age of patients was 52.0 ± 15.0 years, and 52.5% were male. Choroidal melanoma was the most common uveal melanoma, followed by the ciliary body and iris melanoma. The mean thickness of tumors was 8.29 ± 3.29. The majority of patients (n = 111, 67.9%) were managed by brachytherapy with ruthenium-106 plaques. Enucleation was performed primarily in 46 (28%) patients and secondarily in nine (5.5%) patients. The sexual disparity was detected as the proximity of uveal melanoma to the fovea in males. For a 61-month mean follow-up period, mortality occurred in eight of our cases, six of which were due to metastasis. The most common site for distance metastasis was the liver (5/6), followed by the lung (1/6). The five-year and eight-year overall survival (OS) rate was 0.947%± 0.019. The 5-year survival rate reached zero in metastatic patients. OS was not statistically different depending on the age, tumor diameters, the primary treatment received, or the histopathologic findings (p > 0.50 for all). CONCLUSION: In this study, individuals diagnosed with UM exhibited an OS rate of around 94% at the five-year mark, which remained consistent up to eight years. Notably, the presence of distance metastasis emerged as the sole statistically significant factor influencing overall survival.

Pediatric ocular melanoma: a collaborative multicenter study and meta-analysis.

PURPOSE: To investigate clinical manifestations and prognoses in pediatric patients (≤12 years old) with ocular melanoma. METHODS: This was a retrospective, multicenter cohort study with individual participant data (IPD) meta-analysis pooling available published cases, and unpublished cases from an international collaboration of seven ocular oncology centers. RESULTS: There were 133 eyes of 133 pediatric patients with choroidal or ciliary body (n = 66 [50%]), iris (n = 33 [25%]), conjunctival (n = 26 [19%]), and eyelid (n = 8 [6%]) melanoma. Overall, the mean patient age at presentation was 7 years (median, 8; range, 1-12 years), with 63 males (49%). The mean age by tumor site was 6.50 ± 3.90, 7.44 ± 3.57, 9.12 ± 2.61, and 5.63 ± 2.38 years, for choroid/ciliary body, iris, conjunctiva, and eyelid melanoma, respectively (P = 0.001). Association with ocular melanocytosis was seen in 15%, 11%, 4%, and 0%, respectively (P = 0.01). Frequency of ocular melanoma family history did not vary by tumor site (7%, 17%, 9% and 12%, resp. [P = 0.26]). After mean follow-up of 74, 85, 50, and 105 months (P = 0.65), metastasis was seen in 12%, 9%, 19%, and 13% of choroid/ciliary body, iris, conjunctiva, and eyelid melanoma, respectively. Death was reported in 5%, 3%, 8%, and 0%, respectively, with survival analysis indicating higher mortality in choroidal/ciliary body and conjunctival melanoma patients. CONCLUSIONS: Ocular melanoma in the pediatric population is rare, with unique clinical features and outcomes. Iris melanoma accounts for about one-third of pediatric uveal melanoma cases.

Pachychoroid neovasculopathy versus macular neovascularization in age-related macular degeneration with and without shallow irregular pigment epithelial detachment.

To compare the choroidal neovascular features of individuals with pachychoroid neovasculopathy (PNV) and neovascular age-related macular degeneration (nAMD) with and without shallow irregular pigment epithelial detachment (SIPED). Using optical coherence tomography angiography, the choroidal neovascular complexes of 27 patients with PNV, 34 patients with nAMD and SIPED, and 15 patients with nAMD without SIPED were analyzed with FIJI and AngioTool software. PNV compared to nAMD with SIPED had a greater vessel percentage area (P = 0.034), junction density (P = 0.045), average vessel length (P < 0.001), and fractal dimension (P < 0.001). PNV, compared to nAMD without SIPED, had a greater total vessel length (P = 0.002), total number of junctions (P < 0.001), junction density (P = 0.034), and fractal dimension (P = 0.005). nAMD with SIPED, compared to nAMD without SIPED, had greater vessel area, total number of junctions, total vessel length, and average vessel length (all P values < 0.001). Patients with nAMD plus SIPED and individuals with nAMD without SIPED have similar fractal dimension values (P = 0.703). Biomarkers of choroidal neovascular complexity, such as fractal dimension, can be used to differentiate PNV from nAMD with or without SIPED.

Massive Uveal Relapse of Retinoblastoma Presumed to Be Choroidal Tumorous Involvement: Case Series.

We report the choroidal and ciliary body invasion by retinoblastoma (RB) in a salvaged eye after complete and successful primary treatment. Case 1: A 25-month-old boy was referred due to group B RB lesions based on the International Classification of RB (ICRB; groups A-E) in the right eye (OD). His left eye (OS) was enucleated because of advanced group E RB. After 47 months of uneventful follow-up (F/U), a new lesion recurred and was treated with transpupillary thermotherapy. Four months later, a fast-growing pigmented subretinal mass was detected that was treated by brachytherapy with the apical dose of 80 Gy. Three weeks later, the lesion regressed completely, and no recurrence happened after 6 years of F/U. Case 2: A 4-month-old girl with a deletion in chromosome 13 was referred for bilateral RB. OD was enucleated because of unresponsive RB and anterior segment involvement. In OS, group B lesions had multiple recurrences after systemic chemotherapy. After a while, a single mass appeared in the nasal periphery which was controlled well with brachytherapy. Four months later, AC involvement was controlled with IAC, intravitreal, and intracameral chemotherapy, but posterior synechia and cataract appeared later. One year after the last treatment, UBM showed a ring-shaped ciliary body mass. Her parents refused enucleation again, and she received intravenous chemotherapy. Two years later, magnetic resonance imaging showed orbital and optic canal involvement with a deformed globe. In conclusion, RB recurrence can appear as local choroidal and ciliary body involvement even after a time of complete remission. The role of B-scan and UBM in early diagnosis and successful treatment is valuable.

Potential application of foveal structural measurements in treatment decision for retinopathy of prematurity: an OCT-based study.

PURPOSE: To investigate foveal changes in infants with ROP not requiring treatment(nROP) and ROP infants needing treatment (tROP) using a handheld SD-OCT device. METHOD: We performed horizontal SD-OCT scans through the fovea in 156 eyes of 81 infants diagnosed with ROP. Foveal immaturity indices including the presence of inner retinal layers (IRL), absence of foveal outer nuclear layers widening (ONL) and attenuation of hyperreflective outer segment layers (OS), presence and type of cystoid macular edema (CME), epiretinal membrane (ERM), foveal pit depth (FPD), foveal pit width (FPW) and central foveal thickness (CFT) were calculated. The multivariate logistic regression model was used to predict the need for treatment based on OCT measurements. RESULTS: The shape of the foveolar pit was not significantly different among tROP and nROP groups (P-value = 0.287, Chi-square test). IRL extrusion was incomplete in both tROP and nROP groups (P-value = 0.0.41, Chi-square test). Nevertheless, the presence of thicker IRL was more frequent in the nROP group in comparison with the tROP group (100% vs.64.8%, P-value = 0.001). CME was observed in 29% of eyes in the tROP group and 40% of eyes in the nROP group; however, this difference was not statistically significant (P-value = 0.32, Chi-square test). ERM was detected in 15 (75%) and 84 (65.6%) eyes in the nROP and tROP groups, respectively (P-value = 0.39, Chi-square test). Multivariate logistic regression analyses showed that the need for treatment was significantly associated with gestational age (GA), CFT and FPD (P-values 0.001 and 0.002 respectively). CONCLUSIONS: This study demonstrated GA, foveal pit depth and the central foveal thickness could accurately predict the need for treatment with sensitivity, specificity, and diagnostic accuracy of 97%, 65% and 91.7% respectively.

Retinal astrocytic hamartoma complicated by branch retinal vein occlusion in a patient with tuberous sclerosis complex.

Purpose: To report a case with branch retinal vein occlusion secondary to a retinal astrocytic hamartoma in a patient with tuberous sclerosis complex. Observations: A fourteen-year-old boy, a known case of tuberous sclerosis complex, with multiple bilateral retinal astrocytic hamartomas was followed by 6 months intervals. In his last follow-up, 6 months after initial presentation, the patient developed angiographic signs of branch retinal vein occlusion (BRVO) in the superotemporal arcade of the right eye distal to one of the retinal astrocytic hamartomas. He underwent targeted retinal laser photocoagulation. No secondary complication related to BRVO was observed during the next six-month follow-up. Conclusion: And Importance: Although the co-occurrence of branch retinal vein occlusion and astrocytic hamartoma may represent an incidental finding, awareness of BRVO as a possible complication associated with retinal astrocytic hamartoma helps timely diagnosis and prompt treatment of this complication, improving the visual prognosis of these patients.

Dosimetric Investigation of Six Ru-106 Eye Plaques by EBT3 Radiochromic Films and Monte Carlo Simulation.

Background: Ophthalmic brachytherapy using radioactive plaques is an effective technique for the treatment of uveal melanoma. Ru-106 eye plaques are considered as interesting issue due to their steep gradient dose. The pre-planning evaluation of dosimetric parameters is essential for the treatment planning system. Objective: The current study aims at providing dose distributions of six Ru-106 eye plaques (CCA, CCB, CGD, CIB, COB and COD) using radiochromic EBT3 film, Geant4 Monte Carlo toolkit and the treatment planning software (Plaque Simulator). Material and Methods: In this experimental study, an in-house phantom was employed for depth dose measurements with EBT3 films. Also, Geant4.10.5 scoring mesh was implemented to obtain the 2D dose distribution of the plaques. The results were compared with Plaque Simulator software and the manufacturer's (BEBIG) data. The gamma index criterion (3%/3 mm) was used to evaluate dose distributions obtained by the film measurements and Geant4 simulation. Results: A good agreement was achieved between simulation and experimental results. Gamma index passing rate was 94.2%, 89.3%, 88.2%, 82.2%, 92.2% and 90.1% for CCA, CCB, CGD, CIB, COB and COD plaques, respectively. Absolute dose rate (mGy/min) obtained by EBT3 film at the depth of 2 mm was 79.4 mGy/min, 81.0 mGy/min, 78.6 mGy/min, 62.2 mGy/min, 75.2 mGy/min and 81.2 mGy/min for CCA, CCB, CGD, CIB, COB and COD plaques, respectively. Conclusion: The measured dose distributions and lateral dose profiles may be utilized in the treatment planning system to cover clinical volumes such as the clinical target volume and the gross tumor volume.

The Antitumor Effect of Topotecan Loaded Thiolated Chitosan-Dextran Nanoparticles for Intravitreal Chemotherapy: A Xenograft Retinoblastoma Model.

Purpose: This research intended to fabricate the thiolated chitosan-dextran nanoparticles (NPs) containing topotecan (TPH-CMD-TCS-NPs) to assess the ability of NPs in improving the efficacy of intravitreal chemotherapy of retinoblastoma in a rabbit xenograft model. Methods: The coacervation process was used to produce the NPs. The cellular uptake of Cyanine-3 (CY3)-labeled NPs were investigated in human retinoblastoma Y79 cells using confocal microscopy. Also, the prepared TPH-CMD-TCS-NPs were tested in vitro by the tetrazolium dyes II (XTT) and flow cytometry in order to assess their cytotoxicity. In addition, a rabbit xenograft model of retinoblastoma was developed to test the antitumor effectiveness of TPH-CMD-TCS-NPs through intravitreal administration. Results: NPs had a mean diameter, polydispersity index, and zeta potential of 30 ± 4 nm, 0.24 ± 0.03 and +10 ± 3 mV, respectively. NPs (IC50s 40.40 compared to 126.20 nM, P = 0.022) were more effective than free topotecan as a dose-based feature. The tumor reaction to intravitreal chemotherapy with NPs was measured by evaluating the percentage of necrosis in the tumor tissue (91 ± 2%) and vitreous seeds (89 ± 9%) through hematoxylin and eosin (H&E) staining. In comparison with the control group, the TPH-CMD-TCs-NPs treated group showed a significant decrease in tumor volume seven days after the intravitreal injection (P = 0.039). No significant changes were found in the ERG parameters after the intravitreal injection of TPH-CMD-TCs-NPs or TPH (P > 0.05). Conclusion: This investigation revealed definitive antitumor efficacy of TPH-CMD-TCS-NPs by intravitreal administration in the rabbit xenograft retinoblastoma model.

Bacillary Layer Detachment in Diabetic Retinopathy: A Case Report.

To our knowledge, this is the first report to describe bacillary layer detachment (BLD) in a patient with diabetic retinopathy treated with anti-vascular endothelial growth factor. We present the case of a 55-year-old diabetic female who was referred to our hospital complaining of decreased vision in her left eye for 2 weeks. Fundus examination of both eyes was compatible with diabetic retinopathy. Spectral-domain optical coherence tomography of the left eye showed a large dome-shaped cystic space with marginal septa, splitting the myoid zone, consistent with the BLD phenotype. A single dose of intravitreal bevacizumab injection was administered. After 4 weeks, BCVA was improved significantly with complete resolution of BLD. Underlying choroidal ischemia in patients with different vascular disorders like diabetes mellitus may lead to photoreceptor stress and BLD. This study adds to the growing literature, which describes BLD as a marker of fluid accumulation in relation to several macular diseases.

Addition of intravitreal carboplatin with melphalan for management of vitreous seeding in retinoblastoma.

PURPOSE: To evaluate the efficacy and toxicity of intravitreal carboplatin plus melphalan for the treatment of vitreous seeds in eyes with retinoblastoma (RB). METHODS: This retrospective series at a tertiary referral center included 22 consecutive RB patients who had received intravitreal carboplatin (16 µg per 0.05 ml) combined with melphalan (30 µg in 0.03 ml) [IVi (Ca-Me)] for treatment of vitreous seeds. Tumor control and drug toxicities were recorded. RESULTS: There were 22 eyes of 22 patients, divided into primary group (n = 13) without history of previous intravitreal chemotherapy (IViC) and refractory group (n = 9) with history of previous IViC using melphalan and/or topotecan. The demographics and clinical findings of the primary and refractory groups did not differ significantly. The 6-month follow-up revealed complete vitreous seed control (77% vs. 89%, p = 0.47). Vitreous seed recurrence was detected in 1 eye of each group at 6 months. During the next 18-month follow-up period, no recurrence of seed was observed. The response to IVi (Ca-Me) was not significantly influenced by previous IViC (p = 0.70), primary systemic or intra-arterial chemotherapy (p = 0.45), or the type of regression (p = 0.35). The most common tumor treatment complications were retinal detachment (RD) (n = 2), early hypotony (n = 2) and late hypotony (n = 4, unrelated), cataract (n = 2), and severe pigment dispersion (n = 1). Enucleation was performed in 8 eyes, for total RD (n = 1), phthisis bulbi (n = 5), and extensive solid tumor recurrence (n = 2). There was no case of orbital invasion, systemic metastasis, or death. CONCLUSION: Based on this interventional case series for primary and refractory vitreous RB seeds, carboplatin plus melphalan therapy may be effective with few toxic side effects.

Near-Infrared Confocal Reflectance Scanning Laser Ophthalmoscopy (SLO) and Short-Wavelength Autofluorescence Imaging in Cystic Diabetic Macular Edema.

Objective: To characterize results of short-wavelength autofluorescent (SW-AF) and near-infrared confocal reflectance scanning laser ophthalmoscopy (NIR-cR SLO) imaging in cystic diabetic macular edema (DME). Design: Cross-sectional study. Participants: 104 eyes from 52 naïve treatment patients with DME and mild to moderate nonproliferative diabetic retinopathy (NPDR) Methods: complete ocular examination, best-corrected visual acuity (BCVA), and imaging were performed. Results: In NIR-cR SLO, small/medium and large-sized cysts presented with decreased and increased reflectance, respectively. In SW-AF, increased and decreased autofluorescence, corresponding to medium-/large- and small-sized cysts were noted. Mainly, the lower NIR reflectance was associated with petaloid edema pattern in SW-AF (P=0.011), BCVA (logMAR) (P=0.056), subretinal fluid (P=0.035), and the involved layers of retina by cysts (P < 0.001) in Pearson chi-square test. Fair agreement of 0.31 (P < 0.001) between NIR-cR SLO and late FA leakage was found by the weighted kappa test. In regression analysis, NIR-cR SLO abnormality is highly correlated with outer and inner nuclear layers location of the cystic changes. Conclusions: The size of cysts and involved layers affect presenting features of SW-AF and NIR reflectance.

Erratum: Biodistribution of Cy5-labeled Thiolated and Methylated Chitosan-Carboxymethyl Dextran Nanoparticles in an Animal Model of Retinoblastoma.

[This corrects the article DOI: 10.18502/jovr.v17i1.10171.].

Ocular Manifestations of Newly Diagnosed Acute Leukemia Patients.

Purpose: To present primary ocular manifestations in acute leukemia. Methods: This cross-sectional descriptive hospital-based study evaluated all newly diagnosed leukemia patients of three referral hospitals of Tehran University of Medical Sciences in 2015-2016 and Mahak Hospital in Tehran in 2017. Exclusion criteria included the patients with the previous history of chemotherapy, cases of relapsing disease, and the patients with a history of ocular disease or other systemic conditions with ophthalmic manifestations. Results: A total of 85 patients (170 eyes) were evaluated in our study, including 29 children (34.1%) and 43 females (50.6%). The mean patient age was 37.84 ± 11.91 years in the adult group and 6.28 ± 4.70 years in the pediatric category. Ophthalmic involvement was seen in 27 patients (31.8%), including 6 pediatric patients (20.7%) and 21 adult patients (37.5%). Two patients (2.3%) had direct infiltration by leukemic cells and 76 patients (89.41%) of patients were asymptomatic. There was a correlation between ophthalmic involvement and platelet count and hemoglobin level. In patients with ocular signs, higher mortality rates were observed. Conclusions: At the time of diagnosis in acute leukemia patients, complete ophthalmic evaluation including dilated fundus examination is suggested as ocular involvement in these patients is common and sometimes asymptomatic. Ophthalmic involvement in leukemic patients should be identified in a timely manner, particularly in individuals with low platelet counts and hemoglobin levels, due to the potential prognostic relevance.

Management of primary choroidal lymphoma presenting as extensive serous retinal detachment and salmon patch of bulbar conjunctiva: a case report.

BACKGROUND: We describe the outcome of ultra-low-dose radiotherapy plus intravitreal methotrexate and rituximab injections for a patient with primary choroidal lymphoma who presented with nodular conjunctival salmon patches and extensive serous retinal detachment. CASE PRESENTATION: A 34-year-old Iranian man presented with a nodular patch of bulbar conjunctiva in the right eye, and 1+ vitritis. A nearly complete shallow serous retinal detachment, retinal folds, and multifocal yellow choroidal infiltrates were seen during a fundus examination of the right eye. Enhanced depth imaging optical coherence tomography revealed macular retinal folds and an uneven, undulating, "seasick" appearance of the choroidal surface with choriocapillaris compression, intraretinal and subretinal fluid, and clusters of optically dense material at the outer retinal level. An incisional biopsy of the conjunctival lesion confirmed the diagnosis of primary choroidal lymphoma with epibulbar involvement. The patient was treated with ultra-low-dose "boom-boom" radiation (4 Gy delivered in two fractions over two consecutive days) as well as intravitreal methotrexate and rituximab injections. After a year, the lesions had completely disappeared, with no adverse effects or recurrence. CONCLUSION: Ultra-low-dose (boom-boom) radiotherapy combined with intravitreal chemotherapy and/or immunotherapy may be an effective treatment for primary choroidal lymphoma with anterior epibulbar extension and diffuse subretinal fluid with favorable response and minimal side effects.

The Role of Early Vitrectomy in the Healing of Retinal Lesions in Progressive Outer Retinal Necrosis.

Purpose: To report on the efficacy of early pars plana vitrectomy (PPV), silicone oil (SO) tamponade, and intravitreal ganciclovir injection in the treatment of a case with progressive outer retinal necrosis (PORN). Case Presentation. A 33-year-old man with a history of shingles on the chest skin 2.5 months ago presented with progressive vision loss in both eyes over the past 20 days. Fundus examination revealed retinal necrosis with perivascular clearance. Human immunodeficiency virus (HIV) infection was confirmed by western blot analysis. Treatment with intravenous acyclovir and intravitreal ganciclovir injections was unable to stop the progression of retinitis. Along with highly active antiretroviral therapy, the patient underwent PPV with SO tamponade and intravitreal ganciclovir injection in both eyes. A few days after surgery, retinal lesions started to improve. Conclusion: Early PPV, SO tamponade, and intravitreal ganciclovir injection may be considered an effective intervention in PORN patients with an unfavorable response to medical treatment.

Comparison of the Accuracy of Anterior Segment Optical Coherence Tomography and Ultrasound Biomicroscopy in Localizing Rectus Muscle Insertions.

PURPOSE: To compare the accuracy of anterior segment optical coherence tomography (AS-OCT) and ultrasound biomicroscopy (UBM) in localizing rectus muscle insertions. METHODS: The study was performed on 27 patients (39 rectus muscles) who required primary or secondary surgery. Using caliper function in the AS-OCT and UBM software, the distance from the insertion site to the anterior chamber angle was measured. The actual muscle insertion distance from limbus was considered as the measured distance plus 1 mm. The measurements by UBM and AS-OCT were compared with intraoperative measurements and with each other. RESULTS: AS-OCT and UBM were performed on 13 medial rectus, 24 lateral rectus, and 2 superior rectus muscles. Ninety two percent of UBM measurements (36 muscles) were within 1 mm, one was within 1-1.5 mm, and 2 were within 1.5-2 mm of surgery measurements. Eighty five percent of AS-OCT measurements (33 muscles) were within 1 mm, 5 were within 1-1.5 mm, and one was within 1.5-2 mm of surgery measurements. In all cases, the mean absolute error of the UBM (0.54 ± 0.44) and AS-OCT (0.51 ± 0.36) showed no significant difference (p = .76). CONCLUSION: AS-OCT and UBM can be used interchangeably to localize rectus muscle insertions and showed good agreement with intraoperative measurements.

Clinical sign and symptom of primary vitreoretinal lymphoma short-time after retinal reattachment surgery: a case report.

PURPOSE: To describe a case of primary vitreoretinal lymphoma (PVRL), initially presented after successful repair of rhegmatogenous retinal detachment (RRD). CASE PRESENTATION: A 65-year-old man underwent pars plana vitrectomy with silicone oil tamponade for total RRD with grade C proliferative vitreoretinopathy in the right eye. Ten months after silicon oil removal, the patient presented with weakened vision, and multiple small yellow sub-retinal elevations was observed in fundus examination and optical coherence tomography (OCT). A cytopathologic examination of the vitreous showed lymphoid cell infiltration with nuclear atypia, which is strongly indicative of malignant lymphoma. Subretinal lesions continued with no noticeable improvement after 9 sessions of 400 microgram methotrexate therapy. CONCLUSION: We identified the presentation of PVRL in a vitrectomized eye and the response to treatment in this article.

Biodistribution of Cy5-labeled Thiolated and Methylated Chitosan-Carboxymethyl Dextran Nanoparticles in an Animal Model of Retinoblastoma.

PURPOSE: The use of more potent medicine for local chemotherapy of retinoblastoma in order to minimize local and systemic adverse effects is essential. The main goal of this investigation was to assess the biodistribution of thiolated and methylated chitosan-carboxymethyl dextran nanoparticles (CMD-TCs-NPs and CMD-TMC-NPs) following intravitreal (IVT) injection into rat eyes with retinoblastoma. METHODS: An ionic gelation method was used to fabricate Cy5-labelled CMD-TCs-NPs and CMD-TMC-NPs. The NPs were characterized. Cellular internalization of Cy5-labelled NPs was investigated using confocal microscopy and the absorption of labeled NPs was quantified by flow cytometry in human retinoblastoma (Y79) cells. In addition, the Cy5-labeled distribution of nanoparticles in the posterior segment of the eye was histologically imaged by confocal microscopy after IVT injection of NPs into the eyes of rats with retinoblastoma. RESULTS: CMD-TCs-NPs and CMD-TMC-NPs showed a mean diameter of 34 ± 3.78 nm and 42 ± 4.23 nm and zeta potential of +11 ± 2.27 mV and +29 ± 4.31mV, respectively. The in vivo study of intraocular biodistribution of Cy5-labeled CMD-TCs-NPs and CMD-TMC-NPs revealed that there is more affinity of CMD-TCs-NPs to the retina and retinoblastoma tumor after IVT administration while methylated chitosan nanoparticles are immobilized in the vitreous and are not able to reach the retina even after 24 hr. CONCLUSION: The ionic gelation technique was efficient in synthesizing a biocompatible polymeric nanosystem for drug delivery into the posterior segment of the eye. The current study demonstrated increased ocular bioavailability of CMD-TCs-NPs relative to CMD-TMC-NPs in retinoblastoma induced rat eyes.