Bilateral exudative retinal detachments after subretinal gene therapy with voretigene neparvovec-rzyl for RPE65 Leber Congenital Amaurosis.

Purpose: To report panuveitis with exudative retinal detachments in a healthy 27-year-old woman with biallelic mutations in the RPE65 gene, who underwent bilateral sequential gene therapy with subretinal administration of voretigene neparvovec-rzyl. Observations: Visual acuity improved for 30 days after surgery as oral corticosteroids were tapered. At postoperative week 6, vision declined due to sudden onset uveitis and exudative retinal detachments in both eyes. HLA Class II typing revealed the haplotype associated with sympathetic ophthalmia and Vogt-Koyanagi-Harada (VKH). The inflammation improved after corticosteroid, mycophenolate mofetil, and adalimumab therapy while vision remained poor. Conclusions and Importance: Surgically-induced sympathetic ophthalmia is a plausible explanation for the clinical findings; surgery of both eyes within one week would conceal the inciting eye. VKH or inflammation related to the gene therapy are other possible etiologies but severe bilateral panuveitis has not been reported with voretigene neparvovec-rzyl. Informed consent for gene therapy surgery should include a discussion of the rare complication of sympathetic ophthalmia following vitrectomy surgery.

A clinically viable approach to restoring visual function using optogenetic gene therapy.

Optogenetic gene therapies offer a promising strategy for restoring vision to patients with retinal degenerative diseases, such as retinitis pigmentosa (RP). Several clinical trials have begun in this area using different vectors and optogenetic proteins (Clinical Identifiers: NCT02556736, NCT03326336, NCT04945772, and NCT04278131). Here we present preclinical efficacy and safety data for the NCT04278131 trial, which uses an AAV2 vector and Chronos as the optogenetic protein. Efficacy was assessed in mice in a dose-dependent manner using electroretinograms (ERGs). Safety was assessed in rats, nonhuman primates, and mice, using several tests, including immunohistochemical analyses and cell counts (rats), electroretinograms (nonhuman primates), and ocular toxicology assays (mice). The results showed that Chronos-expressing vectors were efficacious over a broad range of vector doses and stimulating light intensities, and were well tolerated: no test article-related findings were observed in the anatomical and electrophysiological assays performed.

Two cases of unilateral cone-rod dysfunction presenting in adult females.

PURPOSE: To describe cases of unilateral cone-rod dysfunction presenting in two middle-aged females. METHODS: This case series highlights two middle-aged female patients with progressive visual decline in one eye. Fundus photography, fundus autofluorescence (FAF), spectral-domain optical coherence tomography (SD-OCT), multi-focal electroretinogram (mfERG), full-field electroretinogram(ffERG), and genetic testing were obtained. RESULTS: In the first patient, mfERG showed an extinguished response and ffERG demonstrated markedly reduced a-wave and b-wave amplitudes (more pronounced under photopic conditions) in the right eye. SD-OCT showed attenuation of the ellipsoid zone of the right eye. Similar findings were appreciated in the second patient. Genetic testing in the first patient identified three heterozygous variants in PRPH2, RCBTB1, and USH2A. The second patient was found to have heterozygous variants in BBS1 and ABCA4. CONCLUSION: These two cases add to the literature of case reports of unilateral cone-rod and rod-cone dystrophies. However, the underlying etiology of the unilateral pattern of cone-rod dysfunction and the significance of the heterozygous mutations found in both cases remains uncertain.

Documentation of recovery from vitamin A deficiency-related retinopathy via multimodal imaging and electroretinogram testing.

PURPOSE: To describe vitamin A deficiency using multimodal functional visual assessments and imaging. METHODS/CASE: A 50-year-old female with past medical history significant for Roux-en-Y gastric bypass surgery complained of nyctalopia and "yellowing" of vision. RESULTS: Vitamin A levels were noted to be < 0.06 mg/L (normal 0.3-0.12 mg/L). Fundus examination was notable for peripheral yellow punctate lesions, superior arcuate defects on HVF 30-2 testing, an indistinct ellipsoid zone on SD-OCT, and absent rod responses and severely reduced amplitudes for the cone photoreceptors on full-field ERG. These findings resolved with initiation of parenteral vitamin A supplementation. CONCLUSION: This report documents an example of vitamin A deficiency in the developed world. We aim to provide a comprehensive description of clinical examination and multimodal imaging findings before and after vitamin supplementation for vitamin A deficiency.

Qualitative and quantitative comparison of ERGs with contact lens and adhesive skin electrodes.

PURPOSE: Traditional ERGs recorded using corneal electrodes can be difficult for some patients to tolerate. In the last several years, adhesive skin electrodes have gained in acceptance. In this report we present a qualitative comparison of waveforms as well as a quantitative analysis of correlation of amplitudes and implicit times of simultaneous ERG recordings using contact lens and skin electrodes. METHODS: 89 subjects were included; all were referred for full-field ERG testing for multiple indications. ERGs (obtained according to ISCEV standards) were recorded simultaneously from both eyes with ERG-jet corneal contact lens electrodes and LKC Technologies Sensor Strip adhesive skin electrodes using multi-channel instrumentation (Diagnosys LLC, Espion3). Waveforms, a-wave and b-wave amplitudes and implicit times were compared. RESULTS: Waveform morphologies were similar between electrode types. Regression coefficients (conversion factors) for a-wave and b-wave amplitudes under both photopic and scotopic conditions were tightly clustered. Regression coefficients for implicit times were nearly equal to 1.0. The regression coefficient for the entire amplitude dataset was 0.349, with an overall correlation of 0. 869 between amplitude recorded with skin and contact lens electrodes. The regression coefficient for the entire implicit time dataset was 0.967, with an overall correlation of 0.964 between skin and contact lens electrodes. CONCLUSIONS: Our best estimate for the conversion factor between ERG amplitudes recorded with adhesive skin electrodes and contact lens electrodes is 0.349-amplitudes with skin electrodes are about 1/3 the amplitudes recorded simultaneously from the same eyes with contact lens electrodes, with a high correlation. Implicit times are nearly identical for the two electrode types.

UNUSUAL EARLY-ONSET VITELLIFORM DYSTROPHY POSSIBLY LINKED TO THE INTERPHOTORECEPTOR MATRIX PROTEOGLYCAN-1 P.LEU154PRO MUTATION.

PURPOSE: To describe a case of symptomatic outer retinal disruption in a patient heterozygous for the p.Leu154Pro interphotoreceptor matrix proteoglycan-1 (IMPG1) mutation implicated in adult-onset foveomacular vitelliform dystrophy. METHODS: Observational case report. RESULTS: We describe a case of a 25-year-old female patient with symptomatic scotoma and vision decrease who exhibited bilateral small foveal yellow spots. Optical coherence tomography revealed disorganization and decreased reflectance of the foveal ellipsoid and interdigitation zones in the left eye more than in the right eye. Fundus autofluorescence imaging showed minimal findings, and dye angiography was unrevealing. Multifocal electroretinogram revealed slightly decreased retinal sensitivity in the central retina of the left eye. Genetic testing identified a heterozygous p.Leu154Pro mutation in the IMPG1 gene. CONCLUSION: The p.Leu154Pro IMPG1 mutation may cause symptomatic outer retinal disturbance in the heterozygous state. Further studies are necessary.

TOXICITY AND EFFICACY OF INTRAVITREAL MELPHALAN FOR RETINOBLASTOMA: 25 µg Versus 30 µg.

PURPOSE: To compare retinal toxicity as measured by electroretinogram, ocular, and patient survival in retinoblastoma treated with intravitreal melphalan at two concentrations (25 vs. 30 µg). METHODS: Single-center, retrospective analysis of retinoblastoma eyes receiving 25-µg or 30-µg intravitreal melphalan from September 2012 to January 2019. Ocular toxicity was measured by electroretinogram of evaluable injections in 449 injections in 136 eyes. A repeated-measures linear mixed model with a random intercept and slope was applied to account for repeated measures for each eye. RESULTS: Average decline in electroretinogram after each additional injection was -4.9 µV (95% confidence interval -6.3 to -3.4); electroretinogram declined by -4.6 µV (95% confidence interval -7.0 to -2.2) after 25-µg injections and -5.2 µV (95% confidence interval -6.6 to -3.8) after 30-µg injections (P = 0.66). Injection at a new clock site hour was associated with a -3.91-µV lower average (95% confidence interval -7.8 to -0.04). CONCLUSION: Electroretinogram-measured toxicity in retinoblastoma eyes treated with intravitreal injections was not found to be different across 25-µg and 30-µg injections. There were no cases of extraocular extension or metastatic deaths in our patient population.

Is intravitreal topotecan toxic to retinal function?

BACKGROUND: Intravitreal injections of topotecan are used in the management of retinoblastoma with vitreous seeds. This study evaluated whether intravitreal topotecan was associated with retinal toxicity. METHODS: Retrospective cohort study of patients with retinoblastoma who were treated with intravitreal topotecan at Memorial Sloan Kettering Cancer Center between December 2014 and May 2019. Electroretinogram (ERG) responses under anaesthesia were measured immediately before treatment with intravitreal topotecan and at the next visitor approximately one-month. Ocular toxicity was defined by a decrease in the ERG response at 30 Hz at follow-up. RESULTS: Ocular toxicity was evaluated by ERG on 50 evaluable injections administered to 28 eyes. 22 (44.0%) injections were performed with concurrent intravitreal melphalan. The median time to ERG measurement following an injection was 27 days. By using a paired t-test, intravitreal topotecan combined with melphalan (n=22) at a dose of 25 µg or 30 µg was associated with a significant decrease in ERG amplitude at follow-up (p=0.046, 95% CI -20.4 µV to -0.2 µV). Among eyes that only received topotecan (n=28) at doses of 20 µg or 30 µg, there was not a significant difference in ERG amplitude measured (p=0.85, 95% CI -7.0 µV to 5.8 µV). CONCLUSION: Intravitreal topotecan combined with intravitreal melphalan was associated with a decrease in ERG amplitude; there was not a significant decrease in ERG amplitude observed in patients who received topotecan alone. These findings suggest that intravitreal topotecan injections at doses of 20 µg or 30 µg are not associated with retinal toxicity in patients with retinoblastoma.

Retinoblastoma management in 13q deletion syndrome patients using super-selective chemotherapies and other cancer-directed interventions.

BACKGROUND: This study aimed to identify best practices for treating 13q deletion syndrome (13q-) patients with retinoblastoma in the era of super-selective ophthalmic artery chemosurgery (OAC) and intravitreal injection therapy (IVIT). METHODS: Retrospective study of 21 eyes from 14 patients with retinoblastoma and 13q- who were treated at Memorial Sloan Kettering Cancer Center (MSKCC) between May 2006 and May 2020, with a mean follow up of 3.7 years. Ocular survival, patient survival, and treatment toxicities were assessed. RESULTS: Nine of the 12 eyes that underwent OAC/IVIT at MSKCC have been progression free for at least 1 year since their last treatments. Fifteen out of 26 OAC cycles resulted in grade 3-4 hematologic toxicity. There was one death from sepsis in the setting of intravenous chemotherapy (IVC) for metastatic disease that occurred after OAC/IVIT therapy. The 2-year Kaplan-Meier ocular survival estimate for the whole cohort was 75% and for the eyes that received OAC or IVIT at MSKCC 83%. For OAC hematologic toxicities, one platelet transfusion and two filgrastim doses were administered, and one patient was hospitalized for neutropenic fevers. CONCLUSIONS: The majority of 13q- eyes treated with OAC/IVIT-based regimens can be cured, and there were no deaths related to complications from OAC or IVIT. 13q- Patients did have increased risk of systemic treatment complications, even from super-selective chemotherapies. Despite these toxicities, only one patient developed febrile neutropenia, one patient required a blood product transfusion, and two patients received filgrastim for both OAC and IVC complications. PRÉCIS: Children with 13q deletion syndrome with retinoblastoma managed with intra-arterial and intravitreal chemotherapy have excellent patient and ocular survival with acceptable toxicity.

Comparison of efficacy and toxicity of intravitreal melphalan formulations for retinoblastoma.

OBJECTIVE: Intravitreal melphalan injections are commonly used in the treatment for intraocular retinoblastoma. This study compares retinal toxicity and ocular survival between two formulations, with and without propylene glycol (Alkeran vs. Evomela, respectively). METHODS: A retrospective cohort study of retinoblastoma patients who received intravitreal injections of Alkeran and Evomela at 30 µg from September 2012 to January 2019 at a single tertiary care center were enrolled. Retinal toxicity was measured using electroretinogram (ERG) and compared using a multivariate analysis of 338 injections in 101 eyes of 96 patients. Ocular survival of 163 eyes in 150 patients was compared across formulations using Cox proportional hazards model. Eyes were censored at the time a patient received a dose other than 30 µg. RESULTS: Overall, ERG decline (mean, 95% CI) for each injection was -5.58 µV (-7.17, -3.99). No significant differences in ERG decrement were found between Alkeran (with alcohol) -5.52uV (-6.99, -4.05). and Evomela (without alcohol) -5.65uV (-8.31 to -2.98) formulations (p = 0.93). Ocular survival at 24 months was 93.6% (95% CI 86.2, 97.1) with alcohol and 91.7% (95% CI 53.9, 98.8) without alcohol. The hazard ratio (HR) for without vs with alcohol was 0.50 (95% CI 0.06 to 4.07); no significant difference in ocular survival was found between formulations (p = 0.52). CONCLUSIONS AND RELEVANCE: No differences were found in retinal toxicity and ocular survival between 30 µg intravitreal injections of Alkeran or Evomela for intraocular retinoblastoma. Given the increased stability of Evomela, intravitreal treatment could be expanded to centers without the ability to supply Alkeran due to its shorter safety window; however, Alkeran is less expensive. For those with existing infrastructure, Alkeran is a comparable, cost-effective alternative.

Oscillatory potentials in patients with birdshot chorioretinopathy.

PURPOSE: The electroretinogram (ERG) has proven to be useful in the evaluation and monitoring of patients with posterior uveitis. ERG oscillatory potentials (OPs) are sometimes reduced in many uveitic eyes with otherwise grossly normal ERG responses. This study compares ERG parameters, including OPs, between patients with birdshot chorioretinopathy, other posterior uveitis, and controls. METHODS: This was a retrospective case-control study. Sixty-four patients seen at a clinical practice had a total of 93 visits during which ERG was performed on both eyes. ERG data from 93 age-matched controls were also collected. Root-mean-squared (RMS) energy of the OPs was calculated using Fourier analysis for 88 patients and 88 age-matched controls for whom complete data were available. Photopic flicker amplitudes, photopic flicker latencies, scotopic b-wave amplitudes, and OP RMS values were compared between patients and controls. Diagnostic performance was assessed using receiver operating characteristic (ROC) curves. RESULTS: The mean ages of patients and controls were 55.9 ± 10.8 (SD) years and 55.1 ± 11.5, respectively. 83% of the patients had a diagnosis of BCR. The mean OP RMS value was significantly different in patients (15.6 µV ± 9.7 µV) versus control eyes (33.0 µV ± 12.7 µV), p < 0.001. Area under the ROC curves (AUROC) was 0.75 for photopic flicker amplitudes, 0.77 for photopic flicker latencies, 0.72 for scotopic b-wave amplitudes, and 0.88 for OP RMS. AUROC was significantly different between OP RMS and photopic flicker amplitudes (p < 0.001), between OP RMS and flicker latencies (p = 0.0032), and between OP RMS and scotopic b-wave amplitudes (p < 0.0001). CONCLUSION: Analysis of OPs shows greater sensitivity and specificity in the diagnosis and evaluation of patients with birdshot chorioretinopathy than photopic and scotopic ERG amplitudes and photopic flicker latencies.

Intravitreal chemotherapy in retinoblastoma: expanded use beyond intravitreal seeds.

BACKGROUND/AIMS: Ophthalmic artery chemosurgery (OAC) has changed the face of retinoblastoma treatment and led to a higher rate of globe salvage. The introduction of intravitreal chemotherapy (IVitC) has further enhanced globe salvage with increased success in treatment of intravitreal seeds. Our group has seen success at treating non-vitreous disease that is refractory to OAC using IVitC. This study was undertaken to quantify and report on this success. METHODS: A retrospective review was used to identify patients treated with IVitC for indications other than vitreous seeds from two centres. The indication, prior and concurrent treatment, response time and duration of treatment were documented. Kaplan-Meier estimates were used to evaluate ocular and recurrence-free survival. Ocular toxicity was evaluated using the 30 Hz flicker electroretinogram (ERG). Continuous and categorical variables were compared with Student's t-test and χ2 test, respectively. RESULTS: Fifty-six eyes from 52 retinoblastoma patients were identified. There were no disease-related or treatment-related deaths. One patient developed a second primary malignancy (pinealoblastoma) and subsequent leptomeningeal spread. Ninety-eight per cent of the eyes showed clinical regression. Recurrence was seen in 14.3%. Of the recurrences, five occurred in retinal tumours and three in subretinal seeds. The Kaplan-Meier estimated risk of recurrence in all patients treated was 83.5% (95% CI 7.9 to 14.1) at 10 months. The mean change in ERG over treatment course was -17.7 µV. CONCLUSIONS: Intravitreal chemotherapy is successful for the treatment of subretinal seeds and recurrent retinal tumours and could be considered as adjunctive therapy in globe-sparing treatment of retinoblastoma.

Modified ERG-Jet™ contact lens electrodes for use in infants and toddlers-update.

PURPOSE: To describe recent changes in the dimensions of the ERG-jet contact lens electrode, and to suggest corresponding changes in the dimensions of cylindrical stents to facilitate the use of ERG-jet contact lens electrodes in infants and small children. METHODS: Upon the observation that existing cylindrical stents no longer fit newly purchased ERG-jet contact lenses, the spacings between the "bumps" on the front surface of old and new electrodes were measured with calipers, and prototype stents were newly machined from acrylic plastic. RESULTS: Cylindrical stents with an outside diameter of 0.277 inches (about 7.04 mm) were found to fit snugly between the front surface "bumps" of new ERG-jet contact lens electrodes. CONCLUSIONS: Recent modifications in the injection molds for ERG-jet contact lens electrodes have resulted in an increase in the space between the "bumps" on the front surface of the electrodes, necessitating a corresponding increase in the outside diameter of cylindrical stents intended to fit snugly between the "bumps" for ease of insertion and prevention of lid closure.

Current Treatment of Bilateral Retinoblastoma: The Impact of Intraarterial and Intravitreous Chemotherapy.

PURPOSE: To evaluate the management and outcomes of naïve bilateral retinoblastoma treated at a single-center over a 5-year period during the era of ophthalmic artery chemosurgery (OAC) and intravitreous chemotherapy. METHODS: Retrospective cohort study of 46 patients (92 eyes) with naïve bilateral retinoblastoma treated at Memorial Sloan Kettering Cancer Center between January 2012 and February 2017. Indirect ophthalmoscopy, fundus photography, ultrasonography, and ultrasonic biomicroscopy were used to evaluate clinical response. Patient, ocular, ocular progression-free, ocular recurrent event-free, and second ocular survivals were assessed by Kaplan-Meier estimates. Retinal toxicity was evaluated by electroretinography. Snellen visual acuity and complete blood count metrics were recorded. RESULTS: Sixty-four eyes (70%) in 41 patients (89%) received ophthalmic artery chemosurgery as part of their treatment. Twenty-six patients (56%) received tandem OAC (bilateral simultaneous infusions). Seven eyes were primarily enucleated. No eye receiving initial OAC was enucleated. There was a single secondary enucleation in an eye initially treated with focal therapy with anterior chamber recurrence. The 3-year Kaplan-Meier estimates for overall ocular, secondary ocular (survival after treatment for recurrence), progression-free, and recurrent event-free survival were 91.3% [95% confidence interval (CI) 83.4-95.5], 98.7% (95% CI 91.3-99.8), 91.5% (95% CI 83.0-95.8), and 78.9% (95% CI 68.2-86.3), respectively. Overall and secondary ocular survivals were 100% for International Classification of Retinoblastoma (ICRB) groups A-C. Overall ocular survival was 91.5% (95% CI 70-97.8) for ICRB group D and 71.4% (95% CI 47.1-79.4) for group E. Secondary ocular survival was 95.4% (95% CI 71.8-99.3) for ICRB group D and 100% for group E. There were no treatment-related deaths, three patients developed trilateral retinoblastoma (one died), and one patient (who did not receive OAC) developed metastatic disease and is in remission at 32-month follow-up. CONCLUSION: The majority (89%) of bilateral retinoblastoma patients in the current era and at this center were treated with OAC. This has resulted in saving a historic number of eyes. A quarter of eyes developed recurrent disease (defined as recurrent disease requiring any treatment including focal), the majority of which occurred in the first year after treatment, and all but one was saved. There has been no compromise in patient survival.

Total retinal detachments due to retinoblastoma: Outcomes following intra-arterial chemotherapy/ophthalmic artery chemosurgery.

PURPOSE: To report on the rate and timing of retinal reattachment and outcomes for retinoblastoma children who have total retinal detachments at presentation to our center and were treated with intra-arterial chemotherapy (ophthalmic artery chemosurgery, OAC). PATIENTS AND METHODS: Single-center retrospective review of retinoblastoma patients who presented with total retinal detachments and were subsequently treated with OAC at MSKCC between May 2006 and July 2016. Endpoints were retinal detachment resolution, visual function, ERG amplitude, ocular survival, and patient survival from metastases. RESULTS: 87 eyes of 84 retinoblastoma patients were included. Using a survival multistate model, by 36 months of follow-up, there was a 54% cumulative probability of complete retinal reattachment and a 76% probability of partial reattachment. 24% of eyes that completely reattached received only OAC without any prior or adjuvant treatments. Eyes that completely reattached were significantly more likely to have been diagnosed at a younger age (p<0.0001) and to have greater initial ERG values (p = 0.006). At final follow-up, 14% of eyes had gained at least 25 µV of ERG activity, and 8.0% had achieved hand motion vision or better, including one to 20/60. 13% of eyes were enucleated. No patient died from metastatic disease, and only one developed metastases. CONCLUSION: OAC can successfully treat previously considered "non-salvageable" retinoblastoma eyes with total retinal detachments, promote retinal reattachment in the majority of eyes, and preserve ocular and patient survival.

Intravitreal chemotherapy and laser for newly visible subretinal seeds in retinoblastoma.

BACKGROUND: There has been no effective method for treating newly visible ("new") subretinal seeding in retinoblastoma except enucleation. The objective of this report is to determine whether intravitreal chemotherapy combined with 810 nm indirect laser can successfully treat retinoblastoma eyes with "new" subretinal seeding which appeared after intra-arterial chemotherapy (ophthalmic arterial chemosurgery: OAC). MATERIAL AND METHODS: Single center retrospective study from a tertiary cancer hospital of a case series of 14 eyes treated with combined intravitreal chemotherapy and laser from 2012 to 2017. Ocular salvage, patient survival, recurrence-free ocular survival, metastases, and extraocular extension were assessed. RESULTS: A total of 14 eyes in 13 unilateral or bilateral retinoblastoma patients with "new" subretinal seeding after initial eye salvage therapy were treated with combined intravitreal injection of melphalan (30 ug) or melphalan (30 ug) and topotecan (20 ug) and with 810 nm indirect continuous wave laser. All eyes were salvaged. Only two eyes (14%) recurred again for subretinal seeds after 6 and 8 months, respectively, and required additional cycles of intravitreal injections and laser. Combined intravitreal injection of melphalan or melphalan plus topotecan with 810 nm indirect continuous wave laser was not associated with any metastatic events, patient deaths, extraocular extension, or need for enucleation. CONCLUSION: There has been no effective treatment for "new" subretinal seeding after OAC except enucleation or second course OAC. Combined intravitreal chemotherapy with 810 nm indirect laser may be an effective and safe alternative to enucleation.

Expanded Retinal Disease Spectrum Associated With Autosomal Recessive Mutations in GUCY2D.

PURPOSE: GUCY2D has been associated with autosomal recessive Leber congenital amaurosis and autosomal dominant cone-rod dystrophy. This report expands the phenotype of autosomal recessive mutations to congenital night blindness, which may slowly progress to mild retinitis pigmentosa. DESIGN: Retrospective case series. METHODS: Multicenter study of 5 patients (3 male, 2 female). RESULTS: All patients presented with night blindness since childhood. Age at referral was 9-45 years. Length of follow-up was 1-7 years. Best-corrected visual acuity at presentation ranged from 20/15 to 20/30 and at most recent visit averaged 20/25. No patient had nystagmus or high refractive error. ISCEV standard electroretinography revealed nondetectable dark-adapted dim flash responses and reduced amplitude but not electronegative dark-adapted bright flash responses with similar waveforms to the reduced-amplitude light-adapted single flash responses. The 30 Hz flicker responses were relatively preserved. Macular optical coherence tomography revealed normal lamination in 3 patients, with abnormalities in 2. Goldmann visual fields were normal at presentation in children but constricted in 1 adult. One child showed loss of midperipheral fields over time. Fundus appearance was normal in childhood; the adult had sparse bone spicule-like pigmentation. Full-field stimulus testing (FST) revealed markedly decreased retinal sensitivity to light. Dark adaptation demonstrated lack of rod-cone break. Two patients had tritanopia. All 5 had compound heterozygous mutations in GUCY2D. Three of the 5 patients harbor the Arg768Trp mutation reported in GUCY2D-associated Leber congenital amaurosis. CONCLUSIONS: Autosomal recessive GUCY2D mutations may cause congenital night blindness with normal acuity and refraction, and unique electroretinography. Progression to mild retinitis pigmentosa may occur.

ISCEV guide to visual electrodiagnostic procedures.

Clinical electrophysiological testing of the visual system incorporates a range of noninvasive tests and provides an objective indication of function relating to different locations and cell types within the visual system. This document developed by the International Society for Clinical Electrophysiology of Vision provides an introduction to standard visual electrodiagnostic procedures in widespread use including the full-field electroretinogram (ERG), the pattern electroretinogram (pattern ERG or PERG), the multifocal electroretinogram (multifocal ERG or mfERG), the electrooculogram (EOG) and the cortical-derived visual evoked potential (VEP). The guideline outlines the basic principles of testing. Common clinical presentations and symptoms are described with illustrative examples and suggested investigation strategies.