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PubMed2006

Visual cycle protein RPE65 persists in new retinal cells during retinal regeneration of adult newt.

Adult newts can regenerate their entire retina through transdifferentiation of the retinal pigment epithelium (RPE). The objective of this study was to redescribe the retina regeneration process by means of modern biological techniques. We report two different antibodies (RPE-No.112 and MAB5428) that recognize the newt homolog of RPE65, which is involved in the visual cycle and exclusively label the RPE cell-layer in the adult newt eye. We analyzed the process of retinal regeneration by immunohistochemistry and immunoblotting and propose that this process should be divided into nine stages. We found that the RPE65 protein is present in the RPE-derived new retinal rudiment at 14 days postoperative (po) and in the regenerating retinas at the 3-4 cell stage (19 days po). These observations suggest that certain characteristics of RPE cells overlap with those of retinal stem/progenitor cells during the period of transdifferentiation. However, RPE65 protein was not detected in either retinal stem/progenitor cells in the ciliary marginal zone (CMZ) of adult eyes or in neuroepithelium present during retina development, where it was first detected in differentiated RPE. Moreover, the gene expression of RPE65 was drastically downregulated in the early phase of transdifferentiation (by 10 days po), while those of Connexin43 and Pax-6, both expressed in regenerating retinas, were differently upregulated. These observations suggest that the RPE65 protein in the RPE-derived retinal rudiment may represent the remainder after protein degradation or discharge rather than newly synthesized protein.

Amino Acid Sequence↗
PubMed1993

A morphological and immunohistochemical study of human retinal pigment epithelial cells, retinal glia, and fibroblasts grown on Gelfoam matrix in an organ culture system. A comparison of structural and nonstructural proteins and their application to cell type identification.

Retinal pigment epithelial (RPE) cells, retinal glia, and fibroblasts undergo marked phenotypical change when outside their usual microenvironment, as occurs in epiretinal membrane formation. To explore their phenotypic potential without the influence of other cell types, each was cultured on Gelfoam matrix and assessed immunohistochemically and ultrastructurally. All cell types demonstrated vimentin and a universal beta-tubulin epitope, TU27. RPE and retinal glial cells were positive for cytokeratin, Leu 7, and neuron-specific (gamma gamma) enolase, as were glia and fibroblasts for S-100 protein and RPE cells and fibroblasts for glutamine synthetase. RPE cells alone showed positivity for class III beta-tubulin and retinal S-antigen (monolayer cultures only); occasional retinal glia, which immunohistochemical findings suggest are Müller cell derived, demonstrated GFA protein. Therefore, class III beta-tubulin may be useful in distinguishing RPE cells from retinal glia and fibroblasts, and Leu-7 may help to identify RPE cells and fibroblasts; these cell types are difficult to distinguish in clinical material using more traditional morphological criteria.

Cells, Cultured↗
PubMed1992

Modulation of potassium transport in cultured retinal pigment epithelium and retinal glial cells by serum and epidermal growth factor.

The ionic environment of retinal photoreceptors is partially controlled by potassium transporters on retinal glial and retinal pigment epithelial cells (RPE). In this study, serum and epidermal growth factor (EGF) were examined as modulators of potassium transport in confluent cultures of human RPE and rabbit retinal glia. EGF is a known mitogen for confluent RPE cultures and was shown here to also stimulate [3H]thymidine incorporation in cultures of retinal glia. For potassium transport studies 86Rb was used as a tracer during a 17-min incubation. For both retinal cell types the mean total 86Rb uptake in 10% serum was approximately 60% above basal, serum-free controls. For EGF, tested in several experiments in a concentration range from 1 to 100 ng/ml, maximal total uptake was 33 and 24% above controls for RPE and glia, respectively. Inhibitor studies suggested that basal and serum-stimulated uptake for both cell types occurred by the ouabain-sensitive Na-K ATPase pump and by the furosemide- or bumetanide-sensitive Na-K-Cl cotransporter. EGF-stimulated uptake appeared to be due predominantly to the cotransporter. The data suggest that serum components and EGF, which may be available to retina-derived cells under pathologic conditions, may not only stimulate proliferation but may also act as short-term modulators of potassium ion movement and thus affect physiologic processes that are sensitive to ion homeostasis.

Animals↗
PubMed1986

Reaggregation of chick retinal and mixtures of retinal and pigment epithelial cells: the degree of laminar organization is dependent on age.

We report here a striking age dependency for tissue reconstruction capacity in rotating cultures of chick retinal cells, in particular in mixtures of retinal and pigment epithelial cells. The comparison of sections after acetylcholinesterase histochemistry delivered the following results. In aggregates from retinal cells, sorting out is clearly observable, but only a minor age-dependent effect is detectable, e.g. the laminar order of aggregates derived from 6-day-old cells is increased compared to aggregates from other stages. In aggregates from mixtures of retinal and pigment epithelial cells, the degree of laminar order is highest with cells from 5-day-old embryos and decreases significantly at older ages. The highest number of aggregates with the reconstruction of all main retinal layers was obtained by the reaggregation of retinal cells of embryonic day 5 (25%). To achieve laminar order in aggregates, at all ages, the addition of pigment epithelial cells seems to be a prerequisite.

Acetylcholinesterase↗
PubMed2004

Reduction of posterior pole retinal thickness in glaucoma detected using the Retinal Thickness Analyzer.

OBJECTIVES: To report evidence of changes in posterior pole retinal thickness in glaucoma and preperimetric glaucoma. DESIGN: Cross-sectional study. PARTICIPANTS: One hundred forty participants (140 eyes): 31 normal subjects, 33 with ocular hypertension, 43 with primary open-angle glaucoma (POAG), and 33 with preperimetric glaucoma. INTERVENTION: Posterior pole retinal thickness measurements using the Retinal Thickness Analyzer (RTA; Talia Technology Ltd., Neve-Ilan, Israel). MAIN OUTCOME MEASURES: The mean foveola average thickness (VAV), foveola minimum thickness (VMI), perifoveal average thickness (PFAV), perifoveal minimum thickness (PFMI), posterior pole average thickness (PPAV), and posterior pole minimum thickness (PPMI) were compared among the groups. The correlation between RTA values and visual field values was evaluated. The area under the receiver operator characteristic (AROC) curve, the optimal cut values, and the predictability values were estimated statistically between normal and the other groups using RTA values. RESULTS: Results from 91 eyes (65%) were included. Perifoveal average thickness values in preperimetric glaucoma (190.4+/-15.6 microm; mean+/-standard deviation) and POAG (185.7+/-16.8 microm) were significantly less than in normal controls (211.4+/-16.8 microm) and in eyes with ocular hypertension (211.6+/-15.9 microm). Perifoveal minimum thickness, PPAV, and PPMI were significantly less in preperimetric glaucoma and in POAG than in normal controls; VAV and VMI were not significantly different among groups. Perifoveal average thickness, PFMI, PPAV, and PPMI significantly correlated with visual field mean defect (R = -0.38, -0.42, -0.36, and -0.41, respectively) and loss of variance (R = -0.29, -0.30, -0.26, and -0.17, respectively). The AROC using PFAV, PFMI, PPAV, and PPMI was significantly larger than 0.5 between normal and preperimetric glaucoma (0.83, 0.92, 0.82, and 0.87, respectively) and between normal and POAG eyes (0.86, 0.97, 0.83, and 0.93, respectively). When using the PFMI, the sensitivities at the minimum specificity cutoffs of 90% were highest in comparisons between normal and preperimetric glaucoma (sensitivity, 75%) and between normal and POAG eyes (sensitivity, 95%). By the logistic regression analysis, PFAV, PFMI, PPAV, and PPMI distinguished between normal and preperimetric glaucoma (R(2) = 0.30, 0.49, 0.27, and 0.37, respectively) and between normal and POAG (R(2) = 0.37, 0.59, 0.31, and 0.51, respectively). CONCLUSIONS: Posterior pole retinal thickness decreases in early- and moderate-stage glaucoma. Reduction of perifoveal retinal thickness is correlated with visual field loss. In vivo measurements of posterior pole retinal thickness may help distinguish between normal and glaucomatous eyes.

Adult↗
PubMed2005

Tissue interaction between the retinal pigment epithelium and the choroid triggers retinal regeneration of the newt Cynops pyrrhogaster.

Complete retinal regeneration in adult animals occurs only in certain urodele amphibians, in which the retinal pigmented epithelial cells (RPE) undergo transdifferentiation to produce all cell types constituting the neural retina. A similar mechanism also appears to be involved in retinal regeneration in the embryonic stage of some other species, but the nature of this mechanism has not yet been elucidated. The organ culture model of retinal regeneration is a useful experimental system and we previously reported RPE transdifferentiation of the newt under this condition. Here, we show that cultured RPE cells proliferate and differentiate into neurons when cultured with the choroid attached to the RPE, but they did not exhibit any morphological changes when cultured alone following removal of the choroid. This finding indicates that the tissue interactions between the RPE and the choroid are essential for the former to proliferate. This tissue interaction appears to be mediated by diffusible factors, because the choroid could affect RPE cells even when the two tissues were separated by a membrane filter. RPE transdifferentiation under the organotypic culture condition was abolished by a MEK (ERK kinase) inhibitor, U0126, but was partially suppressed by an FGF receptor inhibitor, SU5402, suggesting that FGF signaling pathway has a central role in the transdifferentiation. While IGF-1 alone had no effect on isolated RPE, combination of FGF-2 and IGF-1 stimulated RPE cell transdifferentiation similar to the results obtained in organ-cultured RPE and choroid. RT-PCR revealed that gene expression of both FGF-2 and IGF-1 is up-regulated following removal of the retina. Thus, we show for the first time that the choroid plays an essential role in newt retinal regeneration, opening a new avenue for understanding the molecular mechanisms underlying retinal regeneration.

Animals↗
PubMed1998

Perceived head-centric speed is affected by both extra-retinal and retinal errors.

When we make a smooth eye movement to track a moving object, the visual system must take the eye's movement into account in order to estimate the object's velocity relative to the head. This can be done by using extra-retinal signals to estimate eye velocity and then subtracting expected from observed retinal motion. Two familiar illusions of perceived velocity--the Filehne illusion and Aubert-Fleischl phenomenon--are thought to be the consequence of the extra-retinal signal underestimating eye velocity. These explanations assume that retinal motion is encoded accurately, which is questionable because perceived retinal speed is strongly affected by several stimulus properties. We develop and test a model of head-centric velocity perception that incorporates errors in estimating eye velocity and in retinal-motion sensing. The model predicts that the magnitude and direction of the Filehne illusion and Aubert-Fleischl phenomenon depend on spatial frequency and this prediction is confirmed experimentally.

Head↗
PubMed1996

Retinal and non-retinal inputs upon retinopetal RMA neurons in the lamprey: a light and electron microscopic study combining HRP axonal tracing and GABA immunocytochemistry.

A light and electron microscopic study, combining HRP axonal tracing or degeneration and GABA immunocytochemistry, was performed in the lamprey Lampetra fluviatilis in order to analyze retinal and non-retinal inputs upon the retinopetal neurons localized in the reticular mesencephalic area (RMA). The iontophoretic deposit of HRP onto the central stump of the cut optic nerve produced a dense anterograde labeling in the retino-recipient strata marginale and cellular externum of the optic tectum as well as the retrograde labeling of retinopetal neurons in the mesencephalic tegmentum. The large ascending proximal dendrites of the retinopetal neurons constituted a distinct bundle coursing first dorso-laterally in the dorsal mesencephalic tegmentum, and then dorso-medially in the strata fibrosum centrale and cellulare et fibrosum internum of the optic tectum before their distal portions penetrated the retino-recipient tectal layers. The distribution of GABA immunoreactivity was also investigated in the tectal layers and dorsal mesencephalic tegmentum with both pre- and post-embedding methods. The retinal terminals, identified either following HRP iontophoresis in the optic nerve or in early phases of degeneration after short-term survivals following retinal lesion, contained rounded-shaped synaptic vesicles and were always GABA immunonegative. They established asymmetrical synaptic contacts on the distal dendrites of RMA neurons and represented 11.4% of all terminals contacting such neurons (15% of these neurons were GABA immunopositive). The dense extra-retinal input upon the retinopetal RMA neurons was composed of five types of axon terminal profiles, either GABA-immunopositive or -immunonegative. Considering the different cytochemical types of axon terminals contacting RMA neurons, as well as the characteristics of the retinal targets of these neurons, we suggest that, globally, the effects of RMA neurons upon the retina are mainly inhibitory.

Afferent Pathways↗
PubMed2006

A chick retinal proteome database and differential retinal protein expressions during early ocular development.

Proteomics approach as a research tool has gained popularity in a growing number of basic and clinical researches. However, proteomic research has yet to gain significant momentum in eye research. Hence, we decided to build a retinal proteome database using postnatal retinal tissue from chick, a commonly used animal model in eye research. Employing 2-D gels with the coverage of 3-10 pH gradients, we were able to resolve hundreds of proteins from young chick retinae. Among them, 155 high abundant proteins were identified by Peptide Mass Fingerprinting (PMF) after the Matrix-Assisted Laser Desorption Ionization-Time-of-Flight Mass Spectrometry (MALDI-TOF MS). These proteins were then classified according to their functions. Making use of the retinal database, we were able to identify several differentially expressed proteins that might be involved in early retinal development by comparing the 2-DE maps of chick retinal tissues (3, 10, and 20 days after hatching). With the current proteomics approach, we not only documented the most abundant soluble proteins in the chick retinal tissue, but also demonstrated the dynamic protein expression changes during early ocular development. This represents one of the first steps in building a complete protein database in chick retinae which is applicable to the study of eye diseases from a few selected protein candidates to the whole proteome. Proteomic technology may provide a high throughput platform for advancing eye research in the feasible future.

Animals↗
PubMed2002

Does direct ophthalmoscopy improve retinal screening for diabetic eye disease by retinal photography?

AIMS: To identify whether after performing retinal photography, direct ophthalmoscopy can improve the yield of screening for the detection of sight-threatening diabetic eye disease (STDED). METHODS: Patients (n = 408) who had previously received both dilated direct ophthalmoscopy by a diabetologist and retinal photography graded by a diabetologist within 3 months of each other were included. The results of the other screening modality were not available to the grader/screener. The first 308 patients were consecutive attendees at the clinic who fulfilled the study criteria and 100 were selected because they were identified as having potential STDED by either one of these modalities. An ophthalmologist using slit lamp biomicroscopy then examined patients identified with potential STDED. RESULTS: In 357 (88%) patients there was agreement between the two modalities about whether referral to an ophthalmologist was required (kappa 0.62). Retinal photography identified 38 patients for referral to ophthalmology which ophthalmoscopy missed. Of these, the ophthalmologist agreed that STDED was present in 32 (84%) and four patients required early laser. Ophthalmoscopy identified 13 patients for referral who were not identified by photography. Of these, the ophthalmologist agreed with the diabetologist that STDED was present in seven (54%) and one patient required early laser. CONCLUSION: Ophthalmoscopy may identify the occasional patient with diabetes who has STDED which is missed by retinal photography. For a systematic retinal screening programme, adding ophthalmoscopy to retinal photography will increase false-positive referrals and is likely to detect only a few extra patients requiring laser.

Chi-Square Distribution↗
PubMed2000

Which retinal and extra-retinal information is crucial for circular vection?

In contradistinction to conventional wisdom, we propose that retinal image slip of a visual scene (optokinetic pattern, OP) does not constitute the only crucial input for visually induced percepts of self-motion (vection). Instead, the hypothesis is investigated that there are three input factors: 1) OP retinal image slip, 2) motion of the ocular orbital shadows across the retinae, and 3) smooth pursuit eye movements (efference copy). To test this hypothesis, we visually induced percepts of sinusoidal rotatory self-motion (circular vection, CV) in the absence of vestibular stimulation. Subjects were presented with three concurrent stimuli: a large visual OP, a fixation point to be pursued with the eyes (both projected in superposition on a semi-circular screen), and a dark window frame placed close to the eyes to create artificial visual field boundaries that simulate ocular orbital rim boundary shadows, but which could be moved across the retinae independent from eye movements. In different combinations these stimuli were independently moved or kept stationary. When moved together (horizontally and sinusoidally around the subject's head), they did so in precise temporal synchrony at 0.05 Hz. The results show that the occurrence of CV requires retinal slip of the OP and/or relative motion between the orbital boundary shadows and the OP. On the other hand, CV does not develop when the two retinal slip signals equal each other (no relative motion) and concur with pursuit eye movements (as it is the case, e.g., when we follow with the eyes the motion of a target on a stationary visual scene). The findings were formalized in terms of a simulation model. In the model two signals coding relative motion between OP and head are fused and fed into the mechanism for CV, a visuo-oculomotor one, derived from OP retinal slip and eye movement efference copy, and a purely visual signal of relative motion between the orbital rims (head) and the OP. The latter signal is also used, together with a version of the oculomotor efference copy, for a mechanism that suppresses CV at a later stage of processing in conditions in which the retinal slip signals are self-generated by smooth pursuit eye movements.

Adult↗
PubMed1990

[Experimental studies of retinal glial cell proliferation on retinal surface].

Our previous reports described the formation processes of epiretinal membranes composed of retinal glial cells in the experimental vitreous hemorrhage. This report presents the pathological changes of retinal glial cells, inner limiting membranes and vitreous body in the early stage of experimental vitreous hemorrhage. Using an operating microscope, 0.3 ml of autologous whole blood was injected through the pars plana into the vitreous cavity of albino rabbits. The eyes were enucleated at 3, 7, 10, 14 and 28 days after injection. Three days after injection, normal vitreous structure disappeared and vitreous fibers condensed. Seven days after injection, red blood cells were found on the retinal surface. The inner limiting membrane, composed of lamina rara and lamina densa, had a normal appearance. Where the red blood cell were present on the retinal surface, the lamina rara of the inner limiting membrane became thin. Fourteen days after injection, where glial cells showed upheaval, lamina rara disappeared and lamina densa became thin. Afterward, glial cells extruded their cytoplasmic processes onto the retinal surface. Twenty-eight days after injection, the inner limiting membranes were normal in appearance except for the area of glial cells penetrating the inner limiting membranes. The results suggested that, in vitreous hemorrhage, glial cell proliferation onto the retinal surface is an active reaction in order to engulf the debris of the red blood cells.

Animals↗
PubMed1998

Inherited retinal arteriolar tortuosity with retinal hemorrhages.

BACKGROUND: Familial arteriolar tortuosity is an autosomal dominant disorder affecting the retinal arterioles. OBJECTIVES: To report a pedigree with this disorder and describe a systemic workup to determine whether this vascular abnormality is limited to the eye. RESULTS: A 58-year-old woman referred for retinal hemorrhages was found to have retinal arteriolar tortuosity of both eyes, especially in the macular area. Her 63-year-old brother had a history of retinal hemmorhages beginning at age 18 years and had similar fundoscopic examination findings. The proband had an extensive systemic workup, including magnetic resonance imaging, and cardiac and renal angiography, that failed to demonstrate any other sequelae of this inherited ocular syndrome. However, each member of the family expressing this phenotype did have hypertension. CONCLUSION: Inherited retinal arteriolar tortuosity is an autosomal dominant disorder limited to the eye, at least in this pedigree, within the sensitivity of the systemic workup we used.

Adult↗
PubMed1984

Experimental retinal detachment. VII. Intravenous horseradish peroxidase diffusion across the blood-retinal barrier.

Intravenous horseradish peroxidase (HRP) was administered to cynomolgus monkeys to study chorioretinal diffusion in eyes with retinal detachment. In control eyes, HRP was contained within the choriocapillaris and did not penetrate beyond Bruch's membrane. In addition, HRP was confined within blood vessels of the sensory retina. In detached eyes, HRP diffused out of the choriocapillaris and through the intercellular spaces of the retinal pigment epithelium (RPE), where it was blocked by zonulae occludentes. Occasionally HRP was found within pinocytotic vesicles of the RPE. It was also confined within retinal blood vessels by their endothelial cells. It is concluded that the blood-retinal barrier remains intact to HRP following long-term rhegmatogenous retinal detachment. However, a slight alteration exists at the choriocapillaris in detached eyes.

Animals↗
PubMed1996

Redistribution and degeneration of retinal astrocytes in experimental murine cerebral malaria: relationship to disruption of the blood-retinal barrier.

To determine whether astrocytes play a critical role in the pathogenesis of experimental murine cerebral malaria (EMCM), we examined changes in astrocyte morphology and distribution, using retinal wholemounts, in three models: a fatal cerebral malaria (CM) model, in which mice die showing cerebral symptoms; a "resolving" model, in which mice exhibit mild cerebral symptoms, but then recover; and a non-CM model, in which cerebral symptoms are not seen. In the fatal model, retinal astrocytes lost their even distribution from day 3 post-inoculation (p.i.) with malaria parasites, progressing to gliosis (day 5 p.i.), well before the onset of cerebral symptoms on day 6-7 p.i. At the terminal stage of the disease there was a loss of astrocyte processes contacting retinal vessels, often along vessel segments containing adherent monocytes. These features occurred in a mild form in the resolving model and were absent in the non-CM models. To investigate the mechanisms underlying these astrocytic changes, we carried out two experimental manipulations. Firstly, since dexamethasone ameliorates cerebral complications in the fatal CM model, the astrocytic response was monitored after dexamethasone treatment on days 0 and 1 p.i., or days 3 and 4 p.i. Second, to determine whether increased blood-retinal barrier (BRB) permeability initiates the astrocyte changes, breakdown of the BRB was induced experimentally by intra-carotid injection of arabinose and astrocyte morphology and distribution were examined 12, 24, and 48 h later. Retinal astrocytes in both the dexamethasone- and the arabinose-treated groups showed loss of even astrocyte distribution but no loss of astrocyte ensheathment of vessels. It is concluded that: i) astrocytes are involved in the pathogenesis of EMCM, since these changes are only prominent in the fatal model and occur substantially before the onset of cerebral symptoms; ii) the initial changes in astrocyte distribution may be a consequence of the increase in BRB permeability; and iii) the immune response triggered by the malaria parasite may be responsible for the loss of astrocyte ensheathment of vessel segments.

Animals↗
PubMed1992

Characterization of a rat retinal endothelial cell culture and the expression of P-glycoprotein in brain and retinal endothelium in vitro.

Retinal vascular endothelia form one aspect of the blood-retinal barrier and, like the blood-brain barrier, control the passage of molecules and cells into the parenchyma. To facilitate comparative in vitro studies, rat retinal endothelial cells have been cultured and characterised. Using immunocytochemical techniques, retinal endothelium was positive for von Willebrand's factor, tight junction-associated polypeptide (ZO-1) and the transferrin receptor. The cells also expressed high-affinity uptake of acetylated low-density lipoprotein. Using the monoclonal antibodies JSB-1 and C219, the product of the multidrug resistance gene, P-glycoprotein, was found to be expressed on primary cultures of both brain and retinal endothelium.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2004

Determination of the incidence and clinical characteristics of subsequent retinal tears following treatment of the acute posterior vitreous detachment-related initial retinal tears.

PURPOSE: To determine the incidence of subsequent retinal tears (SRT) in patients who were previously treated for acute posterior vitreous detachment (PVD)-related retinal tears. DESIGN: Retrospective chart review. METHODS: A retrospective chart review of 155 eyes of 137 consecutive patients treated for acute PVD-related retinal tears was performed. RESULTS: During a median follow-up of 13 months (range 3 to 157 months) after treatment, SRT developed in 19 (12.2%) of 155 treated eyes. Most of the SRT occurred during the first 6 months (12 of 19 eyes) after initial treatment. Subsequent vetinal tears developed within the first 12 months in 15 of 19 treated eyes, however only six of 15 of these eyes were symptomatic. Of those patients who developed SRT after 12 months, all had new visual symptoms. CONCLUSION: Patients who present with acute PVD-related retinal tears are at a low but significant risk for developing SRT. A significant number of patients treated for PVD-associated retinal tears present within 1 year with SRT without symptoms.

Acute Disease↗
PubMed2005

Central retinal artery occlusion after radial optic neurotomy in a patient with central retinal vein occlusion.

PURPOSE: To describe a patient with a central retinal vein occlusion (CRVO) who developed central retinal artery occlusion after radial optic neurotomy. DESIGN: Interventional case report. METHODS: A 70-year-old woman with CRVO underwent a radial optic neurotomy on her right eye. Her preoperative visual acuity in the affected eye was 20/400. RESULTS: Radial optic neurotomy was performed after phacoemulsification and aspiration for a cataract with intraocular lens implantation. At the insertion of a CRVO knife, pulsating bleeding occurred from the cup of the optic disk; the bleeding was stopped within 2 minutes by elevating the intraocular pressure to 80 mm Hg. On the following day, the patient noticed that she had lost light perception. Fluorescein angiography showed a marked delay of arterial filling, indicating a central retinal artery occlusion. Retinal circulation returned to normal 2 months later; however, her vision was still no light perception. CONCLUSIONS: Ophthalmologists should be aware that severe complications such as central retinal artery occlusion can be associated with radial optic neurotomy, which is an unproven surgical procedure with a questionable pathophysiologic mechanism.

Aged↗