Orbital solitary fibrous tumor.

INTRODUCTION: Solitary fibrous tumor (SFT) is a rare borderline mesenchymal tumor typically arising in the pleura and involving the orbit as its most common extra-pleural location. CASE DESCRIPTION: We herein describe two cases of orbital SFT arising in both a 69-year-old woman presenting with progressive proptosis of the left eye and a 49-year-old woman presenting with binocular diplopia. The diagnoses relied on histopathological analysis of biopsy samples. Because of the poor local prognosis, we decided to perform an orbital exenteration in the first case. In the second case, a complete resection surgery was performed. CONCLUSION: SFT presents classics histological features and immunohistochemical markers that are essential to the diagnosis. SFT is classified as a benign tumor, but in some cases, it can show aggressive behavior with the potential for local tissue invasion and, more scarcely, distant metastasis. This is why complete resection remains the treatment of choice for SFT.

Ptosis secondary to orbital metastasis undetected by magnetic resonance imaging: A case report.

We report a patient with isolated ptosis secondary to orbital metastasis but no evidence of a neoplastic process on magnetic resonance imaging (MRI). A 69-year-old male was referred to our hospital with ptosis of the right upper eyelid and secondary frontalis muscle overaction on the left side for six months. The palpebral fissure was 3mm on the right and 16mm on the left, and levator function was 6mm and 19mm respectively. Three years previously, he had undergone surgical resection of the left lower lobe of the lung due to a T1 N0 M0 adenocarcinoma, and no recurrence had since been observed. An MRI was performed to rule out ptosis secondary to metastasis. Thyroid dysfunction and myasthenia were also ruled out. The ptosis was attributed to an isolated microvascular third nerve palsy. A standard external levator advancement was performed. Six months after the surgery, the patient presented with intense pain, minimal ptosis, edema and diplopia. A new MRI revealed an orbital metastasis measuring 2.4×1.0×1.6cm in the superior orbit, exerting mass effect on the superior rectus and the levator palpebrae superioris muscle. A positron emission tomography scan revealed a recurrence of the lung cancer with multiple bony metastases. The patient underwent chemotherapy consisting of the taxol-carboplatin protocol. Our report highlights the importance of a high index of suspicion of a neoplastic etiology in patients with mild symptoms and a history of cancer even if imaging does not initially reveal a mass or infiltration.

Epidemiological features of ophthalmic emergencies during the COVID-19 lockdown: Impact of the health crisis in a tertiary care center.

PURPOSE: The goal of this study is to examine changing patterns of ophthalmic visits in an emergency eye care unit of a tertiary referral center in Paris, France, during the Coronavirus disease-19 (COVID-19) pandemic compared to a control period. MATERIALS AND METHODS: This was a single-center, retrospective, observational, epidemiological study. We included all visits in the emergency eye care unit of the Quinze-Vingts National Ophthalmology Center, Paris, France, from March 17, 2020 to April 30, 2020, and a corresponding time period in 2016. We analyzed patients' demographic factors, chief complaints, referral patterns, examination findings, treatment provided, hospitalizations and surgical interventions. RESULTS: During the 6weeks of lockdown, 3547 emergency visits were recorded. The control group contained 2108 patients from June 6-19, 2016. There was a decrease of approximately 50% in the number of average daily visitations. The frequency of serious diagnoses (including severe eye inflammation, serious infections, retinal vascular pathologies, surgical emergencies, and neuro-ophthalmology), increased overall during the period (P=0.03). The proportion of low severity pathologies decreased (P<0.001) between the two periods. In addition, an increased amount of ancillary testing was performed (P<0.001). Finally, the rate of hospitalizations was significantly lower during the lockdown period (P<0.001). CONCLUSION: A significant reduction in total ophthalmic presentations in the emergency eye care unit was observed during the lockdown period. However, the proportion of emergencies requiring specialized treatments (surgical, infectious, inflammatory and neuro-ophthalmological pathologies) increased.

Efficacy and safety of intraocular folding sutureless scleral fixating lens versus iris-claw intraocular lens implantation.

PURPOSE: To compare the refractive outcomes of sutureless scleral-fixated Carlevale® intraocular lenses versus Artisan® iris-claw-fixated lenses in terms of surgically induced astigmatism. SETTING: We included patients from the Quinze-Vingts National Ophthalmology Hospital, Paris, from August 2020 to December 2020. DESIGN: This was a single-center retrospective study. METHODS: Each patient included had undergone surgery with a sutureless scleral-fixated Carlevale® foldable intraocular lens or an Artisan® iris-claw lens in the context of secondary implantation. Exclusion criteria included a history of retinal detachment or any other retinal disease. We analyzed postoperative refractive data three months after surgery for the Carlevale group and three months after removal of all sutures for the Artisan group. RESULTS: A total of 25 eyes of 25 patients were included in the Carlevale group and 37 eyes of 36 patients in the Artisan group. At three months, the best-corrected visual acuity was not statistically different, at 0.33(±0.35) and 0.32(±0.33) LogMAR, respectively (P=0.99), and surgically induced astigmatism was significantly lower in the Carlevale group, at 0.538 (±0.560) and 2.30 (±3.97) Diopters, respectively (P<0.001). CONCLUSIONS: In this first comparative study, Carlevale® intraocular lenses appear to offer better refractive accuracy and less induced astigmatism than Artisan® iris-claw lenses, without increasing mean surgical time.

Orbital in juries in wartime: Historical study from Paul Tessier's work in Iran.

INTRODUCTION: Paul Tessier was a leading French oculoplastic surgeon who took part in several surgical missions in Iran to manage victims of the Iraq-Iran conflict in the late 1980's and early 1990's. METHODS: We collected the records of 322 patients who underwent surgical procedures for the management of wartime injuries by Paul Tessier's team in Iran from 1990 to 1993. We also report one of the most representative cases of orbital reconstruction performed by Tessier. RESULTS: Mean age at the time of trauma was 20.65±7.04 years (range: 2--62). Craniofacial CT-scans were available for 54 patients. The bones of the upper third of the face and the orbital contents were affected in 124/322 patients (38.50%). Soft-tissue lesions of the upper third included 13 frontal lacerations (4.04%), 60 orbital injuries (18.63%) and 95 uni- or bilateral enucleations (29.50%). Thirty-nine uni- or bilateral lid injuries (12.11%) and 8 tear duct injuries (2.48%) were reported. A specific case of orbital reconstruction using antero-internal and posterior iliac bone grafts was reported as a representative example of Tessier's techniques. CONCLUSION: This study highlights the challenges of orbital reconstruction in wartime injuries and provides insights on the work of one of the most renowned surgeons in this field.

[Efficacy and tolerance of Latanoprost given as a first intention in the treatment of primitive open angle glaucoma in African melanoderm]. / Efficacité et tolérance du Latanoprost donné en première intention dans le traitement du glaucome primitif a angle ouvert chez le mélanoderme africain.

OBJECTIVE: To assess the reduction in IOP and ocular symptoms in patients newly diagnosed with POAG and treated with latanoprost as monotherapy. PATIENTS AND METHOD: A multicentric, cross-sectional, descriptive study was conducted. We included adults newly diagnosed with POAG. All patients received one drop of preserved latanoprost 0.005% in each eye every night for 12 weeks. Changes in IOP and ophthalmic signs and symptoms were assessed during and at the end of treatment. RESULTS: A total of 524 patients were included, with a participation rate of 93% at 12 weeks. The mean age was 52.79±17.33 years, and the sex ratio M/F was 1.39. At inclusion, the mean IOP was 21.68±9.72mmHg. After 2 weeks of treatment, the mean IOP was 15.49±5.81mmHg, for a reduction of 28.55%. After 12 weeks of treatment, the mean IOP was 13.16±3.54mmHg, for a reduction of 39.30%. The main symptom recorded was a gritty foreign body sensation, the frequency of which was 4.72% at W2 and 2.45% at W12. The main sign was hyperemia (4.33% at W2 and 1.84% at W12). CONCLUSION: Latanoprost given as first-line monotherapy in POAG in blacks considerably reduces IOP. The incidence of side effects remains low; it is higher at the start of treatment.

Late and sustained intraocular pressure elevation related to intravitreal anti-VEGF injections: Cases requiring filtering surgery.

We report cases of delayed, sustained elevated intraocular pressure (IOP) associated with repeated intravitreal anti-VEGF injections (IVI), which ultimately resulted in the need for filtering surgery. Two of the three cases demonstrated severe IOP elevation despite maximal medical treatment following unilateral IVI and required urgent filtering surgery. Optic nerve involvement was severe in all three cases. These intravitreal injections were performed for exudative age-related macular degeneration (AMD), and the patients did not show any sign of glaucoma or ocular hypertension prior to the initiation of treatment. Elevated IOP secondary to intravitreal steroids is a well-known side effect, as is immediate transient IOP elevation associated with anti-VEGF injection. Late, sustained IOP elevation after repeated injections of anti-VEGF, described approximately ten years ago, is often underestimated. Its incidence is estimated between 2.1 % and 13 % according to studies and increases with the number of IVI (cumulative effect). The pathophysiologic process is becoming increasingly understood, and several risk factors for this chronic IOP elevation have been identified. Most often, it is a moderate IOP elevation for which topical monotherapy is sufficient, or sometimes two, three or four medications or even selective laser trabeculoplasty (SLT). However, filtering surgery may rarely be required. Our findings illustrate a little-described phenomenon: a sudden, severe, late IOP elevation in response to anti-VEGF by an "overflow" effect, requiring urgent filtering surgery.

[Boston Keratoprosthesis with temporal aponeurosis graft: A solution when there seems to be no more]. / Kératoprothèse de Boston avec greffe d'aponévrose temporale : une solution quand il semble ne plus y en avoir.

PURPOSE: To report cases of patients with severe bilateral corneal blindness and recurrent refractory perforation to keratoplasty and conventional treatment, for whom Boston keratoprosthesis (KP) was a satisfactory alternative when combined with a temporalis aponeurosis graft. DESCRIPTION OF CASES: The first patient had progressive Lyell syndrome with spontaneous corneal perforation. The second had a severe graft vs. host reaction with a persistent Seidel-positive descemetocele. Despite repeated penetrating keratoplasties, amniotic membrane (AM) transplantations, and buccal mucosal (BM) grafts, they both experienced recurrent corneal perforation. The only solution thus appeared to be Boston Type I KP surgery. One month postoperatively, the first patient had to receive a temporalis aponeurosis (TA) graft, due to thinning of the recipient graft. Six months postoperatively, his visual acuity (VA) was 1/10 without correction, and the corneal status had been stabilized. The second patient underwent KP and TA graft concurrently. Six months after surgery, VA was 2/10 uncorrected, and the local inflammation had been stabilized. OBSERVATION: Boston type I keratoprostheses constitute an alternative in cases of severe bilateral corneal blindness with perforation refractory to conventional treatment and surgery, with satisfactory visual results. DISCUSSION: Patients with preoperative severe ocular surface disease are at greater risk of postoperative keratolysis. For our patients with a higher risk, TA graft prevented corneal melt. TA seems to be more effective than AM or BM in preventing corneal thinning or melt. CONCLUSION: We would recommend performing a TA graft in combination with Boston KP surgery concurrently as first line treatment in eyes with severe ocular surface inflammation.

[Late and sustained intraocular pressure elevation related to intravitreal anti-VEGF injections: Cases requiring filtering surgery (French translation of the article)]. / Hypertonie intraoculaire retardée liée aux injections intra-vitréennes répétées d'anti-VEGF : des cas nécessitant une chirurgie filtrante.

We report cases of delayed, sustained elevated intraocular pressure (IOP) associated with repeated intravitreal anti-VEGF injections (IVI), which ultimately resulted in the need for filtering surgery. Two of the three cases demonstrated severe IOP elevation despite maximal medical treatment following unilateral IVI and required urgent filtering surgery. Optic nerve involvement was severe in all three cases. These intravitreal injections were performed for exudative age-related macular degeneration (AMD), and the patients did not show any sign of glaucoma or ocular hypertension prior to the initiation of treatment. Elevated IOP secondary to intravitreal steroids is a well-known side effect, as is immediate transient IOP elevation associated with anti-VEGF injection. Late, sustained IOP elevation after repeated injections of anti-VEGF, described approximately ten years ago, is often underestimated. Its incidence is estimated between 2.1% and 13% according to studies and increases with the number of IVI (cumulative effect). The pathophysiologic process is becoming increasingly understood, and several risk factors for this chronic IOP elevation have been identified. Most often, it is a moderate IOP elevation for which topical monotherapy is sufficient, or sometimes two, three or four medications or even selective laser trabeculoplasty (SLT). However, filtering surgery may rarely be required. Our findings illustrate a little-described phenomenon: a sudden, severe, late IOP elevation in response to anti-VEGF by an "overflow" effect, requiring urgent filtering surgery.

[Ocular graft-versus-host disease: An often misdiagnosed etiology of dry eye syndrome]. / Réaction oculaire du greffon contre l'hôte : une étiologie de syndrome sec à ne pas méconnaître.

PURPOSE: To report a case of severe ocular graft-versus-host disease (GVHD) after cataract surgery. METHODS: Observational case report. RESULTS: We describe the case of a 59-year-old man with postoperative corneal ulcer on his only functional eye. His past history reported allogenic bone marrow transplant. His visual acuity (VA) was limited to hand motions. Slit lamp examination revealed diffuse conjunctival hyperemia, severe blepharitis, Meibomian dysfunction, total corneal opacification with epithelial and stromal keratitis and neovascular invasion. Because of the severe dry eye symptoms and history of allogenic hematological stem cell transplantation, ocular GVHD was diagnosed. Functional and anatomical improvement occurred rapidly with topical cyclosporine 2%, with improved VA after treatment. CONCLUSION: With any severe dry eye syndrome in the context of allogenic bone marrow transplant, ocular GVHD must be considered. For planned ocular surgery, we recommend adding cyclosporine 0.1% treatment before and after surgery to prevent severe ocular GVHD.

[Is there a need for a therapeutic education with patients suffering with open-angle glaucoma? Preliminary inquiry regarding knowledge and patient adherence]. / Faut-il une éducation thérapeutique des patients atteints de glaucome à angle ouvert ? Enquête préliminaire des connaissances et de l'observance auprès des patients.

PURPOSE: To evaluate the knowledge and compliance of patients with open-angle glaucoma in order to propose an approach by therapeutic education, validated for other chronic pathologies. METHODS: A questionnaire-based interview of all patients in the waiting room of the glaucoma center is performed by the same health care professional. RESULTS: Out of 200 patients, 73% know they will need to be treated throughout their lives and 95% are aware of the risk of blindness in the absence of appropriate treatment. However, 16% respond that they can be cured, and 54% believe that treatment can save their eyesight. Knowledge increases with the length of follow-up of patients at the glaucoma center beyond one year, but the progress is still insufficient in their confidence that treatment can save their eyesight (36% to 57%), and in the decrease in the number of patients who forget their treatment (56% to 30%). CONCLUSION: Cognitive knowledge is insufficient to encourage the patient to comply with treatment. It is necessary to consider therapeutic patient education (TPE) techniques, such as described by WHO, in group and/or individual sessions, aimed at building the patient's confidence that treatment can delay the progression of the disease and blindness, strengthening his/her capacity to properly administer the eye drops, managing his/her treatment and coping with frequent side effects. Within this framework, our knowledge of the patients' representations of their glaucoma and its treatment must improve.

Direct costs of glaucoma and severity of the disease: a multinational long term study of resource utilisation in Europe.

BACKGROUND: Resource utilisation and direct costs associated with glaucoma progression in Europe are unknown. As population progressively ages, the economic impact of the disease will increase. METHODS: From a total of 1655 consecutive cases, the records of 194 patients were selected and stratified by disease severity. Record selection was based on diagnoses of primary open angle glaucoma, glaucoma suspect, ocular hypertension, or normal tension glaucoma; 5 years minimum follow up were required. Glaucoma severity was assessed using a six stage glaucoma staging system based on static threshold visual field parameters. Resource utilisation data were abstracted from the charts and unit costs were applied to estimate direct costs to the payer. Resource utilisation and estimated direct cost of treatment, per person year, were calculated. RESULTS: A statistically significant increasing linear trend (p = 0.018) in direct cost as disease severity worsened was demonstrated. The direct cost of treatment increased by an estimated 86 for each incremental step ranging from 455 euro per person year for stage 0 to 969 euro per person year for stage 4 disease. Medication costs ranged from 42% to 56% of total direct cost for all stages of disease. CONCLUSIONS: These results demonstrate for the first time in Europe that resource utilisation and direct medical costs of glaucoma management increase with worsening disease severity. Based on these findings, managing glaucoma and effectively delaying disease progression would be expected to significantly reduce the economic burden of this disease. These data are relevant to general practitioners and healthcare administrators who have a direct influence on the distribution of resources.

[Electrophysiological monitoring of epileptic patients treated with Vigabatrin]. / Surveillance électrophysiologique des patients épileptiques traités par Vigabatrin.

Vigabatrin is a GABA mimetic antiepileptic agent that has been used for 10 years in cases of epilepsy that resist other treatments. Since 1997, concentric visual field defects have been reported. Before any visual symptom complaint, they quickly become irreversible and highly disabling. To prevent this visual impairment, the monitoring protocol must be defined with reliable and well-supported tests, so that patients treated with Vigabatrin can be regularly monitored. Our purpose was to know if EOG impairments were frequent, if their severity was proportional to visual impairment, and if the Arden ratio could be a predictive criterion of Vigabatrin toxicity. Seventy-two patients treated with Vigabatrin for 2-10 years were examined, and EOG results were compared with a normal population EOG and then the patient's visual field. The monitoring protocol proposed includes EOG, which seems to be the most sensitive and specific diagnostic tool for screening Vigabatrin-treated patients.

[Arteriovenous malformation of the brain revealed through a visual blur and Adie's pupil]. / Tumeur vasculaire cérébrale révélée par un flou visuel concomitant à la découverte d'une pupille d'Adie.

INTRODUCTION: Arteriovenous malformations of the brain (BAVMs) are a relatively rare group involving intracranial vascular lesions (telangiectasia, cavernous malformation, venous anomaly). We report the case of a patient who presented an atypical visual symptomatology revealing a BAVM. OBSERVATION: A 48-year-old woman consulted for a recent bilateral visual blur. In darkness, discrete anisocoria appeared on the left eye. At the biomicroscopy light examination, we found areflexic semi-mydriasis (direct and consensual) on the left eye; the light reflex (direct and consensual) on the right eye was normal. During the accommodative reflex test the left pupil contracted. We propose the diagnosis of Adie's pupil, which was confirmed by the pilocarpine test (0.125%). We decided to examine the visual field because the symptomatology of the visual blur remained unexplained. The visual field showed a left homonymous inferior lateral scotoma. MRI showed a right occipital arteriovenous malformation. DISCUSSION: A quick examination could confuse painless anisocoria with a compression of the IIIrd intrinsic left nerve. This recent scotoma revealed BAVM progression. The natural history of BAVMs shows that the essential risk of these injuries is the onset of an intracranial hemorrhage. To reach a radical therapeutic decision, a cerebral arteriography clarifying the afferent and efferent vascularity of the nidus was carried out. CONCLUSION: This case is original in that it associates the concomitant discovery of a BAVM and Adie's pupil. Symptomatic BAVMs are extremely serious. Planning their treatment requires multidisciplinary cooperation in order to reduce the risk of mortality.

[Acute Retinal Pigment Epitheliitis: spectral-domain optical coherence tomography findings]. / Épithélite rétinienne aiguë : apport de la tomographie par cohérence optique en Spectral Domain.

PURPOSE: Through a case presentation of Acute Retinal Pigment Epitheliitis (ARPE) we highlight the role of spectral-domain optical coherence tomography (SD-OCT) in the management of this rare entity. MATERIALS AND METHODS: A 29-year-old woman presented for reduced visual acuity in the right eye occurring one week after a viral episode. Fundus examination showed zones of macular hyperpigmentation surrounded by yellowish hypopigmented haloes. Fluorescein angiography noted early hyperfluorescence of the hypopigmented lesions. ICG angiography revealed central hyperfluorescence surrounded by a hypofluorescent halo. SD-OCT showed a linear disruption between the photoreceptor inner/outer segments (IS/OS) and an accumulation of material in the photoreceptor outer segments and retinal pigment epithelium (RPE). Spontaneous normalization of visual acuity was noted after 10 weeks. SD-OCT revealed restored and continuous inner segment and outer segment layers and some persistent deposits in the photoreceptor layer. RESULTS: SD-OCT findings suggest that the initial lesion in ARPE is located at the junction between the photoreceptor outer segments and the apical side of the RPE cells. It would correspond to an accumulation of photoreceptor outer segment debris secondary to RPE dysfunction, which can occur as a post-viral reaction. CONCLUSION: SD-OCT provides very specific information about the topography of retinal lesions during ARPE, allowing a better understanding of its pathogenesis.

[Early postoperative intraocular pressure after phacoemulsification: Normal patients versus glaucoma patients]. / Pression intraoculaire en postopératoire précoce de phakoémulsification chez le sujet normal et glaucomateux.

OBJECTIVE: To compare intraocular pressure (IOP) during the first month following cataract surgery among patients with primary open-angle glaucoma (POAG) and non-glaucomatous patients. MATERIALS AND METHODS: This longitudinal observational study included 19 glaucoma patients and 18 healthy patients scheduled for phacoemulsification with IOL implantation between December 2013 and April 2014. IOP was measured preoperatively, on the day of surgery (j0), the next day (j1), one week (j7) and one month after (M1). The usual antiglaucoma medications were continued without any modification compared to the preoperative medications. Oral treatment with a carbonic anhydrase inhibitor was initiated in the case of ocular hypertension above 30mmHg. RESULTS: IOP in glaucoma patients was 18.42 and 21.16mmHg respectively at j0 and j1 versus 12.94 and 13.78mmHg in non-glaucomatous patients. The difference was significant with P=0.05. There was also more ocular hypertension over 30mmHg in the POAG group (31.5% vs. none in the non-glaucomatous group, P<0.05). CONCLUSION: Glaucoma patients, even stabilized on topical medications, are more likely to experience IOP spikes immediately after uncomplicated cataract surgery. High risk patients should have closer monitoring with IOP measurement the day of or the day after surgery. Further studies are needed to evaluate the effectiveness of prophylactic anti-hypertensive treatment.

[Efficacy of intravitreal dexamethasone implants in macular edema excluding venous occlusions: results for a cohort of 80 patients]. / Efficacité des implants intravitréens de dexaméthasone dans l'œdème maculaire hors occlusions veineuses : résultats sur une cohorte de 80 patients.

INTRODUCTION: The intravitreal dexamethasone implant has shown efficacy in the treatment of macular edema (ME) arising after retinal venous occlusions (central or branch), and in the treatment of non-infectious uveitis. The purpose of this study was to evaluate the efficacy of this implant in the treatment of other diffuse macular edemas with an inflammatory mechanism. MATERIALS AND METHODS: We carried out a retrospective cohort study over 2 years: from January 2012 to December 2013, including all patients who received at least one injection of intravitreal dexamethasone implant, excluding venous occlusions and non-infectious uveitis. The primary study parameter was the progression of visual acuity. The study protocol had the approval of the institutional review board of the respective clinical ethics committees, and was conducted in accordance to the tenets of the Declaration of Helsinki. RESULTS: Eighty patients were included. Eighty-eight percent of patients were pseudophakic. The indications for treatment were: diabetic ME when anti-VEGF were ineffective (53%), ME after retinal detachment (RD) (22%), ME of Irvine-Gass syndrome (16%), ME after endophthalmitis (4%), macular telangiectasia (4%), ME secondary to retinitis pigmentosa (1%). The mean ETDRS visual acuity was 53.7 letters prior to injection, improving to 62.3 letters after injection (P<0.001). The average gain in visual acuity was 6.7 letters [4.53;8.84] (P<0.001) in patients treated for diabetic ME, 9.6 letters [6.1;13.1] (P<0.001) in patients with ME after RD, and 15.2 letters [10.25;20.28] (P<0.001) for Irvine-Gass syndrome. The mean duration of efficiency was 4.6 months, with a median of 3.8 months. CONCLUSION: The intravitreal dexamethasone implant appears to be an effective second-line treatment even in patients with diabetic ME after failure or in the case of contraindication of anti-VEGF. It is also effective and well tolerated in patients with ME after RD, as well as in patients with Irvine-Gass syndrome.

Contrast sensitivity in amblyopia: masking effects of noise.

Contrast sensitivities were determined for sinusoidal gratings of varying spatial frequencies with and without the presence of a random noise pattern superimposed on the gratings. Control subjects with normal binocular vision and observers with amblyopia were tested to determine the relative effects of noise on contrast sensitivity. For both amblyopes and normal subjects, contrast sensitivities are reduced by the presence of noise. Effects are maximal at 4 cycles/degree and are minimal at low and high spatial frequencies. Dichoptic presentation of noise and gratings to opposite eyes is equivalent to monoptic results for both amblyopes and normal subjects. Masking effects are eliminated if gratings are drifted while noise patterns are static. The contrast sensitivity of amblyopes is reduced by relatively similar amounts to that of normal subjects when noise is added to the stimulus. Overall, masking effects are virtually identical for amblyopes and for subjects with normal binocular vision.

Localization and characterization of substance P binding sites in rat and rabbit eyes.

Specific and high-affinity binding sites for Substance P (SP) were found in eyes from albino rabbits and rats using an in vitro autoradiographic method with 125I-Bolton Hunter SP (BHSP). autoradiograms were generated by apposing 10-20 microns-thick cryostat eye sections to 3H-Hyperfilm or liquid emulsion and quantified by means of image-analysis procedures. Kinetic studies showed that equilibrium was reached after a 75-min incubation at room temperature. In rat retina, specific binding corresponding to approximately 90% of total binding, was reversible, of high affinity (dissociation constant [Kd], 0.13 +/- 0.02 nM). Half-time for dissociation of 125I-BHSP was about 15 min. Unlabeled SP and the two neurokinins (NK) A and B competed in a concentration-dependent manner for retinal sites labeled by 125I-BHSP with the following order of potencies: SP greater than NKA greater than NKB, in agreement with a pharmacologic profile of a SP receptor site. In both species, specific binding was found in the iris sphincter muscle, choroid, and retina. In rats, detectable amounts of SP-binding sites were also expressed in the corneal epithelium and iridial stroma. Quantitative analysis of the autoradiograms revealed that the highest densities of 125I-BHSP binding sites were localized in the iris sphincter muscle in rabbits and the inner retina in rats.

Autoradiographic localization of D1 and D2 dopamine binding sites in the human retina.

The localization of dopamine binding sites was studied by in vitro autoradiography in the normal human retina using [125I]SCH 23982 for D1 receptor labelling and [125I]iodosulpride for D2 receptors. Results demonstrated that both types of binding sites were present in human retina. Binding of [125I]SCH 23982 to D1 dopamine receptor was blocked by 1 microM SKF 38393, SCH 23390 (D1 specific compounds) whereas bromocriptine and domperidone (D2 specific compounds) were inactive at the same concentration. On the contrary, binding of [125I]iodosulpride to D2 dopamine receptor was inhibited only by D2 drugs. Precise cellular distribution was given by microautoradiographic techniques and showed that binding sites were exclusively localized to the plexiform layers.