Should central serous chorioretinopathy be added to the list of ocular side effects of phosphodiesterase 5 inhibitors?

INTRODUCTION: Rare cases of central serous chorioretinopathy (CSC) associated with the intake of sildenafil citrate have been reported, although CSC is not included in the list of phosphodiesterase 5 (PDE5) inhibitor side effects. MATERIALS AND METHODS: We present a review of the literature and 2 cases of CSC in 2 men taking PDE5 inhibitors (vardenafil and tadalafil) for erectile dysfunction. In both cases chorioretinopathy appeared after intake of the inhibitor, resolved once the latter was discontinued, reappeared when the inhibitor was restarted and resolved once again after the inhibitor had been discontinued for the second time. DISCUSSION: PDE5 inhibitors used for male erectile dysfunction have been associated with ocular side effects including lid edema, hyposphagma, photophobia, mydriasis, dyschromatopsia, and nonarteritic anterior ischemic optic neuropathy. CSC was previously described in patients taking sildenafil citrate. Very recently, a case of CSC after tadalafil intake was reported. The relevant literature is reviewed and possible pathophysiologic mechanisms are discussed. CONCLUSION: The 2 presented cases of CSC after intake of vardenafil or tadalafil with positive dechallenge, rechallenge and second dechallenge reactions provide important arguments for considering CSC as a rare PDE5 inhibitor class-specific side effect.

Distinct mechanisms of form-from-motion perception in human extrastriate cortex.

The exquisite sensitivity of the human visual system to form-from-motion (FfM) cues is well documented. However, identifying the neural correlates of this sensitivity has proven difficult, particularly determining the respective contributions of different motion areas in extrastriate visual cortex. Here we measured visual FfM perception and more elementary visual motion (VM) perception in a group of 32 patients suffering from acute posterior brain damage, and performed MRI-based lesion analysis. Our results suggest that severe FfM perception deficits without an associated deficit of VM perception are due to damage to ventral occipito-temporal cortex (VOT), whereas associated deficits of FfM and VM perception are due to damage either in proximity to area MT+/V5 or an area including lateral occipital complex (LOC) and VOT. These data suggest the existence of at least three functionally and anatomically distinct regions in human visual cortex that process FfM signals.

Subretinal electrode implantation in the P23H rat for chronic stimulations.

BACKGROUND: In age related macular degeneration and inherited dystrophies, preservation of retinal ganglion cells has been demonstrated. This finding has led to the development of various models of subretinal or epiretinal implant in order to restore vision. This study addresses the development of a polyimide subretinal electrode platform in the dystrophic P23H rat in vivo. METHODS: A technique was developed for implanting a subretinal electrode into the subretinal space and stabilising the distal extremity of the cabling on the rat cranium in order to allow future electrical stimulations of the retina. RESULTS: In vivo imaging of the retina with the scanning laser ophthalmoscope demonstrated reabsorption of the surgically induced retinal detachment and the absence of major tissue reactions. These in vivo observations were confirmed by retinal histology. The extraocular fixation system on the rat cranium was effective in stabilising the distal connector for in vivo stimulation. CONCLUSION: This study demonstrates that a retinal implant can be introduced into the subretinal space of a dystrophic rat with a stable external connection for repeatable electrical measurements and stimulation. This in vivo model should therefore allow us to evaluate the safety and efficacy of electrical stimulations on dystrophic retina.

Metastatic infiltration of nerves in the cavernous sinus.

Painful dysesthesia in association with ocular motor palsies characterized intraneural carcinomatous invasion in a 48-year-old man. Transcranial biopsy of the cavernous sinus stopped the pain; the specimen confirmed the diagnosis and provided the rationale for radiation therapy. One year after treatment, the patient was healthy and pain-free, with improved ocular motor function. The source of the carcinoma remains unknown.

Periodic downbeat nystagmus.

The authors observed a periodic downbeat nystagmus with a cycle of 3 minutes 30 seconds, beating downward for a period of 90 seconds every 2 minutes. It lasted 86 hours in a patient with severe hypomagnesemia associated with complications from scleroderma. There was no lesion on brain imaging, and an EEG performed during the nystagmus was normal, indicating that the most likely explanation for this periodic nystagmus is metabolic. This form of nystagmus may have resulted from severe hypomagnesemia, possibly associated with thiamine deficiency.

Statokinetic dissociation in lesions of the anterior visual pathways. A reappraisal of the Riddoch phenomenon.

With standard Goldmann perimetry, physiologic dissociation of kinetic and statis stimuli was first investigated in 15 normal subjects. Variable degrees of statokinetic dissociation (SKD) occurred for white and for red (achromatic perception) targets, but not for chromatic recognition of red. To analyze relative sensitivity of these stimuli in defining field defects, a set of "isopter equivalents," eg, white I2e, red II4c (achromatic perception), and red V4e (chromatic recognition) was empirically established in normal and in pathologic fields of 11 patients with compression of the anterior visual pathways. The "Riddoch phenomenon" (SKD) was documented in defective fields in all patients with tumors; SKD occurred for white or for red achromatic perception. The most sensitive technique for elaborating field defects proved to be static presentation of white or red stimuli (achromatic perception) and chromatic recognition of static or kinetic red. As a rapid, sensitive screening method, especially for subtle defects, we suggest the addition of chromatic recognition of kinetic red stimuli to the application of standard kinetic white stimuli. Our findings are discussed in light of current concepts of retinal ganglion cell physiology.

Threshold perimetry in tilted disc syndrome.

Twelve consecutive patients (17 eyes) with tilted disc syndrome underwent quantified visual field examination with the G1 Octopus program (Interzeag AG, Schlieren, Switzerland). Visual fields were abnormal in all cases. Although field loss was more pronounced in the superotemporal quadrant (P less than .001), it also involved the other three quadrants, thus demonstrating that optic nerve hypoplasia in tilted disc syndrome is apparently not entirely sectorial. Linear regression analysis showed that an increase in mean defect correlated with increase in myopic refractive error (P less than .05). However, the increase in myopic refractive error was found to be related to a decrease in corrected loss variance (P less than .05), indicating that in tilted discs with higher myopia, field loss is more homogeneous. With this series of patients, short-term fluctuation was within normal ranges in all visual fields, showing that this may be an additional clue for differential diagnosis from acquired disorders.

Corneal hypoesthesia.

Decreased corneal sensitivity is an important clinical parameter in neuro-ophthalmological evaluation. It may be associated with such disorders as diabetes, Herpes simplex keratitis, and myasthenia gravis, with corneal toxicity via chemical exposure or ocular drug therapy, and with ocular surgery. In this review, methods and precautions involved in measuring corneal sensitivity are summarized, and the clinical conditions in which corneal hypoesthesia may exist are discussed.

The vanishing of the sun: a manifestation of cortical plasticity.

In Monet's painting impression. Rising Sun, when one steadily fixates the image of a sailor in the center of the picture for several seconds, the solar disk progressively disappears, being replaced in both brightness and color by the surrounding sky. This "filling-in" phenomenon reflects a process of cortical remapping, similar to the one that occurs in the presence of visual field defects. Filling-in is largely ignored by clinicians, despite its major implications in ophthalmologic practice, especially the nonrecognition of visual field deficits.

Ganglion cells from chick retina display multiple functional nAChR subtypes.

We have examined the properties of nicotinic acetylcholine receptors in embryonic chick retinal ganglion cells. Ganglion cells, identified according to morphological and physiological criteria, displayed spontaneous or induced action potentials. In 94/99 cells acetylcholine pulses evoked responses. In current clamp mode, acetylcholine provoked membrane depolarization and triggered action potentials. Under voltage clamp conditions, acetylcholine evoked inward currents that were readily blocked by d-tubocurarine. Antagonists specific for homomeric (alpha-bungarotoxin) and heteromeric (dihydro-beta-erythroidine) receptors revealed that ganglion cells express multiple functional receptor subtypes. These findings demonstrate that ACh modulates the electrical activity of these cells and is likely to mediate synaptic transmission. The presence of multiple receptor subtypes may contribute to processing and transmission of information in the retina.

Helicoid peripapillary chorioretinal degeneration.

Study of a father and son who had helicoid peripapillary chorioretinal degeneration suggests that a progressive tearing and retraction of the retinal pigment epithelium or of Bruch's membrane around the optic disk may be involved in the disorder's pathogenesis. We presume that this tearing results primarily from dysplastic abnormalities of the retinal pigment epithelium that surrounds the optic disk. The dystrophic lesions progress slowly and may affect the macula and even the peripheral retina.

Macular reflexes in optic atrophy.

We investigated the annular reflex of the macula and the foveal reflex in 14 eyes with various degrees of optic atrophy by means of red-free fundus photographs. The patients ranged in age from 13 to 34 years (mean age, 25.9 years). We compared our observations with data obtained from 51 age-matched normal eyes. Optic atrophy was found to be associated with changes in the reflexes of the macular area. Alterations occurred in all eight eyes that had visual acuities of 20/50 or worse. Changes in the annular reflex of the macula were more significant in younger patients (less than or equal to 25 years of age) than in older patients. In the younger group, the annular reflex was blunt, distorted, and fragmented, and showed an irregular extension toward the foveal area, whereas in the old group it showed less specific attenuation. Fading of the foveal reflex was observed in both groups. Changes in the retinal reflexes of these patients result from alterations in the ganglion cell and nerve fiber layer and should be included among the signs of optic atrophy. They can help determine the extent of optic atrophy and can be useful clinical clues in children whose optic disks are difficult to examine. They should not be mistaken for signs of associated primary retinal disorders.

Lagophthalmos in acquired oculomotor synkinesis.

Two consecutive patients who exhibited classic signs of unilateral acquired oculomotor synkinesis demonstrated an inability to appose eyelid margins on the affected side, when attempting gentle closure of the eyes. In one patient, this occurred in conjunction with a unilateral upper eyelid crease on the affected side, and in the other patient it was associated with accentuation of the crease in comparison with that of the opposite side. Bilateral eyelid closure normally induces a contraction of the superior recti muscles. The lagophthalmos and accentuated upper eyelid crease observed in our patients when they attempted gentle eyelid closure presumably resulted from inappropriate coactivation of the levator palpebrae superioris muscle by impulses destined for the superior rectus muscle.

Convergence-evoked eyelid nystagmus.

We studied two patients with eyelid nystagmus induced by ocular convergence. The first patient, a 29-year-old man, had the signs of a cerebellar syndrome after sustaining severe craniocerebral injuries. The second patient, a 12-year-old girl, had a tumor of the anterior vermis cerebelli. After treatment with corticosteroids (Patient 1) and surgery (Patient 2), the eyelid nystagmus gradually disappeared. An alteration in the cerebellar system is the most likely cause of convergence-evoked nystagmus.

Multiple evanescent white dot syndrome after hepatitis B vaccine.

PURPOSE: Hepatitis B vaccine has become an effective means of preventing complications of hepatitis B. However, it occasionally induces serious side effects. We report a case of multiple evanescent white dot syndrome (MEWDS) that occurred following hepatitis B vaccination. METHODS: A 23-year-old woman with a one-week history of progressive loss of vision in the left eye and bilateral photopsia was referred for examination. Her symptoms appeared 24 hours after a booster intramuscular injection of hepatitis B vaccine. RESULTS: Clinical examination, fluorescein angiography, and the course of events were typical of MEWDS. CONCLUSIONS: This case demonstrates the occasional occurrence of MEWDS after hepatitis B vaccine and suggests that hepatitis B virus immunization may be a risk factor for this retinal condition.

Skew deviation after vestibular neuritis.

We treated five patients with vestibular neuritis who had strabismus. Three of them spontaneously noted vertical diplopia. During the following weeks and months, strabismus progressively resolved, indicating the recently acquired nature of the oculomotor condition. In three of these individuals, a change in visual vertical and cyclo-torsion of the globes suggested that strabismus was a form of skew deviation that occurred as a part of an ocular tilt reaction resulting from the peripheral vestibular lesion. Strabismus appears to occur frequently in this common vestibular condition.

Role of the completion phenomenon in the evaluation of Amsler grid results.

PURPOSE: To evaluate the limitations, particularly those related to the perceptual completion phenomenon, of Amsler grid tests in patients with central scotomas caused by macular disorders. METHODS: We tested 15 affected eyes of 15 patients with macular lesions. In each subject, the central visual field was assessed by using four different types of Amsler grid testing and a tangent screen. Tests were conducted in a random order, and the sequence of tests was repeated once. The distance between the fixation point and the closet border of the plotted scotoma was assessed. For each patient, reproducibility in repeated examinations was evaluated by assessing changes in location of the computed center of the defects and by measuring changes in the position of the center of the scotoma. RESULTS: The tangent screen was more sensitive than Amsler grids in delineating the borders of the scotoma, and the results were more reproducible. Furthermore, by using a tangent screen, the fixation point was found adjacent to the scotoma. CONCLUSION: Poor sensitivity and intraindividual variations found with Amsler grid testing are at least partly a result of the perceptual completion phenomenon. This phenomenon proved to be a dynamic and fluctuating process, as the results of two successive Amsler grid tests were not comparable, even when the technique was identical and the time between tests was no more than two to 15 minutes.

Increasing short-term fluctuation by increasing the intensity of the fixation aid during perimetry.

An increase in short-term fluctuation is a clinically useful clue in the diagnosis of acquired disorders of the visual pathways. However, short-term fluctuation can also be increased in normal subjects by several factors. We found an increase in short-term fluctuation occurred in normal subjects when the visual field was tested using a bright fixation aid. Eight normal subjects underwent automated perimetry with the Octopus 2000R, in which the dimmest (12.5 candelas/m2) and brightest (435 cd/m2) available fixation aids were used. Mean short-term fluctuation values were 1.63 +/- 0.27 dB with the dimmest aid, and were 2.65 +/- 1.26 dB with the brightest aid. The difference was significant using the paired t-test (P = .037). Moreover, mean sensitivity was reduced from 35.67 +/- 2.26 dB to 33.66 +/- 1.71 dB when the brightest fixation aid was used (P = .004). In six of eight subjects, the relative changes in short-term fluctuation after an increase in brightness of the fixation aid were more pronounced than those in mean sensitivity. An increase in intensity of the fixation aid may cause visual changes in normal subjects that resemble those induced by disorders in the visual pathways. Whenever possible, minimal intensity of the fixation aid should be used to allow for an adequate interpretation of short-term fluctuation values.

Visual hallucinations immediately after macular photocoagulation.

PURPOSE: To evaluate the incidence of visual hallucinations after macular photocoagulation for choroidal neovascularization. METHODS: After macular photocoagulation for choroidal neovascularization, 60 consecutive patients were asked to respond to an orally administered questionnaire. RESULTS: Twenty-seven patients (45%) described photopsias, flashing lights of various colors. Ten additional patients (16.6%) also described structured hallucinations, including known or unknown faces, flowers, and geometric patterns, which occurred hours or a few days after photocoagulation. Patients with structured hallucinations were older (P =.04) and more often had subfoveal choroidal neovascularization (P =.005) and severe macular disease in both eyes or at least in the treated eye (P =.01). CONCLUSIONS: Visual hallucinations appear to be a frequent, albeit unrecognized, side effect of macular photocoagulation of choroidal neovascularization. The provision of proper information to patients may avoid concern about a psychiatric origin of their hallucinations.

Congenital nystagmus: rebound phenomenon following removal of contact lenses.

Symptoms resulting from congenital nystagmus can be significantly reduced by wearing corneal contact lenses. A 90 minute therapeutic trial with contact lenses was performed on a 20-year-old affected patient and produced a beneficial effect. Upon removal of the lenses however the patient showed a transient rebound phenomenon with oscillopsia lasting about 20 minutes. This phenomenon, although it might be expected in theory, has apparently not previously been observed either because it is rare or because in most patients it is not clinically apparent. The purpose of this report is not to discourage treating patients with congenital nystagmus by means of contact lenses, but rather to draw attention to the occasional occurrence of such a rebound phenomenon and to discuss its theoretical significance.