Retinal abnormalities in a patient with cutis marmorata telangiectatica congenita

Cutis marmorata telangiectatica congenita is a rare congenital vascular malformation characterised by cutaneous vascular abnormalities, typically diagnosed at birth or in the early postnatal period. Although typically benign, this disease is associated with other systemic abnormalities, including rare ocular alterations, such as congenital glaucoma, cataracts and retinopathy.This manuscript describes a female infant, who presented with generalised livedo reticularis, a band of alopecia and cutaneous atrophy in the temporal region above the coronal suture. The patient was diagnosed with cutis marmorata telangiectatica congenita by a paediatrician, and an ophthalmological evaluation was requested. A funduscopy examination in both eyes showed temporal and superior retina with avascular areas with new vessels, venous dilations and shunts, and no retinal detachments. Given these findings, we performed retinal photocoagulation laser treatment with excellent results.This case report highlights the importance of early ophthalmological evaluation of children with this disease to prevent secondary complications, such as vitreous haemorrhage and tractional retinal detachment.

The role of mannose-binding lectin (MBL) in diabetic retinopathy: A scoping review

Diabetes mellitus (DM) is a chronic systemic disease characterized by a multifactorial nature, which may lead to several macro and microvascular complications. Diabetic retinopathy (DR) is one of the most severe microvascular complications of DM, which can result in permanent blindness. The mechanisms involved in the pathogenesis of DR are multiple and still poorly understood. Factors such as dysregulation of vascular regeneration, oxidative and hyperosmolar stress in addition to inflammatory processes have been associated with the pathogenesis of DR. Furthermore, compelling evidence shows that components of the immune system, including the complement system, play a relevant role in the development of the disease. Studies suggest that high concentrations of mannose-binding lectin (MBL), an essential component of the complement lectin pathway, may contribute to the development of DR in patients with DM. This review provides an update on the possible role of the complement system, specifically the lectin pathway, in the pathogenesis of DR and discusses the potential of MBL as a non-invasive biomarker for both, the presence and severity of DR, in addition to its potential as a therapeutic target for intervention strategies.

Optical coherence tomography detection of retinal neural loss in patients with tuberous sclerosis

PURPOSE

Tuberous Sclerosis (TS) is a rare, multisystem genetic disease caused by mutations in the TSC1 and TSC2 genes, leading to abnormalities in cell differentiation and proliferation. This study aimed to evaluate the neural integrity of individuals with TS by using Optical Coherence Tomography (OCT) to examine the peripapillary retinal nerve fiber layer (RNFL) thickness and the macular thickness in patients with TS and to compare with healthy controls.

METHODS

Peripapillary and macular OCT scans (Optopol Revo NX SD OCT) were performed on 41 eyes from 22 TS patients, divided into two groups based on the presence of retinal hamartomas, and compared to 20 eyes from a control group. The average peripapillary RNFL thickness was measured for each quadrant. The macular total thickness and ganglion cell layer (GCL) + inner plexiform layer (IPL) thickness were measured based on the Early Treatment Diabetic Retinopathy Study (ETDRS) map. All measurements were then compared between the groups and controls.

RESULTS

The TS group showed significantly reduced RNFL thickness and macular thickness when compared to the control group. Specifically, patients with retinal hamartomas exhibited an even more pronounced thinning of both RNFL and macular thickness.

CONCLUSIONS

These findings suggest that TS patients undergo significant changes in retinal neurodevelopment and experience axonal loss. This finding may have significant prognostic utility regarding central nervous system degeneration in TS, particularly among patients with retinal hamartomas. OCT may serve as a valuable tool for assessing axonal structural abnormalities in TS patients.

TRIAL REGISTRATION NUMBER

Not applicable.

Retinal hamartomas at different stages in a patient with tuberous sclerosis: A OCT-SS description

Retinal astrocytic hamartoma (RAH) is a benign glial tumor that may be present in patients with tuberous sclerosis (TS), contributing to the diagnosis of this syndrome. While hamartomas identified through indirect ophthalmoscopy are often large enough to affect vessels and optic disc anatomy, RAH not detected in previous fundoscopies may become apparent in optical coherence tomography (OCT). The purpose of this report was to describe and characterize RAH with OCT with swept-source technology (OCT-SS), aiming to establish a more comprehensive classification for these hamartomas due to their diverse presentations. Fundus examination of a 11-year-old girl revealed retinal tumors in both eyes. OCT-SS confirmed the diagnosis of TS, revealing dome-shaped hyperreflective masses at different stages of evolution. Lesion 1: maximum thickness (MT) of 336 μm and ganglion cell layer disorganization. Lesion 2: MT of 438 μm and preserved outer plexiform layer. Lesion 3: posterior shadow, MT of 1478 μm and complete rupture of retinal anatomy. Lesion 4: MT of 342 μm and preserved retinal anatomy. OCT is a noninvasive method which assists the diagnosis of subclinical lesions and clinical characterization of TS patients.

Optic Nerve Sheath Fenestration as Adjuvant Treatment for Severe Pseudotumor Cerebri Syndrome Induced by All-Trans Retinoic Acid

All-trans retinoic acid (ATRA) is a vitamin A derivative which can increase intracranial pressure, causing visual loss and papilledema. Those patients should be treated similarly to others patients with idiopathic intracranial hypertension. We described a case of a 32-year-old woman presenting with severe visual loss and intracranial hypertension induced by ATRA for acute promyelocytic leukemia, which was treated clinically and with optic nerve sheath fenestration. Patients receiving ATRA therapy should be monitored to neurological and ophthalmic signs and symptoms of intracranial hypertension.

Visual Hallucinations as a Major Manifestation of Posterior Reversible Encephalopathy Syndrome: Case Report and Literature Review

We evaluated a 48-year-old woman who had visual hallucinations (VHs) as a major presenting sign of posterior reversible encephalopathy syndrome (PRES). Despite her mild loss of vision, she described various hallucinations after awakening from a comatose state days after a motorcycle collision. VHs are usually accompanied by more severe loss of vision, yet our case and literature review indicate that sudden onset of formed VHs should suggest a possible diagnosis of PRES in patients who have large fluctuations in blood pressure, renal failure, or autoimmune dysfunction, as well as in patients taking cytotoxic agents.

Severe bilateral visual loss as the first sign of IgA nephropathy

We describe a case of a 33-years-old woman who presents with severe acute bilateral visual loss secondary to massive exudative hypertensive maculopathy as the first sign of immunoglobulin A nephropathy. The patient's ophthalmic examination showed bilateral cotton-wool spots, flame-shaped retinal hemorrhages, diffuse narrow arterioles, optic disk edema, and exudative maculopathy. Systemic workup demonstrated a systolic and diastolic blood pressure of 240 mmHg and 160 mmHg, respectively, proteinuria, and hematuria, suggesting kidney disease as the causative condition. A kidney biopsy confirmed immunoglobulin A nephropathy. She was treated with systemic corticosteroids, antihypertensive drugs, and a single bilateral intravitreal injection of aflibercept. There was a prompt resolution of macular edema and vision improvement. Our case draws attention to the fact that severe bilateral visual loss can be the first sign of severe hypertension. Secondary causes, such as immunoglobulin A nephropathy, should be ruled out.

Comparison of Visual Evoked Potentials in Patients Affected by Optic Neuritis From Multiple Sclerosis or Neuromyelitis Optica Spectrum Disorder

PURPOSE

To compare the visual evoked potentials (VEPs) of optic neuritis (ON) patients with multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD), and controls. To evaluate correlations between VEP and optical coherence tomography (OCT), contrast sensitivity (CS), and automated perimetry.

METHODS

Fifty-five eyes with ON from 29 patients (MS = 14 and NMOSD = 15) and 57 eyes from 29 controls were evaluated using VEP, automated perimetry, CS, and optical coherence tomography. Three groups were analyzed: 1) MS eyes with history of ON (ON-MS), 2) NMOSD eyes with ON (ON-NMOSD), and 3) healthy controls. Groups were compared and associations between the parameters were tested.

RESULTS

Compared to controls, ON-MS eyes showed significantly delayed N75 and P100 latencies when using a medium-sized stimulus (30'), and delayed P100 latency when using a large stimulus (1.5°), but similar amplitudes. Compared to controls, ON-NMOSD eyes showed significantly lower N75/P100 amplitudes (both stimulus sizes) and P100/N135 amplitudes (with the 30' stimulus), but latencies did not differ, except for a delayed P100 latency with the 30' stimulus. When comparing the 2 ON groups using the 1.5° stimulus, there was significant delay in P100 latency in ON-MS eyes and a reduction in N75/P100 amplitude in ON-NMOSD eyes. Peripapillary retinal nerve fiber layer, macular inner retinal layers, and CS measurements were significantly smaller in ON patients than in controls. A strong correlation was found between VEP parameters and inner retinal layer thickness in ON-NMOSD eyes.

CONCLUSIONS

ON-MS eyes had normal amplitude and delayed VEP latency, whereas ON-NMOSD eyes displayed reduced amplitude and preserved latency when elicited by checkerboard stimulus with large 1.5° checks. Under such conditions, VEP may help distinguish resolved MS-related ON from resolved NMOSD-related ON.

Serous retinal detachment as an Early manifestation of lúpus choroidopathy

Serous retinal detachment can be caused by a wide range of conditions, including systemic lupus erythematosus. Although this association has been well-described in patients with an established diagnosis of systemic lupus erythematosus, in rare cases, this detachment is the initial manifestation. We have described here an unusually challenging case in which serous retinal detachment required a comprehensive investigation considering that it was an early sign of systemic lupus erythematosus.

Contractile peripapillary staphyloma: OCTA documentation of increased peripapillary vessel density during transient visual loss episodes

Purpose

to describe a patient with a contractile peripapillary staphyloma and transient visual loss (TVL) that underwent repeated OCTA examination documenting disc contraction and increased peripapillary vessel density as the mechanism of TVL.

Observations

a 28-year-old male presented multiple daily episodes of TVL for the last 5 years. Fundoscopic examination revealed a peripapillary staphyloma. The fundus photographs and SS-OCT demonstrated flattening of the posterior polo and crowding of the contracted optic disk, which became hyperemic with tortuous and dilated veins during visual loss episodes. OCTA showed temporary increased peripapillary vessel density, presumably from severe venous congestion leading to TVL during the contraction.

Conclusion and Importance

increased peripapillary vessel density can be demonstrated by OCTA during TVL in contractile peripapillary staphyloma. These findings indicate that severe venous stasis during disc contraction is the cause of TVL.

Morning glory disc anomaly associated with large facial infantile hemangioma as the presenting signs of PHACE syndrome

Infantile hemangioma, the most common benign tumor in infancy, is usually an isolated condition occurring in many different locations in the body. However, large infantile hemangioma may be associated with other systemic malformations, including central nervous system, cerebrovascular, cardiac, and ophthalmology abnormalities, a condition termed PHACE syndrome. In this paper, we describe a case of PHACE syndrome that was presented with the unique association of a large facial infantile hemangioma and morning glory anomaly.

Homonymous quadrantic macular ganglion cell complex loss as a sign of trans-synaptic degeneration from occipital lobe lesion

Purpose

to describe a patient with visual field (VF) defect from an occipital lobe lesion that was found to have macular ganglion cells complex (GCC) quadrantic reduction without significant peripapillary retinal nerve fiber layer (RNFL) loss on optical coherence tomography (OCT). To emphasize that macular GCC loss may be the major ocular manifestation of trans-synaptic optic pathway degeneration in occipital lobe lesions.

Observations

A 15-year-old female was investigated after a VF examination revealed a right homonymous inferior quadrantanopia. Fundoscopic examination was completely normal as were the peripapillary retinal nerve fiber layer (RNFL) thickness measurements on OCT. Macular thickness measurements however, revealed superior homonymous quadrantic GCL reduction evidencing retinal neuronal loss in direct correspondence with her VF defect. Magnetic resonance imaging showed a localized left occipital lobe gliotic lesion as the explanation for her VF defect.

Conclusions and Importance

Small post-geniculate optic pathway lesions may lead to retrograde trans-synaptic degeneration that can be detected on OCT-measured macular GCL measurements despite normal peripapillary RNFL estimates. Awareness of such occurrence in important to avoid diagnostic confusion with other anterior visual pathway diseases.

Acute visual loss and optic disc edema followed by optic atrophy in two cases with deeply buried optic disc drusen: a mimicker of atypical optic neuritis

Background

Sudden visual loss and optic disc edema caused by optic neuritis (ON) is usually followed by significant visual recovery. However, little or no recovery occurs when the loss is caused by atypical ON, especially in patients with neuromyelitis optica (NMO). Optic disc drusen (ODD) is a cause of pseudo optic disc edema and may be a predisposing factor for non-arteritic anterior ischemic optic neuropathy (NAION), thereby mimicking atypical ON. In such cases, if globular concretions are seen protruding from the disc substance, ODD may be suspected. The purpose of this paper is to describe two patients with acute visual loss followed by optic disc atrophy initially labeled as atypical ON. Though not suspected on clinical examination, optical coherence tomography (OCT) revealed deeply buried ODD as a predisposing factor for NAION.

Case presentations

Case 1: A 48-year-old woman had bilateral sequential visual loss associated with optic disc edema. Despite treatment, vision did not improve and severe disc pallor ensued. Atypical ON was suspected. Eventually, she was started on immunosuppressant therapy based on a tentative diagnosis of NMO-spectrum disorder. On examination 5 years later, only severe optic disc pallor was observed, but OCT radial B-scans showed ovoid hyporeflective areas in the retrolaminar region of both eyes, compatible with ODD; this led to a diagnosis of NAION and deeply buried ODD. Case 2. A 35-year-old woman with suspicion of ON in the left eye and a history of previous atypical ON in the right eye was referred for neuro-ophthalmic examination which revealed diffuse optic disc pallor and a dense arcuate visual field defect in the right eye. OCT B-scans passing through the disc showed large ovoid areas of reduced reflectivity in the retrolaminar region of the optic disc in the right eye. These findings helped confirm the diagnosis of NAION in one eye, with deeply buried ODD as predisposing factor.

Conclusions

Deeply buried ODD may be associated with NAION causing irreversible visual loss and optic disc pallor, a condition easily mistaken for atypical ON. Awareness of such occurrence is important to avoid unnecessary testing and minimize the risk of mismanagement.

Mannose Binding Lectin and Pentraxin 3 in Patients with Diabetic Retinopathy

BACKGROUND

Mannose binding lectin (MBL) is a protein of the complement system and pentraxin-3 (PTX3) is an acute phase protein both with an important role in inflammatory diseases, such as diabetic retinopathy (DR).

AIM OF THE STUDY

To evaluate whether plasma MBL and PTX3 levels are associated with the development of DR and if patients with and without DR can be distinguished.

METHODS

The patients were divided into three groups: diabetic without DR; with mild/moderate DR, and with severe/proliferative DR. PTX3 and MBL levels were measured with enzyme-linked immunosorbent assay kits.

RESULTS

A total of 74 patients were included. A significant association was observed between high levels of MBL and severe DR; 47% of patients with severe/proliferative DR had high levels of MBL, whereas 12% of the patients with diabetes but no DR had high levels of MBL (p = 0.008; odds ratio [OR]: 6.06; 95% confidence interval [CI]: 1.4-25.0). High levels of MBL were more frequent in patients with severe/proliferative disease (47%) when compared to those with mild/moderate DR (20%), p = 0.04 (OR: 3.46; 95% CI: 1.0-11.8). PTX3 levels were similar among the groups and were not related to the development or severity of DR.

CONCLUSION

We found a significant association between high plasma MBL levels and DR development as well as with severe/proliferative DR. We observed no relationship between plasma PTX3 levels and the development or severity of DR.

Acute up-beating nystagmus in a pregnant woman with hyperemesis gravidarum

Purpose

To describe a case of sudden onset of nystagmus in a pregnant patient with hyperemesis gravidarum.

Observations

Sixteen days after onset of persistent nausea and uncontrollable vomiting, a 12 week pregnant woman presented up-beating nystagmus, mild memory impairment and reduced sensitivity in the lower limbs. Laboratory tests presented thiamine deficiency and magnetic resonance imaging showed bilateral medial thalami and midbrain lesions. Because of suspected Wernicke's encephalopathy, the patient was treated with thiamine replacement and significant improvement of symptoms took place.

Conclusions and importance

Uncontrollable vomiting can lead to malabsorption of vitamin B1 causing acute onset of nystagmus.

Evaluation of inner retinal layers in eyes with temporal hemianopic visual loss from chiasmal compression using optical coherence tomography

PURPOSE

We measured macular inner retinal layer thicknesses using frequency-domain optical coherence tomography (fd-OCT) and correlated these measures with visual field (VF) in eyes with temporal hemianopia from chiasmal compression and band atrophy (BA) of the optic nerve.

METHODS

Macular fd-OCT scans and VFs were obtained from 33 eyes of 33 patients with temporal hemianopia and 36 control eyes. The macular retinal nerve fiber layer (mRNFL), combined retinal ganglion cell and inner plexiform layers (RGCL+), and the inner nuclear layer (INL) were segmented. Measurements were averaged for each macula quadrant. Scans were assessed qualitatively for microcysts in the INL. The VF was estimated from the central 16 test points. The two groups were compared. Correlations between VF and OCT measurements were assessed.

RESULTS

The mRNFL, RGCL+, and total retinal (TR) macular thickness measurements were significantly smaller in BA eyes than controls. In the nasal quadrants, INL measurements were significantly greater in BA eyes than controls. The mRNFL and RGCL+ measurements had greater discrimination ability than TR measurements in the temporal quadrants. A significant correlation was found between most OCT parameters and their corresponding VF parameters. The strongest association was observed between RNFL and RGCL+ thickness, and VF loss in the corresponding area. The INL microcysts were found in seven eyes with BA, but not in controls.

CONCLUSIONS

Band atrophy leads to mRNFL and RGCL+ thinning, and INL thickening, and mRNFL and RGCL+ measurements are correlated strongly with VF loss. Segmented macular thickness measurements may be useful for quantifying neuronal loss in chiasmal compression.

Pattern electroretinogram in neuromyelitis optica and multiple sclerosis with or without optic neuritis and its correlation with FD-OCT and perimetry

PURPOSE

To evaluate the ability of transient pattern electroretinogram (PERG) parameters to differentiate between eyes of patients with neuromyelitis optica (NMO), longitudinally extensive transverse myelitis (LETM), multiple sclerosis with optic neuritis (MS + ON), multiple sclerosis without optic neuritis (MS - ON), and controls, to compare PERG and OCT with regard to discrimination ability, and to assess the correlation between PERG, FD-OCT, and visual field measurements (VFs).

METHODS

Visual field measurements and full-field stimulation PERGs based on both 48- and 14-min checks were obtained from patients with MS (n = 28), NMO (n = 20), LETM (n = 18), and controls (n = 26). In addition, FD-OCT peripapillary retinal nerve fiber layer (RNFL) and segmented macular layer measurements were obtained and their correlation coefficients were determined.

RESULTS

Compared to controls, PERG amplitude measurements were significantly reduced in eyes with NMO and MS + ON, but not in eyes with LETM and MS - ON. PERG amplitudes were significantly smaller in NMO and MS + ON eyes than in MS - ON eyes. PERG and OCT performance was similar except in NMO eyes where macular thickness parameters were more efficient at detecting abnormalities. A significant correlation was found between N95 amplitude values and OCT-measured macular ganglion cell layer thickness, total retinal thickness, and temporal peripapillary RNFL thickness. PERG amplitude was also significantly associated with VF sensitivity loss. No statistically significant difference was observed with regard to the best-performing parameters of the two methods.

CONCLUSIONS

Pattern electroretinogram measurements were able to detect RNFL loss in MS + ON and NMO eyes, with a performance comparable to OCT. PERG amplitude measurements were reasonably well correlated with OCT-measured parameters.

[Perfluoro-n-octane in orbital cavity after posterior vitrectomy and suture of eye perforating injury: case report]

A case of a perfluoro-n-octane leakage into the orbital cavity after corneoscleral suture, scleral buckling and pars plana vitrectomy in an eye with perforating injury after trauma is reported for the first time. A previously healthy 39-year-old man was sent for ophthalmic evaluation one day after suffering a penetrating ocular trauma in his right eye while hammering a nail. On the initial evaluation, the patient presented sudden reduction of visual acuity on his right eye with a perforating corneoscleral injury, intraocular foreign body and retinal detachment. The patient was submitted to corneoscleral suture, pars plana vitrectomy with perfluoro-n-octane administration to flatten the retina and scleral buckling, when it was found transfixation of the globe by the intraocular foreign body. Postoperatively, computed tomography scans of the orbit were ordered due to proptosis, which showed the presence of hyperdense images, suggesting leakage of perfluoro-n-octane into the orbital cavity. Thus, in cases of perforating eye injury, one should be suspicious about the possibility of intraocular foreign body, as well as possible occurrence of transfixation of the globe when scheduling the surgery.

Pattern-reversal electroretinograms for the diagnosis and management of disorders of the anterior visual pathway

The pattern electroretinogram is an electrophysiological test that assesses the function of inner retinal layers, particularly the ganglion cells layer of retina, using a reversing checkerboard or grating pattern that produces no change in average luminance over time. The normal pattern electroretinogram is composed of a proeminent positive component (P50) and a large later negative component (N95). Since structural damage that compromises the retinal ganglion cell layer can lead to pattern electroretinogram changes, particularly in the N95 amplitude, the test can be useful in the treatment of a number of anterior visual pathway diseases. In this article, we review the methods for recording pattern electroretinogram and its usefulness in the diagnosis and management of diseases including inflammatory, hereditary, ischemic and compressive lesions of the anterior visual pathway.

Multifocal pattern electroretinography for the detection of neural loss in eyes with permanent temporal hemianopia or quadrantanopia from chiasmal compression

AIMS

To evaluate the ability of multifocal transient pattern electroretinography (mfPERG) to detect neural loss and assess the relationship between mfPERG and visual-field (VF) loss in eyes with chiasmal compression.

METHODS

23 eyes from 23 patients with temporal VF defects and band atrophy of the optic nerve and 21 controls underwent standard automated perimetry and mfPERG using a stimulus pattern of 19 rectangles, each consisting of 12 squares. The response was determined for the central rectangle, for the nasal and temporal hemifields (eight rectangles each) and for each quadrant (three rectangles) in both patients and controls. Comparisons were made using variance analysis. Correlations between VF and mfPERG measurements were verified by linear regression analysis.

RESULTS

Mean ± SD mfPERG amplitudes from the temporal hemifield (0.50 ± 0.17 and 0.62 ± 0.32) and temporal quadrants (superior 0.42 ± 0.21 and 0.52 ± 0.35, inferior 0.51 ± 0.23 and 0.74 ± 0.40) were significantly lower in eyes with band atrophy than in controls (0.78 ± 0.24, 0.89 ± 0.28, 0.73 ± 0.26, 0.96 ± 0.36, 0.79 ± 0.26 and 0.91 ± 0.31, respectively). No significant difference was observed in nasal hemifield measurements. Significant correlations (0.36-0.73) were found between VF relative sensitivity and mfPERG amplitude in different VF sectors.

CONCLUSIONS

mfPERG amplitude measurements clearly differentiate eyes with temporal VF defect from controls. The good correlation between mfPERG amplitudes and the severity of VF defect suggests that mfPERG may be used as an indicator of ganglion cell dysfunction.

[Treatment of radiation retinopathy with intravitreal injection of bevacizumab (Avastin®): case report]

PURPOSE

To report a case of radiation retinopathy treatment with intravitreal injection of bevacizumab (Avastin®) in a patient undergoing radiotherapy for lymphoma in the right orbit. Patient of 55 years-old male, diabetic, diagnosed with an orbital MALT lymphoma three years ago, treated with local radiotherapy (dose: 35Gy) two years ago, complaining of reduced visual acuity of the right eye for about four months. During the ophthalmologic evaluation, he had an exam suggestive of radiation retinopathy. Macular thickness at the optical coherence tomography was 480 µm. Patient was referred to intravitreal injection (0.05 ml) of bevacizumab (Avastin®) in the right eye, showing reduction of macular edema and mild improvement of visual acuity. In this case, the treatment of radiation retinopathy with intravitreal injection of bevacizumab (Avastin®) was relatively useful, with mild improvement of visual acuity due to the regression of macular edema.

[Contrast sensitivity in diabetic retinopathy treated with argon laser panphotocoagulation]

PURPOSE

To evaluate contrast sensitivity in patients with diabetic retinopathy (DR) treated with argon laser panphotocoagulation.

METHODS

Prospective study of patients with diabetic retinopathy and 20/20 visual acuity, treated with retinal panphotocoagulation, following ETDRS criteria. The patients were submitted, initially, to complete ophthalmologic evaluation and contrast sensitivity testing (Vision Contrast Test System). After 3 months of treatment, they were reevaluated by means of visual acuity and contrast sensitivity.

RESULTS

The sample comprised 28 patients (28 eyes), all with type II diabetes. A ranged from 45 to 77 years (mean 57.8+/-8.0), 19 (67.9%) patients were male and 9 (32.1%) female. Regarding the type of retinopathy, 18 (64.3%) had proliferative DR and 10 (35.7%) very severe non proliferative RD. No visual acuity alteration was observed after treatment. In relation to contrast sensitivity, there were no alterations between pre and post-treatment in all evaluated spacial frequencies 1.5 (p=0.191); 3.0 (p=0.850); 6.0 (p=0.374); 12.0 (p=0.674) e 18.0 (p=0.443).

CONCLUSION

There was no significant alteration in the contrast sensitivity of patients with diabetic retinopathy after panphotocoagulation with argon laser in the studied period.

An ameloblastoma-like neoplasm of the buccal mucosa. Report of a case

A case of an unusual neoplasm of the buccal mucosa nearly identical to an ameloblastoma is reported. The tumor probably arose from the overlying squamous epithelium in the vicinity of the parotid duct.

Scanning- and transmission electron-microscopic study of lymphatic vessels in the splenic white pulp of the macaque monkey

The fine structure of the lymphatic vessels in splenic white pulp of the macaque monkey was studied by scanning and transmission electron microscopy. Lymphatic vessels were slit-like or widened channels which extended along central arteries and their large branches. The walls of the vessels were very thin in comparison with those of nearby arteries. They were composed only of a layer of endothelium supported by underlying reticular cells. Endothelial cells were mostly ribbon-like and extended along the long axis of the vessels. Perikarya of the endothelial cells were slightly protruded into the lumen. The thin peripheral cytoplasm showed smooth surfaces, except for some tiny processes, especially at boundaries between adjacent cells. The basal surface of the endothelial cells was attached to the lattice of reticular cell processes forming the framework of the white pulp. Basal laminae in strands were intercalated between endothelial cells and reticular cells. Perforations were often seen through the endothelial cell cytoplasm. Lymphocytes or processes of macrophages seen in the perforations were considered to be in migration. Large patent openings through the endothelium were not observed. The wall structure of the lymphatic vessels in the splenic white pulp suggests that lymphocytes in the white pulp may move directly into the lymph flow, in addition to moving into the blood flow via the vascular sinuses.