Dependence of corneal hysteresis on non-central corneal thickness in healthy subjects.

OBJECTIVE: To evaluate the dependence of corneal hysteresis (CH) on non-central corneal thickness. METHODS: Cross-sectional study of 1561 eyes of 1561 healthy volunteers with IOP less than 21mmHg, open angles on gonioscopy and no prior eye surgeries or local or systemic diseases. Pentacam-Scheimpflug technology was employed to segment the cornea into 6 circular zones centered on the apex (zones 1-6) and to determine the mean corneal thickness of these areas. CH was measured with ORA. Univariate and multivariate linear regression models adjusted for age and sex were created to model the dependence of CH on corneal thickness in zones 1 to 6. RESULTS: In the univariate linear regression models, we found that CH was dependent on mean corneal thickness of zone 1 (B=0,004; R2=0.95%; P<0.001), zone 2 (B=0,004; R2=0.57%; P=0.002), zone 4 (B=0,005; R2=1.50%; P<0.001) and zone 6 (B=0,003; R2=0.92%; P<0.001). Similar results were obtained in the multivariate model (R2=3.46%; P<0.001). CONCLUSION: This study suggests a significant dependence of CH on non-central corneal thickness. The model of corneal thickness segmentation into circular zones centered on the corneal apex is able to explain 3.47% of the variation in CH measurements.

Intercritical photophobia in the migrainous patient. Proposal for diagnostic criteria.

INTRODUCTION: Photophobia is a symptom of abnormal light intolerance without pain sensation that requires an anamnesis and an examination to diagnose an underlying etiology. BASIC PROCEDURE: This article focuses on 30 clinical cases with isolated intense photophobia and on the review of the literature. OBJECTIVE: The purpose of this article is to establish diagnostic criteria for photophobia. RESULTS: The etiology of photophobia appears to be at the level of the intrinsically photosensitive retinal ganglion cells known as melanopsin cells and at a neurochemical level mediated by calcitonin-related peptide and the pituitary activating peptide cyclase. CONCLUSION: The treatment of photophobia could consist of monoclonal antibodies against calcitonin-related peptide and/or pituitary activating peptide cyclase.

Optic neuropathy by ethambutol in a patient with multiple sclerosis.

We present the clinical case of a patient who developed a toxic optic neuropathy due to ethambutol in the context of a tuberculosis reactivation and who also had a personal history of multiple sclerosis. The objective is to highlight the importance of making a good differential diagnosis of this adverse effect and of knowing its main clinical, campimetric and tomographic manifestations and characteristics. Furthermore, since the reversibility of damage is still discussed in the literature, early diagnosis is essential. For this purpose, it is important to inform the patient of the possible symptoms and to carry out an ophthalmological examination and colour tests before starting treatment to assess whether there is progression.

Bilateral solar maculopathy in a patient with bipolar disorder.

A case of solar maculopathy is described in a 36-year-old man with a history of bipolar disorder. The patient reported directly looking at the sun for several hours in the setting of a bipolar disorder decompensation. The visual acuity was 0.3 in both eyes (BE). Intraocular pressure and anterior segment were normal. In the fundus exam, a peri-macular halo with loss of the foveolar reflex was observed in BE. The macular optical coherence tomography revealed a disruption of the ellipsoid line and the retinal pigment epithelium. Bilateral central defects were seen in the Humphrey 24-2 visual field. After 6 months of follow-up, the visual clinical picture remains stable with the same degree of visual acuity. Solar maculopathy is a disorder due to the phototoxic effects of radiation, which cause a decrease in visual acuity by disrupting the retinal photoreceptor layer.

Congenital retinal macrovessels: Case presentation.

We present an uncommon case of a unilateral congenital retinal macrovessel documented with retinography, perimetry, fluorescein angiography and macular optical coherence tomography. In the case presented the macrovessel crossed the horizontal meridian, between macula and optic disk. A literature review has been performed on congenital retinal macrovessels, possible structural and visual alterations they may cause and their association with other pathologies.

Intercritical photophobia in the migraineous patient. Proposal for diagnostic criteria. / Fotofobia intercrítica en el paciente migrañoso. Propuesta de criterios diagnósticos.

INTRODUCTION: Photophobia is a symptom of abnormal light intolerance without pain sensation that requires an anamnesis and an examination to diagnose an underlying etiology. BASIC PROCEDURE: This article focuses on 30 clinical cases with isolated intense photophobia and on the review of the literature. OBJECTIVE: The purpose of this article is to establish diagnostic criteria for photophobia. RESULTS: The etiology of photophobia appears to be at the level of the intrinsically photosensitive retinal ganglion cells known as melanopsin cells and at a neurochemical level mediated by calcitonin-related peptide and the pituitary activating peptide cyclase. CONCLUSION: The treatment of photophobia could consist of monoclonal antibodies against calcitonin-related peptide and/or pituitary activating peptide cyclase.

Optic neuropathy by ethambutol in a patient with multiple sclerosis. / Neuropatía óptica por etambutol en paciente con esclerosis múltiple.

We present the clinical case of a patient who developed a toxic optic neuropathy due to ethambutol in the context of a tuberculosis reactivation and who also had a personal history of multiple sclerosis. The objective is to highlight the importance of making a good differential diagnosis of this adverse effect and of knowing its main clinical, campimetric and tomographic manifestations and characteristics. Furthermore, since the reversibility of damage is still discussed in the literature, early diagnosis is essential. For this purpose, it is important to inform the patient of the possible symptoms and to carry out an ophthalmological examination and colour tests before starting treatment to assess whether there is progression.