The response of retrobulbar vasculature to hypercapnia in primary open-angle glaucoma and ocular hypertension.

PURPOSE: To evaluate the physiological effects of hypercapnia on the retrobulbar vasculature in ocular hypertension (OH) and open-angle glaucoma (OAG). METHODS: Peak systolic velocity (PSV), end-diastolic velocity (EDV) and resistive index (RI) of the ophthalmic (OA) and central retinal arteries (CRA) were evaluated in 12 eyes with OH and 8 eyes with OAG using color Doppler imaging. Measurements were taken before and during hypercapnia. RESULTS: Patients with OAG were found to have increased EDV (p < 0.035) of the CRA, and decreased PSV (p < 0.097) and EDV (p < 0.098) of the OA, during hypercapnia. Patients with OH had increased PSV (p < 0.062) and EDV (p < 0.072) of the CRA during hypercapnia. Patients with OH also demonstrated a greater percent change in the calculated RI (p < 0.065) of the CRA in response to hypercapnia when compared to OAG. The mean RI of the CRA decreased during hypercapnia. DISCUSSION: Patients with OH were found to have a normal vasodilatory response within the retrobulbar vasculature during hypercapnia resulting in increased volumetric blood flow to the retina while patients with OAG did not, suggesting there is vasospasm at or downstream from the CRA resulting in decreased volumetric blood flow to the retina.

Idiopathic multiple serous detachments of the retinal pigment epithelium: a report of two cases.

A relatively uncommon entity is described which is characterized by idiopathic serous detachments of the retinal pigment epithelium (RPE). In contrast to RPE detachments associated with the spectrum of age-related macular degeneration and other choroidal diseases, the visual prognosis in this entity is usually good. In some respects, idiopathic serous RPE detachments display characteristics similar to idiopathic central serous chorioretinopathy and could be a variant thereof. The differential diagnosis also includes multifocal Best's vitelliform dystrophy.

Iris microhemangiomas.

Iris microhemangiomas (IM) are benign proliferations of small, twisted blood vessels along the pupillary margin. They are usually bilateral and appear to be developmental in nature. IMs most commonly occur in patients with myotonic dystrophy and adult-onset diabetes mellitus, but have also been associated with respiratory disease, congential heart disease, and central retinal vein occlusion. Additionally, they may be found in individuals without obvious ocular or systemic abnormality. The etiology remains obscure. In this report, illustrative cases are followed by a brief discussion outlining typical clinical manifestations, etiological considerations, and possible implications.

A quality assessment of aphakic correction.

An assessment of the quality of care being provided to meet the needs of postcataract aphakes for refractive correction is presented. The procedure used was a review of patient records originally developed for inpatient care but was here applied to outpatient care in a centralized health facility. This paper demonstrates the feasibility and value of this method of quality assessment.

Isolated bilateral abducens palsy.

This case illustrates the sudden onset and gradual regression of abducens palsy following an isolated brainstem infarct secondary to moderate to marked hypertension. This case also demonstrates that patients presenting with sudden diplopia need to be referred to internal medicine and/or neurology for further documentation of the etiology of this condition.

The BP/IOP ratio in the elderly and its relation to glaucomatous changes.

A group of 32 patients had their blood pressure measured, fields plotted, intraocular pressure determined, and ocular fundi inspected. The ratio of the blood pressures (systolic and diastolic) to the intraocular pressure is shown to be of limited use as a predictor of glaucomatous damage in the eye.

The endpoint of laser speckle pattern meridional refraction.

Motion of the speckle pattern observed by an ametrope viewing laser light reflected from a rotating cylinder with a matte surface is discussed. Mathematical expressions are derived for the apparent speed and direction (angular velocity) of the pattern when spherical neutralizing lenses are put in place and conditions for an endpoint appropriate for meridional refraction are discussed.