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Competing Interests: The authors report no conflicts of interest.

Wölfflin nodules and Brushfield spots were described essentially in light colored irides. The purpose of our study is to determine if these iris features are also present in dark irides, hidden by melanin granules of the anterior leaf of the iris. We examined iris images, taken with standard visible white, as well as with near-infrared light of children with Down syndrome and without. Using white light, Brushfield spots were seen in 21% of children with Down syndrome, and Wölfflin nodules in 12% of controls (p < 0.001), all noted in those with lightly colored irides. Brushfield spots were detected in 67% of children with Down syndrome using near-infrared light compared to 21% using white light (p < 0.001). Wölfflin nodules were detected in 19% of controls using near-infrared light compared to 12% using white light. Peripheral iris thinning was present in 63% of children with Down syndrome but in only 23% of those without (p = 0.001). Contraction furrows were less frequent in children with Down syndrome (16%) compared to controls (74%)(p < 0.001). Near-infrared light unveils Brushfield spots and Wölfflin nodules in dark irides. Clearing this discrepancy should assist in the elucidation of their pathophysiologic origin. A high prevalence of peripheral iris thinning is also present in children with Down syndrome along with a heretofore unreported reduction in iris contraction furrows.

Background: Variable pupillary responses have been described with carotid-cavernous sinus fistulas. These often are associated with a decrease in visual acuity and attributed to retinal ischemia. We propose a novel pathophysiologic mechanism for changes in pupillary reactivity involving anatomic changes secondary to choroidal effusion., Methods: To demonstrate proof-of-concept, we investigated 2 consecutive patients with carotid-cavernous sinus fistulas and pupillary disturbances using repeated refractions and anterior segment ultrasound biomicroscopy., Results: Ultrasound biomicroscopy demonstrated choroidal thickening and ciliary body effusion with forward rotation of the lens-iris diaphragm altering refraction and mechanically limiting iris movements., Conclusions: Where there are acute elevations in orbital venous pressure causing ciliary body effusion, changes in visual acuity and pupillary abnormalities can be produced by mechanical effects.

Purpose: To provide an in-depth re-examination of assumed causes of tissue hypertrophy, port-wine stains, and the Sturge-Weber, Cobb, Klippel-Trénaunay, and related syndromes to support an alternative unifying pathophysiologic mechanism of venous dysplasia producing focal venous hypertension with attendant tissue responses; to provide proof of concept with new patient data; to propose a novel etiological hypothesis for the venous dysplasia in these syndromes and find supportive evidence., Methods: Data from 20 patients with port-wine stains and corneal pachymetry readings was collected prospectively by the author in an institutional referral-based practice. The literature was searched using MEDLINE, and articles and textbooks were obtained from the bibliographies of these publications., Results: Newly obtained dermatologic, corneal pachymetry, fundus ophthalmoscopic, ocular and orbital venous Doppler ultrasonography, and magnetic resonance imaging findings in patients with the Sturge-Weber syndrome or isolated port-wine stains, along with published data, reveal diffusely thickened tissues and neural atrophy in all areas associated with venous congestion., Conclusions: Contrary to traditional understanding, signs and symptoms in the Sturge-Weber and related syndromes, including both congenital and acquired port-wine stains, are shown to arise from effects of localized primary venous dysplasia or acquired venous obstruction rather than neural dysfunction, differentiating these syndromes from actual phacomatoses. Effects of focal venous hypertension are transmitted to nearby areas via compensatory collateral venous channels in the above conditions, as in the Parkes Weber syndrome. A novel underlying etiology-prenatal venous thrombo-occlusion-is proposed to be responsible for the absence of veins with persistence and enlargement of collateral circulatory pathways with data in the literature backing this offshoot hypothesis. The mechanism for isolated pathologic tissue hypertrophy in these syndromes clarifies physiologic mechanisms for exercise-induced muscle hypertrophy to occur via venous compression and increased capillary transudation.

Nanophthalmos is a rare disorder of eye development characterized by extreme hyperopia (farsightedness), with refractive error in the range of +8.00 to +25.00 diopters. Because the cornea and lens are normal in size and shape, hyperopia occurs because insufficient growth along the visual axis places these lensing components too close to the retina. Nanophthalmic eyes show considerable thickening of both the choroidal vascular bed and scleral coat, which provide nutritive and structural support for the retina. Thickening of these tissues is a general feature of axial hyperopia, whereas the opposite occurs in myopia. We have mapped recessive nanophthalmos to a unique locus at 11q23.3 and identified four independent mutations in MFRP, a gene that is selectively expressed in the eye and encodes a protein with homology to Tolloid proteases and the Wnt-binding domain of the Frizzled transmembrane receptors. This gene is not critical for retinal function, as patients entirely lacking MFRP can still have good refraction-corrected vision, produce clinically normal electro-retinograms, and show only modest anomalies in the dark adaptation of photoreceptors. MFRP appears primarily devoted to regulating axial length of the eye. It remains to be determined whether natural variation in its activity plays a role in common refractive errors.

The necessary settings and parameters were determined for ordinary camera and lens systems to faithfully reproduce out-of-focus and distorted imagery as it falls upon the retina of the human eye. Theoretic considerations of both geometric and physical optics were used to calculate the "relative blur" and distortion produced by refractive error added to ordinary camera lenses as opposed to refractive error in an arbitrary thick-lens optical system bounded by air and fluid (i.e. the eye). In both the camera and the eye, "relative blur" was determined to be directly proportional to dioptric defocus and to aperture size, and effectively independent of the focal length. Distortion of imagery was also found to be independent of the focal length. Photographs corroborate the theoretic findings. A given amount of relative blur, however, appeared somewhat greater when recorded on photographic film than when appreciated by the human eye. The Stiles-Crawford effect, the chromatic aberration of the eye, and neural processing probably each contribute to this difference. Previous investigators have grossly exaggerated blur and distortion in photographs intended to simulate ocular imagery and have drawn misleading conclusions from their results.

Purpose: To report the fluorescein angiographic and Doppler ultrasonographic findings in a patient with apparent exclusive ciliary vascular supply of the retina of both eyes., Methods: Case report., Results: The ophthalmoscopic appearance of all arterial vessels emanating from both discs was consistent with a cilioretinal origin. Retinal veins also entered each disc peripherally near the margin, leaving the central part of each disc vacant. Fluorescein angiography showed filling of all arterial vessels simultaneous with the early-phase choroidal background flush bilaterally. Color and power Doppler ultrasonographic imaging demonstrated unequivocally the absence of central retinal vessels within the optic nerves. Both discs were normal in size and excavated with central glial tissue present. The clinical history of monocular, alternating episodes of failing vision with partial resolution and the retinal pigmentation patterns bilaterally were consistent with, though not conclusive for, previous episodes of serous retinal detachments. Coincident systemic anomalies consisted of small kidneys with reduced renal parenchyma discovered on ultrasonography, along with chronic interstitial nephritis., Conclusions: The ophthalmoscopic appearance of optic discs with apparent all-cilioretinal vascular supply has been reported previously, but proof of the absence of central retinal vessels requires Doppler ultrasonographic evidence corroborated by angiographic findings, as exemplified in our case report. We describe the association of this disc anomaly with renal parenchymal disease and its distinction from colobomatous defects.