Biometric studies of the eyeball and retinal detachment.

Meyer-Schwickerath, G; Gerke, E

doi:10.1136/bjo.68.1.29

Cited by 31 publications

(8 citation statements)

References 2 publications

(1 reference statement)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…F rom the late 1940s, ocular size and shape have been described or inferred by a variety of techniques such as entopic phenomena, 1 x-ray tomography, 2 A-and B-scan ultrasound, 3,4 optical coherence reflectometry, 5 and peripheral refraction. 6 -8 Magnetic resonance imaging (MRI) has been used (Miller JM, et al IOVS 2004;45:ARVO E-Abstract 2388), 9 -11 to provide pictorial representations of sections through the living eye at multiple positions, from which a detailed investigation of ocular dimensions can be made.…”

mentioning

confidence: 99%

“…Different interpretations of what is meant by ocular shape has led to confusion in this area. Some studies inferred eye shape from the overall size of the eye-that is, including anterior and posterior segments (Miller JM, et al IOVS 2004;45:ARVO E-Abstract 2388), [1][2][3][4]11 or from the overall appearance of eyes. 9,14 Other indirect estimates of eye shape have been based on peripheral refraction results.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Shape of the Retinal Surface in Emmetropia and Myopia

Atchison

Pritchard

Schmid

et al. 2005

Invest. Ophthalmol. Vis. Sci.

221

203

View full text Add to dashboard Cite

show abstract

mentioning

confidence: 99%

mentioning

confidence: 99%

Shape of the Retinal Surface in Emmetropia and Myopia

Atchison

Pritchard

Schmid

et al. 2005

Invest. Ophthalmol. Vis. Sci.

221

203

View full text Add to dashboard Cite

show abstract

“…Furthermore, Pickett-Seltner et al 15 measured the chemical composition of the vitreous humor of chicken myopes, finding it to be similar to those with normal eyes. Finally, Meyer-Schwickerath and Gerke 16 found that eyes with RD, whether myopic or emmetropic, are of different dimensions from normal eyes, another indication that mechanics plays a role.…”

Section: Discussionmentioning

confidence: 99%

“…Figures 3 and 4 are obtained using the rheological properties of the vitreous humor proposed by Swindle et al 4 Note that the maximum stress on the retina also represents the maximum value of the stress attained in the vitreous body. The tangential stress is significantly larger than the pressure, and it appears at leading order, whereas the pressure first appears at the next order (d) (see equations [16] and [21] in the Appendix). Therefore, the normal stress is close to zero in a domain with an (almost) spherical shape.…”

Section: Myopic Eyesmentioning

confidence: 99%

Shape Change of the Vitreous Chamber Influences Retinal Detachment and Reattachment Processes: Is Mechanical Stress during Eye Rotations a Factor?

Meskauskas

Repetto

Siggers

2012

Invest. Ophthalmol. Vis. Sci.

View full text Add to dashboard Cite

PURPOSE. We aim to understand how mechanical causation influences retinal detachment and reattachment processes. In particular, myopes suffer retinal detachment more frequently than emmetropes, and following a retinal detachment, scleral buckling promotes retinal reattachment. We test the hypothesis that stresses arising from saccadic eye rotations are involved in the processes, and that the alteration in the stress due to the change in the vitreous chamber geometry is sufficient to explain the phenomena. METHODS.The vitreous chamber of the eye has an approximately spherical shape and it is filled with vitreous humor. We developed a mathematical model, treating the vitreous chamber in emmetropic and myopic eyes as a spheroid and in eyes subjected to scleral buckling as a sphere with a circumferential indentation. We assume that the eye performs prescribed small-amplitude, periodic, torsional rotations and we solve semi-analytically for the fluid pressure, velocity, and stress distributions. RESULTS.The shape of the vitreous chamber has a large effect on the retinal stress. The vitreous and the retina of a highly myopic eye continuously experience shear stresses significantly higher than those of an emmetropic eye. An eye fitted with a scleral buckle experiences large stress levels localized around the buckle. CONCLUSIONS.Our results provide a mechanical explanation for the more frequent occurrence of posterior vitreous detachment and retinal detachment in myopic eyes. To understand how the stress distribution in a buckled eye facilitates reattachment, an additional model of the details of the reattachment process should be coupled to this model. (Invest Ophthalmol Vis Sci. 2012;53:6271-6281) DOI:10.1167/ iovs.11-9390 R etinal detachment (RD) is defined as a separation of the sensory part of the retina from the underlying retinal pigment epithelium, and often leads to sight loss. The most common type is rhegmatogeneous retinal detachment, in which, following liquefaction of the vitreous humor and the development of a tear in the retina, the subretinal space is filled with liquefied vitreous humor. In healthy young eyes, vitreous humor is a gel with complex mechanical properties, which have been studied experimentally by several authors. [1][2][3][4][5][6] The gel state is maintained by a network of collagen fibrils, which typically degrades with age, resulting in vitreous liquefaction. The mechanisms underlying this process are not fully understood.The incidence of myopia is correlated with an increased risk of RD, reported to be four times higher if the refractive error is between À1 and À3 diopters (D), and up to 10 times higher if the error is more than À3 D. 7 It is also known that both posterior vitreous detachment (PVD) and lattice degeneration, which are risk factors for RD, are more common in myopes. [8][9][10] To our knowledge, the reasons for these findings are not fully understood. Myopia is typically associated with a shape change in the vitreous chamber; in particular, myopic eyes are on average larg...

show abstract

“…All measurements were performed ultrasonographically using A-mode (Sonomed 2000). In 1984 a study with a similar scope was performed by Meyer- Schwickerath & Gerke (1984).…”

Section: Sound Measurementmentioning

confidence: 99%

The relation between the sagittal and transversal diameters in eyes with retinal detachment

Eissa

Skurczyński

Lewandowski

et al. 1992

Acta Ophthalmologica

View full text Add to dashboard Cite

Using A-mode ultrasonography, the axial length and the width (transversal or equatorial diameter) of both eyes -fellow and affected -have been measured in patients with retinal detachment. For comparison, the same measurements have been performed in healthy controls. The patients have been divided into different groups. It was found that there are some changes in the relation between the axial length and the width of the eyes in patients with retinal detachment, according to the comparison with healthy people, in most cases.

show abstract

Biometric studies of the eyeball and retinal detachment.

Cited by 31 publications

References 2 publications

Shape of the Retinal Surface in Emmetropia and Myopia

Shape of the Retinal Surface in Emmetropia and Myopia

Shape Change of the Vitreous Chamber Influences Retinal Detachment and Reattachment Processes: Is Mechanical Stress during Eye Rotations a Factor?

The relation between the sagittal and transversal diameters in eyes with retinal detachment

Contact Info

Product

Resources

About