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L H Loones

Publications and source records attributed to L H Loones.

6 recordsLinked to original sources
PubMed1987

Determination of the power of a convex-plano intraocular lens in situ from the dioptric keratometer reading of its front surface: extension table for the Javal-Schiøtz ophthalmometer.

The size of the reflex image of keratometer mires can be used to determine the power of an intraocular lens (IOL) inside the eye (in situ). The dioptric scale reading from the front surface of a convex-plano intraocular lens in cases of unknown power is compared with computed values. The accuracy of the method is demonstrated in a series of patients with known IOL power. Though in our study we have assumed convex-plano lenses are in use, the same procedure can sometimes be applied to lenses of different forms. To interpret scale readings below 30 dioptres and over 60 dioptres we compiled an extension table, suited to the ophthalmometer of Javal-Schiøtz (Haag-Streit), making use of low-powered minus and plus auxiliary lenses in front of the tube of the instrument.

Humans↗
PubMed1978

Specular microscopy of the corneal endothelium and lens implant surgery.

Specular microscopy helps to estimate the viability of the corneal endothelium long before clinical signs of decompensation occur. Therefore, specular microscopy is useful for the selection of eyes for lens implantation in general; for the prognosis of the eye with a lens implant; and for the evaluation of the method of cataract surgery, of lens implantation techniques, and possibly of lens design, material, and manufacturing. A long-term study of intracapsular and extracapsular pseudophakic eyes revealed that the intracapsular pseudophakic eyes had significantly less endothelial cells, which could partly be explained by toxicity of the Supramid used as loop material, but mostly by assuming continuing endothelial disintegration in the intracapsular eyes. In 41 patients our extracapsular technique caused an average cell loss of only 6.7%.

Adult↗
PubMed1977

Biomicroscopical observations on corneal endothelium in pseudophakia.

The principle and technique of Maurice's method of microscopy of the corneal endothelium at high magnificant is discussed. An instrument is now available for clinical use (clinical specular microscope). The experience of the authors in patients with an intraocular lens is reported. A rather high deficit of endothelial cells was found in a series of 26 children and young adults, that had suffered injury from 2 to 11 years previously. An average immediate endothelial cell loss of only 6-7% was found in extracapsular cataract extraction with simultaneous implantation of a 2-loop or 4-loop intraocular lens. A striking difference was found between the two eyes of bilateral pseudophakic patients when one eye had undergone intracapsular surgery and the other eye extracapsular surgery. It had to be concluded that barrier deprivation of the intracapsular aphakic eye leads to continuing endothelial cell loss other than through ageing. Subclinical and clinical late corneal dystrophy therefore belong to the "barrier deprivation syndrome" together with retino-vascular accidents (macular and optic disc oedema) and vitreous degeneration.

Adolescent↗
PubMedDate not supplied

Retinal accidents in pseudophakia--intracapsular vs extracapsular surgery.

A follow-up of 120 pseudophakic eyes of 85 patients that underwent surgery for senile cataract showed a definite superiority of extracapsular surgery over intracapsular surgery as far as the longterm fate of the retina concerns. Comparable series have been chosen. Retinal detachment did not occur in extracapsular eyes that never had posterior capsulotomy, and occurred most often after intracapsular surgery. Signs of previous or existing maculopathy were searched for with the usual tests (funduscopy, visual acuity, Amsler test) and moreover with Haidinger's brushes test. The macula turned out to have least suffered after extracapsular surgery without capsulotomy and most after intracapsular surgery. Haidinger's brushes test is a valuable tool for the detection of postoperative macular edema.

Aged↗