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Biomedical subjects

G van Rij

Publications and source records attributed to G van Rij.

At least 55 records · Page 3Linked to original sources
PubMed1986

Hydrogel keratophakia: a microkeratome dissection in the monkey model.

High water content intracorneal implants were fabricated from Vistamarc hydrogel (Vistakon, Inc.) at 58%, 68%, and 72% water content and a range of powers from +7.25 to +17.00 dioptres. The Barraquer microkeratome technique was used to implant the lens at 59.0 +/- 9% (+/- SD) depth in the corneas of 14 rhesus monkey eyes. The contralateral eye served as a control. Three eyes were lost to the study because of complications. The remaining 11 animals were followed up for 51 +/- 2 weeks with the refractive yield being 118 +/- 34% and the keratometric yield being 92 +/- 30%. The measured and theoretically expected refractive changes have a linear regression line correlation coefficient of 0.74, whereas the respective keratometric data had a correlation coefficient of 0.04. The measured refraction became stable within 2 to 3 dioptres after 20 postoperative weeks. The hydrogels were well tolerated within the corneal tissue. There was a minimum of interface problems except along the edge of the implant. Implants with abruptly cut edges versus a fine wedge tended to have more light scattering collagen at the implant margin.

Animals↗
PubMed1985

Postoperative astigmatism after central vs eccentric penetrating keratoplasties.

Six patients with markedly eccentric penetrating keratoplasties had severe corneal astigmatism (mean, 10.38 +/- 2.91 diopters). In four of these patients the flat meridian was lying in the direction of graft displacement. Laboratory experiments disclosed no statistically significant difference in diameter between the major and minor axes of the corneal buttons in the centrally and eccentrically trephined eyes and we could not elucidate the mechanism of the severe astigmatism. However, in the eccentrically trephined eyes the longer axis consistently lay in the direction of decentration whereas in the centrally trephined eyes the long axis was oriented randomly.

Astigmatism↗
PubMed1985

Long-term results of corneal transplantations in keratoconus patients.

In this retrospective study all 86 corneal transplantations performed for keratoconus in the Rotterdam Eye Hospital between 1969 and 1978 were included. Sixty seven perforating and 19 lamellar corneal grafts had been performed. The average follow-up was 59 months. Immune reactions occurred 12 times in 11 eyes with a perforating corneal graft (16%); in no case did this lead to permanent opacities in the graft. The visual result of the perforating graft is in general better than that of the lamellar graft. A lamellar graft is indicated, in our opinion, when the risk of trauma is high and the opportunities for follow-up insufficient, and when the peripheral cornea is markedly thin. In most cases we prefer a perforating graft because the results are better.

Adolescent↗
PubMed1985

Silicone oil keratopathy: indications for keratoplasty.

A penetrating corneal graft was performed in 12 patients for corneal opacification induced by silicone oil. The patients were all aphakic. They had had vitrectomy and silicone oil injection for complicated retinal detachment, often with periretinal proliferation. The average follow-up time was 13.7 months, during which four out of 11 grafts failed (one case was lost to follow-up). One patient developed severe calcific band keratopathy, and three grafts failed from endothelial decompensation. Changes induced by silicone oil include band keratopathy, thinning, and endothelial damage. The indications for keratoplasty for these corneal changes are discussed.

Adult↗
PubMed1984

Changes in corneal curvature induced by sutures and incisions.

To clarify the mechanisms by which incisions and sutures produce corneal astigmatism, we made incisions and wedge resections closed by sutures in the corneoscleral limbus of human eye bank eyes, studying the changes in corneal curvature by shadowgraph photography of the corneal contour, by central keratometry, and by measurement of corneal diameter. The compression of tissue within the sutures or the closure of an excision of a wedge of tissue by sutures induced astigmatism in the meridian of surgery regardless of changes in the sagittal depth of the anterior chamber. Sutures and wedge resections closed by sutures in the anterior part of the cornea compressed or removed more tissue from the anterior part than the posterior part, producing a depression of the limbal cornea toward the anterior chamber and steepening the central cornea in the meridian of surgery. The corneal diameter decreased in that meridian. In the opposite meridian, the cornea flattened, the corneal diameter increased, and the sagittal depth decreased.

Astigmatism↗
PubMed1984

Effect of oxybuprocaine 0.4% in preventing surgically induced miosis.

In a group of 68 patients a double-blind study was performed to assess the effect of preoperative oxybuprocaine 0.4% (Dorsacaine, Novesin) eye drops in comparison with a placebo in preventing surgically induced miosis during extracapsular cataract extraction. One drop of oxybuprocaine 0.4% or placebo was instilled 10 and 5 minutes preoperatively. The pupil diameter was recorded at different stages of the operation. It was found that oxybuprocaine reduced the amount of pupil constriction during the operation significantly as compared with the placebo group, facilitating the removal of lens material and the implantation of an intraocular lens. The effect of oxybuprocaine is considered to be due to anaesthetic action on sensory nerves in the eye, which may inhibit the release of a miotic substance.

Adult↗
PubMed1983

Indomethacin eyedrops and the postoperative irritation after extracapsular cataract extraction combined with intraocular lens implantation.

Indomethacin 0.5% solution eyedrops inhibit the prostaglandin effects after extracapsular cataract extraction combined with intraocular lens implantation. In a double-blind study Indomethacin was compared to Dexamethason and placebo using corneal thickness and iris vessel dilatation and leakage as parameters for postoperative irritation. The present evidence indicates that Indomethacin is an important additive medication to diminish the postoperative reaction.

Cornea↗
PubMed1983

Therapeutic keratoplasty for active herpetic corneal disease: viral culture and prognosis.

Data are presented on a 5-year follow-up of 23 patients with active herpetic corneal disease, who underwent lamellar or penetrating corneal grafts. Excised corneal buttons were virologically examined and positive herpes simplex virus was found in 7 cases. The prognosis of these 7 cases was particularly grave. For comparison 23 cases are reported of patients with inactive herpetic corneal disease. Causes of failure in both groups are discussed.

Corneal Transplantation↗
PubMed1983

Effect of indomethacin in preventing surgically induced miosis.

A double-blind study was performed on 64 patients to assess the effect of preoperative indomethacin in comparison with a placebo in preventing surgically induced miosis during extracapsular cataract extraction. One drop of indomethacin or placebo was instilled at 7.00 p.m. and at 9.00 p.m. the night before surgery and 2 hours, 1 hour, and 15 minutes preoperatively. The pupil diameter was recorded at different stages of the operation. It was found that indomethacin as compared with the placebo significantly reduced the amount of pupil constriction during the operation, making the removal of lens material and the implantation of an intraocular lens easier. The indomethacin is thought to act by inhibiting prostaglandin synthesis caused by iris trauma during surgery.

Adult↗
PubMed1983

Correction of postkeratoplasty astigmatism by razor blade and V-shaped knife wedge resection.

Improvement in microsurgical techniques and tissue storage has resulted in a higher rate of clear grafts after penetrating keratoplasty. The postoperative astigmatism however still remains a major problem. If a high corneal astigmatism cannot be managed successfully with glasses or contact lenses, a surgical approach may be indicated. We developed a V-shaped knife which makes a crescentic wedge resection easier to perform. Before the introduction of the V-shaped knife we obtained an average reduction in corneal astigmatism of 6.6 diopters. With the V-shaped knife the reduction was 8.0 diopters. We think that the V-shaped knife makes a wedge resection easier and safer.

Astigmatism↗
PubMed1982

Multicenter trial of acyclovir and trifluorothymidine in herpetic keratitis.

Acyclovir 3 percent ophthalmic ointment was compared with trifluorothymidine 2 percent ointment in a double-blind trial of 59 herpes keratitis patients. Clinical progress was measured by direct clinical assessment and retrospective photographic evaluation. Ninety percent of acyclovir-treated patients and 75 percent of trifluorothymidine-treated patients had healed within 14 days. There was no significant difference in the rate of healing between the two treatment groups.

Acyclovir↗
PubMed1982

The phlycten, a come-back?

In February 1980 acute keratoconjunctivitis was seen in a girls' class in a school in Rotterdam. Bacteriological and virological examination was performed on 20 girls. The agent causing this epidemic could not be demonstrated. Three patients had phlyctens at the limbus. In the year following this observation (March 1980 till March 1981) 42 cases of phlyctenular keratoconjunctivitis were examined prospectively. The condition was most commonly seen in 13- to 18-year old girls. The phlycten can be considered as an elementary form of inflammation in the conjunctiva and cornea, based on an immune reaction of the delayed type (Gell and Coombs' type IV). The hypersensitivity to tuberculin, which was formerly an important feature of this inflammation ('scrofulous ophthalmia'), is of little importance in the Netherlands at the present day. However, in every case of phlyctenular keratoconjunctivitis tuberculosis should still be excluded by the medical history, and if necessary by a Mantoux reaction.

Adolescent↗
PubMed1982

Intracorneal haemorrhage.

In the vascularized cornea of a 63-year-old woman a haematoma developed which was so large that pupillary block resulted. Evacuation of the haematoma restored the form of the cornea and normalized the intraocular pressure. For the restoration of vision a transplantation was necessary.

Cataract Extraction↗
PubMed1981

Aciclovir and trifluorothymidine in herpetic keratitis. Preliminary report of a multicentered trial.

The efficacy of Aciclovir and Trifluorothymidine (TFT) treatment was tested in a double blind trial of thirty-eight patients with dendritic keratitis. All twenty patients treated with Aciclovir healed within 10 days with an average healing time of 5.0 days. Two of the eighteen patients treated with TFT failed to heal within 22 days, the others healed within ten days, the average healing was 6.6 days. Punctate keratopathy was seen in 70% of both groups. Intense conjunctival hyperaemia developed in two TFT patients.

Acyclovir↗
PubMed1981

Traumatic corneal endothelial rings.

Non-perforating injuries to the eyes of 4 patients resulted in ring-shaped opacities of the corneal endothelium which disappeared spontaneously after a few days and did not lead to a permanent reduction in visual acuity. As the result of explosions multiple small powder particles penetrated the corneal epithelium of the patients. After a few hours ring-shaped opacities of the corneal endothelium appeared under some of these foreign bodies, which first increased in intensity and then gradually disappeared within a few days. The diameter of these rings was between 0.5 and 1.1 mm. The corneal stroma remained clear all the time. In one patient who had worn a hard contact lens too long and had sleep with it, a disc-shaped area of stromal oedema with folds in Descemet's membrane developed, with a ring-shaped opacity of the endothelium with a diameter of about 2 mm. The stromal oedema was clearly visible for 3 days, for which it disappeared without trace within a few days. This paper describes and illustrates the endothelial rings.

Adult↗