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Biomedical subjects

P U Fechner

Publications and source records attributed to P U Fechner.

At least 37 records · Page 2Linked to original sources
PubMed1985

Preparation of 2% hydroxypropyl methylcellulose for viscous surgery.

Since 1976 I have used a solution of hydroxypropyl methylcellulose to prevent corneal endothelial damage during intraocular lens implantation. The substance is inexpensive, readily available, and can be easily dissolved. This paper describes preparation of a 2% solution.

Corneal Injuries↗
PubMed1983

Effect on the retina of an air cushion in the anterior chamber and coaxial illumination.

In an attempt to minimize the danger of light-induced maculopathy during cataract surgery with intraocular lens implantation, we assessed the refractive power of a posterior chamber lens inserted with its convex surface forward (Procedure 1) and with its plano surface placed forward (Procedure 2). In both procedures, a large air bubble is placed in the anterior chamber while the corneoscleral wound is being sutured. With the convex surface forward, parallel rays of light focus 23.6 mm behind the intraocular lens and 5 mm behind the retina. For a pupil 5 mm wide, the diameter of the beam on the retina is 1.03 mm; for a pupil 2 mm wide, the beam is 0.41 mm wide. With the plano surface forward, the refracting surface is in contact with water and its power is therefore reduced. Parallel rays of light focus 97.3 mm behind the intraocular lens and 79.6 mm behind the retina. For a pupil 5 mm wide, the diameter of the beam on the retina is 4.14 mm; for a pupil 2 mm wide, the beam is 1.66 mm wide. Thus, the intensity of the radiation experienced by the retina per surface unit is only 6.19% of that produced when the convex surface is forward.

Air↗
PubMed1983

[Medallion lenses, 500 implantations].

A report is given on the implantation of 500 Medallion lenses, most of which were implanted after intracapsular cataract operation (88%) and were kept under observation for between 3 and 88 months (average 22 months). In 1.2% a severe keratopathy resulted from an operation that was too traumatic, from decentration of the lens or because of postoperative wound rupture. Apart from these events, however, the behavior of the lens was excellent. The track record showed that late complications - particularly those involving the iris and cornea - did not occur in cases in which the operation and postoperative course had been uneventful. Therefore, late complications are unlikely to occur in such eyes. In our opinion the Medallion lens is still an excellent implant although modern posterior chamber lenses might offer certain advantages.

Adult↗
PubMed1983

Methylcellulose and lens implantation.

Methylcellulose has been used since 1976 to prevent damage to the corneal endothelium during operations for implantation of intraocular lenses. Originally one drop of a 1% solution was placed on the artificial lens just before its insertion. Later the anterior chamber was completely filled with a 2% solution of methylcellulose before implantation. In this way it is possible to maintain a space between the cornea and iris even if vitreous pressure is present and to operate without risk to the corneal endothelium. This paper demonstrates the safety of the intraocular use of methylcellulose on the basis of over 400 operations. The substance is cheap, universally available, and can be easily prepared for intraocular use.

Corneal Diseases↗
PubMed1983

Methylcellulose, a viscous cushioning material in ophthalmic surgery.

Methylcellulose has been used since 1976 to prevent damage to the corneal endothelium during operations for implantation of intraocular lenses. With a 2 per cent solution of methylcellulose it is possible to maintain a space between the cornea and iris even if vitreous pressure is present to operate without risk to the corneal endothelium. This paper demonstrates the safety of the intraocular use of methylcellulose based on the results of over 700 operations. The substance is cheap, universally available, and can be easily prepared for intraocular use.

Acetazolamide↗
PubMed1982

[Modification of the 2 loop-Medallion-lens (author's transl)].

The loop diameter was enlarged from 7.6 to 8.5 mm and the holes for the iris fixation suture were placed upwards towards the margin of the haptic. This resulted in a marked decrease of loop-dislocations when comparing two groups with 80 (old lens) and 120 eyes (new lens) respectively. Spontaneous loop-dislocations occurred in 5% with the original lens and in 0.8% with the altered lens, iatrogenic dislocations, i.e. following the instillation of a weak mydriatic, occurred in 10% with the older typ but only in 0.8% with the new lens.

Equipment Failure↗
PubMed1980

[Tadini. Inventor of the artificial lens (author's transl)].

Tadini, an Italian by birth, was an itinerant ophthalmologist who lived in the second half of the 18th century. Advertisements in old newspapers testify to the fact that he performed eye operations in many towns in Europe, including Lübeck and Ghent. Tadini had a box containing artificial lenses made of glass, which he showed to Casanova. It is therefore probable that Tadini first conceived the idea of intraocular correction of aphakia. Presumably Casanova conveyed the idea to Casaamata, an ophthalmic surgeon in Dresden. At any rate, Casaamata was the first to actually attempt the correction of aphakia by implanting a lens.

History, 18th Century↗
PubMed1980

[Premacular hemorrhage: a new indication for argon-laser-therapy (author's transl)].

Fluid blood that has collected in a pocket in front of the macula, either between the retina and the posterior limiting layer of the vitreous, or in the innermost part of the retina adjacent to the latter's internal limiting membrane, will obstruct central vision. By means of a laser the blood can be drained from the pocket into the vitreous cavity. Vision can be expected to return to normal as a result.

Aged↗
PubMed1979

Tadini, the man who invented the artificial lens.

Tadini, an Italian by birth, was an itinerant ophthalmologist living in the second half of the eighteenth century. The eye operations which he performed at many places throughout Europe are documented by his advertisements in newspapers of the day. It is likely that Tadini was the first to conceive the possibility for intraocular correction of aphakia. At any rate, Casanova's memoirs record a meeting with Tadini and make mention of the oculist's box of artificial glass lenses for placement in the eye. Presumably, Casanova conveyed Tadini's idea to Casaamata, an ophthalmic surgeon in Dresden who was the first to actually attempt correction of aphakia with artificial lens implantation.

Germany↗