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Biomedical subjects

H Liesenhoff

Publications and source records attributed to H Liesenhoff.

At least 37 records · Page 2Linked to original sources
PubMed1993

[Indications and contraindications for implantation of bifocal intraocular lenses].

BACKGROUND: Bifocal intraocular lenses (BIOLs) performed satisfactorily in a certain number of patients only. This paper therefore provides an overview of the indications and contraindications of BIOLs. CONCLUSIONS INDICATIONS: BIOLs are indicated in younger and active patients without ocular pathologies. BIOLs should be implanted bilaterally, corneal astigmatism should be less than 1 dpt, emmetropia should be the target refraction, pupil size and responsiveness must be normal, and IOL decentration should be avoided. CONTRAINDICATIONS: Corneal astigmatism in excess of 1 dpt, very small or atonic pupils, ocular pathologies, and a monofocal fellow eye are definite contraindications. In addition, BIOLs are contraindicated in patients who require maximum resolution at low contrast. Relative contraindications include very old patients, eyes with an axial length of more than 24.5 mm or less than 22 mm, and patients who may not tolerate the visual side effects (halos, glare).

Aged↗
PubMed1993

[Contrast sensitivity and defocus curve with various bifocal-IOL].

Simultaneous vision, the basic principle of all bifocal intraocular lenses (IOLs), provides increased depth of focus but also causes a loss in contrast. We therefore measured contrast acuity (CA) (Regan Charts) and the defocus curve at different pupil sizes in 14 patients with a TRUE VISTA bifocal IOL (TV) (Storz Co.), 10 patients with a 3M diffractive bifocal IOL (3M) (3M Co.) and 9 patients with a Nordan Aspheric Varifocal Silicone IOL (VF) (Wright Medical Inc.). CA at distance focus was best with VF; next was TV, and 3M showed the lowest values. At near focus, CA was best with 3M; next was TV, and VF showed the lowest values. Differences between VF and 3M were significant (P = 0.05; t-test). CA at near focus was significantly lower than at distance focus with TV and VF (TV: P = 0.0001; VF: P = 0.005). Pseudoaccommodation was 4.5 D with TV and 3M and 3D with VF. In conclusion, distance CA was best with VF but pseudoaccommodation was not sufficient for reading. Near CA was best with 3M while distance CA was somewhat reduced. TV showed good distance CA while near CA was still sufficient. TV therefore seems to provide a good compromise.

Accommodation, Ocular↗
PubMed1992

Comparison of modulation transfer function and through focus response with monofocal and bifocal IOLs.

We analyzed modulation transfer function (MTF) and through focus response (TFR) of the TRUE VISTA bifocal IOL and monofocal IOLs and compared the experimental and clinical data. MTF and TFR were measured at different pupil sizes (2, 3, 4 mm), base powers (14, 21, 27 D), add powers (2, 3, 4 D), and distance zone diameters (1.25, 1.5, 1.75 mm). Standards were established to correlate MTF and contrast sensitivity, as well as TFR and the defocus curve measured clinically. MTF of TRUE VISTA decreased with increasing pupil size and base power. A near add of 4 D showed the best MTF at distant and near focus. MTF of TRUE VISTA at near focus was lower than at distant focus and MTF at distant focus was lower than MTF of monofocal IOLs. TFR and the defocus curve correlated closely. MTF and contrast sensitivity of TRUE VISTA at far and near focus also correlated closely. MTF and contrast sensitivity of monofocal IOLs and TRUE VISTA at distant focus did not correlate. MTF was considerably better with monofocal IOLs while contrast sensitivity was slightly better only at low contrast. However, MTF of monofocal IOLs was much higher than MTF of a normal eye while MTF of TRUE VISTA at distant focus was only slightly lower than the MTF of a normal eye. Using MTF of a normal eye as a threshold, our results demonstrated a close correlation between experimental and clinical findings. MTF and TFR may therefore reliably predict the performance of bifocal IOLs.

Contrast Sensitivity↗
PubMed1991

[Amyloidosis of the vitreous body. Possibilities of diagnosis].

Vitreous amyloidosis is often the presenting clinical manifestation of type I, type II or Jewish-type familial amyloid polyneuropathy (FAP). FAP is an autosomal dominant inherited disorder. It is caused by systemic deposition of variants of transthyretin (TTR), formerly called prealbumin. TTR is a tetrameric protein with beta pleated sheets (mol wt = 56,000 dalton). In two cases we were able to confirm the clinical diagnosis of vitreous amyloidosis. Immunohistochemistry revealed TTR in vitreous samples after therapeutic pp vitrectomy for vitreous opacity. The same result was found in samples of rectal mucosa. Amyloid was not found in skin. Isoelectrical focusing disclosed that TTR in the serum was the Portuguese (TTR-Met 30) variant. Together with polyneuropathy of the lower limbs, a diagnosis of FAB type I was made. In the second generation of the first patient's family the normal variant was found (the pathologic gene was not inherited). In the second case the pathologic variant was detected in the second generation, but without any pathologic clinical features. The third generation showed the normal variant. The disorder was detectable before any clinical signs were present. These findings are also important for genetic counseling.

Aged↗
PubMed1990

[Therapy of central serous detachment in papillary coloboma. A case report].

A central retinal detachment caused by coloboma of the optic nerve head in one eye of a 34-year-old Caucasian male was treated successfully by pars-plana vitrectomy, endodiathermy of the hole situated at the periphery of the optic nerve head, drainage of the subretinal fluid and injection of silicone oil into the vitreous cavity. After removal of the silicone oil, the retina was still attached and the retinal function was unchanged. The clinical course is described.

Adult↗
PubMed1990

[Loss of corneal endothelial cells following pars plana vitrectomy and silicone oil implantation].

Endothelial cell loss contributes to severe corneal decompensation following pars plana vitrectomy and silicone oil injection into the vitreous cavity. The corneal endothelium of 35 eyes (35 patients) was evaluated prospectively before and after pars plana vitrectomy in a clinical study by means of wide field specular microscopy (Roberts and Koester). Special attention was paid to differences between patients with and without silicone oil in the anterior chamber with respect to postoperative complications and endothelial cell loss. In 12 of the 35 eyes silicone oil was present in the anterior chamber. After a 6-month follow-up we found in all 35 eyes an average decrease in endothelial cell density of 22.9% +/- 13.3% compared to the preoperative values. A correlation between pre- and postoperative cell density (r = 0.827) after six months could be demonstrated. Logistic regression was used to estimate the statistical significance of various factors influencing endothelial cell loss such as inflammatory anterior chamber reaction, elevated intraocular pressure and silicone oil in the anterior chamber. Silicone oil in the anterior chamber was proved to be the main factor causing endothelial cell loss (p less than 0.025). Age group and number of previous intraocular surgical procedures showed no significant influence on endothelial cell loss.

Adult↗
PubMed1985

[Clinical results following revision of covered goniotrepanation (Elliot-Fronimopoulos)].

Among 128 patients with glaucoma, 19 underwent a revision of a goniotrepanation with scleral flap. Adequate regulation of IOP was achieved in this way, in some cases with additional medication. This revision of the filtering bleb can be recommended as the operation of choice for all forms of glaucoma in which goniotrepanation with scleral flap was performed and in which pressure could not be regulated with additional medication.

Follow-Up Studies↗