Biomedical subjects

P W de Waard

Publications and source records attributed to P W de Waard.

8 recordsLinked to original sources

PubMed2000

Retinal vasculitis occurring with common variable immunodeficiency syndrome.

PURPOSE: To report severe retinal vasculitis causing decreased vision in three patients with the common variable immunodeficiency syndrome. METHOD: Case report. Three patients with common variable immunodeficiency syndrome developed decreased vision secondary to retinal vasculitis. Fluorescein angiography was performed in all three patients. Peribulbar injections were given in one patient, and two patients were treated with oral steroids and cyclosporin. RESULTS: All three patients were young and had classic common variable immunodeficiency syndrome. Bilateral retinal vasculitis and diffuse retinal edema were present in all three patients, and two patients had retinal neovascularization in the absence of ischemia. No evidence of intraocular infection was present, and none was detected systematically. Visual acuity decreased in five of the six eyes and was responsive to treatment in only one patient (both eyes). CONCLUSION: Retinal vasculitis may be another autoimmune manifestation of common variable immunodeficiency syndrome.

Capillary Permeability↗

PubMed1999

Trypan blue capsule staining to visualize the capsulorhexis in cataract surgery.

A capsulorhexis may be difficult to perform in the absence of a red fundus reflex. Using 0.1 mL of trypan blue 0.1% to stain the anterior capsule in 30 patients with a mature cataract enabled us to visualize the capsulorhexis during phacoemulsification. No adverse reactions were observed up to 12 months after surgery. Trypan blue staining of the anterior capsule appears to be a safe technique to facilitate the performance of a capsulorhexis in the absence of a red fundus reflex.

Capsulorhexis↗

PubMed1999

[Staining the lens capsule with trypan blue for visualizing capsulorhexis in surgery of mature cataracts].

BACKGROUND: A capsulorhexis may be difficult to perform in the absence of a red fundus reflex. PATIENTS AND METHODS: After application of 0.3 mL trypan blue 0.1%, a quick and homogeneous staining of the anterior lens capsule was obtained in 100 patients with a mature cataract, to visualize the capsulorhexis during a phacoemulsification procedure. RESULTS: No adverse reactions related to the dye were observed up to 18 months after surgery. CONCLUSION: Trypan blue staining of the anterior lens capsule may therefore be a safe technique to facilitate the performance of a capsulorhexis in the absence of a red fundus reflex.

Capsulorhexis↗

PubMed1992

Comparison between postoperative astigmatism after classic extracapsular lens extraction and after phacoemulsification with implantation of a Pearce tripod or Pearce vaulted Y-loop intraocular lens.

We compared the surgically induced astigmatism after standard extracapsular cataract extraction (ECCE) with the astigmatism following cataract extraction by phacoemulsification. The surgically induced corneal astigmatism was assessed on several occasions, ranging from one day to one year postoperatively. After phacoemulsification, this astigmatism was considerably slighter than after ECCE on day 1 postoperatively and after two and six weeks. However, one year postoperatively, this difference was less clear. We then measured slight against-the-rule astigmatism for both surgical techniques.

Astigmatism↗

PubMed1992

Intraocular light scattering in age-related cataracts.

Intraocular light scattering was studied in 34 controls and 65 patients with cortical, nuclear, or posterior subcapsular cataracts by measuring forward scatter and backscatter. Forward scatter was measured by the psychophysical direct compensation method. Backscatter was determined with the Lens Opacity Meter of Interzeag. Contrast sensitivity loss caused by forward scatter was assessed with a glare tester (Vistech MCT 8000). Mean forward scatter was in the upper range for subcapsular cataracts compared to nuclear and cortical cataracts. Experimental results of the glare test (the contrast loss) deviated systematically from expected results based on measured forward scatter. Mean backscatter was largest for nuclear, intermediate for posterior subcapsular, and almost zero for cortical cataracts. Thus, each cataract has a characteristic mean ratio between forward scatter and backscatter. However, this ratio varied considerably among individuals, especially for cortical and posterior subcapsular cataracts. As a rule, forward scatter cannot be derived from backscatter (or the slit-lamp image).

Aged↗

PubMed1991

Dependence of intraocular straylight on pigmentation and light transmission through the ocular wall.

The straylight function of the human eye depends on eye color, especially at larger angles of scattering. As a potential cause for this dependence, transmission of light through the ocular wall was measured, using a psychophysical method. For a light-blue eye effective transmission of the iris was 1% for red and 0.2% for green light. Also the eyewall around the iris transmits a significant amount of light. For the dark-brown eyes of pigmented individuals transmission is lower by two orders of magnitude. Although important, transmission proved to be only partly responsible for the pigmentation dependence, the other cause probably being reflection from the fundus.

Adult↗

PubMed1990

Functional quantification of diaphany.

Intraocular straylight can be measured, in clinical as well as normal cases, by the direct compensation technique. Intraocular straylight is known to originate from the cornea, lens and fundus. We have studied a fourth source: the translucency of the iris and surrounding ocular wall. For lightly-pigmented normal eyes this source proved to be important. In the present paper results are reported from a patient with X-linked megalocornea. He had diaphany of the iris, as is common in these patients, and photophobic complaints. Quantitative measurements showed that the translucency was much increased so that the intraocular straylight was far above the normal level.

Adult↗

PubMed1990

The intraocular straylight function in 129 healthy volunteers; dependence on angle, age and pigmentation.

The direct compensation method allows for an accurate (standard deviation below 0.05 log unit) determination of intraocular light scattering between 3.5 and 25 deg of scattering angle and is suitable for untrained subjects. The method was used to study population behaviour and individual variation in 129 volunteers between 20 and 82 yr of age, visual acuity equal to or better than one and no apparent eye pathology. The results indicate straylight to increase with the 4th power of age, doubling at 70. In addition to the age dependence, there was great variation between individuals. Part of this is due to negative correlation with pigmentation.

Adult↗