Publications by authors named "Zwaan J"

Purpose: To retrospectively investigate the one-year clinical outcome following a standardized treatment protocol for immediate loading. The protocol mandates predefined requirements for implant stability. If fulfilled, immediate loading of the implants is performed with a simplified prosthetic protocol which includes one-time impression at the time of surgery and definitive restoration within eight weeks.

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Therapeutic Change Process Research (TCPR) connects within-therapeutic change processes to outcomes. The labour intensity of qualitative methods limit their use to small scale studies. Automated text-analyses (e.

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Background: Obesity and hyperinsulinaemia are frequently encountered in the equine population and risk factors for the development of laminitis. There are many options for hoof support that claim a beneficial effect, but often the scientific evidence is scarce.

Objectives: To quantify the effect of frog-supportive shoes on hoof kinetics in normal and obese ponies.

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Purpose: To study the clinical/radiographic outcomes and stability of a tapered implant design with a hydrophilic surface when placed in the maxilla using various protocols and followed for one year.

Methods: Ninety-seven consecutive patients treated as part of daily routine in two clinics with 163 tapered implants in healed sites, in extraction sockets and together with bone augmentation procedures in the maxilla were evaluated after one year in function. Individual healing periods varying from 0 to 6 months had been used.

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People are able to comfort others by talking about their problems. In our research, we are exploring whether computers can provide social support in a similar manner. Recently, we proposed a design for an empathic virtual buddy that supports victims of cyberbullying.

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Aim: To study the correlation between severity of primary congenital glaucoma (PCG) and success of three types of surgery.

Methods: This was a retrospective review of all records of patients diagnosed with PCG up to age 1 year who underwent goniotomy, trabeculotomy, or combined trabeculotomy-trabeculectomy with mitomycin C as initial procedure between 1982 and 2002 at the King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia. 532 paediatric glaucoma patients below age 1 year (820 eyes) with a minimum 1 year follow up were identified.

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Purpose: Three congenital fibrosis of the extraocular muscles phenotypes (CFEOM1-3) have been identified. Each represents a specific form of paralytic strabismus characterized by congenital restrictive ophthalmoplegia, often with accompanying ptosis. It has been demonstrated that CFEOM1 results from mutations in KIF21A and CFEOM2 from mutations in PHOX2A.

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We describe a new dysmorphic syndrome in an inbred Saudi Arabian family with 21 members. Five males and one female have similar craniofacial features including wide open calvarial sutures with large and late-closing anterior fontanels, frontal bossing, hyperpigmentation with capillary hemangioma of the forehead, significant hypertelorism, and a broad and prominent nose. In addition, these individuals have Y-shaped sutural cataracts diagnosed by 1-2 years of age.

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Isolated strabismus affects 1-5% of the general population. Most forms of strabismus are multifactorial in origin; although there is probably an inherited component, the genetics of these disorders remain unclear. The congenital fibrosis syndromes (CFS) represent a subset of monogenic isolated strabismic disorders that are characterized by restrictive ophthalmoplegia, and include congenital fibrosis of the extraocular muscles (CFEOM) and Duane syndrome (DURS).

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Background: Inadvertent perforation of the globe is a well-recognized complication of extraocular muscle surgery. We evaluated the incidence, risk factors, and sequelae of this complication at our institution.

Methods: Medical records of patients who underwent extraocular muscle surgery at King Khaled Eye Specialist Hospital, Saudi Arabia, between September 1983 and April 1997, were reviewed for the occurrence of globe perforation.

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Background: Primary intraocular lens (IOL) implantation after cataract aspiration is a widely accepted means of correcting pediatric aphakia. However, little is available in the literature on secondary IOL implantation in children. We present our experience over the past 6 years.

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Objective: To document clinical features and subsequent management of pyramidal anterior polar cataracts in children.

Design: Retrospective, noncomparative case series and clinicopathologic correlation.

Participants: Fifteen patients who presented to the pediatric ophthalmology clinic.

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Objective: To review the results of combined trabeculotomy and trabeculectomy as a primary procedure in congenital glaucoma.

Methods: A retrospective review of 100 consecutive eyes in 60 children undergoing surgery from December 30, 1991, to April 17, 1996. Features at initial examination, ie, corneal size and clarity, presence or absence of anterior segment structural abnormalities, and intraocular pressure (IOP), were noted.

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Background: In glaucoma associated with Sturge-Weber syndrome (SWS), medical treatment often fails to control intraocular pressure, thus requiring surgical intervention that may result in serious complications.

Methods: Eighteen consecutive patients with SWS were reviewed retrospectively at the King Khaled Eye Specialist Hospital. An intraocular pressure less than 20 mm Hg, plus stable optic nerve cup-to-disc ratio and corneal diameter (or visual fields where appropriate), were parameters chosen to indicate that the glaucoma was being controlled.

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Purpose: To examine the safety of mitomycin C (MMC) use in pediatric glaucoma surgery.

Design: Retrospective interventional case series.

Participants: One hundred eighty pediatric glaucoma patients younger than 7 years of age (254 eyes) who underwent glaucoma surgery and were followed for at least 1 year participated.

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The extraocular fibrosis syndromes are congenital ocular-motility disorders that arise from dysfunction of the oculomotor, trochlear, and abducens nerves and/or the muscles that they innervate. Each is marked by a specific form of restrictive paralytic ophthalmoplegia with or without ptosis. Individuals with the classic form of congenital fibrosis of the extraocular muscles (CFEOM1) are born with bilateral ptosis and a restrictive infraductive external ophthalmoplegia.

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Background And Objective: To determine the efficacy of topical tissue plasminogen activator (tPA) for the resolution of postoperative or inflammatory intraocular fibrinous exudates.

Patients And Methods: Each treatment consisted of drops of 1 mg/ml tPA given 9 times 5 minutes apart. Records were reviewed and the results at 24 and 48 hours were recorded.

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Background And Objective: To study the results of combined intraocular and strabismus surgery.

Patients And Methods: Combined surgery was done in 14 patients. In 10 of these patients, cataract and strabismus surgery were combined.

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Objective: The study aimed to review pediatric intraocular lens (IOL) implantations performed in the authors' institution for the past 7 years.

Study Design: The study design was a retrospective chart review.

Participants: All children who underwent IOL placement between January 1, 1989, and January 31, 1996, at ages 2 to 16 years were studied.

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Background: Intraocular lens (IOL) implantation is increasingly accepted as a means of correcting pediatric aphakia. However, few large series have been reported. We present our experience over the past 6 years.

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A 4-month-old infant received an accidental intraocular injection of methylprednisolone while undergoing penetrating keratoplasty for congenital, hereditary endothelial dystrophy. This was not discovered until 4 months later, at which time the intraocular pressure (IOP) was increasing and an early cataract was forming. A lensectomy and vitrectomy were performed when the child was 12 months old.

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Background And Objectives: The treatment of congenital nasolacrimal duct (NLD) obstruction continues to be a subject of controversy. Some authors advocate early probing and irrigation in an office setting, whereas others recommend that the procedure be performed under general anesthesia when the child is at least 1 year old. The focus of this study was to compare the results of probing and irrigation of congenital NLD obstruction among children younger than 1 year of age, those 1 to 2 years of age, and those older than 2 years.

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Background: We studied long-term visual acuity in children who had macular hemorrhages at birth.

Methods: Of 11 involved children, seven had eye examinations at about age 10. Two were contacted by telephone; two were lost to follow up.

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