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Biomedical subjects

K P Cheng

Publications and source records attributed to K P Cheng.

At least 19 recordsLinked to original sources
PubMed1997

Secondary intraocular lens implantation after cataract surgery in children.

PURPOSE: To report results of secondary intraocular lens implantation after cataract surgery in children. METHODS: We reviewed clinical records for a 5-year period of patients who had cataract surgery in childhood and received a secondary intraocular lens implant. We studied indications for secondary intraocular lens placement; surgical procedures for intraocular lens implantation; preoperative and postoperative visual acuity, refractive error, and binocular status; and complications of the procedure. RESULTS: A secondary intraocular lens was placed in 28 eyes of 25 patients who had cataract surgery in childhood. In 20 eyes, the lenses were placed in the ciliary sulcus. The other eight eyes had insufficient capsular support for an intraocular lens; in two, the intraocular lens was placed in the anterior chamber and, in six, in the posterior chamber with suture fixation to the sclera. Twenty of 28 eyes (71%) had measurable improvement in visual acuity; only one eye had a decrease in visual acuity of 2 lines. Fifteen patients (54%) had a final refraction within 1.50 diopters of the fellow eye; 21 (75%) were within 3.00 diopters. During follow-up, two eyes developed glaucoma. One had transient pressure elevation; one required two filtration procedures. Three patients required Nd:YAG capsulotomy. Six patients demonstrated Worth fusion at distance and near; three demonstrated 200 seconds of arc or better stereo visual acuity. CONCLUSION: Secondary placement of an intraocular lens in the posterior chamber appears to be a safe, effective alternative for correction of aphakia in the contact lens- or spectacles-intolerant child or young adult.

Adolescent↗
PubMed1996

Early retinal vessel development and iris vessel dilatation as factors in retinopathy of prematurity. Cryotherapy for Retinopathy of Prematurity (CRYO-ROP) Cooperative Group.

OBJECTIVE: To determine whether the extent of retinal vessel development present on early screening examinations for retinopathy of prematurity has prognostic value? DESIGN: The prospectively collected data from the Multicenter Trial of Cryotherapy for Retinopathy of Prematurity were used to compare the development of acute retinopathy of prematurity and long-term structural and visual outcomes for eyes with differing extents of retinal vessel development. PATIENT: Study patients had eyes with the following vessel development. In zone I eyes, vessels extended from the disc less than twice the distance from the disc to the macula. In zone II eyes, vessels extended beyond zone I but not to the nasal ora serrata. Transitional eyes had vessels partly in zone I and partly in zone II. RESULTS: The chance of developing threshold retinopathy of prematurity was inversely related to the early degree of vessel development: 54% for zone I eyes, 25% for transitional eyes, and 8% for zone II eyes. The presence of prominent iris vessels at 34 to 35 weeks of postmenstrual age was associated with increased risk for all three groups; zone I eyes almost always needed treatment (94%). The chance of having an unfavorable anatomic alteration of the posterior fundus, or poor vision at the ages of 1 year and 3 1/2 years, was also inversely related to the degree of early vessel development. Vessel development was an independently important factor even when birth weight, gestational age, and race were considered. CONCLUSIONS: The degree of early retinal vessel development is a significant predictor of outcome from retinopathy of prematurity. Iris vessel dilatation is an important indication for greater vigilance in following these infants.

Cryosurgery↗
PubMed1996

Results following secondary intraocular lens implantation in children.

BACKGROUND: Placement of a secondary intraocular lens (IOL) in a child may be considered in children with congenital monocular cataracts who have had complete opacities removed early in life and who later become contact lens intolerant, in eyes that have received trauma which precluded placement of a primary IOL, and in young adults who have bilateral aphakia who become resistant to use of contact lenses or spectacles. METHODS: Clinical records of all children in our practice who received a secondary IOL between January 1988 and December 1994 were reviewed. Indications, biometry, type of procedures, preoperative and postoperative acuity, refractive error, binocular status, and complications were studied. RESULTS: During the 7-year period, 242 cataract operations were performed. Fifty-nine eyes received a lens implant, and 28 of these were secondary implants. There was a mean interval between the initial cataract operation and the procedure for the secondary implant of 77 months. The mean follow-up was 35 months (range, 3 to 71) for the 28 eyes that received a secondary implant. Two received anterior chamber implants. Eight eyes had insufficient capsular support for an IOL. Six implants were placed in the posterior chamber and required suture fixation to the sclera. Twenty of 28 eyes had a measurable improvement in visual acuity. Only 1 eye had a decrease in visual acuity of 2 lines. Fifteen patients (54%) had a final refraction within 1.50 diopters of the fellow eye, and 75% were within 3.00 diopters. During the follow-up period, 2 eyes developed glaucoma. One had a transient pressure elevation, and the second has required 2 filtration procedures. Three patients required a Nd: YAG capsulotomy. Six patients demonstrated Worth fusion at distance and near, but only 3 patients demonstrated 200 seconds of arc or better stereo acuity. CONCLUSION: Placement of contemporary-style, secondary intraocular lenses in children and young adults appears to provide a safe and effective alternative for correction of aphakia in children who become contact lens or spectacle-intolerant.

Adolescent↗
PubMed1996

Pediatric cataracts.

The treatment of an infant or child with a cataract requires a different decision process and surgical technique compared with the treatment of an adult with a cataract. The pediatric cataract literature of the past year reminds the reader that the indications for surgery and preoperative management of the pediatric cataract patient are different, that the response to surgery is different, necessitating the use of new techniques for surgery, and that complications after surgery are more common. These differences are caused by the anatomy of the pediatric eye and the susceptibility of the developing visual system to amblyopia. The literature of the past year supports with laboratory study and clinical reports the current trend toward more common use of intraocular lenses in children.

Adult↗
PubMed1995

Penicillium marneffei infection in a patient with SLE.

We describe a patient with SLE who was infected by the fungus Penicillium marneffei. She was initially misdiagnosed as having disseminated tuberculosis. The correct diagnosis was finally made by bone marrow culture and she responded to a prolonged course of amphotericin B, flucytosine and itraconazole. The clinical presentation and histology of penicilliosis are very similar to those of Mycobacterium tuberculosis. In Southeast Asia, penicilliosis should be considered as a differential diagnosis in patients with SLE who present with fever and lymphadenopathy.

Adult↗
PubMed1992

Risk factors for complications following pediatric epikeratoplasty.

We studied the prevalence and types of complications that occurred in children treated with epikeratoplasty to identify risk factors. A review of the clinical records of 88 consecutive patients (106 eyes; 114 procedures) revealed that no complications occurred in 58 grafts (54%). Refractive complications (refractive error greater than 3.00 diopters spherical equivalent from emmetropia or astigmatism greater than 3.00 diopters) occurred in 30 eyes (28%). Medical complications occurred in 22 eyes (19%); these included epithelial defects (14 grafts), interface opacities (six grafts), graft vascularization (eight grafts), graft infection (two grafts), graft necrosis (five grafts), graft haziness (four grafts) or opacification (11 grafts), and graft dehiscence (three grafts). Eleven grafts (10%) were removed and five eyes received new grafts. Epikeratoplasty in children will be more successful if risk factors such as patient age less than one year, microcornea, corneal endothelial cell dysfunction, mental retardation, and combining the procedure with cataract surgery are avoided.

Adolescent↗
PubMed1992

A prospective, randomized, controlled comparison of retrobulbar and general anesthesia for strabismus surgery.

A prospective, randomized controlled study (n = 95) was conducted to compare the morbidity and length of hospital stay associated with retrobulbar neuromuscular blockade (LA) with that associated with general anesthesia (GA) for monocular strabismus surgery in adult patients. A scoring system was developed to assess postoperative nausea and vomiting, pain, level of consciousness, oral intake, and activity while in the hospital and for the first 3 postoperative days. There was no significant difference in the postoperative nausea and vomiting associated with the two anesthetic techniques. Although patients receiving LA experienced less immediate postoperative discomfort (P < .01) and had greater levels of activity (P < .0001) while in the hospital, the discomfort and activity levels of the two groups were similar at home. The LA group was discharged from the hospital sooner (mean, 135 minutes vs 250 minutes; P < .001), allowing more efficient use of hospital resources. Both techniques provided excellent anesthesia for monocular strabismus surgery.

Adolescent↗
PubMed1991

Visual recovery in patients with optic neuritis and visual loss to no light perception.

We reviewed the records of 151 patients with optic neuritis examined over an eight-year period. Of these patients, 12 developed visual acuity of no light perception during the first episode of optic neuritis in the affected eye. Eight of the 12 patients recovered visual acuity of 20/40 or better. Of these, five patients had visual acuity of 20/20 or better, one had visual acuity of 20/25, one had visual acuity of 20/30, and one had visual acuity of 20/40. Four of the 12 patients recovered peripheral visual fields but had dense central scotomas and visual acuity of less than 20/400. Dyschromatopsia persisted after visual recovery in 11 of 12 patients.

Adolescent↗
PubMed1991

Disseminated intravascular coagulopathy associated with rifampicin.

A case of subclinical disseminated intravascular coagulopathy due to antituberculosis drugs, probably rifampicin, is described. The patient also developed marked leucocytosis, a 'flu-like illness, intravascular haemolysis, and acute renal failure as part of the drug reaction.

Adult↗
PubMed1991

Herpes zoster associated encephalitis in dialysis patients.

Two patients on dialysis because of chronic renal failure who developed herpes zoster associated encephalitis are reported. Both developed overt encephalopathy despite treatment with oral acyclovir for the preceding herpes zoster eruption. The encephalopathy responded rapidly to intravenous acyclovir.

Acyclovir↗
PubMed1991

Congenital dacryocele. A collaborative review.

Fifty-four cases of congenital dacryocele from several medical centers were reviewed retrospectively. There was strong female preponderance (73%) and unilateral involvement (88%). Lacrimal sac contents could be expressed by local massage through the puncta in 21% of cases. Probing and irrigation were done under general (27.8%) or local (55.6%) anesthesia, while in other cases (16.7%), the cyst resolved before intervention. Recurrence of the dacryocele occurred in 10 patients (22%) after probing. Nasal cysts were visualized in six cases. Marsupialization of nasal cysts was necessary in four cases. In one center, after conservative therapy, 80% of cysts resolved spontaneously and 20% developed dacryocystitis. Surgical intervention is indicated in cases of dacryocystitis, cellulitis, breathing difficulty from large nasal cysts, recurrent dacryocele, and lack of its resolution after a short trial of digital massage.

Child, Preschool↗
PubMed1991

Visual results after early surgical treatment of unilateral congenital cataracts.

The authors reviewed the records of 25 consecutive patients who had been operated on for unilateral congenital cataracts at 1 year of age or younger and who had been followed for a period of 5 years or longer. Excluded were patients who demonstrated retinal and optic nerve anomalies. Five eyes achieved 20/40 or better Snellen visual acuity, 5 eyes achieved 20/50 to 20/100 visual acuity, and 15 eyes had 20/200 or less visual acuity. All patients with visual acuity of 20/40 or better had cataract surgery performed before 17 weeks of age, the critical period, and surgery was scattered within this time frame. For surgery performed between 17 weeks and 1 year of age, the best achieved visual acuity in children with surgically significant unilateral congenital cataracts was between 20/50 and 20/100. There was no correlation between the age at the time of surgery and the attainment of these visual levels in this patient subset.

Age Factors↗
PubMed1990

Bilateral phakic hypermetropic epikeratoplasty for accommodative esotropia.

Optical correction of high hypermetropia with glasses is the primary treatment for accommodative esotropia. These glasses are often poorly accepted by adolescents and young adults for they are cosmetically undesirable, heavy, and esotropia occurs with their removal. We report an 11 1/2-year-old, physically mature female with high hypermetropia and accommodative esotropia corrected to orthophoria with glasses who was unable to be weaned from her glasses. She became intolerant to glasses wear, refused contact lenses, and was treated successfully with bilateral phakic hypermetropic epikeratoplasty. Two years postepikeratoplasty her visual acuity is 20/40 and 20/20 uncorrected and the vision in the amblyopic right eye has remained at its maximum preoperative level. She is orthophoric at distance and has a 2 prism diopter monofixational esophoria at near without glasses. Epikeratoplasty is an option in the treatment of accommodative esotropia for patients who are past the amblyopia forming age, have a stable angle of strabismus, and who require their full hypermetropic optical correction to maintain orthophoria.

Accommodation, Ocular↗