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Biomedical subjects

A Singalavanija

Publications and source records attributed to A Singalavanija.

12 recordsLinked to original sources
PubMed2001

Corneal abnormalities in diabetes.

OBJECTIVE: To compare corneal thickness and endothelial morphology in patients with diabetes mellitus and age-matched normal subjects, and to determine whether the duration of diabetes mellitus, severity of diabetic retinopathy, and glycemic control are correlated with these measurements. DESIGN: Single center, case-control study. PARTICIPANTS: Sixty eyes of thirty diabetic patients and sixty eyes of thirty healthy nondiabetic subjects were studied. INTERVENTION: Corneal thickness was measured by ultrasonic pachymeter. Corneal endothelial morphology was examined with a contact specular microscope. MAIN OUTCOME MEASURES: Corneal endothelial cell density, mean,cell area, coefficient of variation, percentages of hexagonal cells, and corneal thickness were measured. RESULTS: There was statistically significant increased corneal endothelial cell density and decreased mean endothelial cell area in the diabetic patients. The diabetic corneas had an increased coefficient of variation of endothelial cell area, a decreased percentage of hexagonal endothelial cell and an increased corneal thickness compared with the control subjects, but these differences were not statistically significant. The duration of diabetes mellitus was significantly correlated with pleomorphism, polymegathism and corneal thickness. Severity of diabetic retinopathy was correlated with endothelial cell density, but these correlations were low. The corneal changes were not correlated with glycemic control. CONCLUSIONS: The diabetic corneas tended to be thicker and had more pleomorphism and polymegathism, though this was not statistically significant. Duration of diabetes mellitus correlated significantly with these corneal changes. This suggests that corneal changes should be evaluated and confirmed before intraocular surgery in chronic diabetic patients.

Adult↗
PubMed2001

Ocular diseases and blindness in elderly Thais.

The prevalence of ocular disease and blindness in 2,092 Thai subjects, aged 60 years and over, in 33 communities in the vicinity of Siriraj Hospital, Bangkok was studied. The subjects were examined by a team which consisted of 3-4 ophthalmologists, 6 nurses and a trainee health officer. The history, visual acuity and ocular tension were recorded. The anterior and posterior segments of the eye were assessed by using a portable slit lamp biomicroscope, and a direct and indirect ophthalmoscope. The examination revealed disease of the lens in 1656 cases (79.16%), cornea 852 cases (40.72%), lid 516 cases (24.67%), conjunctiva 462 cases (22.08%), retina 300 cases (14.34%), glaucoma 128 cases (6.12%) and of the optic nerve in 39 cases (1.86%) respectively. There were 66 cases of blindness (3.15%) and 743 cases of low vision (35.5%). The causes of blindness were cataract, glaucoma, late age-related maculopathy, optic atrophy and corneal opacity.

Aged↗
PubMed2000

Potassium iodate toxic retinopathy: a report of five cases.

BACKGROUND: Potassium iodate (KIO3) is an iodized salt used for iodine supplementation in areas endemic for goiter. KIO3 overdose in humans is rare. The authors report unusual cases of retinal toxicity from KIO3 overdose that caused acute vision loss. METHODS: The clinical manifestations, toxic dosage of iodate, and ocular changes in five patients who had taken a KIO3 overdose were analyzed. Electroretinography, visual evoked potential (VEP), and fundus fluorescein angiography (FA) were performed to study retinal function and changes. RESULTS: Two men and three women (age 22-65 years) ingested KIO3 solution at a concentration between 187 and 470 mg/kg body weight. Visual acuity ranged from light perception with projection to counting fingers and decreased from 2 to 12 hours after ingestion. Fundus FA showed bilateral extensive areas of retinal pigment epithelial (RPE) window defects, and electroretinography and VEP showed marked impairment of retinal function. Visual acuity improved from counting fingers to 20/80 in 3 months. CONCLUSION: Potassium iodate can produce retinal toxicity that damages RPE and photoreceptor cells. The recovery of retinal function depends on the amount of chemical absorption, the regeneration of RPE, and the recovery function of photoreceptor cells.

Administration, Oral↗
PubMed1999

Surgical management of nondiabetic vitreous hemorrhage.

Sixty-one patients (62 eyes) with vitreous hemorrhage were studied. None were associated with diabetic retinopathy or perforating injuries and all required surgical treatment. The patients had dense vitreous hemorrhage with preoperative visual acuity of counting finger or worse in 55 eyes (88.7%). After the operation, a final visual acuity of 6/60 or better was found in 32 eyes (51.6%). The common causes of vitreous hemorrhage were subretinal neovascularization, blunt trauma, branch retinal vein occlusion, post-cataract extraction, retinal detachment with tears, and retinal vasculitis. There was no association between the postoperative visual outcome and either the preoperative visual acuity or the duration of vitreous hemorrhage. The pathological change at the macular area was the main factor which influenced the visual outcome.

Adolescent↗
PubMed1998

Removal of dislocated intravitreal lens nucleus and lens fragments.

Forty-four eyes of 43 patients with retained intravitreal entire lens, lens nucleus and lens fragments were analysed. The causes of lens dislocation were post couching, following phacoemulsification, trauma and Mafan's syndrome. Sixteen eyes (36%) with small lens fragments required only pars plana vitrectomy for surgical removal. The entire lens, lens nucleus or large lens fragments in 28 eyes (64%) were removed by a standard three-port pars plana vitrectomy, lifting the lens into the anterior chamber by vitrectomy probe under high vacuum suction and then delivered through a limbal incision. All cases were successfully removed and most of the visual outcome was better than the preoperative check up. The technique of lifting the lens into the anterior chamber is simple and safe.

Adolescent↗
PubMed1996

Retinal detachment with macular hole.

Retinal detachment with macular hole was treated by different methods. Intravitreal SF6 injection was helpful to seal the macular hole and reattach the retina. In cases of retinal detachment with macular hole and peripheral retinal tear, the retinal reattachment could be achieved by scleral buckling procedure. When vitreous traction adjacent to the macular hole or proliferative vitreoretinopathy was present, vitrectomy combined with internal temponade by SF6 gas injection was indicated. Failure of the operation was caused by inadequate removal of the vitreous traction and post-operative vitreoretinopathy. In a successful operation, visual acuity of 6/60 or better was found in eight of thirty-one patients. (25.8%)

Adolescent↗
PubMed1994

Potassium iodate retinopathy.

A case of potassium iodate toxicity in a 22-year-old man was reported. After taking a solution of highly concentrated potassium iodate, the patient developed nausea, vomiting, diarrhea and blurred vision. The visual acuity was hand motion in both eyes. The funduscopic examination showed retinal edema with subsequent pigmentary change at the macula and retinal pigment clumping resembling retinitis pigmentosa. The fundus fluorescein angiography and electrophysiologic studies showed degenerative changes of the retinal pigment epithelium and photoreceptor cells.

Adult↗
PubMed1989

Retinal detachment in toxemia of pregnancy.

A case of exudative retinal detachment in a 16-year-old Thai woman with toxemia of pregnancy was reported. The patient developed bilateral retinal detachment during toxemia of pregnancy. After termination of pregnancy, the blood pressure returned to normal level, the subretinal fluid reabsorbed and the retina reattached. The visual acuity improved from 6/60 to 6/9 both eyes.

Adolescent↗
PubMed1986

Intravitreal angiostrongyliasis.

A case of intravitreal angiostrongyliasis is reported in a Thai female who had eaten raw snails. After immobilising the worm by use of an intravitreal cryoprobe it was successfully removed via the pars plana with vitreous foreign body forceps.

Aged↗