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.

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.

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.

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.

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%)

Retinal degeneration due to potassium iodate overdosage.

The potassium iodate toxicity in three patients who accidentally took an overdose of potassium iodate solution was reported. After ingesting the iodate solution in the oral dose of 187, 247 and 470.5 milligrams per kilogram body weight respectively. All patients had nausea vomiting and diarrhea. The visual loss developed within 2 to 20 hours later. All of the patients had visual acuities of hand motion in both eyes. The eye examination revealed retinal edema, hypopingment at macula with subsequent pigmentation at posterior pole and midperiphery of the fundus. The fluorescein angiogram and electroretinogram showed degenerative change of retinal pigment epithelium and photoreceptor cells. The visual acuity of the first case improved to 6/24 both eyes after 3 months.

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.

Krypton laser treatment of central serous retinopathy.

Fourty-seven patients with central serous retinopathy analysed at Siriraj Hospital. Twenty-three eyes were treated by krypton laser photocoagulation. It was found that the duration of resolution of subretinal fluid and recovery of visual acuity was about 3-4 weeks. In most eyes, the visual acuity returned to 6/9 and 6/6. After treatment, changes in pigment at macular area and esidual symptoms such as metamorphopsia, micropsia of scotoma were found in some patients. The treatment by krypton laser photocoagulation shortens the duration of the disease but organic and functional change of the macula may be found.