Retinopathy of Prematurity and Perinatal Risk Factors

PURPOSE: The incidence of retinopathy of prematurity(ROP) which is one of the most common cause of childhood blindness has not decreased despite the restricted use of oxygen. There may be other factors responsible for ROP which could not be explained solely by improved survival of very low birth weight infants. We tried to clarify perinatal risk factors that are nrelated to the occurrence of ROP. METHODS: We enrolled 239 infants with gestational ages less than 33 wks or with birth weight less than 1,800 gm who had received ophthalrnologic examination between Jan. 1995 and Dec. 1997. The patients were categorized into two groups,' "No ROP" group as control(n=185) and ROP group as study population(n=54), and we compared the perinatal risk factors between the two. RESULTS: 54(22.6%) out of 239 infants were diagnosed as having ROP. The annual incidence of ROP decreased but the incidence of treated ROP increased. The incidence of ROP decreased with longer gestation and higher birth weight. Mean gestational age was 30.3 weeks in the study group vs 31.0 weeks in the control group, and mean birth weight was 1,390 gm and 1,586 gm, respectively. Significant factors contributing to increased incidence of ROP included: duration of oxygen therapy, ventilator therapy, total parenteral nutrition and hospitalization, frequency of hyperoxia, hypercarbia, and transfusion and respiratory distress syndrome, umbilical artery catheterization, intraventricular hemorrhage, sepsis, bronchopulmonary dysplasia, use of dexamethasone and aminophylline, pneumonia, air leak syndrome, and hyperglycemia. The incidence of ROP and treated ROP was not influenced by the mode of surfactant treatment(prophylactic vs rescue) in RDS patients and the mode of dexamethasone treatment(short vs long) in BPD patients. CONCLUSION: The risk factors for retinopathy of prematurity included gestational age, birth weight and duration of oxygen, as well as other aforementioned perinatal factors. The occurrence of ROP can be decreased by preventing preterm birth, minimizing the use of oxygen, and further morbidity can be prevented by performing proper ophthalmologic examination and doing an appropriate follow-up.

Clinical Evaluation of Vitrectomy with Silicone Oil Comparison of Different Viscosity

We analyzed the surgical result of pars plana vitrectomy using silicone oil tamponade and evaluated the effect of different silicone oil viscosity on the result. Of all 66 patients, 48 were male and their mean age was 45.9 years. The most common underlying disease was proliferative vitreoretinopathy (29 patients) and 54 patients (81.9%) had visual acuity of 5/200 or less. Mean follow-up period was 8.94 months. Twenty eight patients had undertaken two or more vitreoretianl surgeries. Anatomical and functional success was achieved in 57 (86.4%) and 31 patients (47.0%), respectively. Complications included hypotony (7 patients), increased intraocular pressure (6 patients), keratopathy (4 patients) and closure of inferior iridectomy (3 patients) on the last follow-up. There was statistically significant correlation between preoperative and final visual acuity (p=0.0001), anatomical success and improvement of visual acuity (p=0.0057), and frequency of vitreoretinal surgery and final visual acuity (p=0.0143). There was no statistically significant difference in the surgical result between eyes using 1,000 cSt and 5,000 cSt silicone oil. This result suggests silicone oil injection may effectively support the surgical treatment of intractible retinal detachment. However, difference of its viscosity seems to make little effect on the surgical result.