Cataract in infants treated with argon laser photocoagulation for threshold retinopathy of prematurity.

PURPOSE: Previous studies of lens opacities occurring after argon laser photocoagulation for retinopathy of prematurity indicate that the lens in these laser-treated eyes may be at risk for cataract. We studied the occurrence of permanent, visually significant cataracts in four infants after laser therapy for retinopathy of prematurity. METHODS: The records of 51 consecutive patients (100 eyes) treated only with argon laser photocoagulation for threshold retinopathy of prematurity at our institution were reviewed. Patient characteristics and treatment variables were compared between infants who developed cataracts and those who did not. RESULTS: Complete opacification of the lens nucleus and cortex developed in six eyes of four patients between 19 and 99 days after laser therapy. An additional patient developed a transient, focal, anterior capsular, and subcapsular opacity in one eye that cleared by one month postoperatively. Eyes that developed permanent cataracts were noted to have a prominent anterior tunica vasculosa lentis at the time of treatment. After laser therapy, these eyes developed hyphema, shallowing of the anterior chamber, corneal edema, and progressive opacification of the lens. When compared with eyes that did not develop cataract, no statistically significant difference in number of burns, zone or clock hours of extraretinal proliferation, birth weight, gestational age, or age at treatment was found. CONCLUSIONS: Cataract is a potential vision-threatening complication of argon laser photocoagulation that must be considered before choosing a treatment modality for infants with threshold retinopathy of prematurity.

In vitro excystation of metacercarial cysts of Echinostoma trivolvis from Rana species tadpoles.

In vitro excystation studies were done on the metacercarial cysts of Echinostoma trivolvis obtained from the kidneys of naturally infected Rana species tadpoles. Cysts were excysted in an alkaline trypsin-bile salts medium and the percentage of excystation was compared with that from previous studies done on cysts obtained from the kidneys of snails. The percentage of excystation of E. trivolvis metacercariae from tadpole kidneys was similar to that reported for previous studies on cysts obtained from experimentally infected gastropod hosts. The possible role of tadpoles as an agent for the transmission of Echinostoma and echinostomiasis to humans is discussed.

Management of advanced retinopathy of prematurity in the older patient.

The authors studied 11 eyes of 10 patients who complained of a recent decrease in vision and whose eyes had the clinical appearance of stage 5 retinopathy of prematurity (ROP) as diagnosed by the presence of a dense, opaque retrolenticular membrane. Patients ranged in age from 4 to 33 years, and birth weights ranged from 680 to 1077 g. All eyes underwent vitrectomy, lensectomy, and membrane peeling and were found intraoperatively to have areas of retina that were attached (stage 4B). Preoperatively, a reproducible visual-evoked potential waveform appeared to better predict this retinal configuration and potential retinal function than did the contact B scan ultrasound of the globe. Postoperatively, seven (63.6%) eyes demonstrated an improvement in vision. Vitreous surgery may be beneficial in selected eyes of older patients with advanced ROP to clear media opacities and to uncover areas of functional, attached retina, which may allow these patients to more effectively use the vision they possess.

Histochemical and thin-layer chromatographic analyses of neutral lipids in various host sites infected with Leucochloridiomorpha constantiae (Trematoda).

Histochemical and thin-layer chromatographic (TLC) analyses were used to study the effects of trematode parasitism by Leucochloridiomorpha constantiae on sites occupied by this fluke. Oil Red O staining showed that the epithelium in infected sites, i.e., bursa of Fabricius of the domestic chicken, chorionic ectoderm of the chick embryo, and uterus of Campeloma decisum snails, was positive for neutral lipids. TLC showed that infection in the bursa caused an increase in free fatty acids and triglycerides in that organ; infection of the chick chorioallantois caused a decrease in free sterols and sterol esters in the membrane; the uterus of infected snails showed elevated free sterols.

Cystoid macular edema following extracapsular cataract extraction and posterior chamber intraocular lens implantation.

The outcome of clinical cystoid macular edema (CME) was studied in 20 symptomatic eyes in which extracapsular cataract extraction and posterior chamber intraocular lens implantation had been performed. Resolution of symptoms and apparent resolution of the macular edema were observed in 18 (90%) of the 20 cases. Clearing occurred within one year in 14 (78%) of these 18 eyes and in 17 (94%) within two years. In all eyes in which macular edema resolved, visual acuity returned to 20/40 or better. This study suggests that clinical cystoid macular edema occurring in association with a posterior chamber intraocular lens has a relatively favorable course.

Pseudophakic retinal detachments. The relationships between retinal tears and the time following cataract surgery at which they occur.

The types and locations of retinal tears associated with 268 pseudophakic retinal detachments were studied as a function of the time at which they occurred following cataract surgery. Retinal detachments occurring more than two years following cataract extraction were significantly more likely to have their most posterior retinal break located at the posterior margin of the vitreous base than at or behind the equator. This distribution of tears was not observed in detachments occurring within six months of cataract surgery, with equatorial tears being significantly more common in early onset detachments than in those occurring after two years. The anterior tears which cause most retinal detachments long after cataract extraction are due to persistent chronic traction upon the vitreous base rather than to acute posterior vitreous detachment.

Diabetic retinopathy: a review for the primary care physician.

Hyperglycemia can result in key biochemical reactions that may contribute to thickening of basement membranes, dysfunction of pericytes and endothelial cells, and closure of retinal vessels. The Diabetes Control and Complications Trial has proved the value of good glycemic control in preventing retinopathy and/or delaying its progression. The primary care physician has a crucial role in translating these results into practice. Recognition and management of other risk factors, such as proteinuria, smoking, and hypertension, are easily done in the primary care setting. Also, appropriate referral to an ophthalmologist for retinal evaluation and treatment is both necessary and cost effective in reducing the burden of this devastating complication of diabetes.