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Purpose To determine the incidence of retinal detachment (RD) after neodymium:YAG (Nd:YAG) laser capsulotomy for posterior capsule opacification (PCO) and define the characteristics of this type of RD. Setting A private practice, with statistical evaluation at a university department. Methods Five hundred twenty-six consecutive eyes that had Nd:YAG capsulotomy because of visually disturbing PCO were followed prospectively for up to 52 months (median 21 months) to determine the incidence of RD. The median age of the 142 men and 320 women was 76 years and the median axial length, 23.3 mm (range 20.5 to 31.3 mm). Before the capsulotomy, all eyes had uneventful phacoemulsification with implantation of a posterior chamber intraocular lens (PC IOL). Eyes with additional surgical procedures or with panretinal laser photocoagulation were excluded. Eyes in which a retinal hole had been treated before Nd:YAG (n = 4) were included. The fundus was examined by binocular indirect ophthalmoscopy with a 2.2 diopter Volk lens in full mydriasis. If necessary, an examination with a 3-mirror lens was done. Results The incidence of RD was 0% (0/483; 95% confidence interval [CI], 0.0%-0.8%) at 6 months, 0% (0/407; 95% CI, 0.0%-0.9%) at 12 months, and 0.5% (1/213; 95% CI, 0.0%-2.6%) at 24 months. Twenty-one months after Nd:YAG capsulotomy, 1 eye developed an RD that occurred as the result of a horseshoe tear that reopened. The tear, which formed 7 months after phacoemulsification and PC IOL implantation and 6 years before Nd:YAG capsulotomy, had been immediately treated with argon laser photocoagulation. Excluding the 4 eyes with preexisting tears, presumably sealed retinal holes, the incidence at 24 months was 0% (0/212; 95% CI, 0.0%-1.7%). No other eye developed RD over the follow-up. Conclusions Retinal detachment after Nd:YAG capsulotomy for PCO was rare in eyes that had previous uneventful phacoemulsification and PC IOL implantation. The exact relationship between the 2 events remains to be established.

The isometric tension development of a one-dimensional regionally ischemic muscle was analyzed theoretically. The model consist of a one-dimensional normal segment in series with a one-dimensional ischemic segment. Each segment is modeled as a three-element muscle. The inputs to the various elements, except the contractile element in ischemic segment, were obtained from published data for cat papillary muscles. To be consistent with segment length measurements on ischemic canine hearts, it was assumed that the ischemic contractile element contracted normally at the beginning of contraction and then at some tension, TM, fell behind in its rate of tension development compared to the contractile element in the normal segment. Rate of tension development of various lengths of the ischemic segment and strengths of the ischemic contractile element. At the tension, TM, the ischemic segment begins undergoing paradoxical expansion and, simultaneously, as a result of the expansion. the time derivative of the tension produced by the regionally ischemic muscle exhibits a sudden decrease.