THE RATE AND SOURCE OF ALBUMIN ENTRY INTO SALINE-FILLED EXPERIMENTAL RETINAL DETACHMENTS

Citation
A. Takeuchi et al., THE RATE AND SOURCE OF ALBUMIN ENTRY INTO SALINE-FILLED EXPERIMENTAL RETINAL DETACHMENTS, Investigative ophthalmology & visual science, 35(11), 1994, pp. 3792-3798
Citations number
24
Categorie Soggetti
Ophthalmology
ISSN journal
01460404
Volume
35
Issue
11
Year of publication
1994
Pages
3792 - 3798
Database
ISI
SICI code
0146-0404(1994)35:11<3792:TRASOA>2.0.ZU;2-U
Abstract
Purpose. To investigate the rate and source of albumin entry into expe rimental nonrhegmatogenous detachments. Methods. Detachments were made in Dutch rabbits by injecting Hanks' balanced salt solution into the subretinal space through a micropipette. Subretinal fluid was withdraw n 0 to 4 hours later through a similar micropipette and analyzed for o smolality and albumin content (by gel electrophoresis). Sodium iodate was injected intravenously in some rabbits to damage the retinal pigme nt epithelium (RPE). In some rabbits fluorescein isothiocyanate albumi n (FITC-albumin) was injected intravitreally or intravenously to measu re its entry into the subretinal fluid by fluorophotometry. Results fr om 4 to 8 eyes were averaged for each data point. Results. The albumin concentration and total amount of albumin in the subretinal fluid inc reased steadily over 4 hours in retinal detachments initially filled w ith Hanks' solution. Pretreating rabbits with sodium iodate injection resulted in a 50-fold increase in the rate of albumin entry, although the levels were still low relative to those of serum. Intravitreal FIT C- albumin entered the subretinal fluid at a rate independent of sodiu m iodate damage, but intravenous FITC-albumin only entered the subreti nal space after RPE damage. Subretinal fluid osmolality remained withi n the range of 291 to 294 mOsm/kg, irrespective of sodium iodate damag e or differences in the rate of fluid absorption. Conclusions. These r esults indicate that albumin can diffuse into the rabbit subretinal sp ace from both vitreous and bloodstream, although entry from serum requ ires damage to the RPE. Subretinal fluid appears to be transported act ively (control eyes) or passively (iodate-damaged eyes) out of the sub retinal space, despite albumin entry and without major osmolar shifts.