Outward transport of fluorescein from the vitreous in aphakic eyes.
(57/91)By administering fluorescein intravenously to 95 patients we calculated the ratio of fluorescein concentration in the vitreous at the time of its peak level compared with the estimated unbound concentration of fluorescein in the plasma at the same time. We studied 12 normal phakic and 83 aphakic eye approximately two months, one year, and more than two years after cataract extraction. All the eyes had undergone intracapsular cataract extraction or extracapsular cataract extraction, with or without posterior capsulotomy, because of senile cataract. The calculated ratio in patients with intracapsular and extracapsular lens extraction was statistically significantly reduced at two months and one year after cataract extraction and was normalised at more than two years after the operation in comparison with normal subjects. The ratio was statistically extracapsular extraction at two months and one year after surgery. Posterior capsulotomy had no effect on the ratio. The ratio, we considered, at least partially reflects the outward transport of fluorescein from the vitreous cavity. Although the findings reflect subclinical phenomena, they are of importance when considering postoperative sequelae. The posterior lens capsule, zonule, and intact anterior vitreous face may be essential for the anterior uvea to function in the outward transport of fluorescein from the vitreous cavity. (+info)
Surgical incision alters the swelling response of the human cornea.
(58/91)The ocular characteristics and responses were examined in patients who had undergone extracapsular cataract extraction (ECCE), intracapsular cataract extraction (ICCE) and penetrating keratoplasty (PKP) in one eye only. In each of the three groups, corneal sensitivity (the inverse of corneal touch threshold), oxygen uptake rate, and endothelial cell density were lower in the operated eye than in the normal healthy fellow eye. For the subjects as a whole, the differences in ocular characteristics between the two eyes were proportional to the angular size of the corneal incision, with ECCE patients (33 degrees incision) showing the least differences and PKP patients (360 degrees incision) showing the greatest differences. Five patients from the ICCE group were subjected to an osmotic stress test. There was no statistically significant difference in the corneal swelling response between the operated eye (5.1%) and the unoperated eye (4.7%), indicating that surgically induced scar tissue does not restrict the swelling properties of the cornea. When subjected to a hypoxic stress test, all three groups manifested less corneal edema in the operated eye (ECCE -0.7%, ICCE -4.0%, and PKP -3.3%). The reduction in hypoxic corneal swelling could not be attributed to removal of the crystalline lens since a similar reduction was seen in the PKP group who had phakic eyes. The corneal swelling response correlated inversely with the corneal touch threshold and directly with epithelial oxygen uptake, but did not correlate with endothelial cell density.(ABSTRACT TRUNCATED AT 250 WORDS) (+info)
Results of 100 aphakic detachments treated with a temporary balloon buckle: a case against routine encircling operations.
(59/91)One hundred patients with aphakic detachment were treated with temporary balloon buckles. The balloons were deflated and withdrawn after seven to 10 days. Permanent attachment depended on cryo- or laser-induced adhesions round the break. The procedure was initially successful in 79 patients. Ten retinas became detached again after the balloon was withdrawn and required a more permanent buckle. Sixty-nine retinas remained attached. The final results after additional operations were equivalent to those obtained by traditional methods, but significantly fewer complications occurred. The balloon procedure tests the validity of routinely encircling aphakic detachment. (+info)
'Silicone rubber' lenses in aphakia.
(60/91)Tesicon, one of the commercially available 'silicone rubber' lenses, was used in the correction of aphakic patients. In 74% of cases the lenses were considered successful for a daily wear regimen by the patient. Furthermore, a small number of patients could wear this lens without interruption for 3 to 6 days at a time. Despite this good acceptance by patients, corneal problems (mainly staining) and lens problems (dry surfaces) were frequently encountered. (+info)
Enhancement of the sensitivity of the peripheral visual field of aphakic eyes by a soft contact lens correction.
(61/91)Goldman perimetric field examination was done on 42 glaucomatous eyes, with aphakic spectacles and a soft lens correction. There was a 79% +/- 20% SD overall average enhancement of field size with the soft lens, but the difference varied linearly as a direct function of the initial spectacle field size. There appears to be a significant advantage to the patient in the use of soft lens correction for serial peripheral field measurements. (+info)
Extended wear of hydrophilic contact lenses in aphakia - an alternative to intraocular lens implantation.
(62/91)Since not every patient will be a candidate for an intraocular lens, there will always be a portion of aphakic patients who are candidates for extended wear hydrophilic lenses. Aphakic patients to be fitted successfully with extended wear contacts must be motivated, aware of the risks, and require frequent lens cleaning and replacement on an individual basis. While future improvement of hydrophilic lenses is to be expected and anticipated, the extent of these improvements is still uncertain. However, preliminary reports are encouraging. Extended wear contact lenses are not the only answer to aphakia. They are but one alternative available to the ophthalmologist for maximizing the visual rehabilitation of the aphakic patient. Even with the increasing use and acceptance of intraocular lenses, the use of extended soft lens wear has a place in this rehabilitation. (+info)
Aphakic macular oedema: a two-year follow-up study.
(63/91)A 2-year follow-up study was carried out on patients known to have developed aphakic macular oedema 6 weeks postoperatively, and the results were compared with those in a control group who had not developed oedema. Four eyes (12%) still had macular oedema, the visual acuities ranging between 6/5 and 6/9. There was no significant difference in visual acuities at 2 years between the 2 groups of patients. Visual acuity had significantly improved between 6 weeks and 2 years in the eyes that had macular oedema at 6 weeks after extraction. Factors causing persistence of aphakic macular oedema are discussed. (+info)
Fluorescein angiography and fluorophotometry of the iris in pseudoexfoliation of the lens capsule.
(64/91)Fluorescein iris angiography and fluorophotometry were performed on a series of 9 patients with bilateral and 11 with unilateral pseudoexfoliation, 12 bilateral aphakes with pseudoexfoliation, and 7 unilateral aphakes with bilateral pseudoexfoliation. Angiography showed a loss of radial iris vessels, a heavy leak of fluorescein from the pupil margin, progressive neovascularisation of the outer 2/3 of the iris, and less constantly a network of fine new vessels in the inner 1/3 of the iris stroma. These changes were absent in unaffected eyes. After cataract extraction there seemed to be a definite lessening of fluorescein leak from the pupil margin. Fluorophotometry showed a much higher fluorescein concentration at the anterior focus in eyes with pseudoexfoliation than in normal controls or in fellow unaffected eyes. There was a much smaller rise in fluorescein concentration at the posterior focus in a minority of affected eyes. The ranges of fluorescein concentrations at the anterior focus in both phakic and aphakic patients with bilateral pseudoexfoliation did not differ significantly. The concentration at the anterior focus of unilateral aphakes with bilateral pseudoexfoliation was lower than in the fellow phakic eye. These findings suggest that the neovascular reaction seen in pseudoexfoliation is associated with patchy occlusion of the normal iris vasculature, occurs in the anterior segment of the eye, and does not continue to progress after removal of the lens. (+info)