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Biomedical subjects

P Algvere

Publications and source records attributed to P Algvere.

At least 19 recordsLinked to original sources
PubMed2001

The Swedish national survey of surgical excision for submacular choroidal neovascularization (CNV).

PURPOSE: To compare the visual outcome after surgical removal of subfoveal choroidal neovascularization (CNV) in patients younger and older than 50 years of age. METHODS: Patient records from all Swedish centers performing submacular CNV surgery were reviewed and 90 patients treated between 1992-1999 with a follow-up of 6 months or more were included. The results obtained in 49 patients aged 51-89 years (median=72 years) with neovascular disease caused by age-related macular degeneration (AMD) were compared with the outcome of 41 patients aged 6-49 years (median=36 years) with CNV secondary to non-AMD causes. The main outcome measure was the improvement or deterioration in visual acuity (standardized in logMAR units) at 6 months following surgery. Secondary endpoints were recurrent CNV and surgical complications. RESULTS: The level of preoperative visual acuity was not significantly different between younger patients with CNV associated with non-AMD and older patients with visual loss due to AMD (p=0.069). However, visual acuity at 6 months after surgery was better (p=0.0042) in younger patients (median improvement=0.19 logMAR) than in older patients (median improvement=0.0 log MAR). Marked visual improvement (>1 log MAR unit) was seen in 29% of non-AMD patients <50 years compared to 0% in the AMD group >50 years. CONCLUSION: Surgical removal of submacular CNV does not appear to improve visual acuity in patients > 50 years of age. However, it may be beneficial for younger patients where a substantial improvement of visual acuity is seen in a subset of these patients. Further studies are required to assess the long-term outcome.

Adolescent↗
PubMed1996

Retinal cell transplantation in the macula: new techniques.

Transplantation of RPE allografts into the submacular space after the removal of neovascular membranes in "wet" forms of ARMD usually leads to chronic leakage around the transplant, whereas this seldom occurs in transplants in "dry" forms of ARMD. The former may be the result of chronic rejection because of a compromised blood/retinal barrier. This is supported by the fact that visual function remains over the transplant in the dry forms of ARMD at 6 months after transplantation. Whether this function can slow or reverse the progression of ARMD remains to be seen. The possibility of transplantation of photoreceptors in retinal degenerations is also reviewed.

Aged↗
PubMed1993

Results of cryotherapy for retinopathy of prematurity.

Results are presented from a case material of 22 prematurely born infants (43 eyes) who received cryotherapy for retinopathy of prematurity (ROP); 20 eyes were treated at stage 3, 14 at stage 3 plus, and nine at stage 4A. Follow-up examinations at the age of 26 to 52 months (average 38 months) showed regression of ROP in all eyes and visual acuities of 6/60 or better. The timing of cryotherapy is discussed. The present experience indicates treatment earlier than recommended by the US Cryotherapy of Retinopathy of Prematurity Study Group. There are, as yet, no reliable clinical criteria that can predict which eyes will progress from stage 3 to stages 4 or 5 (tractional retinal detachment or retrolental fibroplasia). Hence, infants at risk should be repeatedly examined and a progression towards impending retinal detachment diagnosed.

Child, Preschool↗
PubMed1992

Efficacy of cryotherapy for retinopathy of prematurity.

This is a retrospective study of the benefit of transconjunctival cryotherapy for retinopathy of prematurity (ROP) in 43 eyes of 22 infants (birth weight 716-1675 g) from July 1985 to January 1988. Nine eyes were treated at ROP stage 4A (early), 14 eyes at stage 3 plus disease, and 20 eyes at stage 3. Cryotherapy was applied to the retinal avascular zone. In 13 eyes the ridge of extraretinal fibrovascular proliferation was also treated. Two eyes with peripheral exudative retinal detachment in two quadrants had additional treatment of the area of elevated retina. Reexamination was performed at the age of 26 to 52 months (average 38 months). Regression of the ROP was found in all eyes. Seven eyes showed a lateral traction of the temporal vascular arcades, six of these eyes had a slight macular ectopia. None of the eyes progressed to stage 4B or 5. Visual acuity was 6/60 or better. Twelve children (60%) achieved 6/18 or better and 5 (25%) 6/9 or more. Our data indicate that cryotherapy for ROP grade 3 and early stage 4A prevents the progression to advanced stages. The results also imply a functional benefit of cryotreatment in infants with progressive severe ROP.

Child, Preschool↗
PubMed1990

[Macular degeneration--a treatable disease?].

Age-related macular degeneration (AMD) is the most common cause of blindness over the age of 50. The patho-physiological changes and clinical findings in AMD are outlined. Recent findings indicate that some cases of AMD-related choroidal neovascularization can be successfully treated with argonlaser. These results are discussed from a Swedish perspective, and the need of a meticulous work-up is emphasized.

Aged↗
PubMed1990

Fibrovascular response to retinal tacks in the rabbit and monkey eye.

In order to evaluate the tissue response to metal retinal tacks experiments were carried out on 4 monkey eyes and compared to those on 4 rabbits. Non-magnetic retinal tacks (Grieshaber, Switzerland) and tacks made of 24 carat gold (our own brand) were inserted into the ocular fundus under microscopic control. The animals were kept for 3 months. In monkey eyes, histological examination disclosed a considerable fibrovascular proliferation around the retinal tack canal, including an inflammatory response, formation of collagenous tissue and glial proliferation. There was a local intra-retinal and epi-retinal neovascularization. In the rabbit retina, only a slight inflammation and thin collagenous tissue developed. Thus the tissue response was much more severe in the primate eye than in the avascular rabbit retina.

Animals↗
PubMed1990

Reversibility of canthaxanthin deposits within the retina.

As reported earlier, crystalline yellow-glistening deposits in the retinal inner layer were identified in 22 of 53 patients treated with PHENORO (containing 10 mg beta-carotene and 15 mg canthaxanthin per capsule) for various light sensitive dermatoses at cumulative doses of canthaxanthin of up to 178 g for up to 12 years. 14 of the 22 patients with deposits could now be investigated again, 5 years after discontinuation of treatment. There was an extensive reduction of the number of deposits, confirming other reports which have demonstrated that the formation of the crystalline deposits is reversible. Analysis of serum samples revealed significant concentrations of canthaxanthin, resulting from the intake of this carotenoid via food.

Adult↗
PubMed1988

Success and complications of pneumatic retinopexy.

Fifty-eight consecutive patients with rhegmatogenous retinal detachment were treated by pneumatic retinopexy using intravitreal perfluoropropane gas. Reattachment was achieved in 29 of 35 eyes (83%) having single retinal breaks (up to 45 degrees in extent), including dialyses (up to 60 degrees), and groups of breaks within one clock hour. The cumulative reattachment rate was 37 of 58 eyes (64%), including eyes with detachments with multiple breaks 30 to 120 degrees apart and vitreous hemorrhage as well as aphakic and pseudophakic eyes. Pneumatic retinopexy was successful in 18 of 22 (82%) myopic eyes (-3 to -11 diopters). Virtually all complications developed in the inferior retinal quadrants, and included preretinal vitreous condensations or membranes in 27 of 58 eyes (47%), new retinal breaks in seven eyes (12%), and rhegmatogenous or tractional detachments in previously attached areas in 14 eyes (24%). Postoperative proliferative vitreoretinopathy occurred in six eyes (10%) and macular pucker in two (3%).

Adult↗
PubMed1988

The development of vitreous membranes and retinal detachment induced by intravitreal carbon microparticles.

We induced intravitreal cellular proliferation by injection of carbon microparticles (size 20-70 nm) into the vitreous of 21 eyes of 11 cynomolgus monkeys. Pathological changes were evaluated by light and electron microscopy. At 1 week, there was conspicuous cyclitis showing exudative separation of the nonpigmented and pigmented ciliary epithelium, inflammatory cells, mononuclear phagocytes, and premacular vitreous detachment. At 3 weeks, continued macrophagic response was accompanied by fibrovascular proliferation with ingrowth of vessels from the ciliary body into the vitreous. At 4-5 weeks, deposition of extracellular fibrous material and traction retinal detachment (RD) were found. At 10 weeks, all eyes had extensive RD with pre- and subretinal collagenous cellular membranes. Carbon-laden macrophages were aggregated over the optic disc and fovea with prepapillary neovascularization and cystoid macular edema. Thus, intravitreal fibrovascular proliferation, vitreous contraction, and RD were induced by inflammatory and phagocytic response to carbon particles.

Animals↗
PubMed1987

Proteinuria and blood glucose levels in a population with diabetic retinopathy.

In a population-based study of all insulin-treated diabetic patients on the Swedish island of Gotland, we compared the prevalence and severity of retinopathy with those of nephropathy as measured by proteinuria and serum creatinine levels. Of 365 diabetic patients, 66 (18%) had proteinuria. Of these 66, 39 (59%) had retinopathy. Proteinuria and serum creatinine correlated with increasing severity of retinopathy (P less than .001). Of 47 patients with proliferative retinopathy, 19 (40%) had proteinuria. Of 124 patients with retinopathy of other grades of severity, 20 (16%) had proteinuria. Visual acuity in the best eye was negatively correlated to proteinuria, which was present in 17 of 203 (8.4%) patients with a visual acuity of 20/20, compared with eight of 15 (53%) of those with a visual acuity of 20/200 or less. Blood glucose, determined two hours postprandially, was satisfactory (less than 10 mmol/l) in 162 patients (44%), unsatisfactory (10 to 14 mmol/l) in 89 (24%), and poorly regulated (greater than 14 mmol/l) in 114 (31%). Increasing mean blood glucose correlated to retinopathy (P less than .05).

Adolescent↗
PubMed1987

Visual acuity in a diabetic population.

In a population study of all insulin-treated diabetics and a random sample of those treated with oral antihyperglycaemic agents (OHA) in Gotland, Sweden, the visual acuity (VA) was determined. The prevalence rates of visual impairment (VA 0.1-0.2) and blindness (VA less than 0.1) in the insulin-treated group were 4.9 and 4.4%, respectively, and in OHA-treated diabetics 7.2 and 1.4%. The impairment and blindness were due to diabetic retinopathy (Rp) in 72% of the insulin-treated group, but only in 14% of the OHA-treated diabetics in whom cataract and age-related maculopathy were the predominant causes. Blindness was four times more frequent among insulin-treated females than males. On simple logistic regression test VA correlated with Rp, age at examination, age at onset of diabetes, duration of diabetes and sex. However, on multiple logistic regression analysis the only significant relationships with VA were in the insulin-treated group, a correlation with Rp and age; and in the OHA-treated group, a correlation with age only. Thus the higher frequency of blindness in insulin-treated women was explained by Rp and age. When standardizing for age, the fraction of blind patients was found to be significantly higher among the insulin-treated than in the OHA-treated diabetics (6.7 vs 1.4%).

Adult↗
PubMed1987

Visual and social benefits of vitreous surgery in diabetics. A long-term follow-up evaluation.

Eighty diabetics underwent vitreous microsurgery from 1977 to 1979 for severe vitreo-retinal disease. At follow-up examinations 5 to 9 years (mean 6.6 years) after surgery, 21 patients (26%) were deceased, and 8 subjects had been lost to re-examination. Among 51 patients (53 eyes), aged 28 to 71 years (mean 47 years), visual acuity increased to 0.1-1.0 in 28 eyes (53%) at 3 months after surgery. This visual improvement was also maintained in 28 eyes during 5 to 9 years; 13 eyes (25%) were then amaurotic. Diabetic retinopathy showed a remarkable regression after vitreous surgery, proliferations did not recur (except in 2 eyes following haemorrhage), and background retinopathy remained quiet. Personal interviews with 37 patients indicated substantial social benefits from vitreous surgery. Their working capacity had improved, from 3 subjects (8%) at work pre-operatively to 14 (38%) after surgery. The number of patients who could manage their own household duties had doubled after surgery.

Adult↗
PubMed1987

Implantation of fibroblasts into vitrectomized eyes. Dose-response relationship and the putative inhibitory effect of sodium hyaluronate.

To determine whether or not sodium hyaluronate (NaHA) has any inhibitory effect on cellular proliferation in the vitreous space, we implanted 3 X 10(5) or 1 X 10(6) homologous fibroblasts into the vitreous cavity of 21 vitrectomized albino rabbits. Sixteen eyes received 0.7-0.8 ml of a 1% solution of NaHA intravitreally and 18 eyes got BSS only. Ophthalmoscopy and histological examination showed that 5 of 10 BSS-injected and 2 of 8 NaHA-injected eyes in the group receiving 3 X 10(5) fibroblasts developed retinal detachment (RD) after 4-8 weeks. All BSS- and NaHA-injected eyes implanted with 1 X 10(6) fibroblasts developed RD. The results indicate that NaHA has an unsatisfactory inhibitory effect on fibrovascular growth in response to moderate and large inocula of fibroblasts.

Animals↗
PubMed1986

Relationship of duration and onset of diabetes to prevalence of diabetic retinopathy.

In a population study of all registered insulin-treated diabetic patients on the Swedish island of Gotland, the prevalence of diabetic retinopathy was determined with ophthalmoscopy, biomicroscopy, and color photography. Retinopathy was present in 173 of 368 patients (47%) and reached a prevalence of 100% after 30 years of diabetes. Proliferative retinopathy was found in 48 subjects (13%) and was more common in females (17%) than in males (9.4%) (P = .01). By simple logistic regression test, the prevalence of total and proliferative retinopathy was correlated with both duration and age at onset of diabetes (P less than .001). However, on multiple regression analysis only the relationship with duration was statistically significant (P less than .001); age at onset was not (P greater than .2). Age had an additional influence only on background retinopathy with hard exudates, which were more frequent in older subjects (P less than .01). Thus, age at onset of diabetes was not correlated with the prevalence of total or proliferative retinopathy.

Adolescent↗