[Programmed cell death (apoptosis) in excised subretinal neovascularization].
BACKGROUND
The occurrence of apoptosis in choroidal neovascularizations (CNV) has only been described previously in a few cases. However, little is known about the extent and function of apoptosis. We analyzed the incidence of apoptosis in order to find new options in the therapy of CNV. Particular attention was given to the length of time that the process existed before surgery in patients with age-related macular degeneration (AMD).


METHODS
In 34 patients (18 women, 16 men) ranging in age from 20 to 91 years (mean 70.3 years), CNV was detected by angiography. The majority of patients (n = 29) with CNV had AMD, which in most patients affected both eyes. In two patients CNV was due to post-traumatic proliferative vitreoretinopathy, in two other patients CNV occurred after a penetrating bulbus injury, and in one patient pseudoxanthoma elasticum was found. Thirty-four CNV membranes were excised by pars plana vitrectomy via retinotomy, fixed in formalin and embedded in paraffin. Sections were stained with PAS and H&E and examined microscopically. The in situ cell-detection kit (TUNEL) was used for immunohistochemical detection of apoptotic cells from fragmented DNA.


RESULTS
In 74% (n = 25) of all patients and in 76% (n = 22) of patients with AMD, disseminated or focal apoptotic cells were detectable in the connective tissue, retinal pigment epithelium and in the vascular endothelium. In AMD patients with apoptotic cells, the SNV existed 1-12 months (mean 5.5 months) before surgical intervention. In patients without apoptotic cells, the CNV were present 5-36 months (mean 17 months) before surgery. At the time of surgery, the loss of reading ability had on average been going on 3 months; in patients with apoptotic cells, the mean time from the onset of this symptom was 2.4 months (1 week to 11 months); and in patients without apoptotic cells it was 5 months (1-12 months).


CONCLUSIONS
Programmed cell death as a regulating pathomechanism was observed in all tissue parts of CNV with variable extension. In patients with AMD, a correlation existed between the length of time that CNV existed before surgery and the incidence of apoptotic cells. Apoptosis was found more frequently in recent CNV than in long-standing lesions. The various activity found in CNV suggests that the success of treatment may depend on the moment of intervention. To characterize the role of apoptosis further inducing and inhibiting factors have to be analyzed.
Wiezorrek
R
R
Augenklinik, Universitäts-Krankenhaus, Hamburg-Eppendorf.
Schäfer
H
H
Bialasiewicz
A A
AA
Richard
G
G
D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D017209:Apoptosis; D020256:Choroidal Neovascularization / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery; D053938:DNA Fragmentation; D004253:DNA Nucleotidylexotransferase; D005131:Eye Injuries / Q000150:complications; D005260:Female; D006652:Histological Techniques; D006801:Humans; D007124:Immunoenzyme Techniques; D008268:Macular Degeneration / Q000473:pathology / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D013997:Time Factors; D014821:Vitrectomy
D004253:DNA Nucleotidylexotransferase