Related Experiment Videos
[Programmed cell death (apoptosis) in excised subretinal neovascularization]
R Wiezorrek1, H Schäfer, A A Bialasiewicz
1Augenklinik, Universitäts-Krankenhaus, Hamburg-Eppendorf.
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).
Patients And 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).
Conclusion:
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.
Insights
Apoptosis, or programmed cell death, is common in choroidal neovascularizations (CNV), especially in recent cases of age-related macular degeneration (AMD). Its presence suggests that treatment timing is crucial for successful outcomes in CNV therapy.
Area of Science:
- Ophthalmology
- Cell Biology
- Pathology
Background:
- Choroidal neovascularizations (CNV) are a leading cause of vision loss, particularly in age-related macular degeneration (AMD).
- The role and extent of apoptosis (programmed cell death) in CNV development and progression are not well understood.
- Investigating apoptosis in CNV may reveal new therapeutic strategies.
Purpose of the Study:
- To analyze the incidence and distribution of apoptosis in surgically excised CNV membranes.
- To correlate the presence of apoptosis with the duration of CNV and clinical presentation in patients with AMD.
- To explore the potential therapeutic implications of apoptosis in CNV.
Main Methods:
- Surgical excision of 34 CNV membranes from patients with various conditions, including AMD, post-traumatic proliferative vitreoretinopathy, and penetrating eye injuries.
- Histological examination using Periodic Acid-Schiff (PAS) and Hematoxylin and Eosin (H&E) staining.
- Immunohistochemical detection of apoptotic cells using the in situ cell-detection kit (TUNEL) assay.
Main Results:
- Apoptotic cells were detected in 74% of all CNV samples and 76% of AMD-related CNV samples.
- Apoptosis was more prevalent in recent CNV (existing 1-12 months) compared to long-standing lesions (existing 5-36 months).
- In AMD patients, the duration of vision loss was shorter in those with detectable apoptosis.
Conclusions:
- Programmed cell death is an active mechanism in CNV tissue with variable involvement.
- A correlation exists between the duration of CNV and the incidence of apoptosis in AMD patients.
- The findings suggest that the timing of intervention may significantly impact treatment success for CNV.