- Viagra and Sildenafil
- Description of Blue-Tinted Vision as a Side Effect
- Role of Phosphodiesterase 6 (PDE6)
- Understanding Rod Cells and their Sensitivity
- Examination of Cyanopsia and its Relation to Blue-Tinted Vision
- Duration and Variance of the Side Effect
- Exploration of Rare Cases and Persistent Vision Changes
- Investigation into Individual Variations within the Population
- Discussion on Drug Metabolism and Elimination
- Examination of High Concentrations of the Drug in the Bloodstream
- Importance of Seeking Medical Attention for Persistent Vision Changes and Other Side Effects
Viagra and Sildenafil
Viagra, known generically as sildenafil, is a drug widely used to treat erectile dysfunction. It works by enhancing blood flow to the penis, facilitating the process of achieving an erection. However, the drug has several side effects, one of which is the phenomenon of blue-tinted vision.
Description of Blue-Tinted Vision as a Side Effect
Blue-tinted vision, also known as cyanopsia, is one of the side effects associated with sildenafil use. This condition makes everything appear to have a blue hue. Apart from this unusual color perception, some users may also experience blurred vision.
Role of Phosphodiesterase 6 (PDE6)
Sildenafil acts by inhibiting an enzyme called phosphodiesterase 5 (PDE5), which is primarily found in the penis. However, it also exerts a minor inhibitory action against phosphodiesterase 6 (PDE6), an enzyme present exclusively in rod and cone photoreceptors in the eyes. This inhibition of PDE6 is what leads to visual disturbances, including cyanopsia.
Understanding Rod Cells and their Sensitivity
Rod cells are photoreceptor cells in the retina of the eye that detect light and provide vision in low-light conditions. The inhibition of PDE6 by sildenafil makes these rod cells more sensitive, altering color perception and leading to cyanopsia or blue-tinted vision.
Examination of Cyanopsia and its Relation to Blue-Tinted Vision
Cyanopsia often occurs temporarily for some people after using sildenafil. This condition is characterized by seeing everything tinted with blue and is a direct result of the increased sensitivity of the rod cells in the eyes, caused by the inhibition of PDE6.
Duration and Variance of the Side Effect
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For most people, the vision changes, including cyanopsia, clear within a day or two and may be mild. However, in some men, visual impairment may last as long as three weeks. It's reported that most side effects, including vision disturbances, usually disappear within 5 hours.
Exploration of Rare Cases and Persistent Vision Changes
While the blue vision effect is usually temporary, there have been rare instances where men experience persistent vision changes that last for several weeks. Men who regularly use erectile dysfunction drugs like Viagra are reportedly more likely to develop serious vision-related side effects than men who don't take these medicines.
Investigation into Individual Variations within the Population
The way sildenafil affects individuals can vary.
For example, some people may break down and eliminate the drug from their bodies more efficiently than others.This could potentially affect the intensity and duration of side effects experienced, including blue-tinted vision.
Discussion on Drug Metabolism and Elimination
The body's ability to metabolize and eliminate sildenafil effectively can influence the concentration of the drug in the bloodstream. If sildenafil is not broken down and eliminated efficiently, high concentrations can accumulate, potentially exacerbating side effects like cyanopsia.
Examination of High Concentrations of the Drug in the Bloodstream
High concentrations of sildenafil in the bloodstream may contribute to the severity and duration of the blue-tinted vision. These high levels could potentially increase the drug's inhibitory effect on PDE6, heightening the sensitivity of the rod cells in the eyes and leading to more pronounced cyanopsia.
Importance of Seeking Medical Attention for Persistent Vision Changes and Other Side Effects
While most side effects of Viagra, including blue-tinted vision, are transient and mild, anyone experiencing persistent vision changes or other severe side effects should seek medical attention immediately. This is particularly important as persistent vision changes could indicate a more serious underlying condition.
- can viagra give you a headache?
- is it illegal to buy viagra online
- what is sildenafil 20mg used for?
- what are the new treatments for ed 2023?
- why do i get performance anxiety in bed?
- is erectile dysfunction caused by clogged arteries?
- is there a daily viagra?
- does viagra cure impotence?
- does norvasc cause erectile dysfunction?
- who owns the patent for viagra?
- can erectile dysfunction make you hard?
- can i take flomax and cialis together?
- can tramadol help a man last longer in bed?
- is there a safe herbal viagra?
- how long does 20mg viagra last?
- what is the best pill to take for erectile dysfunction after prostatectomy
- Erectile Dysfunction
- Viagra and Sildenafil
- Description of Blue-Tinted Vision as a Side Effect
- Role of Phosphodiesterase 6 (PDE6)
- Understanding Rod Cells and their Sensitivity
- Examination of Cyanopsia and its Relation to Blue-Tinted Vision
- Duration and Variance of the Side Effect
- Exploration of Rare Cases and Persistent Vision Changes
- Investigation into Individual Variations within the Population
- Discussion on Drug Metabolism and Elimination
- Examination of High Concentrations of the Drug in the Bloodstream
- Importance of Seeking Medical Attention for Persistent Vision Changes and Other Side Effects
Viagra and Sildenafil
Viagra, known generically as sildenafil, is a drug widely used to treat erectile dysfunction. It works by enhancing blood flow to the penis, facilitating the process of achieving an erection. However, the drug has several side effects, one of which is the phenomenon of blue-tinted vision.
Description of Blue-Tinted Vision as a Side Effect
Blue-tinted vision, also known as cyanopsia, is one of the side effects associated with sildenafil use. This condition makes everything appear to have a blue hue. Apart from this unusual color perception, some users may also experience blurred vision.
Role of Phosphodiesterase 6 (PDE6)
Sildenafil acts by inhibiting an enzyme called phosphodiesterase 5 (PDE5), which is primarily found in the penis. However, it also exerts a minor inhibitory action against phosphodiesterase 6 (PDE6), an enzyme present exclusively in rod and cone photoreceptors in the eyes. This inhibition of PDE6 is what leads to visual disturbances, including cyanopsia.
Understanding Rod Cells and their Sensitivity
Rod cells are photoreceptor cells in the retina of the eye that detect light and provide vision in low-light conditions. The inhibition of PDE6 by sildenafil makes these rod cells more sensitive, altering color perception and leading to cyanopsia or blue-tinted vision.
Examination of Cyanopsia and its Relation to Blue-Tinted Vision
Cyanopsia often occurs temporarily for some people after using sildenafil. This condition is characterized by seeing everything tinted with blue and is a direct result of the increased sensitivity of the rod cells in the eyes, caused by the inhibition of PDE6.
Duration and Variance of the Side Effect
For most people, the vision changes, including cyanopsia, clear within a day or two and may be mild. However, in some men, visual impairment may last as long as three weeks. It's reported that most side effects, including vision disturbances, usually disappear within 5 hours.
Exploration of Rare Cases and Persistent Vision Changes
While the blue vision effect is usually temporary, there have been rare instances where men experience persistent vision changes that last for several weeks. Men who regularly use erectile dysfunction drugs like Viagra are reportedly more likely to develop serious vision-related side effects than men who don't take these medicines.
Investigation into Individual Variations within the Population
The way sildenafil affects individuals can vary.
For example, some people may break down and eliminate the drug from their bodies more efficiently than others.This could potentially affect the intensity and duration of side effects experienced, including blue-tinted vision.
Discussion on Drug Metabolism and Elimination
The body's ability to metabolize and eliminate sildenafil effectively can influence the concentration of the drug in the bloodstream. If sildenafil is not broken down and eliminated efficiently, high concentrations can accumulate, potentially exacerbating side effects like cyanopsia.
Examination of High Concentrations of the Drug in the Bloodstream
High concentrations of sildenafil in the bloodstream may contribute to the severity and duration of the blue-tinted vision. These high levels could potentially increase the drug's inhibitory effect on PDE6, heightening the sensitivity of the rod cells in the eyes and leading to more pronounced cyanopsia.
Importance of Seeking Medical Attention for Persistent Vision Changes and Other Side Effects
While most side effects of Viagra, including blue-tinted vision, are transient and mild, anyone experiencing persistent vision changes or other severe side effects should seek medical attention immediately. This is particularly important as persistent vision changes could indicate a more serious underlying condition.
- can viagra give you a headache?
- is it illegal to buy viagra online
- what is sildenafil 20mg used for?
- what are the new treatments for ed 2023?
- why do i get performance anxiety in bed?
- is erectile dysfunction caused by clogged arteries?
- is there a daily viagra?
- does viagra cure impotence?
- does norvasc cause erectile dysfunction?
- who owns the patent for viagra?
- can erectile dysfunction make you hard?
- can i take flomax and cialis together?
- can tramadol help a man last longer in bed?
- is there a safe herbal viagra?
- how long does 20mg viagra last?
- what is the best pill to take for erectile dysfunction after prostatectomy
- Erectile Dysfunction
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About GreenLight: For men with bladder outflow obstruction due to an enlarged prostate, this technique allows genuine day case surgery with dramatic early results and minimal early side-effects. Most men can now be treated without a post-operative catheter. It is possible for prostates of all sizes to be treated. Even patients with retention of urine can go home the same day, sometimes with no catheter. Bleeding and recovery time are usually minimal. As the first team in the UK to use the GreenLight system, and having pioneered and developed the GreenLight prostate vaporisation system in Europe, we have now virtually given up other surgical methods of benign prostate surgery. GreenLight Patient Information How does it work? Information for GP's Training Courses for Surgeons
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Watch patient information video |
By clicking on the flash image you will be able to watch a video where patients share their experiences and an explanation is given of the techniques. You will need to have Flash player installed to watch it. To download our operation information (Adobe PDF) click here
If you prefer to read the information online then click here to go to our operation info page |
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NHS Innovation Awards The adoption of this technique led to the NHS clinical excellence award for innovation being awarded to King's College Hospital.
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How does it work?
Although we had in TURP a very good and tested operation, there are side effects and costs associated with it. This led to many minimally invasive approaches over the last decade. Sadly most of these were abandoned due to or a high risk of pain or other side effects compared to TURP, or because they simply did not work!
Previous Attempts with Lasers
Many laser energies have been used in the prostate before now, but limitations on laser power have meant removal of significant amounts of prostate tissue (the real test) has been impossible or unfeasibly slow. The only two contenders for the TURP crown up until now have been prostate electrovaporisation (easy to learn but higher risk of infection, impotence and incontinence) and holmium laser prostate enucleation (as effective as TURP but extremely difficult to learn and associated with severe operative complications in all but the most expert hands).
The Greenlight HPS system from AMS addresses this problem by means of delivering a very powerful modulated laser beam which is absorbed by the haemoglobin pigment in tissue. This means that when the laser is applied to prostate tissue massive localised heating of the tissue occurs resulting in instantaneous vaporisation: due to the laser - characteristically bleeding is close to zero.
Our results show that prostates of any size can be treated, with most men seeing their symptoms improve by two or three fold in the first six weeks. Many men have continuing benefits developing up to nine months after surgery
The technique allowsrapid creation of a generous prostate cavity with almost no bleeding. More than 50% of men can leave hospital on the day of surgery without a catheter, with most others having a soft small catheter for around 18 hours at home (many men remove this themselves)Althoughwe placed catheters post operatively in our initial evaluation period, only a few men have had to have a catheter for more than 12 hours (these have usually been in urinary retention patients, and nearly all have voided extremely well on final catheter removal. Strikingly, very few patients report pain after the procedure: pain and burning on urinating have limited both laser techniques and TURP in the past. About one man in ten will get some burning which may need a fe weeks of simple painkillers to ease the discomfort. Sexual side effects are reduced compared to the standard technique. While very long term results are awaited, the figures after five years of follow up show improvements in symptoms and urological measurements comparable to historical TURP data (about one man in fifty requiring reintervention each year). In particular it appears the prostate tissue removal seen at the time of surgery is genuine when assessed by post-operative prostate ultrasound (between 40-60% of tissue reduction is seen).
Post operative bleeding and discomfort can occur, but aremuch less than with standard TURP, and many men have gone back to work or normal activities within a couple of days, with sport and other activities being possible within a week or two. Of course, some men do take longer to recover and those men with very overactive bladders or catheters pre-operatlively may take some time to settle afterwards.
Anticoagulation, large prostate size (>100g) and poor cardiac status are not contraindications to the procedure, even as a day case.
Our results have been presented at a number of international meetings including the European Association of Urology and the American Urological Association Meeting. In particular our data on large prostates and the absence of absorption of irrigating fluid has attracted much interest. Mr Muir isa founder member of the International GreenLIght Users' Group, which seeks to fine tune and improve further the results from this therapy.
IPSS Symptom scores changes following PVP to one year
The initial score of 23 on the IPSS system shows that most men were suffering severe symptoms which reduced by almost threefold within sixweeks.
Urine flow rates at the same stage and out to five years in our series showimprovements of more than 100%.
GreenLight Training Courses at King's College Hospital
(for urological surgeons wishing to learn the technique)
Course director: Gordon Muir, Consultant Urologist
The course will be in the format of small group teaching with a mixture of didactic presentations linked to live 2 way videoconferencing observing a number of prostate vaporisations in the operating theatre downstairs from our conference room.. There will be an opportunity to visit our state of the art integrated operating theatres during procedures to observe the set-up and logistical issues relating to prostate laser surgery.
The objectives of the course will be that at the end of the course participants will be able to:
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Understand the indications and contraindications for GreenLight PVP
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Explain the mechanism of action and efficacy of high power KTP-YAG laser energy
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Control an operating theatre with a GreenLight laser installation
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Apply their understanding of the GreenLight PVP procedure to their clinical practice
Topics covered in the course include:
GreenLight PVP results
Previous lasers: problems and successes
Why green light? Laser physics and safety
Live cases
Theatre and nursing issues
Discussion: how to startup, avoiding complications
Certificates of GreenLight laser training and CME credits will be awarded to those who have successfully completed the training course. CME accreditation has been applied for.
Refreshments and lunch are included in the course fee
Course dates at King's College Hospital
6th April 2009
11th May 2009
8th June 2009
6th July 2009
Training video (NB this is NOT a substitute for attending a properly run course and having mentoring for the surgical technique)
for further information on courses contact [email protected]
Copyright (c) 1999-2001 GH Muir. All rights reserved.
[email protected]