Argon laser problem

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I've been having a hard time using the argon laser in my office and I was wondering if anyone else has had any similar problems or suggestions.

The problem is that I can't get the slit lamp close enough to put things in focus when using a 3 or 4 mirror lens. The laser is mounted on the front of the slit lamp and I can get things almost in focus as I edge it forward, but inevitably the front of the laser apparatus ends up hitting the lens and putting pressure on the pts eye.

I usually do the exam with my glasses off. My RX is approximately -2.50 + 2.50 @ 90 ou. I have no trouble doing normal exams at the slitlamp with my glasses off. If I wear my glasses it seems there is a lot of glare and so on. I've tried adjusting the oculars to -1.25 or so to see if it helps but it doesn't.

My partner and the one other person who uses it don't have the same problem. My partner says he has to get pretty close, but not so close that the laser hits his lens.

I'm at a bit of a loss and would love to hear any thoughts or suggestions. I've had to cancel a couple of PRPs because I was just unable to get a view because of this.

Yea, as you know adjusting the eye pieces only corrects spherical aberration so you can might maybe want to get anti-reflective coating on your glasses or tape -2.50 cyl x180 lenses on the eye pieces when you use the laser. Wish I could help more.

I'm going to have to agree with Shnurek, as much as it pains me to do so. ;-)

Trying to laser with that much uncorrected cylinder is going to be a continuing problem, regardless of how you set the oculars.

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Originally Posted by visionary

i'm going to have to agree with shnurek, as much as it pains me to do so. ;-)

Had this problem with our argon too. While this won't help if in fact there's an issue with astigmatism (though I presume you did a lot of lasers in training just fine and you had a similar refraction then). Turns out the laser had shifted on the track plus it had other servicing issues. Worth checking out if no one has serviced the laser in a long time. Your partners may have just gotten used to the fact that it is super close.

Originally Posted by Pastrami King

Had this problem with our argon too. While this won't help if in fact there's an issue with astigmatism (though I presume you did a lot of lasers in training just fine and you had a similar refraction then). Turns out the laser had shifted on the track plus it had other servicing issues. Worth checking out if no one has serviced the laser in a long time. Your partners may have just gotten used to the fact that it is super close.

Hmm thanks, that may be it. Yeah I really don't think its the astigmatism, as you surmised that hasn't changed and I've used multiple other setups (not to mention just all the slitlamp exams day-to-day) without a problem, its just on that one slitlamp where we have the laser set up. I can actually use this one with a few select lenses but others I end up too close.

What is the working distance of your slit lamp microscope? One reason that longer focal length microscopes (f125 vs f100) were made--besides giving those with orangutan arms some relief, was to allow placement of laser apparatus in the space in front of the objective while still allowing a practical working distance to the treatment lens.

This usually isn't a problem with laser-dedicated slit lamps which are usually specified for laser treatment working distances, but it could be with diagnostic slit lamps onto which an adapter has been fitted.

Is there any improvement with wearing your spectacles or changing the power on the microscope?

Originally Posted by orbitsurgMD

What is the working distance of your slit lamp microscope? One reason that longer focal length microscopes (f125 vs f100) were made--besides giving those with orangutan arms some relief, was to allow placement of laser apparatus in the space in front of the objective while still allowing a practical working distance to the treatment lens.

This usually isn't a problem with laser-dedicated slit lamps which are usually specified for laser treatment working distances, but it could be with diagnostic slit lamps onto which an adapter has been fitted.

Is there any improvement with wearing your spectacles or changing the power on the microscope?

It is a diagnostic slit lamp that has been jerry-rigged with a laser, so that is probably part of the problem. Really no improvement with my glasses or adjusting the scope. I've learned that there are just certain lenses I can use and certain ones I can't-- ie the lenses that are physically shorter are ok but some of them are quite long and those are the ones I end up running into.

Originally Posted by odieoh

It is a diagnostic slit lamp that has been jerry-rigged with a laser, so that is probably part of the problem. Really no improvement with my glasses or adjusting the scope. I've learned that there are just certain lenses I can use and certain ones I can't-- ie the lenses that are physically shorter are ok but some of them are quite long and those are the ones I end up running into.

Ah, that's different. I think orbitsurgMD is onto something. Based on your initial description, it sounded like an issue with your optics, rather than the slit lamp's. You may want to try and change slit lamps to one with a longer working distance. You could even see if there's another in your clinic that the laser could be moved over to. If not, it's probably worth investing in one. Could probably get one used. The Haags, in particular, last forever.

Originally Posted by odieoh

I've been having a hard time using the argon laser in my office and I was wondering if anyone else has had any similar problems or suggestions.

The problem is that I can't get the slit lamp close enough to put things in focus when using a 3 or 4 mirror lens. The laser is mounted on the front of the slit lamp and I can get things almost in focus as I edge it forward, but inevitably the front of the laser apparatus ends up hitting the lens and putting pressure on the pts eye.

I usually do the exam with my glasses off. My RX is approximately -2.50 + 2.50 @ 90 ou. I have no trouble doing normal exams at the slitlamp with my glasses off. If I wear my glasses it seems there is a lot of glare and so on. I've tried adjusting the oculars to -1.25 or so to see if it helps but it doesn't.

My partner and the one other person who uses it don't have the same problem. My partner says he has to get pretty close, but not so close that the laser hits his lens.

I'm at a bit of a loss and would love to hear any thoughts or suggestions. I've had to cancel a couple of PRPs because I was just unable to get a view because of this.

What is the model of the photocoagulator and the slit lamp it's using?
Many have focus adjustments that can be accidentally dialed out.
Contact lenses will increase the aberrations, as they usually have lens power.
A contact lens which is not coated for laser (specific) will also hinder somewhat, but 3 mirror usually do OK.
Photos of your system would help me identify mismatches of laser and delivery system or a type of unit which may have adjustments.

Laserdude to the rescue!! Thank you for your interest, I have largely fixed the problem by just being selective about what lenses I use, but I'll try and take a photo and post it if you like. I don't know the model offhand but ill get it.