Monday November 9, 2009
Morning of cataract surgery in glaucoma patients
It turns out that the pre-operative challenge with the axial length discrepancy was nothing compared with the first post-operative day surprise; this one hurt but was a learning experience. Pre-operatively, there was a 3D difference in axial length based on contact ultrasound. We therefore repeated the test with the IOL Master, still showing a discrepancy that could not be fully accounted for by axial length and corneal curvature, but only 1.25 D off instead of 3D. I therefore aimed for the IOL Master selection.
Surgery went smoothly, and on the first post-operative day his visual acuity was already much better for distance without correction as 6/12. "But Doctor, it's not clear for reading and you said it would be." 99% of my patients opt for full distance correction when selecting the lens implant for their cataract surgery. It is only a handful of patients who really want to be corrected for near with their intraocular lenses and wear glasses for the distance. In this case, as a College professor, most of his work is at near. In reviewing his chart, I did notice that two visits back I had written to correct him for near when it comes time to do the cataract surgery. When we had a cancellation one week prior and he was in the office wondering when his cataract surgery was going to take place, we rushed him in for this week to fill in for the cancellation. We had not clearly flagged his electronic medical record with the fact that we had agreed to a near correction for his final refraction and paid the price by ending up with a good visual outcome for the wrong distance.
He was booked back for an IOL exchange the following week. Fortunately, the use of the Bausch & Lomb Akreos MI60 lens allowed for relatively easy explanting but did require cutting the lens in half within the anterior chamber. The cornea was quite swollen afterwards, markedly blurring his vision, and we still await full recovery.
Prior to this, I had long intended to use procedure specific consent forms, and had even downloaded them from OMIC and posted links to them on my website. However, I had yet to enforce their use in my office as our hospital does not require procedure specific consent forms. By the time he was back for the IOL exchange, procedure specific consent forms were fully implemented into our office; we created on-line versions for our Electronic Medical Record system for cataract and glaucoma procedures. The cataract form includes the patient documenting correction for near or far and whether glasses will be needed for far or near. Options also include monovision correction with one eye for distance and the other for near and toric correction option if astigmatism present. I am still not a believer in multifiocal IOLs so do not offer these to my patients but do offer to refer them elsewhere if that is an option they would like to pursue.
The only extra information noted at the time of surgery was that the cataract wound needed to be hydrated to assure water-tight as was otherwise a bit leaky at the end of the case. Visual acuity was 6/24 pre-op, 6/18 first day, and 6/12 at one week post-op uncorrected. He continues to be followed.
When the anaesthetist did arrive, she advised the patient to see her family doctor regarding her low K+ and we were able to proceed with the cataract surgery. One day post-operative her vision was 6/6 uncorrected and there was not even a pressure spike despite her chronic open angle glaucoma.
Afternoon of glaucoma surgery
This patient was 4 months out from me having performed a trabeculectomy with mitomycin in her left eye, which was stable with an IOP of 7. She was referred back for surgery for her right eye as she was showing progressive damage with IOP 17-20 on Xalatan, Alphagan and Cosopt. She had prior cataract surgery as well in both eyes.
Despite no cardiac or stroke history, this patient has been taking aspirin daily which might explain the difficulty I had in controlling her bleeding during this surgery. This is where the topical application of 1:1,000 epinephrine can be quite helpful in constricting the leaking blood vessels to help control the bleeding so that these blood products don't result in the surgery failing.
The IOP on the first post-operative day was 6 with some suspended droplets of blood in the viscoelastic in her anterior chamber. Unfortunately, it is too difficult for this patient to continue her follow-up visits at my office, even though the referring ophthalmologist is only about 15kms away across town. I really prefer seeing my patients through the post-operative period but also have to make life easier for my patients.
This patient was showing significant progression despite prior laser treatment and maximum tolerated medications. Pre-op visual acuity was 6/9 OD and 6/60 OS with IOPs of 9 OD and 31 OS @1140hrs.
At the time of surgery, again there was some difficulty in controlling bleeding, but it was otherwise straightforward. The pressure on the first post-operative day was just 4 with a low diffuse bleb and no blood in the anterior chamber. However, given the bleeding at the time of surgery, the patient was advised to stay off aspirin products for at least 3 more days. IOP was 3 with VA of 6/24 at the 1 week visit and IOP was 7 with VA of 6/21 at the 3 week visit.
Do you advise patients to stop aspirin products prior to their glaucoma surgery? If so, how much beforehand? When do you have them resume therapy?
This gentleman developed chronic angle closure following a Central Retinal Vein Occlusion. Pre-operative IOP was 29 with visual acuity of Count Fingers at 1'. The angle was almost completely closed with pigmented debris and the were no signs of any active new vessel growth by the time they were referred to see me. He had already undergone several Avastin injections into the vitreous to decrease the new vessel growth. As noted in the tweet that I had posted above, there was a prior extracapsular cataract surgical wound which was penetrated at the time of the trabeculectomy.
IOP was 3 on the first post-operative day with 3+ red blood cells suspended in the anterior chamber but no layered hyphema. Six days post-operative, the patient presented to the emergency department of our hospital and was seen by the resident on call. His IOP was 30 and I instructed the resident on digital massage, pressing on the eye at the limbus at the 6:00 position through the lower lid with the patient looking upward. He was able to get the IOP down to 4 before discharging him to see me the next day.
The IOP was 41 when the patient came to see me the next day. I have a rule of thumb to never lyse the scleral sutures until at least the 3 week mark, except when I break my own rule if the pressure seems like it won't stabilize otherwise. This was once such case. After suture lysis, the IOP was 29 and I refrained from massaging the eye as I did not want to over-do things and end up with a hypotonous eye. If the pressure does get too low in the early post-operative period, there is a chance that it will never recover and will result in ongoing visual loss.
Questions to consider:
1. In the face of prior extracapsular cataract surgery, would you go directly to a tube device such as an Ahmed Glaucoma Valve or Baerveldt implant rather than doing a trabeculectomy?
2. Do you perform ocular massage on patients if the pressure is high? Do you instruct patients on how to perform these massages themselves?
3. When would you lyse the scleral sutures and how often do you end up lysing sutures?