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Top-Nine of the American Society of Cataract and Refractive Surgery 2013 Glaucoma Day
April, 19, 2013, San Francisco, CA, USA
Thomas W. Samuelson
- Recent studies suggest an increasing incidence of late in-the-bag IOL dislocation in pseudoexfoliation eyes that does not appear to be preventable and occurs on average about eight years post surgery. However, there have been dramatic refinements in the surgical treatment of this late complication by utilizing a simplified micro-incision ab-externo approach to suture fixate the existing IOL/capsular bag complex. (Garry Condon, USA)
- Recent clinical trials have confirmed earlier reports that modern cataract surgery with phacoemulsification should be considered an intraocular pressure (IOP) lowering procedure. The degree of average IOP lowering is positively related to the level of IOP with greater expected reduction in those with the highest baseline IOP. (Kuldev Singh, USA)
- The 360-degree suture or cannula trabeculotomy is better for congenital glaucoma than a goniotomy, both in terms of pressure control with a single operation and long-term maintenance of vision. The trabeculotomy procedures are more work and require greater technical skill but the results are worth it. (ASCRS Glaucoma Clinical Committee)
- Mansberger reported on changes in intraocular pressure in 63 eyes within the observation arm (n = 806) of the Ocular Hypertension Treatment Study following cataract surgery and compared those eyes to 743 eyes that did not undergo surgery. While IOP remained 23-24 mmHg in the control group, post-operative IOP in the cataract group was significantly reduced (4.1 mmHg) from a baseline of 24 mmHg (p < 0.001). The effect, which amounted to a 16.5% reduction in IOP, was sustained for 36 months. Roughly 40% of patients experienced at least a 20% reduction in IOP, the same proportion of patients in the OHTS treatment arm that had their IOP controlled with one drop. (ASCRS Glaucoma Clinical Committee)
- IOL power calculations for the high to extreme axial myope should include an adjustment of the axial length if the measurement is by optical biometry (IOLMaster and Lenstar) as recommended by Wang. The adjusted axial length is obtained as follows: Adjusted AL = (0.8814 x measured AL) + 2.8701 This adjusted axial length is then used with the older Holladay 1 formula. If near emmetropia is desired, the IOL power corresponding to the least minus refractive target is selected. Standard optical biometry Holladay 1 Surgeon Factor lens constants are used, such as 1.80 for the SN60WF and 1.87 for the MN60MA. (Warren Hill, USA)
- It is becoming known that contrast sensitivity is reduced in patients with glaucoma, even those with minimal visual field defects. Diffractive optics multifocal IOLs trade contrast for two simultaneous images. For patients with glaucoma, taking a hit in contrast sensitivity from two different directions may make the long-term placement of a diffractive optics multifocal IOL problematic, with a gradually increasing visual disability. (Warren Hill, USA)
- When establishing a baseline set of visual fields, obtain two and separate them by less than one month. Generally, if you explain to the patient that this is the baseline that they are going to have to compare against for many years, they will endorse the plan.
- Whenever a significant event occurs, e.g., glaucoma filtration surgery, it is important to establish a new baseline of functional (i.e., visual field) and structural (i.e., OCT, GDx, or HRT) testing. (ASCRS Glaucoma Clinical Committee)
- Present day cataract surgery does not make future glaucoma care, including glaucoma surgery, more difficult. Removing the cataract first, for example, may improve the likelihood of longterm trabeculectomy success as one significant cause of bleb failure is post trabeculectomy cataract surgery. (Kuldev Singh, USA)
