advertisement

Glaucoma Dialogue IGR 14-2

Response

Comment by Steve Mansberger on:

50418 Reduction in Intraocular Pressure after Cataract Extraction: The Ocular Hypertension Treatment Study, Mansberger SL; Gordon MO; Jampel H et al., Ophthalmology, 2012; 119: 1826-1831

Find related abstracts

I (on behalf of the other authors) want to thank the editors of the International Glaucoma Review for choosing our manuscript for comment. Commenter #1 wondered why our study used both eyes of a particular patient. We used both eyes of a particular patient to increase the sample size of the study, and used a previously validated mixedeffects model with subject number as a random effect to control for the intra-individual variability of both eyes requiring cataract surgery. While our results document the results in ocular hypertension, we are unable to comment on its effect in glaucoma patients. Therefore, we agree with the commenters that one should use caution when extrapolating the results to glaucoma patients, or patients who are already on ocular hypotensive medications. We hoped to predict who would have the most IOP lowering from cataract surgery and who may have minimal benefit from cataract surgery and require simultaneous or subsequent glaucoma surgery. Unfortunately, only higher pre-operative intraocular pressure was associated with greater IOP lowering. In other words, those who had the highest pre-operative IOP were those that would have the most IOP lowering. This creates the classic decision to determine 'risk versus benefits'. Those ocular hypertension patients with visually significant cataract and the highest IOP have the highest risk of worsening glaucoma, but also may have the greatest benefit to cataract surgery. If cataract surgery does not lower IOP adequately, they are also at highest risk of requiring urgent glaucoma surgery. Overall, we agree with the commenters that eye surgeons should counsel their patients regarding the wide differences in IOP lowering after cataract surgery, and the possibility of subsequent glaucoma surgery if their IOP is not controlled with topical ocular hypotensive medications. Hopefully, researchers may discover other predictive factors for IOP lowering after cataract surgery. These may include anterior chamber configuration, pigmentation of the trabecular meshwork, the size of the intumescent cataract, the characteristics of the cataract surgery such as phacoemulsification time, the amount of post-operative inflammation and pigment release, and the characteristics of the posterior chamber intraocular lens within the lens capsule. Several of these factors have been previously associated with success of laser or glaucoma surgery for lowering intraocular pressure. Finally, researchers using minimally invasive glaucoma surgeries need to report the amount of IOP lowering when used with and without simultaneous cataract surgery.

• ← Previous
• Next →