Five year results of the Glaucoma Intensive Treatment Study (GITS)
Key Takeaways
- Swedish researchers investigated whether early intensive treatment for glaucoma resulted in better patient outcomes than standard glaucoma treatment.
- The results suggest that initial intensive treatment may be beneficial for glaucoma patients with high untreated IOP at diagnosis but should not be given routinely to all glaucoma patients.
Most patients with glaucoma are offered intraocular pressure (IOP)-lowering treatment immediately after diagnosis. The most common and recommended approach when initiating glaucoma treatment is to set a target IOP and to adjust treatment until this IOP level is reached. Once the target IOP has been reached, the patient is followed with tonometry (test that measures IOP) and repeated functional and structural tests to determine whether the glaucoma damage seems stable or is progressing.
It is important to realize that target IOP is “an estimate” or a “guesstimate,” and that there is little evidence to support any particular algorithm for choosing a target IOP. Considering that there is no general agreement as to how to set a correct target IOP at diagnosis, one might hypothesize that an intensive initial treatment strategy might be more effective than the commonly used escalating strategy. The most obvious expected advantage is that, with a larger initial IOP reduction, a higher percentage of glaucoma eyes might meet their “true” target IOP value more rapidly, and that intensively treated eyes might experience slower disease progression with potentially fewer clinical visits. Disadvantages of an intensive initial treatment strategy are higher costs for glaucoma medications and potentially more side effects, both local and general, as well as greater risk of poor adherence.
Thus, researchers at Lund University in Sweden started the Glaucoma Intensive Treatment Study (GITS) with the aim of studying the effect of intensive initial treatment in comparison with the standard escalation strategy. A total of 242 patients with newly detected early or moderate untreated open-angle glaucoma were randomly allocated 1:1 to receive either intensive initial treatment or standard therapy. The patients were then followed for five years.
The researchers found that visual field outcomes were not overwhelmingly better in the intensive-treatment group, but an analysis conducted after study completion showed definite benefit in patients with higher untreated IOP. (Visual field is how wide of an area your eye can see when you focus on a central point. Damage to visual field is an indicator of glaucoma progression.) Based on the results of this study, the authors suggest that initial intensive treatment may be considered in glaucoma patients with high untreated IOP at diagnosis, although they found no evidence that multi-therapy should be given routinely to all glaucoma patients.
Edited by Miriam Kaplan, PhD
Source: Bengtsson et al, “The Glaucoma Intensive Treatment Study (GITS): A Randomized Controlled Trial Comparing Intensive and Standard Treatment on 5 Years Visual Field Development.” American Journal of Ophthalmology, June 21, 2024; DOI: https://doi.org/10.1016/j.ajo.2024.06.017