Sleep Disturbance in Glaucoma Patients Due To Retinal Ganglion Cell Death

MedicalResearch.com Interview with: Carolina P B Gracitelli, M.D. Ophthalmology - PhD Candidate/ Research Fellow University of California San Diego - Hamilton Glaucoma Center  Medical Research: What is the background for this study? What are the main findings?  Dr. Gracitelli:  Of all the diseases that can lead to blindness, glaucoma is one of the most important diseases; it affects more than 70 million people worldwide, of whom approximately 10 % are bilaterally blind. Different studies have reported that the damage caused by glaucomatous disease lead to retinal ganglion cell (RGC) loss and consequently loss of intrinsically photosensitive retinal ganglion cells (ipRGCs), which is a subtype of RGC. This subpopulation of RGC is clearly related with non-image-forming visual function such as photic synchronization of circadian rhythms  and the pupillary light reflex. However, the true impact of glaucoma on sleep quality, sleep disturbance or circadian rhythm was until nowadays controversial. The main clinical finding of our study was that glaucoma leads to RGC death, including ipRGC death. These cells are connected to several non-image-forming functions, including circadian photoentrainment and pupillary reflexes. Therefore, the image-forming and non-image-forming visual systems are associated with glaucoma. Circadian function has not been well investigated in clinical daily practice, but it can interfere with the quality of life of these patients. Concerns about sleep disturbances in glaucoma patients should be incorporated into clinical evaluations.   Medical Research: What should clinicians and patients take away from your report? Dr. Gracitelli:  Our data support the concept that glaucoma is associated with a loss of ipRGCs that mediate the pupillary light response, particularly to the sustained component of the blue flash with a luminance of 250 cd/m2. Additionally, glaucoma patients had significant sleep disturbances that were inversely correlated with a measure of ipRGC function, the pupillary light reflex. These results suggest that the loss of ipRGCs in glaucoma may also lead to sleep disturbances. Both non-visual functions of ipRGCs are correlated, indicating that attention should be paid to the non-image forming visual functions in glaucoma patients.   Medical Research: What recommendations do you have for future research as a result of this study?  Dr. Gracitelli:  Sleep disorders is a complex system, therefore, some conclusions in this study should be carefully evaluated. Further studies with larger cohorts could also help to elucidate the association between the pupillary reflex and the polysomnography parameters. And longitudinal studies can better explain the associations between sleep disorders and glaucoma progression.  In addition, we know that there are several types of ipRGCs and they have specific functions (pupillary reflex or circadian rhythms), therefore, evaluations would also need to include a more thorough assessment to understand better the specific role of ipRGCs in sleep disturbances. However, it is true that these ipRGCs functions are impaired in glaucoma, affecting the quality of life of these patients.   Citation:   Intrinsically Photosensitive Retinal Ganglion Cell Activity Is Associated with Decreased Sleep Quality in Patients with Glaucoma  Gracitelli, Carolina P.B. et al. Ophthalmology Published Online: April 06, 2015 DOI: http://dx.doi.org/10.1016/j.ophtha.2015.02.030MedicalResearch.com Interview with:
Carolina P B Gracitelli, M.D.
Ophthalmology – PhD Candidate/ Research Fellow
University of California San Diego – Hamilton Glaucoma Center

Medical Research: What is the background for this study? What are the main findings?

Dr. Gracitelli: Of all the diseases that can lead to blindness, glaucoma is one of the most important diseases; it affects more than 70 million people worldwide, of whom approximately 10 % are bilaterally blind. Different studies have reported that the damage caused by glaucomatous disease lead to retinal ganglion cell (RGC) loss and consequently loss of intrinsically photosensitive retinal ganglion cells (ipRGCs), which is a subtype of retinal ganglion cell. This subpopulation of RGC is clearly related with non-image-forming visual function such as photic synchronization of circadian rhythms and the pupillary light reflex. However, the true impact of glaucoma on sleep quality, sleep disturbance or circadian rhythm was until nowadays controversial.

The main clinical finding of our study was that glaucoma leads to retinal ganglion cell death, including ipRGC death. These cells are connected to several non-image-forming functions, including circadian photoentrainment and pupillary reflexes. Therefore, the image-forming and non-image-forming visual systems are associated with glaucoma. Circadian function has not been well investigated in clinical daily practice, but it can interfere with the quality of life of these patients. Concerns about sleep disturbances in glaucoma patients should be incorporated into clinical evaluations.

Medical Research: What should clinicians and patients take away from your report?

Dr. Gracitelli: Our data support the concept that glaucoma is associated with a loss of ipRGCs that mediate the pupillary light response, particularly to the sustained component of the blue flash with a luminance of 250 cd/m2. Additionally, glaucoma patients had significant sleep disturbances that were inversely correlated with a measure of ipRGC function, the pupillary light reflex. These results suggest that the loss of ipRGCs in glaucoma may also lead to sleep disturbances. Both non-visual functions of ipRGCs are correlated, indicating that attention should be paid to the non-image forming visual functions in glaucoma patients.

Medical Research: What recommendations do you have for future research as a result of this study?

Dr. Gracitelli: Sleep disorders is a complex system, therefore, some conclusions in this study should be carefully evaluated. Further studies with larger cohorts could also help to elucidate the association between the pupillary reflex and the polysomnography parameters. And longitudinal studies can better explain the associations between sleep disorders and glaucoma progression.

In addition, we know that there are several types of ipRGCs and they have specific functions (pupillary reflex or circadian rhythms), therefore, evaluations would also need to include a more thorough assessment to understand better the specific role of ipRGCs in sleep disturbances. However, it is true that these ipRGCs functions are impaired in glaucoma, affecting the quality of life of these patients.

Citation:

Intrinsically Photosensitive Retinal Ganglion Cell Activity Is Associated with Decreased Sleep Quality in Patients with Glaucoma

Gracitelli, Carolina P.B. et al. Ophthalmology Published Online: April 06, 2015

DOI: http://dx.doi.org/10.1016/j.ophtha.2015.02.030

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MedicalResearch.com Interview with: Carolina P B Gracitelli, M.D. (2015). Sleep Disturbance in Glaucoma Patients Due To Retinal Ganglion Cell Death 

Last Updated on June 10, 2015 by Marie Benz MD FAAD

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