[Dependency of intraocular pressure on body posture in glaucoma patients : New approaches to pathogenesis and treatment]

Effect of Sleeping Position on the Retinal Nerve Fiber Layer in Individuals with Glaucoma

Aims and background

To evaluate the effect of sleeping in the lateral decubitus position on the average thickness of the retinal nerve fiber layer (RNFL) in the peripapillary region of the optic nerve since the effect of posture on intraocular pressure (IOP) and glaucoma progression is not yet sufficiently understood.

Materials and methods

A cross-sectional observational study was carried out with 40 volunteers who preferably slept in a right lateral decubitus (RLD) (RLD group N = 20) and left lateral decubitus (LLD) (LLD group N = 20) position. IOP was measured in both eyes, first in the sitting position and again after 10 minutes in a supine position, right lateral, and LLD, respectively. The mean thickness of the RNFL and the vertical papillary cup were measured by optical coherence tomography.

Results

The average age of the volunteers was 60.53 ± 7.26 years. There were 32 female and eight male. There was an increase in IOP with the change from the sitting position to the lateral decubitus of 2.7 and 3.6 mm Hg in the RLD group (p < 0.001) and an increase of 3.0 and 3.15 mm Hg in the LLD group (p < 0.001), right eye (RE) vs left eye (LE), respectively. However, there was no difference in IOP values between the groups. The average thickness of the RNFL was in the RLD group-75.10 vs 78.05 μm (p = 0.325) and in the LLD group-81.55 vs 79.95 μm (p = 0.580). Vertical papillary excavation was in the RLD group-0.70 vs 0.65 (p = 0.175) and in the LLD group-0.65 vs 0.65 (p = 1.000), RE vs LE, respectively.

Conclusion

We found no relationship between the lateral decubitus position when adopted preferentially for sleeping and the reduction of the RNFL.

Clinical significance

Search for risk factors for the asymmetrical development of glaucoma, especially in well-controlled IOP in daytime measurements.

How to cite this article

Vaz RT, Montenegro AAL, Quintas Segundo ADS, et al. Effect of Sleeping Position on the Retinal Nerve Fiber Layer in Individuals with Glaucoma. J Curr Glaucoma Pract 2024;18(2):57-62.

Differences Between Angle Configurations in Different Body Positions by Ultrasound Biomicroscopy in Patients with Cortical Age-Related Cataract

Purpose

To investigate the differences in parameters related to angle configuration and lens position in patients with cortical age-related cataract by ultrasound biomicroscopy (UBM) in different body positions.

Methods

Prospective study with 55 patients with cortical age-related cataract proposed for phacoemulsification, examined using a Compact Touch STS UBM (Quantel Medical, France). UBM bag/balloon technology was applied to measure the central anterior chamber depth (ACD) and lens vault (LV) in horizontal and vertical orientation in sitting and supine positions, angle opening distance (AOD500), trabecular iris angle (TIA) and iris lens angle (ILA) in four quadrants: superior, inferior, nasal, and temporal.

Results

We found no significant difference in ACD between sitting and supine positions (p = 0.053); LV was significantly greater in the supine position (p < 0.001); AOD500 in superior and inferior quadrants were significantly longer in the sitting position (p = 0.001; p < 0.001); TIA in superior and inferior quadrants was significantly greater in the sitting position (p < 0.001; p < 0.001), and TIAmax-min was significantly smaller in the sitting position (p = 0.001); ILA in temporal quadrant was significantly larger in the sitting position (p = 0.015) and ILAmax-min was significantly smaller in the sitting position (p < 0.001).

Conclusion

The anterior chamber angle was narrower and the lens was positioned more anteriorly in the supine than in the sitting position in cortical age-related cataract. Different positions may affect the angle configuration and the relative space of lens through different directions of mechanics and modes of action.

Influence of Body Position on Intraocular Pressure After Descemet Membrane Endothelial Keratoplasty: A Prospective Randomized Trial

PURPOSE

The purpose of this study was to analyze the influence of patient positioning on intraocular pressure (IOP) after Descemet membrane endothelial keratoplasty (DMEK) in pseudophakic patients treated for Fuchs endothelial corneal dystrophy.

METHODS

Forty patients were included in this prospective, single-blinded, randomized controlled clinical trial. Patients received a YAG iridotomy 1 day before surgery and an 80% anterior chamber tamponade [20% concentration of sulfur hexafluoride (SF6)]. Postoperative positioning was either supine (group 1) or seated (group 2, at least 30 degrees upper-body high position). IOP was measured with iCare.

RESULTS

There was no statistically significant difference in IOP postoperatively [group 1 vs. group 2-after 1h: 13.9 mm Hg (±4.2 mm Hg) versus 13.6 mm Hg (±4.1 mm Hg) ( P = 1.00); after 2h: 13.9 mm Hg (±5.4 mm Hg) versus 15.3 mm Hg (±4.6 mm Hg) ( P = 0.370); after 4h: 13.8 mm Hg (±4.2 mm Hg) versus 15.2 mm Hg (±4.2 mm Hg) ( P = 0.401]. In group 1, 10% of patients showed IOP decompensations well above 30 mm Hg, and in group 2, there were no IOP decompensations. Seated position led to relative risk reduction of 100% and absolute risk reduction of 10% regarding IOP decompensations. The number of patients needed to position seated to prevent 1 additional IOP decompensation was 10. Rebubbling rates, best spectacle-corrected visual acuity, and reduction of corneal thickness were comparable between the 2 groups in the follow-up period up to 1 month.

CONCLUSIONS

After DMEK in pseudophakic eyes with 80% anterior chamber tamponade, positioning patients with at least 30 degrees elevation of the upper body up immediately after surgery until bedtime prevents IOP decompensations.

Comparing posture induced intraocular pressure variations in normal subjects and glaucoma patients

AIM

To compare the posture-induced variations in intraocular pressure (IOP) between the primary open angle glaucoma (POAG) and non-glaucomatous eyes.

METHODS

A case-controlled age matched study was conducted in 55 successive newly diagnosed POAG and 56 non-glaucomatous patients seen in glaucoma clinic and general outpatient eye clinic in the Alex Ekwueme University Teaching Hospital, Abakaliki. The IOPs of eligible correspondents were measured with Perkin's hand-held tonometer in the sitting, supine flat and supine with pillow positions respectively. Measurement of IOP in each position was done after 15min of assuming such posture.

RESULTS

The IOP difference between the sitting and supine flat position was significantly higher in the POAG than non-glaucoma subjects (7.68±2.08 vs 4.03±0.13 mm Hg, P<0.001). The IOP difference between the sitting and supine with pillow positions was 2.61±1.49 mm Hg for POAG and 1.44±0.70 mm Hg in non-glaucoma (P<0.001), while difference between supine flat and supine with pillow positions was 5.07±2.24 mm Hg in POAG and 2.59±0.66 mm Hg in non-glaucomatous patients (P<0.001).

CONCLUSION

Greater variations in posture induced IOP occurred in POAG patients than non-glaucomatous. The posture induced IOP variation is lowest in the sitting position and highest in the supine flat position. Evaluation of posture induced IOP changes may be an important tool in the management of glaucoma.