Diurnal functional and anatomical changes in X-linked retinoschisis

Abstract

Background To investigate the changes in macular cystic schisis (MCS) and sensitivity during the day in X-linked retinoschisis (XLRS) patients. Methods Treatment-naïve patients with genetically verified XLRS underwent best-correlated visual acuity (BCVA) testing with ETDRS charts, spectral domain optical coherence tomography, and microperimetry (MP) twice a day, at 9 a.m. and 4 p.m., to measure changes in central retinal thickness (CRT), macular volume (MV), average threshold (AT), and fixation stability parameters (P1 and P2). Results At baseline, the BCVA of the 14 eyes of 8 patients amounted 0.73 (± 0.23) LogMAR. Between timepoints, the BCVA increased in 3.21 letters (p = .021), the AV improved in 1.84 dB (p = .03, 9.73%), the CRT decreased in 24.43 µm (p = .007, − 4.05%), and the MV dropped in 0.27 µm3 (p = .016, − 2.68%). P1 and P2 did not variate. The collapse of the MCS led to the reduction of macula thickness. CRT at baseline correlated with the decrease of CRT (Spearman’s ρ: − 0.83 [p = .001]). Age and change of BCVA, CRT, and AV did not correlate among one another. Eyes with disrupted ellipsoid zone showed a more prominent change in CRT (p = .050). Photoreceptor outer segment length and integrity of the external limiting membrane and cone outer segment tips were not associated with BCVA, AT, or CRT variation. Conclusion Eyes of treatment-naïve XLRS patients show diurnal macular thickness and function changes. Eyes with pronounced macular thickness show a greater reduction of the MCS. These results should be taken into consideration in upcoming clinical trials in XLRS. Trial registration number Institutional Review Board of the Hamburg Medical Chamber (Ethik-Kommission der Ärztekammer Hamburg): 2020–10,328.

Morphological and functional parameters in X-linked retinoschisis patients–A multicentre retrospective cohort study

“…However, these studies employed varied treatment protocols and follow-up durations with no control group. ICC is prone to substantial spontaneous fluctuations, as evidenced by Mautone et al, who observed significant diurnal changes in macular thickness and visual function ( 38 ). Campbell et al showed complete spontaneous resolution of ICC with significant vision improvement in two case reports (6 years; 23 years).…”

“…Regarding functional endpoints, BCVA might not be suitable due to poor symmetry between both eyes, the very slow rate of deterioration, and the lack of improvement after CAI treatment. On the other hand, retinal sensitivity as measured by microperimetry, has shown improvement following the reduction of ICC in XLRS patients (38), mirroring a pattern established with the resolution of intraretinal fluid in diabetic macular edema (40). Therefore, considering its significance as a crucial functional parameter in other gene therapy trials (41), microperimetry measurement could be considered the optimal choice for evaluating functional outcomes in a gene therapy trial for XLRS.…”