Background/purpose: To evaluate in craniosynostosis: 1) the diagnostic accuracy of fundoscopy and optical coherence tomography (OCT) to detect intracranial hypertension (ICH); 2) the time course of retinal thickness after treatment of ICH; and 3) the relation between high hyperopia (HH) and fundoscopy/OCT scan findings. Methods: Syndromic, multisuture, unicoronal, unilambdoid and sagittal synostosis patients visiting our national center were included in this longitudinal cohort study and formed a consecutive series. Retinal layers on OCT, OCT fundus image and fundoscopy were evaluated. ICH was scored according to presence of abnormal intracranial pressures, hydrocephalus, progressive cerebellar tonsillar herniation or fingerprinting and growth arrest. Diagnostic accuracy of OCT, fundoscopy and fundus image, the time course of retinal thickness after ICH and interference of HH were analyzed using linear mixed models. Results: 577 OCT scans in 307 patients were included. ICH was found in 7.2%. Combining total retinal thickness (TRT), OCT fundus image and fundoscopy resulted in a sensitivity of 76% and 81% specificity to detect signs of ICH. TRT was increased in patients who have had signs of ICH versus patients who never had signs of ICH (β+44.9 µm in patients who have had ICH, 95%CI 9.0-80.8,P=0.01). TRT decreased to normal in the years after surgery (β -3.6 µm/year, 95%CI -7.2 - -0.05, P=0.047). There were greater odds of having increased TRT in patients with HH (OR 2.9, 95%CI 1.1-7.6,P=0.03). Conclusions: The correlation between TRT, OCT fundus image, fundoscopy and particularly for the combination of these parameters with ICP surrogate markers is fair. Increased TRT in the presence of a clinical suspicion of ICH warrants further screening.