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Purpose: To evaluate the effect of pterygium excision on the posterior corneal surface and analyze the factors associated with those changes. Methods: A prospective, interventional study including 33 eyes of 31 patients who underwent pterygium excision at the Tel Aviv Medical Center (Tel Aviv, Israel). Exclusion criteria included corneal dystrophy, pseudopterygium, corneal scarring, or previous ocular surgery in the treated eye. Data were obtained by using the Galilei dual Scheimpflug analyzer. Recorded posterior corneal data included steep keratometry, flat keratometry, mean keratometry, corneal astigmatism, best-fit sphere, and the squared eccentricity index (e2). Posterior surgically induced astigmatism (SIA) was calculated to demonstrate the astigmatic effect of surgery. Anterior-segment high resolution optical coherence tomography was used to measure pterygium dimensions (depth and horizontal/vertical size). Results: The mean age was 53.7 ± 16.7 years. Posterior corneal SIA was 0.9 ± 1.1 D (P < 0.001) and was significantly correlated with age (r = 0.568, P = 0.002), horizontal pterygium size (r = 0.387, P = 0.046), and preoperative posterior astigmatism (r = 0.688, P < 0.001). In a multivariable analysis, only age (coefficient = 0.010, P = 0.038) and preoperative posterior astigmatism (coefficient = 0.648, P = 0.002) remained significant. Pterygium dimensions were not significantly associated with SIA magnitude. Flat keratometry steepened by 0.5 ± 1.1 D (P = 0.019), mean keratometry steepened by 0.3 ±0.6 D (P = 0.035), posterior astigmatism was reduced by 0.4 ± 1.2 D (P = 0.072), and e2 decreased by 5.1 ± 17.3 (P = 0.021). Conclusions: Pterygium excision has a significant astigmatic effect on the posterior corneal surface. The astigmatic effect increases with age and with higher preoperative posterior astigmatism. Pterygium depth and size are not associated with the degree of surgical astigmatic effect.

Optic pathway glioma (OPG) presents in childhood and can cause significant morbidity and visual loss. Magnetic resonance imaging (MRI) is the current imaging modality of choice for evaluation of OPG progression, but it is a relatively limited resource often requiring sedation in the pediatric age group. Additionally, OPG progression on MRI does not always correlate with clinical progression. As a result, several other modalities for evaluating OPG are being investigated, including optical coherence tomography (OCT), a readily available imaging technique in ophthalmic practice. The purpose of the present study was to examine the association between retinal nerve fiber layer (RNFL) thickness measured using OCT and optic nerve function in children with OPG with and without neurofibromatosis-1 (NF-1). A retrospective chart review was conducted to identify children diagnosed with OPG from 2001 to 2015 at a tertiary pediatric medical center. The correlation between OCT measurements and clinical visual parameters was statistically analyzed. Included were 23 children with imaging-confirmed OPG and spectral domain OCT: 10 with NF-1 (mean age at diagnosis 5.8 years) and 13 without (mean age at diagnosis 5.9 years). The glioma involved the chiasma-hypothalamus in 19 patients, optic nerve in 11, and optic tract in 7; more than one anatomic site was affected in 15. Symptoms were reported in 2 patients with NF-1 and most patients without NF-1. Visual field defects included monocular, bitemporal, nasal, and homonymous hemianopia. Initial mean RNFL was 85.4 μm in the NF-1 group and 65 μm in the non-NF-1 group. Visual acuity deteriorated in 1/10 patients and 5/13 patients, respectively. Repeated OCT showed continued RNFL thinning in 3 patients (5 eyes) in the NF-1 group and in 8 patients (11 eyes) in the non-NF-1 group, often associated with a decrease in optic nerve function. In conclusion, visual function in children with OPG is correlated with repeated OCT measurements and weakly with neuroimaging. Children without NF-1 are usually symptomatic and have a worse clinical outcome. These findings may have important implications when considering initiating, continuing or stopping chemotherapy for OPG. The application of OCT in the assessment of OPG and the correlation of the findings to clinical progression can have a significant impact on OPG patient management.