Effect of Light Intensity on the Relative Afferent Pupillary Defect in Unilateral Neuro-ophthalmic Pathology.

SIGNIFICANCE: Objective pupillometry with standardized light intensities allows a comprehensive assessment of the relative afferent pupillary defect in patients with unilateral neuro-ophthalmic pathology. PURPOSE: This study aimed to determine the impact of varying light intensities on the grade of relative afferent pupillary defect in unilateral neuro-ophthalmic pathology vis-à-vis healthy controls. METHODS: Monocular pupillary light reflexes of 20 controls (14 to 50 years) and 31 cases (12 to 72 years) with clinically diagnosed relative afferent pupillary defect were measured thrice using 1-second-long light pulses, followed by 3 seconds of darkness, at eight light intensities (6.4 to 1200 lux) using objective pupillometry. The relative afferent pupillary defect was quantified as the ratio of the percentage change in the direct light reflexes of the left and right eyes. Its change with light intensity was described using standard exponential fits. RESULTS: The median (25th to 75th interquartile range) defect score of 54.8% cases decreased from baseline values of 1.58 (1.25 to 1.87) for right eye pathology and 0.45 (0.39 to 0.55) for left eye pathology to saturation values of 1.18 (1.05 to 1.31) and 0.98 (0.95 to 1.06), respectively, at light intensities between 56.9 and 300.5 lux. Like controls (1.01 [1.00 to 1.06]), the defect scores of the remaining 45.2% cases were constant with light intensity at 1.23 (1.18 to 1.46) and 0.87 (0.86 to 0.89) for right and left eye pathologies, respectively. CONCLUSIONS: Relative afferent pupillary defects may decrease with test light intensity in a significant proportion of patients with unilateral neuro-ophthalmic pathology. This highlights the importance of objective pupillometry with standardization light intensities for clinical assessment of afferent pupillary defects.

New insights on the systematics and reproductive behaviour in tree frogs of the genus Feihyla, with description of a new related genus from Asia (Anura, Rhacophoridae).

The taxonomy of the Asian tree frog genus Feihyla has been in a state of flux ever since its proposal in 2006. Allocation of species to Feihyla remains confusing, particularly with respect to the closely related genus Chirixalus (formerly Chiromantis sensu lato). At the same time, several Chirixalus species are known only from cursory descriptions and remain poorly studied. In this study, we review the systematics of the genus Feihyla and clarify the generic placement of its members along with all other species currently assigned to Chirixalus. Based on integrative evidence gathered from new collections, examination of types and original descriptions, morphological comparisons, phylogenetic relationships inferred from a multi-gene (three mitochondrial + two nuclear) 1,937 bp dataset, as well as reproductive modes including egg-laying, nesting behaviour, and clutch morphology, our results show that the six species formerly attributed to Feihyla represent three morphologically and phylogenetically distinct groups: (1) the type species of the genus, F. palpebralis, along with F. fuhua constitute the Feihyla palpebralis group or Feihyla sensu stricto; (2) F. inexpectata and F. kajau represent the Feihyla vittiger group and are closely related to the Feihyla palpebralis group; (3) 'F. hansenae' and 'F. vittata' constitute another distinct and reciprocally monophyletic lineage, more closely related to Chirixalus + Chiromantis. In light of long-standing taxonomic confusions and unresolved phylogenetic relationships, we propose recognition of a new genus to accommodate 'F. hansenae' and 'F. vittata' in order to stabilise the classification of several Asian rhacophorid species that have been frequently confused and transferred within the Chirixalus-Chiromantis-Feihyla complex. Based on integrative evidence, eight species previously attributed to the genus Chirixalus or Feihyla are formally transferred to Rohanixalus gen. nov., two Chirixalus members are allocated to Feihyla, and one synonymised with Rhacophorus bipunctatus. In addition, we report the first member of the tree frog family Rhacophoridae from the Andaman Islands of India-Rohanixalus vittatus, along with description of its male advertisement call, reproductive behaviour including parental care by the female, and larval morphology. Extended distributions are also provided for Rohanixalus species across Northeast India. The study further reveals the presence of potentially undescribed diversity in the new genus. Altogether, the revised classification and novel insights presented herein will facilitate a better working taxonomy for four phylogenetically distinct but morphologically related groups of Old World tree frogs.