The relationship between age, axial length and retinal nerve fiber layer thickness in the normal elderly population in Taiwan: The Chiayi eye study in Taiwan.

AIMS: To interpret how the thickness of the peripapillary retinal nerve fiber layer (RNFL) changes with increasing age, axial length, or anterior chamber depth as measured by spectral domain optical coherence tomography (OCT) in the normal elderly population in Taiwan. METHODS: A total of 82 volunteers (143 eyes) were enrolled. Generalized estimating equations were used to evaluate the correlation. RESULTS: The RNFL was significantly thinner in the superonasal (p = 0.004), inferotemporal (p = 0.046), and temporolower (p = 0.009) segments with age. The same trend was also observed in the superotemporal (p = 0.330) segment, although it was not statistically significant. The global RNFL thickness decreased by 4.97 µm per decade (ß = -0.497; p = 0.021), and thinning was significant in the superonasal (-9.90 µm per decade, p < 0.001) and temporolower (-6.78 µm per decade, p < 0.001) segments; the same trend showed borderline significance in the superotemporal (-6.96 µm per decade, p = 0.073) and inferotemporal (-7.23 µm per decade, p = 0.059) segments. In eyes with longer axial length, the RNFLs significantly decreased in the non-temporal segments. Global RNFL thickness decreased by 3.086 µm for each additional millimeter of axial length (ß = -3.086; p < 0.001). CONCLUSIONS: Changes in RNFL thickness were correlated with age in the superonasal, superotemporal, inferotemporal, and temporolower segments, and were correlated with axial length in the non-temporal segments. Anterior chamber depth was not correlated with RNFL thickness.

Small-Field Measurements of 3D Polymer Gel Dosimeters through Optical Computed Tomography.

With advances in therapeutic instruments and techniques, three-dimensional dose delivery has been widely used in radiotherapy. The verification of dose distribution in a small field becomes critical because of the obvious dose gradient within the field. The study investigates the dose distributions of various field sizes by using NIPAM polymer gel dosimeter. The dosimeter consists of 5% gelatin, 5% monomers, 3% cross linkers, and 5 mM THPC. After irradiation, a 24 to 96 hour delay was applied, and the gel dosimeters were read by a cone beam optical computed tomography (optical CT) scanner. The dose distributions measured by the NIPAM gel dosimeter were compared to the outputs of the treatment planning system using gamma evaluation. For the criteria of 3%/3 mm, the pass rates for 5 × 5, 3 × 3, 2 × 2, 1 × 1, and 0.5 × 0.5 cm2 were as high as 91.7%, 90.7%, 88.2%, 74.8%, and 37.3%, respectively. For the criteria of 5%/5 mm, the gamma pass rates of the 5 × 5, 3 × 3, and 2 × 2 cm2 fields were over 99%. The NIPAM gel dosimeter provides high chemical stability. With cone-beam optical CT readouts, the NIPAM polymer gel dosimeter has potential for clinical dose verification of small-field irradiation.

Stevens-Johnson syndrome following cataract surgery.

A case of Stevens-Johnson syndrome in a healthy 58-year-old woman who underwent cataract surgery under topical anesthesia is reported. General skin erosions developed 2 hours after surgery. The patient's family doctor diagnosed that she was allergic to seafood. One month later, she underwent phacoemul-sification surgery in the other eye. After surgery, she developed Stevens-Johnson syndrome with general skin lesions, erythema nodosa, genital mucosa erosion, oral ulcers, gastritis, and conjunctiva edema. The symptoms subsided 2 weeks later after immunotherapy. Although nonpreserved anesthesia (2% lidocaine) has seldom been reported to cause allergic reactions via the intravenous or the intramuscular route, it is possible that an intracameral injection of 0.2% lidocaine during cataract surgery can induce Stevens-Johnson syndrome. Careful evaluation of the patient's history and proper treatment were recommended to prevent additional complications.