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INTRODUCTION: Tear sampling is an attractive option for collecting biological samples in ophthalmology clinics, as it offers a non-invasive alternative to other invasive techniques. However, there are many tear sampling methods still in consideration. This study explores the suitability of Schirmer's test strip and microcapillary tube as reliable and satisfactory methods for tear sampling. METHODS: Tear samples were collected from eight healthy volunteers using the standard Schirmer's test strip method with or without anesthesia and microcapillary tubes. The total tear protein concentrations were analyzed via spectrophotometry and bicinchoninic acid (BCA) protein assay. The protein profile was determined by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). The optimal wetting length of Schirmer's strip and suitable buffer solutions were compared. Discomfort levels reported by participants and the ease of execution for ophthalmologists were also evaluated. RESULTS: Tear samples exhibited typical protein profiles as shown by SDS-PAGE. The mean total protein obtained from an optimum wetting length of 20 mm using Schirmer's strip without anesthesia in phosphate-buffered saline (PBS) yielded substantial quantities of protein as measured by nanophotometer (220.20 ± 67.43 µg) and the BCA protein assay (210.34 ± 59.46 µg). This method collected a significantly higher quantity of protein compared to the microcapillary tube method (p=0.004) which was much more difficult to standardize. The clinician found it harder to utilize microcapillary tubes, while participants experienced higher insecurity and less discomfort with the microcapillary tube method. PBS used during the tear protein extraction process eluted higher tear protein concentration than ammonium bicarbonate, although the difference was not statistically significant. Using anaesthesia did not ease the sampling procedure substantially and protein quantity was maintained. CONCLUSION: Good quality and quantity of protein from tear samples were extracted with the optimized procedure. Schirmer's strip test in the absence of local anesthesia provided a standard, convenient, and non-invasive method for tear collection.
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Soemmering's ring and spontaneous lens absorption are two distinct conditions that are uncommon and unlikely to occur simultaneously. We report a case of a 67-year-old man who presented with blurred vision in his left eye and has had poor eyesight since birth. His right and left eye visual acuities were 6/7.5 and hand movement (HM), respectively. There was no relative afferent pupillary defect (RAPD). The right eye's examination was unremarkable. The left eye revealed a spontaneous rupture of the anterior lens capsule with partially absorbed lens material and the presence of Soemmering's ring. There was no evidence of phacodonesis. The left fundus appeared slightly hazy, while the retina appeared flat. Extraction of the left eye lens was performed for the patient, and he was left aphakic. In this case, the patient's Soemmering's ring was linked to the ruptured anterior lens capsule followed by spontaneous partial absorption of lens material, which caused deposition of residual lens filaments near the equator of the capsule sac. In addition to ocular trauma, patients with congenital rubella infection of the eye, uveitis, and Morgagnian cataract have reported spontaneous absorption of lens material. The exact mechanism by which cataracts dissolve spontaneously is unlikely to be the same in all patients. This patient who has had an unsightly left eye since birth is presumed to have been born with an ocular infection complicated by amblyopia. The presence of both the Soemmering's ring and spontaneous lens absorption is unusual in this case. Early attention to the precious fellow eye is critical to ensure that the other unaffected eye maintains an adequate vision and allows independent patient mobility.
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PURPOSE: The aim of this study was to evaluate the choroidal and photoreceptor thickness in highly myopic eyes and its correlation with visual acuity. METHODS: This is a cross-sectional, observational study involving 57 eyes of 57 highly myopic subjects [spherical equivalent ≥ -6 diopters (D) or axial length ≥ 26 mm] seen in a tertiary institutional center. Eyes with any clinical evidence of maculopathy or amblyopia were excluded. All subjects underwent a refraction assessment, visual acuity, axial length measurement using the IOL Master, and full ocular assessment. Eyes were imaged using Spectralis Optical Coherence Tomography by one experienced operator. Two independent investigators manually measured subfoveal choroidal thickness (SFCT) and foveal photoreceptor thickness (FPT). RESULTS: The mean SFCT was 195.88 ± 87.63 µm (range: 32-373) and mean FPT was 96.68 ± 11.23 µm (range: 67-100), after correction for ocular magnification. The best corrected visual acuity (BCVA) in LogMAR was negatively correlated with SFCT (r = -0.510, p = 0.001) and FPT (r = -0.397, p = 0.002) and positively correlated with age (r = 0.418, p = 0.001) and axial length (r = 0.551, p = 0.001). Multiple linear regression analysis showed that age, axial length, and corrected FPT were significant risk factors for poorer BCVA (p = 0.021, < 0.001, and 0.02, respectively). CONCLUSION: FPT, age, and axial length are significant moderate predictive factors for poorer visual acuity in highly myopic eyes without myopic maculopathy. Thinner SFCT does not translate into poorer vision.
