Comparison between Optic Disc Torsion of Fellow Eyes in Unilateral Normal-tension Glaucoma and Normal Eyes

PURPOSE: To determine the association between optic disc tilt and torsion of glaucomatous and fellow eyes of unilateral normal-tension glaucoma (NTG) patients and normal. METHODS: We measured optic disc tilt and torsion of 23 unilateral NTG patients and 23 normal controls by analyzing fundus photography and compared 3 groups. We also measured retinal nerve fiber layer (RNFL) thickness through optical coherence tomography in 23 unilateral NTG patients and compared the findings with those of normal eyes. RESULTS: The mean values of optic disc tilt ratio and torsion degree in glaucomatous eyes were 1.17 ± 0.19° and 15.57 ± 8.16°, respectively, while those in fellow eyes were 1.10 ± 0.10° and 8.26 ± 5.20°. There was no significant difference in tilt ratio (p = 0.109), but there was a significant difference in torsion degree (p = 0.001). The mean values of optic disc tilt ratio and optic disc torsion in the controls were 1.11 ± 0.07° and 3.25 ± 2.69°, respectively. Also, there was no significant difference in optic disc tilt ratio (p = 0.601), but a significant difference in optic disc torsion between fellow eyes and controls (p < 0.001). The RNFL thickness of the same torsion direction in unilateral NTG eyes was measured to be 49.35 ± 17.18 µm smaller than the normal value (mean RNFL thickness: 71.91 ± 16.92 µm). Reduced RNFL thickness of the same torsion direction between glaucomatous eyes and fellow eyes was significantly different (p < 0.001). In addition, it was confirmed that RNFL thickness was significantly decreased according to the degree of disc torsion (p = 0.024). CONCLUSIONS: The optic disc torsion showed a significant difference between glaucomatous and fellow eyes in unilateral NTG patients and normal controls. Also, the RNFL thickness significantly decreased according to the degree of the optic disc torsion. Therefore, fellow eyes of unilateral NTG patients need to be carefully monitored for the progression of glaucoma.

Measurement of Orbital Volume from Facial CT Scans Using a Semi-Automatic Computer Program

PURPOSE: To measure the orbital volume from facial CT scans using a semi-automatic computer program. METHODS: Axial and coronal slices of 35 facial CT scans were used to measure the orbital volume. The cross-sectional area was determined from each slice using a semi-automated computer program (MATLAB 2009a). Next, the orbital volume was calculated from serial reconstruction of the cross-sections. RESULTS: The measured value in males was 26.34 +/- 3.09 cm3 in the right orbit and 26.30 +/- 3.21 cm3 in the left orbit from axial scans, and 26.58 +/- 2.76 cm3 in the right orbit and 26.59 +/- 2.75 cm3 in the left orbit from coronal scans. In females, the values were 23.84 +/- 2.29 cm3 in the right orbit and 23.89 +/- 2.33 cm3 in the left orbit from axial scans, and 24.06 +/- 2.90 cm3 in the right orbit and 24.10 +/- 2.82 cm3 in the left orbit from coronal scans. There was high positive correlation (r = +0.832, p = 0.0001) in measured orbital volume between axial and coronal scans. CONCLUSIONS: The orbital volume measurement from facial CT scans using a semi-automatic computer program is very useful. This method should prove useful in further studies examining the correlation of orbital volume variation in many ophthalmologic disorders.

A Study for Effective Gaze Fixation Induction Methods in PC-Based Visual Field Testing

PURPOSE: The present study explored novel methods in visual field tests that actively induce the gaze of the examinee to the fixation target in the center vision and compared their effectiveness. METHODS: Four gaze induction methods (dot-on, dot-off, number-on, and number-off) were prepared by combining 2 types of fixation targets (dot and number) and 2 conditions of sound presence (on and off). The gaze induction methods were implemented to a PC-based visual field testing system and the 24-2 visual field testing protocol was administered to 14 participants without glaucoma. The performance of the gaze induction method was evaluated in terms of fixation error rate, target detection rate, and subjective satisfaction (7-point scale, 1 for least satisfied and 7 for most satisfied). RESULTS: The fixation error rates of dot-on (5.7%) and number-on (6.4%) were relatively lower than the other methods; the target detection rates of the induction methods were very high (95-96%) without significant differences, and the subjective satisfaction levels of dot-on (5.7) and number-on (5.4) were significantly higher than the other methods. CONCLUSIONS: In the present study we determined number-on as the preferred effective gaze induction method compared to the conventional dot-off method when fixation error rates and subjective satisfaction were considered.

A Case of Diagnosed Renal Cell Carcinoma with Orbital Metastasis Presenting with Proptosis

PURPOSE: To report a very rare case of lacrimal gland metastasis of renal cell carcinoma presenting with proptosis. CASE SUMMARY: A 68-year-old man visited our clinic with a 3-month history of proptosis in the right eye. Corrected visual acuity was 0.8 in the right eye and 0.9 in the left eye and 11 mm proptosis of the right eye was observed. There were no specific findings except cataracts in both eyes. Orbital computed tomography (CT) demonstrated a solid lacrimal gland mass which was 24 x 36 x 29 mm in size and showed irregular enhancement. The CT scan also showed bone destruction around the orbital lateral wall and infiltration to the lateral rectus muscle. A metastatic tumor was suspected, thus a chest CT and abdominal CT were performed. The CT scan showed a large exophytic hypervascular mass with heterogeneous enhancement. The mass size was confirmed by the abdominal CT and malignant tumors were suspected. Regarding the left renal mass, a urology surgeon performed nephrectomy and adrenalectomy and regarding the lacrimal gland mass we performed an incisional biopsy via lid crease incision. Both masses were diagnosed as renal cell carcinoma based on the pathophysiologic findings. CONCLUSIONS: Lacrimal gland metastasis of renal cell carcinoma is very rare and extensive systemic evaluation for metastatic malignancy should be performed. In the present study, the authors report of a primary tumor found by chest CT a review of the literature.

A Case of Diagnosed Renal Cell Carcinoma with Orbital Metastasis Presenting with Proptosis

PURPOSE: To report a very rare case of lacrimal gland metastasis of renal cell carcinoma presenting with proptosis. CASE SUMMARY: A 68-year-old man visited our clinic with a 3-month history of proptosis in the right eye. Corrected visual acuity was 0.8 in the right eye and 0.9 in the left eye and 11 mm proptosis of the right eye was observed. There were no specific findings except cataracts in both eyes. Orbital computed tomography (CT) demonstrated a solid lacrimal gland mass which was 24 x 36 x 29 mm in size and showed irregular enhancement. The CT scan also showed bone destruction around the orbital lateral wall and infiltration to the lateral rectus muscle. A metastatic tumor was suspected, thus a chest CT and abdominal CT were performed. The CT scan showed a large exophytic hypervascular mass with heterogeneous enhancement. The mass size was confirmed by the abdominal CT and malignant tumors were suspected. Regarding the left renal mass, a urology surgeon performed nephrectomy and adrenalectomy and regarding the lacrimal gland mass we performed an incisional biopsy via lid crease incision. Both masses were diagnosed as renal cell carcinoma based on the pathophysiologic findings. CONCLUSIONS: Lacrimal gland metastasis of renal cell carcinoma is very rare and extensive systemic evaluation for metastatic malignancy should be performed. In the present study, the authors report of a primary tumor found by chest CT a review of the literature.