Obstructive Sleep Apnea in Patients with Branch Retinal Vein Occlusion: A Preliminary Study

PURPOSE: Our study aimed to determine whether obstructive sleep apnea (OSA) is common among branch retinal vein occlusion (BRVO) patients without systemic risk factors using a Watch PAT-100 portable monitoring device. METHODS: The study participants included consecutive patients with BRVO of less than 3 months duration without any risk factors known to be associated with OSA (diabetes, coronary artery disease, stroke, hematologic diseases, autoimmune disease, etc.) except for hypertension. All patients underwent full-night unattended polysomnography by means of a portable monitor Watch PAT-100 device. The apnea-hypopnea index (AHI) was calculated as the average number of apnea and hypopnea events per hour of sleep, and an AHI score of five or more events was diagnosed as OSA. RESULTS: Among 19 patients (6 males and 13 females), 42.1% (8 of 19) had an AHI reflective of OSA. In the 13 patients who had no concurrent illness, including hypertension, 30.8% (4 of 13) had positive test results for OSA; three of these patients were ranked as mild OSA, while one had moderate OSA. The OSA group had an average AHI of 12.3 ± 7.8, and the average AHI was 2.0 ± 0.9 in the non-OSA group. Although it was not statistically proven, we found that OSA patients experienced a more severe form of BRVO. CONCLUSIONS: We found a higher than expected rate of OSA in BRVO patients lacking concomitant diseases typically associated with OSA. Our findings suggest that OSA could be an additional risk factor in the pathogenesis of BRVO or at least a frequently associated condition that could function as a triggering factor.

Recurrent Bilateral Retinal Vasculitis as a Manifestation of Post-streptococcal Uveitis Syndrome

We report a case of post-streptococcal uveitis mainly presenting with bilateral recurrent retinal vasculitis in Korea. A 14-year-old Asian female presented with decreased visual acuity of 20 / 30 in the right eye and 20 / 25 in the left eye. The patient had a history of glomerulonephritis nine months before onset of uveitis. The manifestation of uveitis was predominantly retinal vasculitis. We presumed post-streptococcal uveitis because probable streptococcal infection was confirmed by anti-streptolysin O titer elevation. With topical and oral steroid treatments, the patient experienced complete vision recovery. Post-streptococcal uveitis occurs rarely and mostly involves young patients in the form of non-granulomatous anterior uveitis. However, as this case shows, it may primarily involve the posterior uvea without anterior inflammation and may recur.

Retinal Vascular Caliber Changes on OCT after Intravitreal Bevacizumab Injection in Diabetic Macular Edema

PURPOSE: To investigate retinal vascular caliber changes with Spectral Domain OCT after intravitreal bevacizumab injection in diabetic macular edema patients. METHODS: Thirty-four eyes of 29 diabetic macular edema patients who were intravitreously injected with bevacizumab (1.25 g/0.05 ml) were studied. Twenty-four fellow eyes of 24 patients with bevacizumab injection were also recruited as a control group. We measured retinal vascular caliber a distance of 0.5-1 disc sizes from the disc margin with Spectral Domain OCT at baseline and 1-month and 3-month follow-up visits. Central macular thicknesses were also measured. RESULTS: Over the 3 months of study, there was a significant reduction of arteriolar caliber compared to baseline (p = 0.024), There was significant reduction of venular caliber at 1 month (p = 0.001) and 3 months (p = 0.000) compared to baseline. Venular caliber reduction at the 3-month follow-up was significantly correlated with central macular thickness (R = 0.487, p = 0.003). CONCLUSIONS: Retinal venular caliber reduction was significant at 1- and 3-month follow-up, and arteriolar caliber reduction was significant at 3-month follow-up compared to baseline. After 3 months of treatment, venular caliber reduction was correlated with reduction of central macular thickness.

The Effect of the Concurrent Therapy of Glucosamine and Aspirin in Uveitis

PURPOSE: To report the anti-inflammatory effect and best-corrected visual acuity (BCVA) response after oral glucosamine (Glucosamine Sulfate 750(R), General Nutrition Companies, Inc.) and aspirin (Aspirin protect(R), Bayer) therapy in patients with uveitis. METHODS: Twenty-seven patients (43 eyes) with uveitis, not easily managed with conventional therapy, were treated with oral glucosamine 750 mg and aspirin 100 mg daily, and underwent BCVA testing and slit-lamp examination of anterior chamber inflammation. Changes in the dose of previously-used oral steroids and immunosuppressants were recorded at baseline, every 2 weeks for the first 2 months, and once every month thereafter. RESULTS: The mean follow-up period was 15.0+/-3.69 weeks and inflammation started to improve within 4.6 weeks. The change in visual acuity was not statistically significant, but grade of inflammation decreased by as much as 1.02+/-1.28, significantly (p<0.01) after treatment. In 12 patients (19 eyes, 44.2%) the dosage of systemic steroids and immunosuppressants could be Reduced. 7 patients (10 eyes, 23.3%) experienced aggravation of uveitis and the dosage of glucosamine and aspirin was increased. CONCLUSIONS: Concurrent oral administration of glucosamine and aspirin could not completely inhibit the recurrence of inflammation nor control it, but consistent use of these drugs may help to reduce inflammation without serious side effects. A longer prospective control study with larger sample size is required to further evaluation of the efficacy of the medication.

Epidemiologic and Clinical Features of Uveal Melanoma in Korean Patients

PURPOSE: To investigate the epidemiologic and clinical features of uveal melanomas in Korean patients. METHODS: The medical records of 35 patients (35 eyes) with the diagnosis of uveal melanoma between September 2004 and December 2006 were reviewed retrospectively. RESULTS: Of the 35 patients, 22 were males (62.9%) and 13 were females (37.1%), with a mean age at diagnosis of 48.2+/-14.1 years (range, 24-82 years). Decreased visual acuity was the most common symptom in 23 patients (65.7%), while 6 patients (17.1%) were detected without prior symptoms. The shape of the uveal melanoma was dome-shaped in 27 eyes (77.1%) and mushroom-shaped in 8 eyes (22.9%). The mean largest basal diameter of the tumors was 9.0+/-3.3 mm (2.4-19.0 mm), and the mean apical height was 6.2+/-2.6 mm (1.1-13.0 mm). The tumors were classified according to their size; a small melanoma was found in 4 eyes (11.4%), a medium melanoma in 29 eyes (82.9%), and a large melanoma in 2 eyes (5.7%). CONCLUSIONS: Uveal melanomas manifest earlier in Korean patients than in Caucasian patients. At the time of diagnosis, 33 eyes (94.3%) had small or medium melanomas that could be treated.

Imaging Techniques for the Diagnosis of Primary Uveal Melanoma

PURPOSE: To investigate various imaging techniques for the diagnosis of primary uveal melanomas in Korean patients. METHODS: We retrospectively reviewed the medical records of 35 eyes in 35 patients (22 males, 13 females) diagnosed with uveal melanomas between September 2004 and December 2006. The findings of fundus photographs, ultrasonography, CT scan, MRI, and PET scan were documented. RESULTS: A/B scan ultrasonography showed typical findings of uveal melanomas in 74.3% (26 eyes) of the patients. On CT scan, the mass appeared as a homogenous hyperdense lesion, and on MRI, the typical signal of hyperintensity on the T1-weighted image and hypointensity on the T2-weighted image was seen in 89.3% (25 eyes), with contrast enhancement in only 46.4% (13 eyes) of the patients. A PET scan revealed positive tumor uptake in 22.7% (5 eyes) of the patients. CONCLUSIONS: Although ultrasonography is the most useful and accurate method for the diagnosis of uveal melanoma, it provides more atypical cases in Korean patients than Caucasian patients. CT scans and MRI can be used for a differential diagnosis, but the diagnostic efficacy of PET scans is low.

Ahmed Valve Implantation Result and TGF-beta and VEGF in the Aqueous Humor of Neovascular Glaucoma Patients

PURPOSE: To assess the relationship of transforming growth factor-beta (TGF-beta) and vascular endothelial growth factor (VEGF) levels in the aqueous humor of neovascular glaucoma (NVG) patients and the results of Ahmed valve implantation surgery. METHODS: We compared surgical outcomes of NVG patients who underwent Ahmed valve implant surgery from January 2002 through October 2002 at severance hospital with levels of TGF-beta1, TGF-beta2 and VEGF in the aqueous humors of these patients. RESULTS: Nineteen eyes (19 patients) were analyzed in the study. The success of surgery was defined as intraocular pressure maintained as 6-20 mm Hg regardless of additional glaucoma medications taken. Twelve eyes (63%) satisfied successful surgery. TGF-beta1 concentration was 1.51 ng/ml in the success group and 2.31 ng/ml in the failed group (p=0.295). TGF-beta2 concentration was 5.19 ng/ml in the success group and 5.73 ng/ml in the failed group (p=0.367). VEGF concentration was 10.21 ng/ml in the success group and 9.87 ng/ml in the failed group (p=0.516). All showed no statistical difference between the groups. CONCLUSIONS: In our study, no significant relationship between levels of TGF-beta1, TGF-beta2, or VEGF in the aqueous humor and the surgical outcomes of Ahmed valve implantation were found in patients with NVG.

Nerve Growth Factor Concentration and Implications in Photorefractive Keratectomy Versus Laser in Situ Keratomileusis

PURPOSE: To determine whether tear nerve growth factor (NGF) concentration correlates with corneal sensation and ocular surface dryness after photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK). METHODS: A prospective, non-randomized comparative clinical trial. Seventy eyes of 35 patients and 76 eyes of 38 patients underwent PRK and LASIK procedures to correct myopia and myopic astigmatism, respectively. Total tear protein level, tear NGF concentration, corneal sensation, tear film break-up time (BUT) and Schirmer values were measured before and 1 day, 1 week, 1 month, 3 months, and 6 months after the surgery. RESULTS: The postoperative mean tear NGF/total tear protein ratio (NGF/tP) increased in both PRK and LASIK patients compared to their preoperative levels (p<0.0001). At 1 week and 1 month postoperatively, the NGF/tP ratio was higher in PRK than in LASIK subjects (p<0.0001). Up to 6 months postoperatively, the mean corneal sensation after LASIK in the ablated zone was lower than the preoperative sensation (p<0.0001), whereas this was not the case in PRK subjects. Mean BUT and Schirmer values were significantly lower in LASIK-treated eyes compared to PRK-treated eyes up to 6 months postoperatively (p<0.0001). The early postoperative tear NGF/tP ratio correlated with the postoperative 6 month corneal sensation, BUT and Schirmer values. CONCLUSIONS: The difference in postoperative corneal sensation and ocular surface dryness between PRK- and LASIK-treated eyes was related to the difference in the early postoperative levels of NGF/tP, which implies NGF might influence corneal nerve regeneration after these two surgeries.

Recurrent Intraocular Pressure Elevation during Hemodialysis in a Patient with Neovascular Glaucoma

PURPOSE: To report a patient with symptomatic intraocular pressure (IOP) elevation in an eye with neovascular glaucoma (NVG) during hemodialysis. METHODS: Case report. RESULTS: Recurrent episodes of severe ocular pain and elevated IOP in the NVG eye were noted during hemodialysis in a 29-year-old man. The patient was recently diagnosed at our ophthalmology clinic with NVG due to central retinal vein occlusion. IOP was temporarily controlled after the Ahmed valve implantation. However, after the fibrous membrane developed and occluded the tip of the Ahmed valve, IOP elevation during hemodialysis recurred. Further treatments with intravenous mannitol, oral carbonic anhydrase inhibitor, topical antiglaumatic agents and subconjunctival 5-fluorouracil (5-FU) injections all failed to control relapsing pain and IOP elevation. Eventually, evisceration and hydroxyappatite implantation were performed. CONCLUSIONS: Physicians must be alert to the possibility of IOP elevation in glaucomatous eyes during hemodialysis.