Effect of Ambient Light Exposure on Ocular Fatigue during Sleep.

BACKGROUND: To investigate the influence of nocturnal ambient light on visual function and ocular fatigue. METHODS: Sixty healthy subjects (30 men and 30 women) aged 19 through 29 years with no history of ocular disease were recruited. All subjects spent 3 consecutive nights in the sleep laboratory. During the first and second nights, the subjects were not exposed to light during sleep, but during the third night, they were exposed to ambient light, measuring 5 or 10 lux at the eye level, which was randomly allocated with 30 subjects each. The visual function and ocular fatigue were assessed at 7 a.m. on the 3rd and 4th mornings, using best-corrected visual acuity, refractive error, conjunctival hyperemia, tear break-up time, maximal blinking interval, ocular surface temperature, and subjective symptoms reported on a questionnaire. RESULTS: Three men and three women subjects failed to complete the study (4 in the 5 lux; 2 from the 10 lux). For the entire 54 subjects, tear break-up time and maximal blinking interval decreased (P = 0.015; 0.010, respectively), and nasal and temporal conjunctival hyperemia increased significantly after sleep under any ambient light (P < 0.001; 0.021, respectively). Eye tiredness and soreness also increased (P = 0.004; 0.024, respectively). After sleep under 5 lux light, only nasal conjunctival hyperemia increased significantly (P = 0.008). After sleep under 10 lux light, nasal and temporal conjunctival hyperemia, eye tiredness, soreness, difficulty in focusing, and ocular discomfort increased significantly (P < 0.05). CONCLUSION: Nocturnal ambient light exposure increases ocular fatigue. Avoiding ambient light during sleep could be recommended to prevent ocular fatigue.

Effects of a high level of illumination before sleep at night on chorioretinal thickness and ocular biometry.

The choroid is affected by many factors. One of the factors, change in illumination has been suggested to influence choroidal thickness. However, the effects of bright light before sleep at night on the human eye are not well established. The purpose of this study was to investigate the effects of a high level of illumination in the evening on ocular measurements. Twenty-seven men with myopia spent seven consecutive nights in the sleep laboratory. During the first two nights, subjects were exposed to light at 150 lux between 20:00 and midnight. Then, for five consecutive nights, they were exposed to ambient light at 1000 lux between 20:00 and midnight. Ocular parameters and their diurnal variations were compared between the two periods and the effects of a high level of illumination were analyzed. After subjects were exposed to 1000 lux of illumination, axial length increased with borderline significance (p = 0.064). Macular volume and retinal thickness did not change. However, subfoveal choroidal thickness after exposure to 1000 lux of illumination (245.37 ± 52.84 µm) was significantly lower than that after 150 lux of illumination (268.00 ± 57.10 µm), (p < 0.001). Significant diurnal variations were found in mean keratometry (p = 0.039), intraocular pressure (IOP, p = 0.003), ocular perfusion pressure (OPP, p < 0.0001), macular volume (p = 0.019), and subfoveal choroidal thickness (p < 0.0001). A high level of illumination had significant effects on only IOP and OPP (p = 0.027 and 0.017, respectively). Bright light exposure before sleep at an intensity as high as 1000 lux reduced subfoveal choroidal thickness in healthy young men. In conclusion, diurnal variation in choroidal thickness can be affected by bright light exposure before sleep.

Esotropia Surgery Considering the Angle under General Anesthesia.

PURPOSE: To compare the amount of esotropia corrected by surgery under general anesthesia and in a conscious state in esotropia surgery. METHODS: The charts of 42 patients who underwent surgery under general anesthesia for correction of esotropia were reviewed. Angle of deviation was measured by the alternate prism cover test in awakened state one day before and after surgery. Under general anesthesia, angle of deviation was measured by Hirschberg or Krimsky test in 5 prism diopters (PD) scale 30 minutes after induction and at the end of the surgery. The amount of the angle of esodeviation corrected by surgery measured in awakened state (A-correction) and under general anesthesia (G-correction) was compared and analyzed to identify significant differences. RESULTS: The median age was 4.0 years and the median preoperative esodeviation angle was 30.0 PD. The median amount of G-correction of 30.0 PD was significantly different compared with that of A-correction at postoperative day one (p=0.003). However, differences between A-correction and G-correction were not evident at postoperative one week, one month, and final follow-up examination (p= 0.191, 0.215, and 0.396, respectively). CONCLUSIONS: Esotropia in A-correction was comparable to that in G-correction only at postoperative day one. These results suggest that it is desirable to perform esotropia surgery according to the initial surgical plan of awakened state regardless of the divergence of eye position. When in doubt, it could be useful to confirm whether the actual amount of surgical correction under general anesthesia is consistent with the plan and modifying the surgical dose nomogram.

Peripapillary choroidal thickness in patients with early age-related macular degeneration and reticular pseudodrusen.

PURPOSE: The purpose of this study was to investigate peripapillary and macular choroidal thickness (CT) in patients with early age-related macular degeneration (AMD) with or without reticular pseudodrusen (RPD). METHODS: We investigated the medical records of 89 patients (89 eyes) with early AMD. The eyes were grouped into three categories according to the extent of RPD: no RPD, localized RPD, and diffuse RPD. Peripapillary and macular CT were measured with images obtained by spectral domain optical coherence tomography. CT in the peripapillary and macular areas was compared among groups. RESULTS: Both RPD groups exhibited an older subject age and a greater female predominance compared to the non-RPD group (P = 0.007 and P = 0.030, respectively). Macular and peripapillary CT were different among the three groups (all, P < 0.001), and both RPD groups showed a thinner choroid in all areas compared to the non-RPD group after adjusting for age and sex (all, P ≤ 0.016). Temporal peripapillary and nasal macular CT at 500 µm and 1500 µm, respectively, from the fovea in eyes with diffuse RPD were significantly thinner than that in eyes with localized RPD (P = 0.008, P = 0.016 and P < 0.001, respectively). CONCLUSIONS: In addition to the macular area, the peripapillary CT, including the area outside the macula, was thinner in eyes with RPD than in those without RPD. Significant differences in the papillomacular choroid were observed based on RPD distribution type, which suggests that variation in CT is based on the extent of RPD.

Demographic features of idiopathic macular telangiectasia in Korean patients.

PURPOSE: To investigate the clinical and demographic features of idiopathic macular telangiectasia (MacTel) in Korean patients since the introduction of spectral domain optical coherence tomography (SD-OCT). METHODS: We reviewed medical records of patients who were diagnosed with MacTel from 2009 to 2013. All patients underwent fluorescein angiography and SD-OCT and were classified as type 1 or type 2 according to the classification system proposed by Yannuzzi. RESULTS: Over a period of 5 years, 4 (18.2%) patients were diagnosed with type 1 MacTel and 18 (81.8%) patients were diagnosed with type 2 MacTel. All patients with type1 MacTel were male, and their mean age was 51 ± 8.6 years. Among patients with type 2 MacTel, 3 (16.7%) were male, 15 (83.3%) were female, and the mean age was 60 ± 13.6 years. Whereas all type 1 MacTel patients had either metamorphopsia or mild scotoma, of the 18 patients with type 2 MacTel, only 4 (22.2%) had those symptoms, 10 (55.6%) complained of only mild visual impairment, and the other 4 (22.2%) had no symptoms. Intraretinal cystoid spaces were observed in 26 (72.2%) of 36 eyes with type 2 MacTel by SD-OCT. These cystoid spaces had irregular boundaries and did not correspond to angiographic leakages. CONCLUSIONS: Type 2 MacTel was most common in the present study. The wider availability of SD-OCT may have contributed to the diagnosis of type 2 MacTel. Type 2 MacTel may be more prevalent than type 1 in Koreans, which corresponds to the results of Western countries.

Stability of Y-splitting procedure combined with hang-back recession of the rectus muscle in rabbit eyes.

BACKGROUND: The Y-splitting procedure has been used both to treat up-shoots and down-shoots in Duane syndrome, and as a substitute for posterior fixation suture. The Y-split is often performed in conjunction with a hang-back recession when a large amount of recession or an adjustable suture is necessary. Herein, we evaluated the stability of Y-splitting hang-back recession in the rectus muscle. METHODS: Under general anesthesia, a 5-mm hang-back recession of the superior rectus muscle (SR) with Y-splitting was performed in ten eyes from ten rabbits (hang-back group). A conventional recession was performed in the SR of the fellow eye (control group). Six weeks after the procedure, the distance between the original insertion and the recessed SR (recession amount) and the width between the nasal and temporal halves of the SR were measured. These values were compared to the measurements taken at the time of surgery. RESULTS: The hang-back group had a significantly larger forward displacement than the control group (P < 0.001 for both the nasal and temporal halves). The width change between the nasal and temporal halves was also significantly larger in the hang-back group (4.94 ± 1.32 mm) than in the control group (1.14 ± 0.60 mm, P < 0.001). Additionally, the Y-configuration appeared to be more collapsed in the hang-back group than in the control group. CONCLUSION: Y-splitting of the rectus muscle may be unstable when it is combined with a hang-back recession. Surgeons should consider this possibility when performing Y-splitting procedures.

The effect and applications of acellular dermal allograft (AlloDerm) in ophthalmic plastic surgery.

PURPOSE: To describe the use and efficacy of AlloDerm in ophthalmic plastic and reconstructive surgery. METHODS: A retrospective review was conducted of 31 eyes of 25 patients who underwent an AlloDerm graft procedure for correction of lower lid retraction, anophthalmic socket contraction, superior sulcus deformity, implant exposure, or skin defect. Clinical outcomes were measured by the degree of improvement and incidence of complications. Operation success and reoperation rates were also evaluated. RESULTS: There were 15 cases of lower lid retraction, 10 anophthalmic socket contractions, 2 superior sulcus deformities, 2 orbital implant exposures, and 2 periorbital skin defects. The mean age of the patients was 44.7 (±2.8) years. The mean follow-up period was 16.7 (±2.5) months. Twenty-seven eyes (87.1%) had successful outcomes and 4 eyes of 4 patients required further surgery. Three of those were due to undercorrection, and the other was due to severe adhesion. Applications of AlloDerm skin substitute were satisfactory at the 6-month follow-up examination. There were no statistically significant factors, such as underlying causes or degrees and locations of defects that impacted on outcome. CONCLUSIONS: AlloDerm is an excellent material for correction of lid retraction, contracted socket, superior sulcus deformity, and implant exposure. In patients for whom periorbital skin grafts or flaps are inappropriate or difficult to perform, the use of AlloDerm to cover skin defects may be a good option.

The effect of perforated punctal plugs in the management of acquired punctal stenosis.

OBJECTIVE: The objectives of this study were to report the success rates for perforated punctual plug (PPP) in the management of acquired punctual stenosis and to evaluate the factors influencing success rates. DESIGN: This was a retrospective, cross-sectional, comparative study. PARTICIPANTS: There were 20 patients. METHODS: Twenty eyes of 20 patients who underwent PPP implantation for the management of acquired punctual stenosis and punctual obstruction were retrospectively evaluated regarding sex and age of the patients and the duration and severity of epiphora, associated blepharitis, and the success of treatment. In all patients, punctum dilation was performed carefully to prevent damage to the ampulla before the insertion of plugs. Perforated punctual plugs were removed 2 months after insertion. RESULTS: There were 7 cases of punctal stenosis, 9 cases of membranous obstruction, 2 punctal burns, 1 papilloma, and 1 nevus involving the punctum causing epiphora. The mean age of patients was 41.4 (SD, 3.9) years. The mean interval between the onset of epiphora and PPP implantation was 32.1 (SD, 10.7) months. Associated chronic blepharitis was detected in 13 eyes. Success was achieved in 17 eyes (85%). Patients whose procedures failed were older (67.7 vs 36.8, P = 0.019) and more likely to have blepharitis (100: 23.5%, P = 0.031). Spontaneous plug loss was noted in 4 eyes between the 1- and 2-month follow-up examination. No patients had residual epiphora. CONCLUSIONS: Perforated punctual plug implantation for the treatment of acquired punctual stenosis and obstruction is very effective. However, careful punctum dilation should be performed, and the patient age and comorbidities should be considered before treatment.

Three-dimensional configuration of subretinal fluid in central serous chorioretinopathy.

PURPOSE: The purpose of this study was to characterize the 3-dimensional (3D) configuration of subretinal fluid (SRF) in idiopathic central serous chorioretinopathy (CSC) using spectral-domain optical coherence tomography (SDOCT). METHODS: The OCT images of patients with CSC were reviewed retrospectively. The 3D configurations of SRF were assessed using a modified segmentation algorithm of SDOCT. The differences of the configurations between acute and chronic CSC were compared. For the patients with acute CSC, we investigated a possible relationship between early change in 3D configuration and disease prognosis. RESULTS: We included 69 eyes of 68 patients in this study. The mean volume, the greatest basal diameter (GBD), and the area of SRF were not different between acute and chronic CSC. The mean peak height (PH) of SRF and the ratio of PH to GBD in acute CSC (298.13 ± 92.67 µm, 9.44 ± 2.57%) were significantly greater than those in chronic CSC (192.97 ± 71.05 µm, 5.97 ± 1.90%; P < 0.001, P < 0.001, respectively). In patients with acute CSC, the early changing pattern of 3D configurations was significantly different according to the SRF prognosis (P = 0.003). In situ decrease of SRF was observed in 94.7% of the spontaneously resolving group. However, downward elongation of SRF was observed more frequently in the persistent group (58.3%) than in the spontaneously resolving group (6.3%). CONCLUSIONS: The 3D configurations of SRF were different between acute and chronic CSC. In patients with acute onset, the early change of 3D configuration was different and varied according to the SRF prognosis.

Effects of interpupillary distance on stereoacuity: the Frisby Davis distance stereotest versus a 3-dimensional distance stereotest.

PURPOSE: To evaluate the effect of interpupillary distance (IPD) on stereoacuity using 2 kinds of stereoacuity tests in a normal population. METHODS: The distance stereoacuities of 33 healthy volunteers with no evidence of ocular diseases were measured with the Frisby Davis distance (FD2) stereotest and a 3-dimensional monitor-based distance stereotest (distance 3-D stereotest). These 2 kinds of stereotests were repeated using horizontal periscopes to increase the IPD 2- and 3-fold in order to investigate the effect of IPD increase on stereoacuity. RESULTS: The mean age of the participants was 28.5 years (range 20-41 years). The mean logarithms of the individual minimum angle of stereodiscrimination (logMAS) were 1.04 ± 0.23 (range 0.70-1.48 logMAS) with the FD2 stereotest and 1.52 ± 0.19 (range 1.00-1.85 logMAS) with the distance 3-D stereotest. As the IPD increased 2- and 3-fold, the logMAS measured with the FD2 stereotest improved from 1.04 to 0.98 and 0.91 (P = 0.061 and P = 0.003), respectively, and those measured with the distance 3-D stereotest worsened from 1.52 to 1.73 and 1.85 (P < 0.001 and P < 0.001), respectively. CONCLUSIONS: Changes in IPD measured with the FD2 stereotest exhibited opposite effects to those measured with the distance 3-D stereotest. This reflects what is known to happen in the real world, i.e., that stereoacuity improves as IPD increases.

Hyperreflective external limiting membranes after successful macular hole surgery.

PURPOSE: To evaluate changes in external limiting membranes (ELMs) in the foveae of patients with surgically closed macular holes. METHODS: In this retrospective observational case series, spectral-domain optical coherence tomography scan images were obtained from eyes of patients with macular holes closed after vitrectomy. The integrity of the ELMs was evaluated at the fovea. In eyes with a restored ELM, the reflectivity of the ELM was estimated. RESULTS: At a mean of 19 months (range, 3.0-59.7 months) after surgery, the integrity of the ELM was restored in 21 (77.8%) of 27 eyes with closed macular holes. The ELM was not restored in six eyes with glial sealing, in which glial tissues were present in the entire retinal layer. All 21 eyes with restored ELMs had an area of hyperreflectivity within the ELM observed at the thinnest part of the fovea; this was associated with an underlying photoreceptor defect. CONCLUSION: Abnormally hyperreflective ELMs were frequently observed at the thinnest point of the fovea after macular hole surgery. These hyperreflective ELMs may be newly formed after surgery.