The practical and educational value of scleral buckling with chandelier illumination.

PURPOSE: To compare the surgical results in cases of primary rhegmatogenous retinal detachments between standard scleral buckling (SSB) and scleral buckling with chandelier illumination (SBC) and to analyse the differences in SBC surgical results between an experienced ophthalmologist and inexperienced ophthalmologists. METHODS: Consecutive surgical case series of 155 eyes that underwent scleral buckling were retrospectively reviewed and divided into four groups: SSB performed by an experienced ophthalmologist (n = 54), SBC performed by an experienced ophthalmologist (n = 52), SBC performed by inexperienced ophthalmologists (n = 40) and SSB performed by inexperienced ophthalmologists (n = 9). Then, these four groups were compared. RESULTS: No significant differences were observed between SSB and SBC procedures both performed by the experienced ophthalmologist with regard to demographics, preoperative findings, contents of the surgery, intraoperative complications, retinal reattachment, postoperative findings and postoperative complications. Between SBC performed by the experienced ophthalmologist and SBC performed by the inexperienced ophthalmologists, no significant differences were found regarding intraoperative complications, retinal reattachment, postoperative findings and postoperative complications. Between SSB and SBC procedures both performed by the inexperienced ophthalmologist, a significant difference was found regarding intraoperative complications. CONCLUSION: There were no significant differences in surgical results between SSB and SBC when both were performed by the experienced ophthalmologist. In addition, the surgical results were equal between the experienced ophthalmologist and the inexperienced ophthalmologist as far as SBC was concerned. Learning scleral buckling skills by using SBC is a reasonable course of action for inexperienced ophthalmologists.

Visual acuity after intravitreal ranibizumab with and without laser therapy in the treatment of macular edema due to branch retinal vein occlusion: a 12-month retrospective analysis.

AIM: To identify factors contributing to visual improvement after treatment of macular edema (ME) secondary to branch retinal vein occlusion (BRVO), and to assess the interaction between laser therapy and intravitreal ranibizumab (IVR). METHODS: We retrospectively reviewed the medical records of patients who had been treated for BRVO-related ME at our hospital. Records were traceable for at least 12mo, and evaluated factors included age, sex, medical history, smoking history, treatment methods, foveal hemorrhage, and change in visual acuity. Treatments included laser therapy, IVR, sub-Tenon's capsule injection of triamcinolone (STTA), a combination, or no intervention. Multivariate logistic regression analysis and interaction terms were used to assess the clinical efficacy of the treatments, and odds ratios (OR) and 95% confidence intervals (CI) were calculated. RESULTS: Seventy-three patients (34 men, 39 women; 73 eyes) with a mean age of 69.4±12.1y were included. Patients who underwent IVR monotherapy, laser monotherapy, and STTA+laser had significantly higher best corrected visual acuity at 12mo compared to baseline (P<0.001, <0.001, and 0.019, respectively). Logistic regression analysis without interaction terms found that IVR was a significant visual acuity recovery factor (adjusted OR: 3.89, 95%CI: 1.25-12.1, P=0.019). Adjusted OR using an interaction model by logistic regression was 16.6 (95%CI: 2.54-108.47, P=0.003) with IVR treatment, and 8.25 (95%CI: 1.34-50.57, P=0.023) with laser treatment. No interaction was observed (adjusted OR: 0.07, 95%CI: 0.01-0.75, P=0.029). CONCLUSION: IVR contributes to improvements in visual acuity at 12mo in ME secondary to BRVO. No interaction is observed between laser therapy and IVR treatments.

Operative Complications of Glaucoma Drainage Implant Tube Insertion Through the Sulcus for Pseudophakic Eye.

PRECIS: Malposition of the tube through the ciliary sulcus is more frequently observed with the Ahmed glaucoma valve (AGV) than the Baerveldt drainage implant (BDI) due to the weaker rigidity of the Ahmed tube. PURPOSE: To report intraoperative and early postoperative complications of ciliary sulcus tube insertion of glaucoma drainage implants (GDIs). PATIENTS AND METHODS: We performed retrospective analysis of 104 eyes of 94 patients with GDI tube insertion through the ciliary sulcus were performed. The rigidities of tubes were also examined using a microcompression tester. RESULTS: The mean observation period was 20.0 (range, 6 to 60) months. Thirteen eyes were treated with the BDI and 91 were with the AGV. The mean age of the patients was 69.3 (34 to 90) years. The mean intraocular pressure was 27.9 mm Hg before surgery and 12.9 mm Hg after surgery (P<0.01). Upon tube insertion 42/91 eyes (46%) with the AGV required reinsertion of the tube due to malpositioning, whereas only 1/13 (8%) eyes with BDI did (P<0.01). Transient hyphema (12 eyes) and hypotony (12 eyes) were observed as early postoperative complications with the AGV. Seven eyes with hypotony were treated by proline stenting of the tube. We could not accomplish sulcus insertions in 4 eyes. Microcompression analysis of the tubes showed that the BGI tube was more rigid than that of the AGV. CONCLUSIONS: Ciliary sulcus insertion of the tube is an effective method to control intraocular pressure. The tube of the AGV was more difficult to insert through the sulcus than the BDI due to its weaker rigidity.

Alteration of gene expression in mice after glaucoma filtration surgery.

To clarify the early alterations of gene expression using a mouse model of glaucoma filtration surgery, we carried out microarray expression analysis. Using BALB/c mice, a filtration surgery model was made by incision of the limbal conjunctiva, followed by the insertion of a 33G needle tip into the anterior chamber, and 11-0 nylon sutures. Subgroups of mice were treated intraoperatively with 0.4 mg/ml mitomycin-C (MMC). At day 3 after surgery the bleb was maintained. The bleb region tissue was sampled 3 days after the filtration surgery, and gene expression analysis was carried out using a mouse Agilent 8 × 60 K array. We found 755 hyperexpressed transcripts in the bleb region compared to control conjunctiva. The hyperexpressed transcripts included epithelial cell metaplasia-related (Il1b, Krt16, Sprr1b), inflammation-related (Ccl2, Il6) and wound healing-related (Lox, Timp1) genes. We also found downregulation of a goblet cell marker gene (Gp2) in the bleb conjunctiva. MMC treatment suppressed elastin (Eln) gene expression and enhanced keratinization-related gene expression (Krt1, Lor) in the bleb region. Our results suggest the importance of epithelial wound healing after filtration surgery, and this filtration surgery model will be a useful tool for further pathophysiological analysis.

Proline-assisted Tube Insertion Through Sulcus in Ahmed Valve.

To prevent corneal endothelial cell loss, ciliary sulcus tube insertion is preferred for the pseudophakic eye. However, we sometimes encounter technical difficulties when inserting the tube through the sulcus. Even in cases in which we are able to insert a 23-G needle through the sulcus into the space between the iris and intraocular lens, the tube of Ahmed valve may stray into the vitreous cavity or under Elschnig pearls. To remedy such conditions, we developed a new tube insertion method using a 4-0 proline stent as a guide to insert the tube in the appropriate position.

Effects of the Numbers and the Shapes of Venting Slits on Intraocular Pressure after Baerveldt Glaucoma Drainage Implant.

Purpose: Venting slits are widely used as an effective method to avoid the high intraocular pressure (IOP) phase immediately after the implantation of non-valved glaucoma drainage devices. However, there have been no detailed reports comparing the types of needles used and the numbers of slits made. In this study we investigated the effects of different needle types and the number of venting slits. Methods: IOP was measured using a Keyence NR-600 transducer connected to the limbus of a pig eye with a 27G needle. A microsyringe pump was also connected to the corneal limbus using a 27 G needle to make a continuous perfusion system at the rate of 200 µl/hr. The silicone tube of a Baerveldt glaucoma drainage implant (BG101-350) was ligated near the plate and then implanted in the anterior chamber of the pig eye. The tube was covered with scleral tissue of another pig eye after 1 or 3 venting slits were created in the middle of the outer diameter using different types of needles (7-0 Vicryl®, 7-0 PDSⅡ®, 5-0 PDSⅡ®, 3-0 PDS Plus®). IOP measurement was started from 50 mmHg and then we monitored the chronological changes of IOP for 15 minutes. Results: The IOPs at 15 minutes after continuous perfusion with the venting slits made using 7-0 Vicryl needles were 29.0 ± 2.5 mmHg (1 slit) and 23.1 ± 8.3 mmHg (3 slits). The IOPs were 23.1 ± 3.1 mmHg and 23.5 ± 4.7 mmHg with 7-0 PDS needles (1 slit and 3 slits, respectively), 21.8 ± 2.2 mmHg and 20.8 ± 4.3 mmHg with 5-0 PDS needles (1 slit and 3 slits, respectively), and with 3-0 PDS needles they were 12.2 ± 3.0 mmHg for one slit and 13.2 ± 3.5 mmHg for 3 slits. Conclusions: Usage of a round (PDS) needles produces more predictable IOP than a spatulated (Vicryl) needle.

Visual impairment as an independent risk factor for falls in hospitalized patients.

OBJECTIVE: To investigate the association between visual impairment and the risk of falls in hospitalized patients. DESIGN: Individually matched case-control study. METHODS: The medical records of patients who fell while hospitalized at Juntendo Tokyo Koto Geriatric Medical Center (JTKGMC) from January to December 2014 were reviewed retrospectively. Among them, 36 patients who were recorded as visiting the Ophthalmology Outpatient Clinic from 1 year before to 1 year after the fall were included as cases. As the control subjects, 36 individually matched patients were chosen who were hospitalized in the same beds in the same hospital wards. Visual impairment and blindness were defined according to U.S. criteria. Conditional logistic regression analysis was used for both univariate and multivariate analyses. Based on previous reports, multivariate analysis was performed with adjustment for age, sex, a history of falls, and use of walking aids. This study was approved by the institutional review board of JTKGMC and was performed according to the tenets of the Declaration of Helsinki. RESULTS: The crude odds ratio (OR) for visual impairment was 6.0 (95% confidence interval [CI]: 0.72-49.83). For a history of falls and use of walking aids, the crude OR (95% CI) was 2.5 (0.97-6.44) and 2.8 (0.88-8.64), respectively. After adjustment for age, sex, a history of falls, and use of walking aids, the association between falls and visual impairment was significant (OR: 13.9; 95% CI: 1.0004-194.41). CONCLUSION: These findings suggest that visual impairment could be an independent risk factor for falls among hospitalized patients.

The Effect of Cumulative Dissipated Energy on Changes in Intraocular Pressure After Uncomplicated Cataract Surgery by Phacoemulsification.

PURPOSE: To investigate the association between ultrasound energy, expressed as cumulative dissipated energy (CDE), and changes in intraocular pressure (IOP) after uncomplicated cataract surgery by phacoemulsification. METHODS: In this prospective study, nonglaucomatous subjects underwent cataract surgery by phacoemulsification. IOP was compared by clustered linear regression at 4 separate time-points: preoperative, 1 day, 1 month, and 3 months after cataract surgery. Changes in the IOP were evaluated as a function of CDE using univariate and multivariate clustered linear regression models, which adjusted for sex, ethnicity, age, axial length, spherical equivalent, mean preoperative Shaffer gonioscopy grade of all 4 quadrants, cataract grade, preoperative IOP, central corneal thickness, and use of both eyes in the same subject. RESULTS: One hundred sixty-one eyes (89 Asian, 49 white, 12 African, and 11 Hispanic) from 116 nonglaucomatous subjects were analyzed. The 161 eyes included 81 right and 80 left eyes. The 89 Asian eyes included 46 Chinese, 35 Filipino, and 8 Vietnamese. Preoperative IOP was 14.9±3.2 mm Hg. Postoperative IOP significantly increased to 16.0±4.9 mm Hg at 1 day (P=0.037) and decreased to 12.4±3.1 and 12.3±3.0 mm Hg at 1 and 3 months, respectively (both P<0.0001). IOP changes at 1 day, 1 month, and 3 months did not demonstrate significant associations with CDE measurements in either univariate or multivariate clustered linear regression analyses (all P>0.05). CONCLUSIONS: The amount of ultrasound energy delivered to the eye during phacoemulsification, expressed as CDE, was not associated with postoperative changes in IOP.

Hypothyroidism and Glaucoma in The United States.

PURPOSE: To investigate the association between hypothyroidism and glaucomatous disease. METHODS: This cross-sectional study included all subjects above the age of 40 years from two nationwide surveys: the 2008 National Health Interview Survey (NHIS) as well as the 2007 and 2008 National Health and Nutrition Examination Survey (NHANES). The presence or absence of glaucoma, thyroid disease and other demographic and health-related information including comorbidities was ascertained via interview. Blood samples were collected from NHANES subjects and analyzed for thyrotropin (TSH). RESULTS: A total of 13,599 and 3,839 NHIS and NHANES participants respectively were analyzed to assess for a possible relationship between self-reported glaucoma, and self-reported hypothyroidism as well as self-reported thyroid disease. The unadjusted odds ratio (OR) for NHIS showed a significant association between self-reported glaucoma and self-reported hypothyroidism (OR 1.46, 95% confidence interval [CI] 1.07-1.99). Multivariate logistic regression analysis adjusted for age, gender, race, comorbidities, and health-related behavior, however, showed no association between self-reported glaucoma and hypothyroidism or thyroid disease in both surveys (OR 1.60, 95%CI 0.87-2.95 for NHIS; OR 1.05, 95%CI 0.59-1.88 for NHANES). CONCLUSION: A previously reported association between hypothyroidism and glaucomatous disease was not confirmed in two large U.S. health survey populations. While such an association was noted in the univariate analysis for the NHIS survey, such a relationship was not found in the multivariate analysis after adjustment for potential confounding variables.

Association between baseline iris thickness and prophylactic laser peripheral iridotomy outcomes in primary angle-closure suspects.

OBJECTIVE: To evaluate the association between baseline measurements of iris thickness at 3 positions and change in anterior segment biometric parameters after prophylactic laser peripheral iridotomy (LPI). DESIGN: Prospective clinical cohort study. PARTICIPANTS: Fifty-two eyes of 52 nonglaucomatous subjects with anatomically narrow angles. METHODS: Anterior segment optical coherence tomography (ASOCT) images captured before and after LPI were analyzed using customized software, the Zhongshan Angle Assessment Program (ZAAP) (Zhongshan Ophthalmic Centre, Guangzhou, China). Differences in preoperative and postoperative measurements for anterior segment biometric parameters were compared by paired Student t tests. Multivariate linear regression models, adjusted for age, sex, ethnicity, and preoperative pupil diameter, were used to examine the association between the baseline measurements of iris thickness at 3 positions and the change in anterior segment biometric parameters after LPI. MAIN OUTCOME MEASURES: Baseline iris thickness measured at 750 µm from the scleral spur (IT750), iris thickness measured at 2000 µm from the scleral spur (IT2000), and maximal iris thickness (ITM). Changes in iris curvature (ICURV) and trabecular-iris space area at 500 µm from the scleral spur (TISA500) and 750 µm from the scleral spur (TISA750) after LPI. RESULTS: The ICURV significantly decreased, whereas TISA500 and TISA750 significantly increased after LPI (all P < 0.0001). Lower baseline IT750 was significantly associated with greater postoperative increases in TISA500 and TISA750 (both P < 0.05). Lower baseline IT2000 and ITM were significantly associated with greater postoperative decrease in ICURV (both P < 0.05). CONCLUSIONS: Our results showed that lower baseline measurements of iris thickness are associated with greater decrease in ICURV and increases in TISA500 and TISA750 after LPI. This suggests that eyes with thinner irides undergoing LPI were more likely to exhibit greater magnitude of change in terms of flattening of the iris convexity (i.e., ICURV) and widening of the anterior chamber angle (i.e., TISA500 and TISA750).

Correlation between central corneal thickness and myopia in Taiwan.

The aim of the study was to explore the correlation between central corneal thickness (CCT) and the degree of myopia in Taiwanese adults. A total of 528 individuals were enrolled to undergo myopic laser refractive surgery from January 2004 to December 2006. Preoperative CCT was measured using the Orbscan corneal topography system and refractive status was determined by cycloplegic spherical equivalent. The relationship between CCT and refractive error was investigated by interindividual and intraindividual analyses. Participants had a mean age of 34.8 ± 7.3 years, and 79.9% were female. The mean refractive error was -7.27 ± 2.96 diopters and the mean CCT measurement was 560 ± 35 µm. CCT revealed that there was no association with age. However, CCT was significantly (p = 0.012) less in females than in males. The CCT also showed no significant association with refractive error (p = 0.49). Among the 67 participants with myopic anisometropia, the mean difference between both eyes was 3.09 ± 1.06 diopters. There was no association between the intereye CCT difference and refractive error (p = 0.57). The results remained the same after adjusting for age and sex. In conclusion, there was no correlation between CCT and the degree of myopia among adults in Taiwan. These data might contribute to the ongoing discussion about the role of CCT in the higher incidence of development and progression of glaucoma in myopic individuals.

Comparison of anterior segment morphology following prophylactic laser peripheral iridotomy in Caucasian and Chinese eyes.

BACKGROUND: To compare anterior segment biometric parameters between Caucasians and Chinese before and after laser peripheral iridotomy. DESIGN: Prospective clinical cohort study. PARTICIPANTS: Caucasian and Chinese primary angle-closure suspects. METHODS: Anterior segment optical coherence tomography images captured before and after laser peripheral iridotomy were analysed to measure anterior segment biometric parameters. Paired Student's t-tests were used for within-ethnic group comparisons. Univariate and linear mixed-effect regression models were used for between-ethnic group comparisons. MAIN OUTCOME MEASURES: Angle opening distance, angle recess area, iris thickness, iris curvature, anterior chamber area, anterior chamber volume and anterior chamber width. RESULTS: Caucasians had significantly greater preoperative angle recess area, anterior chamber width, and iris curvature and lower preoperative iris thickness compared to Chinese (P < 0.05). Significant postoperative increases in angle opening distance, angle recess area, anterior chamber area, anterior chamber volume, and anterior chamber width along with significant postoperative decrease in iris curvature were observed within both ethnic groups (P < 0.05). However, the amount of laser peripheral iridotomy-induced changes in angle opening distance, angle recess area, anterior chamber area, anterior chamber volume, anterior chamber width, and iris curvature did not differ between the two ethnic groups (P < 0.05). CONCLUSION: Both Caucasian and Chinese demonstrated opening of anterior chamber angle width, expansion of anterior chamber dimensions, and flattening of iris convexity after laser peripheral iridotomy. Although certain aspects of anterior segment anatomy differed between Caucasians and Chinese preoperatively, they did not translate into significant ethnic differences in the amount of laser peripheral iridotomy-induced changes in the anterior segment biometric parameters.

Ethnic variation in optic disc size by fundus photography.

PURPOSE: To compare optic disc size among Caucasian, Chinese, African, Filipino and Hispanic subjects recruited from a university-based general ophthalmology clinic. METHODS: In this retrospective cross-sectional study, optic disc size was calculated from fundus photographs. Differences in age, sex and spherical equivalent among the ethnic groups were examined with either Kruskal--Wallis test or Chi-square test. Ethnic differences in optic disc size were evaluated with linear mixed-effects regression models that adjusted for age, sex, spherical equivalent, glaucoma status, lens status and use of both eyes in the same subject. RESULTS: Five hundred and seventy-four eyes of 305 subjects were analyzed. The mean and standard deviation of the optic disc size were 2.16 ± 0.41 mm(2) for Caucasian, 2.30 ± 0.56 mm(2) for Chinese, 2.31 ± 0.41 mm(2) for Filipino, 2.38 ± 0.40 mm(2) for African and 2.40 ± 0.38 mm(2) for Hispanic subjects. Age and spherical equivalent differed among the ethnic groups by Kruskal--Wallis test (p < 0.05). Sex differed among the ethnic groups by Chi-square test (p < 0.05). Ethnic differences in optic disc size were not observed among African, Hispanic, Filipino and Chinese subjects in linear mixed-effects regression analyses (p > 0.05). However, Caucasian differed from the other ethnicities in linear mixed-effects regression analyses (p < 0.05). CONCLUSIONS: Optic disc size was significantly smaller in Caucasian compared to the other ethnic groups. Optic disc size differences among non-Caucasian ethnic groups were not significant.

Association between baseline angle width and induced angle opening following prophylactic laser peripheral iridotomy.

PURPOSE: To evaluate the association between baseline angle width and laser peripheral iridotomy (LPI)-induced opening of the anterior chamber angle. METHODS: Anterior segment optical coherence tomography images captured before and after LPI were analyzed to determine the angle opening distance at 250 µm (AOD250), 500 µm (AOD500), and 750 µm (AOD750) from the scleral spur; trabecular-iris space area at 500 µm (TISA500) and 750 µm (TISA750) from the scleral spur; angle recess area at 750 µm (ARA750) from the scleral spur; and trabecular-iris angle (TIA). Differences in preoperative and postoperative measurements for the anterior chamber angle width parameters were compared by paired Student's t-tests. Univariate and linear mixed-effects regression models were used to examine the association between baseline and LPI-induced opening of anterior chamber angle width parameters. RESULTS: Eighty-four eyes of 52 primary angle closure suspects were included in the analysis. AOD250, AOD500, AOD750, TISA500, TISA750, ARA750, and TIA significantly increased following LPI by paired Student's t-tests (all P < 0.0001). Lower baseline measurements were significantly associated with greater postoperative opening in all anterior chamber angle width parameters in both univariate and linear mixed-effects regression analyses (all P < 0.05). CONCLUSIONS: Our results showed significant opening of the anterior chamber angle width after LPI and demonstrated an inverse association between baseline and LPI-induced opening of the anterior chamber angle width, such that eyes with a more crowded anterior chamber angle undergoing LPI had a greater magnitude of increase in anterior chamber angle width after the procedure.

Trabecular meshwork length in men and women by histological assessment.

PURPOSE: To evaluate the length of the trabecular meshwork (TM) from the scleral spur (SS) to Schwalbe's line (SL) and assess the detectability of the SS in histopathology specimens. METHODS: This study included 158 angle images from 79 cross-sectional slides derived from eyes enucleated for melanoma. The slides were stained with hematoxylin-eosin (HE) or periodic acid schiff (PAS). Two ophthalmologists evaluated the TM length by using the slides stained with HE to assess the interobserver reproducibility. For intraobserver reproducibility, the first observer assessed 79 images in a different session. Also, 30 images that were randomly selected for PAS stain were evaluated to assess the agreement of the measurements between HE and PAS staining. Interclass correlation coefficients (ICC) were calculated to evaluate reproducibility of measurements. The images were also evaluated for detectability of the scleral spurs. RESULTS: Among the 79 included subjects, 40 were male and 39 were female. The average trabecular meshwork length was 694.9 ± 109.0 µm in the male group and 713.2 ± 106.9 µm in the female group (p = 0.29). Intraobserver and interobserver ICC were 0.89 and 0.62, respectively. ICC for agreement between HE and PAS was 0.89. Among the 158 angles graded, the first observer graded 40 images (25.3%) and the second observer graded 45 (28.5%) as difficult to identify the scleral spur. CONCLUSIONS: There was no statistically significant difference between the average trabecular meshwork length in men and women. Among the angles evaluated, 25.3-28.5% were graded as difficult to identify the scleral spur.

Ethnic differences in intraocular pressure reduction and changes in anterior segment biometric parameters following cataract surgery by phacoemulsification.

BACKGROUND: To determine the association between ethnicity and changes in intraocular pressure and anterior segment biometric parameters following cataract surgery by phacoemulsification in nonglaucomatous subjects. DESIGN: Prospective clinical cohort study. PARTICIPANTS: Caucasian and Asian subjects. METHODS: Customized software was used to calculate parameters from anterior segment optical coherence tomography images obtained preoperatively and at 3 months following cataract surgery by phacoemulsification. The percentage changes in intraocular pressure and anterior segment biometric parameters following cataract surgery by phacoemulsification were modelled as a function of ethnicity using linear mixed-effects regression, a likelihood ratio test function that adjusted for age, sex and the use of both eyes in the same subject, to determine the association between ethnicity and postoperative outcomes. MAIN OUTCOME MEASURES: Intraocular pressure, angle opening distance, anterior chamber depth, anterior chamber volume, and angle recess area. RESULTS: Fifty Asian and 23 Caucasian nonglaucomatous eyes were analysed. Postoperative decrease in intraocular pressure and increases in angle opening distance, anterior chamber depth, anterior chamber volume and angle recess area were observed within each ethnic group (P < 0.005). The percent changes in intraocular pressure, angle opening distance, anterior chamber depth, anterior chamber volume and angle recess area did not differ between ethnic groups (P > 0.05). CONCLUSIONS: In this study, regardless of ethnic classification, subjects who received cataract surgery by phacoemulsification experienced a significant postoperative decrease in intraocular pressure and increases in angle opening distance, anterior chamber depth, anterior chamber volume and angle recess area. The percent changes in postoperative outcomes did not differ significantly by ethnicity.

Comparison of optic nerve head topography and retinal nerve fiber layer in eyes with narrow angles versus eyes from a normal open angle cohort - a pilot study.

PURPOSE: To compare the optic nerve head (ONH) and retinal nerve fiber layer (RNFL) in eyes with narrow angles and normal intraocular pressure (IOP) to normal control eyes. MATERIALS AND METHODS: A total of 70 eyes of 52 subjects with narrow angles and 40 eyes of 34 normal subjects were enrolled. Narrow angle eyes were defined as the following: (i) the pigmented trabecular meshwork was not visible for ≥ 180° on gonioscopy, (ii) untreated IOP ≤ 21 mmHg, (iii) no peripheral anterior synechiae (PAS) was observed, and (iv) optic discs were without glaucomatous changes, defined as neuroretinal rim thinning, focal notching, disc hemorrhages, or focal RNFL defects. ONH and peripapillary RNFL imaging were obtained with Heidelberg Retina Tomograph (HRT II) and Fourier-domain optical coherence tomography (RTVue OCT). RESULTS: No significant difference was found in mean age between the two groups (p = 0.06), but the narrow angle group had significantly more women (p = 0.04). The narrow angle group had significantly higher IOP and smaller mean angle width (both p < 0.001). Vertical cup-to-disc ratio (VCDR) was significantly larger in the narrow angle group (p = 0.02). In visual field (VF) results, the mean deviation (MD) was significantly lower and pattern standard deviation (PSD) was significantly higher in the narrow angle group (both p < 0.001). After adjusting for disc area, the RNFL thickness of the inferior-temporal region was significantly thinner in the narrow angle group (135 ± 21.7 µm) compared with normal group (149 ± 22.1 µm, p < 0.01). This finding remained significant after Bonferroni correction for multiple comparisons. Smaller angle width was a significant predictor of RNFL thinning in the inferior-temporal region (p < 0.001). CONCLUSION: These data suggest that eyes with narrow angles may develop glaucomatous optic nerve damage in the absence of IOP elevation during office hours.