Assessment of the impact of N95 respirators or surgical masks use on the retinal microvasculature.

PURPOSE: To determine the possible impact of wearing N95 respirator or surgical masks on retinal vessel diameters and choroidal thickness in healthy healthcare workers. METHODS: Diameters of peripapillary retinal arteries and veins and choroidal thickness values at the foveal center and at 1000 µm distances from the foveal center in both nasal and temporal directions were measured before mask wearing using a spectral-domain optical coherence tomography. After four hours (h) of N95 or surgical mask wearing vessel diameter and choroidal thickness measurements were repeated. RESULTS: A total of 52 eyes from 52 participants (28 F [53.8%]; 24 M [46.2%]) were enrolled in this study. The mean age of patients was 34.58 ± 5.24 years (25-44 years). The diameters of all measured arteries [inferior temporal artery (p = 0.003), superior temporal artery (p < 0.001), inferior nasal artery (p = 0.003), and superior nasal artery (p = 0.004)] and veins,with the exception of superior nasal vein, (inferior temporal vein (p = 0.031), superior temporal vein (p = 0.027), inferior nasal vein (p < 0.001), and superior nasal vein (p = 0.063)] increased significantly after four hour use of N95 respirators and surgical maskswhen compared to baseline. There was also a significant diameter increase of the superior temporal (p < 0.001), inferior nasal veins (p < 0.001), and superior temporal artery (p = 0.037) for N95 respirators and surgical masks use, respectively. The differences in central subfoveal, temporal, and nasal choroidal thickness between baseline and after 4 h use of N95 respirators were statistically significant (From 366.73 ± 70.81 µm to 381.23 ± 69.29µm,p < 0.001 for the subfoveal; from 324.00 ± 64.13µm to 335.40 ± 61.35 µm, p = 0.007 for the temporal; from 297.40 ± 68.18 µm to 308.23 ± 74.51µm, p = 0.002 for the nasal thicknesses). Choroidal thickness values were also increased with surgical mask use. But only the increase in central subfoveal thickness was statistically significant (From 366.78 ± 71.00 µm to 372.58 ± 76.56 µm, p = 0.031 for the central subfoveal; from 297.42 ± 68.35 µmto 302.79 ± 73.05 µm, p = 0.068 for the nasal; from 324.01 ± 64.21µm to 330.33 ± 65.84, p = 0.117 for the temporal thicknesses). CONCLUSION: With four hours use of N95 respirators or surgical face masks, retinal vessel diameters and choroidal thicknesses showed an increase in comparison to baseline measurements. Hemodynamic changes seen secondary to hypercapnia due to prolonged use of N95 respirators or surgical masks may also be observed in the retinal and choroidal circulation. Furthermore, the use of face masks should be taken into account while assessing the retinal microvasculature.

Assessment of the lamina cribrosa in attention-deficit hyperactivity disorder.

PURPOSE: The aim of this study was to determine the usefulness of the lamina cribrosa thickness (LCT) and lamina cribrosa depth (LCD) in adolescence with attention-deficit hyperactivity disorder (ADHD) and compare with those receiving methylphenidate (MPH) and healthy controls. METHODS: Fifty-five children with ADHD (9.23 ± 1.92 years, mean ± standard deviation), 41 children with ADHD given MPH (9.24 ± 1.84 years), and 86 healthy controls (9.95 ± 2.16 years) were recruited for the study. All subjects were subjected to a complete eye exam and optical coherence tomography (OCT) was used to assess LCT and LCD. The severity of ADHD symptoms was evaluated by using parent-report measures, including Conners's Parent Rating Scale-Revised: Short Form (CPRS-R: S) and the Strengths and Difficulties Questionnaire: Parent Form (SDQ: P). RESULTS: The study showed a significant finding between the research groups with regard to LCT. LCT was shown to be significantly increased in ADHD subjects given MPH compared with the controls. However, LCD was not significantly different between cohorts. Also, a significant inverse correlation was found between the SDQ: P-Emotional Problems Subscale and LCT (r = -0.253; P = 0.030) in ADHD patients. CONCLUSION: Changes in lamina cribrosa (LC) in ADHD children receiving MPH suggest that the mechanism of action for MPH may target developing LC structures. More studies to define the relationship between MPH medications and the LC variations are defensible.

Assessment of the Effect of Attention-Deficit Hyperactivity Disorder on Choroidal Thickness Using Spectral Domain Optical Coherence Tomography.

OBJECTIVES: This study was a comparison of the thickness of the choroid in pediatric patients with attention-deficit hyperactivity disorder (ADHD) and healthy pediatric controls. METHODS: This study was comparative, cross-sectional, and observational in design. The healthy controls were age- and sex-matched with the members of the ADHD group and had no history of psychosis. Choroidal thickness was determined using spectral-domain optical coherence tomography. RESULTS: A total of 138 patients were enrolled with a male:female ratio of 54 (69.2%): 24 (30.8%) in the ADHD group and 41 (68.3%): 19 (31.7%) in the control group (p=0.910). The ADHD patients had a mean age of 9.4±1.9 years (range: 6-12 years) and the controls had a mean age of 9.9±2.2 years (range: 6-12 years) (p=0.213). The ADHD group (n=78 eyes tested) had a significantly higher mean choroidal thickness at 1.5 mm (temporal-to-fovea, TTF) measurement than the controls (n=60 eyes tested) (281.12±46.63 µm vs. 264.40±48.61 µm, p=0.042). There were no significant differences in any of the other choroidal thickness measurements (p>0.05). CONCLUSION: The choroidal thickness measurement (TTF) at 1.5 mm was significantly greater in the ADHD patients. These findings suggest that choroidal thickness alterations may have a potential role in the underlying etiology of ADHD.

Long-term Outcomes of Accelerated Corneal Cross-linking in the Treatment of Keratoconus: Comparison of Hypotonic Riboflavin Solution With Standard Riboflavin Solution.

PURPOSE: To determine 2-year efficacy of accelerated corneal cross-linking (CXL) in keratoconus treatment using standard riboflavin-dextran or hypotonic riboflavin solutions. METHODS: Patients undergoing accelerated CXL (epitheliumoff 10 minutes, 9 mW/cm2 protocol) with standard riboflavin solution (48 eyes of 48 patients) or hypotonic riboflavin solution (43 eyes of 43 patients) were included and followed up for 2 years. Thinnest corneal thickness (TCT), maximum keratometry, and visual acuity were measured and changes from baseline to postoperative 6, 12, and 24 months were compared between the two groups. RESULTS: The preoperative mean TCT with intact epithelium was 472.0 ± 23.9 and 427.5 ± 22.3 µm in the standard riboflavin and hypotonic riboflavin groups, respectively (P < .001). The decreases in the mean TCT values from baseline to postoperative 6 months were similar between the standard riboflavin (from 472 to 436 µm) and hypotonic riboflavin (from 427 to 394 µm) groups. This suggested that the hypotonic riboflavin solution was comparable with the standard riboflavin solution in preserving corneal thickness in keratoconus. There were no significant differences between the study groups regarding the postoperative changes in maximum keratometry or visual acuity. CONCLUSIONS: The efficacy of accelerated CXL with hypotonic riboflavin solution was comparable to that with the standard riboflavin solution in reducing keratoconus progression in a 2-year follow-up period. [J Refract Surg. 2020;36(2):110-117.].

Evaluation of Posterior Ocular Structures in Patients with Isolated Iris Coloboma.

OBJECTIVES: To measure lamina cribrosa thickness (LCT), lamina cribrosa depth (LCD) and subfoveal choroidal thickness (SFCT) by imaging posterior ocular structures in pediatric cases with isolated unilateral iris coloboma and to investigate the differences as compared with healthy contralateral eyes of these cases (fellow eyes) and healthy control eyes. METHODS: This cross-sectional, comparative prospective study included seven children (age range, 9-17 years) with unilateral isolated iris coloboma. The healthy contralateral eyes of these cases formed the fellow group. An age-matched (age range 8-17 years) control group (n=9), including children with both eyes having either normal or corrected-to-normal visual acuity, was formed. A detailed ophthalmic examination was performed. The posterior ocular segments were evaluated using spectral domain-optical coherence tomography (SD-OCT) with enhanced depth imaging (EDI) technique. RESULTS: The SFCT was 372.0±48.8 µm, 375.3±44.0 µm, and 386.5±71.8 µm, respectively, and the LCD was 362.4±68.3 µm, 354.4±47.1 µm, and 350.7±38.1 µm, respectively, in the coloboma, fellow, and control eyes. There was no difference between the groups regarding SFCT and LCD. The mean LCT was significantly thinner in the coloboma eyes (200.2±9.5 µm) than in the fellow (238.8±26.7 µm; p=0.023) and control eyes (240.0±12.9 µm; p<0.001). The LCT showed no significant correlation with age, axial length or spherical equivalent. CONCLUSION: Better visual prognosis is expected in isolated iris coloboma. However, detailed examinations using new technologies, such as SD-OCT, may reveal some structural changes. Longitudinal studies are required to understand if a thinner LCT in coloboma eyes is associated with any future problems.

Serum Vitamin D Levels in Patients with Keratoconus.

Purpose: To evaluate serum 25-hydroxyvitamin D levels in patients with keratoconus (KC) and its association with disease severity and to compare vitamin D levels with those of age- and sex-matched healthy individuals.Methods: This study included 100 patients with KC and 100 non-atopic healthy controls. Serum vitamin D levels were measured using liquid chromatography-tandem mass spectrometry and compared between the study groups. KC severity was graded as mild (K = 43.1-46.9 D), moderate (K = 47-50 D), and severe (K > 50 D). Vitamin D levels were classified as deficient (≤10 ng/mL), insufficient (11-20 ng/mL), and optimal (>20 ng/mL).Results: The mean serum vitamin D level was significantly lower in the KC group than in the control group (12.18 ± 5.05 ng/mL vs 15.18 ± 5.81 ng/mL; p < .001). Vitamin D deficiency (≤10 ng/mL) was observed in 54.0% of the KC patients and 34.0% of the controls (p = .011). Multivariable logistic regression analysis revealed that having deficient vitamin D level increased the presence of KC 2.9 fold (p = .021, 95% confidence interval, 1.17-6.95). Decreasing serum vitamin D levels were not significantly associated with increasing severity of KC (p = .311). Although the rate of patients with deficient vitamin D was the highest in the severe KC group, distribution of vitamin D levels were not significantly different among KC groups (p = .326).Conclusion: The patients with KC had lower serum vitamin D levels than those of age- and sex-matched healthy controls. The present study could be a valuable entry point for further researches investigating the potential link between vitamin D and KC.

Evaluation of choroidal changes in adolescent idiopathic scoliosis using enhanced depth imaging optical coherence tomography.

BACKGROUND: We aimed to evaluate the choroidal thickness (CT) in patients with adolescent idiopathic scoliosis (AIS) using enhanced depth imaging optical coherence tomography (EDI-OCT). METHODS: In this cross-sectional, observational comparative study, 56 eyes of 56 patients with AIS and 56 eyes of 56 age- and sex-matched healthy subjects were included. All participants underwent complete ophthalmologic examination and CT measurements at the fovea and at 750 µm intervals from the fovea to 1,500 µm in the nasal and temporal site obtained by spectral domain EDI-OCT. RESULTS: The mean subfoveal CT was lower in the AIS patients (285.2 ± 24.4 µm) than that of the controls (313.2 ± 28.8 µm; p < 0.001). The difference was also significant at all extrafoveal measurement points (p < 0.001 for all). There were negative correlations of CTs at subfoveal and extrafoveal locations with the Cobb's angle in the AIS patients (for subfoveal location: r = -0.71 and p < 0.001; and for extrafoveal locations: r = -0.66 and p < 0.001 at 750 µm in the nasal side; r = -0.64 and p < 0.001 at 1,500 µm in the nasal side; r = -0.71 and p < 0.001 at 750 µm in the temporal side; and r = -0.69 and p < 0.001 at 1,500 µm in the temporal side). CONCLUSION: This preliminary study showed that AIS patients have thinner CT compared to that of healthy subjects. The lower CT was correlated with the increased angle of scoliosis.

Lamina cribrosa thickness in children with hyperopic anisometropic amblyopia.

AIM: To determine lamina cribrosa thickness (LCT) in the optic nerve head region of the eyes in children with hyperopic anisometropic amblyopia and to compare this thickness with that of fellow eyes, hyperopic non-amblyopia, and age-matched controls. METHODS: Thirty-two patients (12.0±1.8y, mean± standard deviation) with hyperopic anisometropic amblyopia, 31 subjects with age- and refractive error-matched hyperopic non-amblyopia (10.7±2.2y), and 32 age-matched controls (11.2±2.0y) were included in this prospective, cross-sectional study. LCT was measured using an enhanced depth-imaging program of a spectral domain optical coherence tomographic instrument in all participants, and the correlation between LCT and axial length was calculated. RESULTS: The mean LCT was 180.9±29.4 µm in amblyopic eyes, 247.7±19.0 µm in fellow eyes, 251.6±27.3 µm in hyperopic non-amblyopic eyes, and 240.2±15.8 µm in control eyes. Lamina cribrosa in amblyopic eyes was significantly thinner than fellow, hyperopic non-amblyopic, and control eyes (P<0.05). There was no significant correlation in LCT and axial length between amblyopic (P=0.16) and control (P=0.31) group. CONCLUSION: Lamina cribrosa of eyes with hyperopic anisometropic amblyopia is significantly thinner than that of fellow eyes, hyperopic non-amblyopia, and age-matched controls. The LCT profile in amblyopic eyes is different from that observed in fellow, hyperopic non-amblyopic, and control eyes.

The effect of smoking cessation on posterior ocular structures / O efeito da suspensão do tabagismo em estruturas oculares posteriores

ABSTRACT Purpose: This study evaluated changes in cho­roidal and macular thickness in healthy volunteers and chronic smokers. Methods: Thirty-three eyes of 33 chronic smokers (study group) and 33 eyes of 33 healthy controls who had never smoked were prospectively evaluated. Comprehensive ophthalmic assessment included slit lamp biomicroscopy, stereoscopic fundus examination, and intraocular pressure measurement. Spectral domain optical coherence tomography was used to measure choroidal and macular thickness 1 month before smoking cessation (smoking period) and after 3 months of smoking cessation (nonsmoking period). Results: The mean age of the participants was 41.88 ± 6.52 years (range, 26-52), and the average smoking duration was 8.6 ± 2.5 years (range, 5-16). The thickness of the paracentral choroid (nasal: 1,500 mm, p=0.001 and temporal: 1,500 mm, p=0.001) had significantly decreased after 3 months of smoking cessation. The thicknesses of the subfoveal choroid in the smoking and nonsmoking periods were not significantly different (p=0.194). The mean central macular thickness was 267.21 ± 18.42 mm in the smoking period and 268.42 ± 18.28 mm in the nonsmoking period (p=0.022). Conclusions: Smoking was associated with statistically significant changes in paracentral choroidal and central macular thickness in healthy volunteers. Pathological studies should be performed to evaluate the effects of smoking on posterior ocular structures.

RESUMO Objetivo: Este estudo avaliou as mudanças na espessura da coroide e da mácula em voluntários saudáveis e fumantes crônicos. Métodos: Trinta e três olhos de 33 fumantes crônicos (grupo estudado) e 33 olhos de 33 controles saudáveis que nunca fumaram foram avaliados prospectivamente. A avaliação oftalmológica abrangente incluiu biomicroscopia de lâmpada de fenda, exame de fundo estereoscópico e medição da pressão intraocular. A tomografia de coerência óptica de domínio espectral foi utilizada para medir a espessura da coroide e da mácula um mês antes da cessação do tabagismo (período de fumar) e após 3 meses da cessação do tabagismo (período de abstinência). Resultados: A idade média dos participantes foi de 41,88 ± 6,52 anos (faixa de 26-52 anos) e a duração média do tabagismo foi de 8,6 ± 2,5 anos (faixa, 5-16 anos). A espessura da coroide paracentral (nasal: 1.500 mm, p=0,001, temporal: 1.500 mm, p=0,001) diminuiu significativamente após 3 meses de cessação do tabagismo. As espessuras de coroide subfoveal nos períodos de tabagismo e não-tabagismo não foram significativamente diferentes (p=0,194). A espessura macular central média foi de 267,21 ± 18,42 mm no períodos de tabagismo e 268,42 ± 18,28 mm no períodos de não-fumantes (p=0,022). Conclusões: O tabagismo foi associado a mudanças estatis­ticamente significativas na espessura paracentral de coroide e macular central em voluntários saudáveis. Estudos patológicos devem ser realizados para avaliar os efeitos do tabagismo nas estruturas oculares posteriores.

The effect of smoking cessation on posterior ocular structures.

PURPOSE: This study evaluated changes in cho-roidal and macular thickness in healthy volunteers and chronic smokers. METHODS: Thirty-three eyes of 33 chronic smokers (study group) and 33 eyes of 33 healthy controls who had never smoked were prospectively evaluated. Comprehensive ophthalmic assessment included slit lamp biomicroscopy, stereoscopic fundus examination, and intraocular pressure measurement. Spectral domain optical coherence tomography was used to measure choroidal and macular thickness 1 month before smoking cessation (smoking period) and after 3 months of smoking cessation (nonsmoking period). RESULTS: The mean age of the participants was 41.88 ± 6.52 years (range, 26-52), and the average smoking duration was 8.6 ± 2.5 years (range, 5-16). The thickness of the paracentral choroid (nasal: 1,500 mm, p=0.001 and temporal: 1,500 mm, p=0.001) had significantly decreased after 3 months of smoking cessation. The thicknesses of the subfoveal choroid in the smoking and nonsmoking periods were not significantly different (p=0.194). The mean central macular thickness was 267.21 ± 18.42 mm in the smoking period and 268.42 ± 18.28 mm in the nonsmoking period (p=0.022). CONCLUSIONS: Smoking was associated with statistically significant changes in paracentral choroidal and central macular thickness in healthy volunteers. Pathological studies should be performed to evaluate the effects of smoking on posterior ocular structures.

Macular and Peripapillary Choroidal Thickness in Patients With Keratoconus.

BACKGROUND AND OBJECTIVE: To investigate and compare macular and peripapillary choroidal thickness and profiles of patients with keratoconus and age-matched controls and correlate subfoveal choroidal thickness with keratoconus severity. PATIENTS AND METHODS: This was a prospective, observational, cross-sectional study comprising 45 keratoconus patients and 56 healthy controls. Choroidal thicknesses at the fovea and at 750-µm intervals from the fovea to 1.5 mm in the nasal and temporal directions were measured by spectral-domain optical coherence tomography. Peripapillary choroidal thickness was measured at six segments along the circle scan. RESULTS: Mean age did not differ between the patients with keratoconus and controls (24.5 ± 7.2 vs. 22.5 ± 7.4 years, P = .170). Mean subfoveal choroidal thickness was higher in the keratoconus group (427.48 µm ± 78.51 µm) than in controls (351.03 µm ± 99.08 µm; P < .001). Mean subfoveal choroidal thickness did not differ between mild and severe keratoconus (437.82 ± 53.4 vs. 418.87 ± 113.9 µm; P = .660). In the macular area, choroidal thickness was lower at 1.5 mm nasal to the fovea (P < .0001) in both groups. The choroid was thinner at 0.75 mm temporal to the fovea than under the fovea in the keratoconus group (P < .001). The peripapillary choroid was thinner in the inferonasal and inferotemporal segments than in the other segments in both groups (P < .001). The peripapillary choroid was thinner in the inferonasal segment than in the inferotemporal segment in the keratoconus group (P = .018). CONCLUSION: Subfoveal choroidal thickening is observed in keratoconus eyes. The pathophysiological role of choroidal thickness variations should be considered in the natural history of keratoconus. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:664-673.].

Evaluation of the lamina cribrosa in patients with diabetes mellitus using enhanced depth imaging spectral-domain optical coherence tomography.

PURPOSE: To compare the lamina cribrosa thickness and anterior lamina cribrosa depth between patients with and without diabetes mellitus and to investigate the effect of metabolic control and duration of diabetes mellitus on lamina cribrosa thickness and anterior lamina cribrosa depth using enhanced depth imaging spectral-domain optical coherence tomography. METHODS: A total of 70 patients were enrolled in this cross-sectional study and were divided into the diabetes and control groups. Intraocular pressure, circumpapillary retinal nerve fibre layer thickness, anterior lamina cribrosa depth and lamina cribrosa thickness were compared between the groups. RESULTS: In the control group, the mean intraocular pressure was 14.6 ± 3.1 (mean ± standard deviation) mmHg, mean circumpapillary retinal nerve fibre layer thickness was 105.41 ± 5.86 µm, mean anterior lamina cribrosa depth was 420.3 ± 90.2 µm and mean lamina cribrosa thickness was 248.5 ± 5.4 µm. In the diabetes group, the mean intraocular pressure was 13.9 ± 2.2 mmHg, mean circumpapillary retinal nerve fibre layer thickness was 101.37 ± 10.97 µm, mean anterior lamina cribrosa depth was 351.4 ± 58.6 µm and mean lamina cribrosa thickness was 271.6 ± 33.9 µm. Lamina cribrosa thickness was significantly higher ( p < 0.001) and anterior lamina cribrosa depth was significantly lower ( p = 0.003) in the diabetes group. There was no statistical difference between the groups with regard to age, spherical equivalent, axial length, circumpapillary retinal nerve fibre layer thickness and intraocular pressure ( p = 0.69, 0.26, 0.47, 0.06 and 0.46, respectively). Lamina cribrosa thickness and anterior lamina cribrosa depth were not significantly correlated with duration of diabetes mellitus (lamina cribrosa thickness: r = -0.078, p = 0.643; anterior lamina cribrosa depth: r = -0.062, p = 0.710) or HbA1c levels (lamina cribrosa thickness: r = -0.078, p = 0.596; anterior lamina cribrosa depth: r = -0.228, p = 0.169). CONCLUSION: The results of this study showed that the optical coherence tomography measurement of lamina cribrosa revealed thicker and more anteriorly positioned lamina cribrosa for patients with diabetes mellitus compared with those for healthy controls.

Lamina Cribrosa Thickness in Patients With Keratoconus.

PURPOSE: To evaluate the thickness and depth of lamina cribrosa (LC) in the optic nerve head region of the eyes in patients with nonglaucomatous keratoconus and to compare the thickness and depth with those of age-matched controls. METHODS: This was a cross-sectional, observational study comprising 45 patients with keratoconus and 56 healthy subjects. Analysis of LC imaging was performed using spectral domain optical coherence tomography. Data collected included spherical equivalent, central corneal thickness, axial length, intraocular pressure, and keratometry. RESULTS: Eyes with keratoconus had significantly thinner LC (174.9 ± 11.4 vs. 249.1 ± 4.9 µm, P < 0.001) compared with control group eyes. There was no statistically significant difference in the depth of LC between the keratoconus and control groups (P = 0.3). Multivariable analysis, controlled for age and sex, showed that the thickness of LC significantly correlated with central corneal thickness (P < 0.001). This association persisted (P < 0.001) after controlling for intraocular pressure in addition to age and sex. There was no significant correlation with other factors, including the spherical equivalent (P = 0.93) and keratometry (P = 0.46). CONCLUSIONS: The results of this study showed that optical coherence tomography measurement of LC revealed thinner LC for patients with keratoconus compared with healthy controls. The structural properties of the cornea may be related to the optic nerve.

Comparison of the corneal biomechanical properties, optic nerve head topographic parameters, and retinal nerve fiber layer thickness measurements in diabetic and non-diabetic primary open-angle glaucoma.

The purpose of this study is to investigate the corneal biomechanical properties, optic nerve head (ONH) topographic parameters, and retinal nerve fiber layer (RNFL) thickness changes in primary open-angle glaucoma (POAG) patients with and without diabetes, as well as to evaluate the effect of the metabolic control of diabetes on corneal biomechanical properties, ONH topography, and RNFL thickness. A total of 101 eyes of 101 POAG patients (60 with diabetes and 41 without diabetes) were recruited in this prospective study. Corneal hysteresis and corneal resistance factor (CRF) were both measured using the ocular response analyzer. Optic disk parameters were evaluated using the Heidelberg Retina Tomograph-III. RNFL thickness was measured by using Spectralis HRA + OCT. CRF, mean rim area, and rim volume were found to be significantly higher in the diabetic group when compared with non-diabetic group (p = 0.01 for CRF, p = 0.04 for rim area and p = 0.02 for rim volume). ANCOVA analysis showed statistically insignificant effects of age, gender, MD, and PSD values over rim area and rim volume (p > 0.05). CRF was not significantly correlated with HbA1c levels (p > 0.05). Cup area (CA), cup volume (CV), and cup shape measure (CSM) were weakly correlated with HbA1c levels (r = 0.35 and p = 0.006 for CA; r = 0.32 and p = 0.01 for CV; r = 0.32 and p = 0.01 for CSM). The difference in mean RNFL thickness values between the groups was found to be insignificant (p > 0.05). The results of this study raise doubts whether or not diabetes does in fact shield POAG patients from glaucomatous optic nerve damage from various perspectives.

Comparison of Optic Nerve Head Topographic Parameters in Patients With Primary Open-Angle Glaucoma With and Without Diabetes Mellitus.

PURPOSE: To evaluate the optic nerve head (ONH) parameters of primary open-angle glaucoma (POAG) patients with and without diabetes and to investigate the effect of the metabolic control of diabetes on ONH topography. MATERIALS AND METHODS: A study group of 60 eyes of 60 POAG patients with type 2 diabetes mellitus and a control group of 41 eyes of 41 POAG patients without diabetes were recruited for the study. Complete ophthalmic examinations of all patients were performed and the quantitative optic disc parameters were evaluated with Heidelberg retina tomography (HRT) III. HbA1c measurements of diabetic patients were assessed on the same day when the ophthalmic assessments were performed. RESULTS: Mean rim area and rim volume of the study group was statistically higher than the control group (P=0.04 for rim area and P=0.02 for rim volume). The difference in other parameters of the HRT between the groups were insignificant (P>0.05). In the study group, the duration of the diabetes was not significantly correlated to rim area and rim volume (r=0.03, P=0.81 for rim area; r=0.03, P=0.79 for rim volume). Analysis of covariance showed insignificant effects of age, sex, MD, and PSD values over rim area and rim volume (P>0.05). There were weak but statistically significant correlations between HbA1c levels and some HRT parameters including disc area, cup area, cup volume, and cup shape measure (r=0.35 and P=0.006 for disc area; r=0.35 and P=0.006 for cup area; r=0.32 and P=0.01 for cup volume; r=0.32 and P=0.01 for cup shape measure). CONCLUSIONS: The results of this study imply the protective effect of diabetes over glaucomatous optic nerve damage in POAG patients. However, larger and controlled studies are warranted to confirm those findings.