Outcomes and success of amniotic membrane transplantation for the treatment of corneal diseases.

PURPOSE: The amniotic membrane (AM), the inner layer of the placenta, is a semitransparent, avascular, and thin tissue that is useful due to its structure. Amniotic membrane transplantation (AMT) avoids the need for keratoplasty to prevent corneal perforating. The purpose of the study was to evaluate the visual (gain of or no change in visual acuity) and corneal outcomes (closure of the ulcer or corneal healing) of AMT in patients with ocular surface diseases. MATERIALS AND METHODS: This was a retrospective case control study (success or failure of the surgery). It was undertaken at a single academic center. The study cohort consisted of subjects with ocular surface diseases. Patients were treated with AMT for refractory ocular surface diseases. They were divided into five subgroups according to the preoperative diagnosis. The technique of AMT used was the onlay method with two layers of AM. Primary outcome measures included best corrected visual acuity (BCVA), the number of AMTs, and reepithelization of the corneal epithelium at the end of the treatment. Two weeks to six months were given to consider epithelial closure. Treatment success was defined as corneal healing within 6 months. RESULTS: A total of the 66 eyes of 66 patients (39 male/27 female) with a mean age of 44 ± 23 years (range 1-88 years) were included in the study. A single AMT procedure achieved epithelial closure in 74.2% (n = 49) of the eyes (53% in <15 days, 19.6% in 15-30 days, and 1.5% in 1-6 months). The fastest reepithelization occurred in neurotrophic keratopathy, 76.9% of which cases occurred within 15 days after the AMT procedure. Treatment failure was observed in five patients (7.5%), four with keratitis and one with neurotrophic keratopathy. The highest closure rates were found in persistent epithelial defects, graft-versus-host disease (GvHD), and bullous keratopathy, although there was no statistically significant difference in BCVA. Pairwise comparisons were made of neurotropic keratoplasty versus bullous keratopathy (P = 0.025), neurotrophic keratopathy versus keratitis (P = 0.004), GVHD versus keratitis (P = 0.003), and lastly, GvHD versus bullous keratopathy (P = 0.023). CONCLUSIONS: AMT is a safe, valuable, and fast treatment technique to treat corneal epithelial defects stemming from different etiologies that are refractory to conventional treatment.

Short-term effect of macular edema on the peripapillary retinal nerve fiber layer in patients with wet age-related macular degeneration and diabetic macular edema: A comparative study.

BACKGROUND: The combined presence of glaucoma and age-related macular degeneration (ARMD), or glaucoma and diabetes mellitus (DM), occur fairly frequently, especially in elderly patients. This study was intended to compare the effect of resolving macular edema due to DM and wet ARMD on peripapillary retinal nerve fiber layer (RNFL) thickness. METHODS: This cross-sectional study included 76 patients with macular edema secondary to DM (n = 40, 52.6%) or wet ARMD (n = 36, 47.4%). The control group was comprised of 34 age and sex-matched healthy subjects. All study participants underwent evaluation of central macular thickness (CMT) and the peripapillary RNFL using spectral domain-optical coherence tomography (SD-OCT). Data from eyes that received an anti-VEGF injection were obtained one month after the procedure and were compared with pre-injection data. RESULTS: The average initial thickness of the global peripapillary RNFL was 98.9 ± 16.7 (61-163) µm in the macular edema group and 92.0 ± 16.0 (84-115) µm in the control group (p = 0.045). The post-injection global peripapillary RNFL thickness was 97.3 ± 19.0 (61-163) µm in the macular edema group and 92.2 ± 18.0 (81-126) µm in the control group (p = 0.187). In the DM group, the changes in global RNFL thickness, as well as central and temporal quadrant thicknesses, were found to correlate significantly with the change in CMT (r = 0.356, p = 0.024; r = 0.545, p < 0.001, respectively). CONCLUSIONS: Macular edema in wet ARMD appeared not to affect RNFL thickness. Differences in the etiology of macular edema can have varied effects on peripapillary RNFL. It is recommended that peripapillary RNFL thickness be evaluated cautiously in DM patients receiving intravitreal anti-VEGF therapy.

The Effect of Mask Use on the Ocular Surface During the COVID-19 Pandemic.

Objectives: The new coronavirus disease 2019 (COVID-19) pandemic emerged in Wuhan, China in October 2019 and spread rapidly all over the world, making extended mask use an inescapable rule of daily life. Literature data indicate that the use of face masks increases the symptoms of dry eye in addition to preventing the spread of COVID-19. The aim of our study was to evaluate the relationship between the clinical signs and symptoms of dry eye and the duration of mask use in healthy individuals using regular face masks. Materials and Methods: Thirty-five patients aged 20-60 years with no additional ophthalmologic pathology were included in the study. Participants were stratified by duration of face mask use: ≤6 hours/day (group 1) and >6 hours/day (group 2). The patients were assessed with the Ocular Surface Disease Index (OSDI) questionnaire, fluorescein ocular surface staining, and tear break-up time (TBUT) to evaluate the effect of extended mask use on the ocular surface. Results: A total of 62 eyes of 35 patients, 20 women (57.1%) and 15 men (42.9%), were included in the study. The two mask use duration groups had similar OSDI values (p=0.736). When the ocular surface staining pattern was examined according to the Oxford scale, 50% (10/20) of the eyes in group 1 were assessed as stage 1 and the other 10 eyes as stage 0. In group 2, 47.6% (20/42) of the eyes were assessed as grade 1, 11.9% (5/42) as grade 2, and 4.7% (2/42) as grade 3. Conclusion: Prolonged face mask use was shown to cause decreased TBUT and increased ocular surface staining even in healthy individuals. Further studies are needed to investigate changes in the tear film after extended daily mask use.

Optic nerve head microvascular characteristics in patients with unilateral pseudoexfoliation syndrome: an optical coherence tomography angiography study.

PURPOSE: To compare vascular microcirculation changes of the optic nerve head (ONH) and to evaluate the peripapillary retinal nerve fiber layer (RNFL) in the patients with unilateral pseudoexfoliation syndrome (PEXS), other eyes of these patients without PEXS and healthy control eyes using optical coherence tomography angiography (OCTA) and spectral domain optical coherence tomography (SD-OCT). METHODS:  This cross-sectional study enrolled 29 pseudoexfoliative (PEX) and 29 fellow eyes of patients with unilateral PEXS, and 28 healthy eyes as controls. According to inclusion criteria the study group with asymmetric PEXS were normotensive and no glaucoma diagnosis. The vascularity of optic disc was evaluated with OCTA and peripapillary retinal nerve fiber layer with SD-OCT. ONH 4.5 × 4.5 mm OCTA gave us perfusion density (PD) and flow index (FI). Differences between the groups according to continuous variables were determined by independent samples t test. A p value less than 0.05 was considered as significant. RESULTS: Twenty-nine patients with the mean age of 66.21 ± 7.55 (49-79) years was compared with 28 individuals in control group with mean age of 66.79 ± 4.43 (60-75) years. There was no difference regarding the age (p = 0.725). Female and male distribution in two groups were same (p = 0.219). Intraocular pressure (IOP) in PEXS group was measured as 16.17 ± 4.58 (10-21) mmHg, however IOP in the fellow eye was measured as 14.79 ± 3.35 (11-19) mmHg (p = 0.064) and control group was measured as 12.53 ± 1.66 (10-17) mmHg (p = 0.000). In the group with PEXS, the superior FI was found to be lower 0.39 ± 0.06 (0.26-0.45) (p = 0.008) than control group 0.42 ± 0.21 (0.36-0.45), and temporal FI in PEXS eyes was measured 0.42 ± 0.06 (0.32-0.52), which was significantly lower than control group (p = 0.022). Nasal FI was the parameter which was found significantly different from the PEXS free fellow eyes. The nasal FI value of eyes with PEX was 0.40 ± 0.05 (0.30-0.46), while the same value in PEX free fellow eyes was 0.42 ± 0.04 (0.33-0.47) (p = 0.029). CONCLUSIONS: ONH evaluation with OCTA especially in the nasal segment is important for early diagnosis. OCTA can be a new method in follow-up and early diagnosis of patients with asymmetric PEXS to control ONH microcirculation and to evaluate early glaucomatose changes in both eyes.

Correlation of Ocular Biometric Parameters and Macular Ganglion Cell Layer in Normal Eyes.

PURPOSE: To determine the association between ocular biometric parameters and macular ganglion cell layer (MGCL) thickness in normal eyes. METHODS: This observational cohort study was conducted with 76 eyes of 76 healthy subjects. Keratometry, pachymetry, corneal volume, iridocorneal angle were measured with Sirius (CSO, Florence, Italy); axial length, anterior chamber depth, anterior chamber volume, corneal diameter were measured with IOL Master (Carl Zeiss Meditec, Dublin, California). For all participants, serial horizontal Spectralis Domain Optical Coherence Tomography (SD-OCT, Heidelberg Engineering, GmbH, Dossenheim, Germany) scans of the macula and peripapillary retinal nerve fiber layer (RNFL) analysis were obtained using SD-OCT. The relationship between numerical variables was given by Pearson correlation coefficient. RESULTS: The mean age of the subjects was 36.3 ± 11.9 years (between 19 and 70 y). Fifty-one patients were female (67.1%) and twenty-five patients were male (32.9%). MGCL was found to be correlated with anterior chamber depth, anterior chamber volume, iridocorneal angle, axial length and white to white (p = .015 r = 0.594, p = .002 r = 0.365, p = .013 r = 0.299, p = .004 r = 0.335, p = .013 r = 0.289, respectively). In addition, MGCL was correlated positively with the mean global and superotemporal RNFL (p ≤ 0.005). However, neither central corneal thickness nor keratometry values were found to be correlated with MGCL. CONCLUSION: The results of this study showed that MGCL thickness is affected by ocular biometric parameters. Therefore, these parameters should be taken into consideration when interpreting MGCL thickness measurements in the diagnosis of glaucoma.

Is macular pigment optical density really involved in fixation preference?

PURPOSE: To evaluate macular pigment optical density in healthy children and to compare the values with those of strabismic children with respect to fixation preference. METHODS: The study recruited 54 healthy and 41 strabismic children. Two groups were matched in terms of gestational age, birth weight, and body mass index. All participants underwent complete ophthalmological evaluation and macular pigment optical density measurement and filled a self-reported food frequency questionnaire. Strabismic children were categorized according to fixation preference. RESULTS: The mean age was 9.87 ± 2.39 years in healthy children and 9.07 ± 2.07 years in children with strabismus (p = 0.091). Mean macular pigment optical density was 0.23 ± 0.25 in healthy eyes and 0.25 ± 0.27 in non-preferred eyes of strabismic children (p = 0.964). Macular pigment optical density was significantly higher in preferred eyes of strabismic children (0.43 ± 0.34) compared to non-preferred eyes (p = 0.004) and healthy eyes (p = 0.001). There was a difference of macular pigment optical density between both eyes in patients with grades 1, 2, and 3 fixation preference, whereas patients with grade 4 preference had similar macular pigment optical density in both eyes (p = 0.008). There was a statistically significant positive correlation between macular pigment optical density in preferred eyes and body mass index (r = 0.354, p = 0.023). CONCLUSION: Preferred eyes of children with strabismus seem to have higher macular pigment optical density readings. This difference may emerge from the higher tendency of recognizing the flicker stimulus while preferred eye is under testing. Similar macular pigment optical density in healthy and non-preferred eyes and the fact that both lower than preferred eyes remain unexplained. It should be kept in mind that macular pigment optical density results should be carefully interpreted and macular pigment optical density in cases with strabismus should be further investigated.

Assessment of corneal backward light scattering in the healthy cornea and factors affecting corneal transparency.

PURPOSE: To quantify normative corneal optical density (COD) values of healthy individuals and to investigate alterations in the COD in relation to their ocular and demographic characteristics. STUDY DESIGN: Prospective, cross-sectional, and observational. METHODS: In total, 588 eyes from 588 healthy participants with clear corneas were consecutively enrolled. Corneal densitometry values expressed in standardized grayscale units (GSU) from different corneal layers and zones obtained using the rotating Pentacam Scheimpflug system were analyzed. RESULTS: The mean (SD) COD over the 12-mm diameter area was 14.4 ± 2.74 GSU. A significant positive correlation was found between the participants' age and the total COD (r = 0.756, P < .001). No significant differences were found between males and females with respect to COD (P = .51). No significant correlation was found between the COD measurements and refractive error, pachymetry, and keratometry (P > .05 for all comparisons). On the other hand, COD was negatively correlated with white-to-white (WTW) corneal diameter (r = - 0.415, P < .001). Moreover, the WTW corneal diameter was correlated with the COD in any zone and layer of the cornea (P < .05 for all comparisons). CONCLUSIONS: Wide variations in COD can be detected even in corneas deemed clinically clear. Age and corneal diameter that seem to influence corneal transparency should be taken into account when evaluating corneal backscatter.

Intravitreal Bevacizumab and Ranibizumab in the Treatment of Acute Central Serous Chorioretihopathy: A Single Center Retrospective Study.

OBJECTIVES: To evaluate and compare the anatomical and functional outcomes of patients with acute central serous chorioretinopathy (CSC) who did not receive any intervention or treatment with intravitreal bevacizumab or ranibizumab. METHODS: A single-center retrospective comparative study. Seventy eyes of 70 patients were recruited for the study; 27 patients were only observed without any medication or intervention (observation group), 23 were treated with intravitreal bevacizumab (IVB group), and the remaining 20 were treated with intavitreal ranibizumab (IVR group). The best-corrected visual acuity (BCVA) and central macular thickness (CMT) obtained by spectral-domain optical coherence tomography were compared between the groups. RESULTS: There were no significant differences between the groups with regard to age, sex, and follow-up periods (p>0.05). The mean time from baseline to initial complete resolution of subretinal fluid was 3.52±1.64 months in the observation group, 1.19±0.60 months in the IVB group, and 1.11±0.47 months in the IVR group; the resolution time was significantly longer in the observation group (p<0.001). While the CMT was significantly thicker in the observation group when compared to the IVB and IVR groups in the first month (p=0.001), it was similar between the groups in the third, sixth, and twelfth months (p>0.05). Additionally, pairwise comparisons of the IVB and IVR groups revealed that there were no significant differences between these groups regarding CMT at any follow-up time (p>0.05). CONCLUSIONS: Compared with observation alone, neither IVB nor IVR had a positive effect in terms of anatomical and functional outcomes for acute CSC. Although the resolution time of SRF is shorter by using ranibizumab, both the ranibizumab and bevacizumab could be effective in achieving rapid resolution of serous detachment in patients with acute CSC.

Relationship between anterior segment and optic nerve head parameters in healthy subjects.

PURPOSE: To determine the relationship between anterior segment and optic nerve head (ONH) parameters. METHODS: Two hundred healthy subjects were enrolled in this study. The par-ticipants underwent measurement of anterior segment parameters with a Pentacam Scheimpflug system and imaging of the optic disc with confocal scanning laser ophthalmoscopy. Pearson's correlation coefficient was calculated to assess the associations between ONH and anterior segment parameters. Multivariate regression analyses controlling for age and disc area as confounding factors were also conducted. RESULTS: There were significant negative relationships between optic disc area and corneal thickness (p=0.03, r=-0.217) and volume (p=0.017, r=-0.239). Corneal refractive power was significantly correlated with cup area, rim area, rim volume, and cup/disc ratio (p<0.05 for all). An increase of 1 diopter in anterior corneal refractive power corresponded to a decrease of 0.022 in cup/disc ratio. Rim volume was negatively correlated with anterior chamber depth and anterior chamber volume (p<0.05 for both). A 1-mm3 increase in anterior chamber depth corresponded to a 0.154-mm3 decrease in rim volume. Mean and maximum cup depth measurements were not associated with any of the anterior segment parameters. CONCLUSIONS: In nonglaucomatous eyes, the dimensions and shape of the ONH may be related to anterior segment morphology. Therefore, it may be helpful to take anterior segment parameters into consideration in evaluating the OHN.

Relationship between anterior segment and optic nerve head parameters in healthy subjects / Relações entre os parâmetros do segmento anterior e da cabeça do nervo óptico em indivíduos saudáveis

ABSTRACT Purpose: To determine the relationship between anterior segment and optic nerve head (ONH) parameters. Methods: Two hundred healthy subjects were enrolled in this study. The par­ticipants underwent measurement of anterior segment parameters with a Pentacam Scheimpflug system and imaging of the optic disc with confocal scanning laser ophthalmoscopy. Pearson's correlation coefficient was calculated to assess the associations between ONH and anterior segment parameters. Multivariate regression analyses controlling for age and disc area as confounding factors were also conducted. Results: There were significant negative relationships between optic disc area and corneal thickness (p=0.03, r=-0.217) and volume (p=0.017, r=-0.239). Corneal refractive power was significantly correlated with cup area, rim area, rim volume, and cup/disc ratio (p<0.05 for all). An increase of 1 diopter in anterior corneal refractive power corresponded to a decrease of 0.022 in cup/disc ratio. Rim volume was negatively correlated with anterior chamber depth and anterior chamber volume (p<0.05 for both). A 1-mm3 increase in anterior chamber depth corresponded to a 0.154-mm3 decrease in rim volume. Mean and maximum cup depth measurements were not associated with any of the anterior segment parameters. Conclusions: In nonglaucomatous eyes, the dimensions and shape of the ONH may be related to anterior segment morphology. Therefore, it may be helpful to take anterior segment parameters into consideration in evaluating the OHN.

RESUMO Objetivo: Determinar a relação entre os parâmetros do segmento anterior e da cabeça do nervo óptico (CNO). Métodos: Duzentos indivíduos saudáveis foram incluídos neste estudo. Os participantes foram submetidos à medição dos parâmetros do segmento anterior com o sistema Pentacam Scheimpflug e à obtenção de imagens de disco óptico com oftalmoscopia a laser de varredura confocal. O coeficiente de correlação de Pearson foi calculado para avaliar as associações entre CNO e os parâmetros do segmento anterior. Realizaram-se também análises de regressão multivariada que controlam a idade e a área do disco como factores de confusão. Resultados: Houve uma relação negativa estatisticamente significativa entre a espessura da córnea, o volume da córnea e a área do disco óptico (p=0,03, r=-0,217 e p=0,017, r=-0,239, respectivamente). As medições do poder de refração da córnea mostraram correlações significativas com a área da escavação, a área da rima, o volume da rima (RV) e a relação escavação/disco (C/D). (P<0,05 para todos). Um aumento de dioptria no poder de refração corneana anterior corresponde a uma diminuição de 0,022 em C/D. O RV mostrou correlação negativa com a profundidade da câmara anterior (PCA) e volume da câmara anterior. (P<0,05 para ambos). O aumento de 1 mm3 na PCA corresponde a uma diminuição de 0,154 mm3 no RV. As médias e as medidas máximas de profundidade de rima não mostraram associação com nenhum dos parâmetros do segmento anterior. Conclusões: Em olhos não glaucomatosos, as dimensões e forma da CNO podem estar relacionadas com a morfologia do segmento anterior. Portanto, pode ser útil levar em consideração os parâmetros do segmento anterior na avaliação da CNO.

Evaluation of biomechanical properties of the cornea in patients with primary hyperparathyroidism.

The purpose of this study is to compare the corneal biomechanical properties in primary hyperparathyroid patients and healthy control subjects. The study consisted of 31 patients with primary hyperparathyroidism (study group) and 31 healthy subjects (control group). Corneal biomechanical properties, including corneal hysteresis (CH), corneal resistance factor (CRF), and intraocular pressure (IOP) were measured with an ocular response analyzer (ORA). IOP was also measured using Goldmann applanation tonometry (GAT), and central corneal thickness (CCT) was measured with an ultrasonic pachymeter. The differences in ORA parameters and CCT between study and control group participants were analyzed. The mean CH in study and control groups was 8.7 ± 1.9 mmHg (5.3-13.7 mmHg) and 9.8 ± 1.5 mmHg (7.7-14.3 mmHg), respectively (p = 0.018). The mean CRF was 9.5 ± 1.8 (5.5-13.7) in the study group compared with 9.8 ± 1.5 (6.2-12.8) in the control group. The difference for CRF was not statistically significant (p = 0.41). In study and control group, corneal-compensated IOP (IOPcc) values were 18.2 ± 4.2 and 16.9 ± 2.7 mmHg, respectively (p = 0.12). Mean IOP measurement values with GAT were 16.3 ± 3.4 mmHg for study group and 16.5 ± 2.7 mmHg for control group (p = 0.71). The mean differences of IOPcc and IOPGAT in the study group eyes were higher than that of control group eyes (1.9 vs. 0.4 mmHg). CCT was 536.5 ± 25.4 µm (490-593 µm) in study group eyes compared with 534.2 ± 31.4 µm (472-602 µm) in control eyes (p = 0.75). Hyperparathyroidism could be associated with a decrease of CH. The differences between IOPcc and IOPGAT in these patients were higher than normal subjects. Underestimation of IOP readings with GAT may be a consequence of the lower CH in patients with hyperparathyroididsm.

Effect of Pseudoexfoliation on Corneal Transparency.

PURPOSE: To perform a comparison of the corneal optical density (COD) parameters in eyes with pseudoexfoliation syndrome (PES) and age-matched controls. METHODS: This study was designed as a prospective cross-sectional study. Pentacam HR-Scheimpflug imaging system was used to observe the COD of PES, normal fellow, and normal control eyes. Forty-two patients with unilateral PES and 40 age- and sex-matched normal subjects were included. Group 1 included eyes with PES, group 2 included the clinically unaffected fellow eyes, and group 3 included right eyes of healthy patients. Main outcome measures were densitometry values of the cornea. RESULTS: There was no significant difference between groups in means of central corneal thickness (P > 0.05). Eyes of unilateral PES patients and eyes of controls differed in COD parameters. Mean total COD in group 1 eyes (21.9 ± 4.9) and group 2 eyes (21.95 ± 5.1) was higher than that in group 3 eyes (17.72 ± 4.7) (P < 0.0001). CONCLUSIONS: This research demonstrates that the presence of pseudoexfoliation material can cause decrease in the transparency of clear cornea.

Oxidant/antioxidant balance in the aqueous humor of patients with glaucoma.

AIM: To evaluate total antioxidant status (TAS), total oxidant status (TOS), and the oxidative stress index (OSI) of the aqueous humor (AH) in patients with glaucoma. METHODS: The prospective study was composed of a study group (n=31) and a control group (n=31). Fifteen patients in the study group were diagnosed with primary open angle glaucoma (POAG), and 16 patients were diagnosed with pseudoexfoliation glaucoma (PEG). The control group was composed of non-glaucomatous patients with cataracts. AH samples were collected and analyzed for TAS, TOS, and OSI levels. RESULTS: Mean AH TAS level was significantly higher in patients with glaucoma than that in the control group (P<0.01). Mean TOS and OSI levels tended to increase in patients with glaucoma. No significant differences in TAS, TOS, or OSI levels were observed between patients with POAG and PEG. CONCLUSION: High levels of TAS were observed in patients with glaucoma, which was likely a response to the increased oxidative stress observed in these patients.

Disturbed oxidant/antioxidant balance in aqueous humour of patients with exfoliation syndrome.

PURPOSE: To establish the total oxidant status (TOS), total antioxidant capacity (TAC) and oxidative stress index (OSI) of the aqueous humour in patients presenting exfoliation syndrome (EXS) without glaucoma. METHODS: The TOS, TAC and OSI of the aqueous humour of patients with EXS (group 1, n = 17) and patients without EXS (group 2, n = 25) who underwent cataract surgery were evaluated. Samples were measured spectrophotometrically using a colourimetric method. The Mann-Whitney U, independent-samples t tests, Pearson correlation and analysis of covariance tests were used in the statistical analyses. RESULTS: The mean TOS in group 1 and 2 patients was 57.6 ± 32.4 and 30.4 ± 22.6 mmol/L, respectively, which is a statistically significant difference (p = 0.001). The mean TAC level in group 1 and 2 patients was 2.3 ± 0.7 and 2.5 ± 0.7 mmol/L, respectively, and although TAC was decreased in group 1 relative to group 2, the difference was not statistically significant (p = 0.55). The mean OSI in group 1 and 2 patients was 27.4 ± 17.1 and 12.5 ± 8.3 mmol/L, respectively, with the mean OSI level statistically higher in group 1 (p = 0.03). CONCLUSION: Our findings provide evidence that the aqueous humour of EXS patients is characterised by increased oxidative stress and a disturbed oxidant/antioxidant balance. The increased oxidative stress and decreased levels of antioxidants in ocular fluids of EXS patients may play a significant role in the pathogenesis and complications of EXS.

Changes of total antioxidant capacity and total oxidant status of aqueous humor in diabetes patients and correlations with diabetic retinopathy.

AIM: To measure changes of total oxidant status (TOS) and total antioxidant capacity (TAC) of aqueous humor (AH) in diabetic retinopathy (DR) patients, and to determine if there were any differences in TOS and TAC of AH in diabetic patients without retinopathy compared with non-diabetic patients. METHODS: One hundred and three eyes of 103 patients who were enrolled for cataract surgery were included in this study. Patients were grouped according to presence of diabetes and stage of DR. Prior to cataract surgery, 0.1mL to 0.2mL of AH was aspirated and analyzed for TAC and TOS level using a colorimetric method. RESULTS: TOS levels were highest among proliferative diabetic retinopathy (PDR) patients and lowest in patients with only cataracts. Results were statistically significant between all groups (P<0.05). Whereas result between diabetic without retinopathy patients and non-proliferative diabetic retinopathy (NPDR) patients was not statistically significant (P=0.757). TAC levels were highest in patients with only cataract and lowest among PDR patients and results were statistically significant between all groups (P<0.05). CONCLUSION: Aqueous humor TAC levels are low in diabetic patients and reduced further in DR patients, TOS levels are increased in diabetic patients and this is exacerbated in DR patients.

Optic disc and retinal nerve fiber layer parameters of eyes with keratoconus.

BACKGROUND AND OBJECTIVE: To evaluate optic nerve head (ONH) characteristics and retinal nerve fiber layer (RNFL) thickness measurements in patients with nonglaucomatous keratoconus. PATIENTS AND METHODS: This was a cross-sectional, observational study in which 46 patients with keratoconus and 74 healthy subjects were included. Analysis of ONH and RNFL imaging were performed by confocal scanning laser ophthalmoscopy and optical coherence tomography, respectively. RESULTS: Eyes with keratoconus had larger disc area (2.37 ± 0.5 vs 2.17 ± 0.36 mm(2)) (P = .013), larger cup area (0.65 ± 0.53 vs 0.49 ± 0.28 mm(2)) (P = .035) and deeper cup depths (for mean cup depth 0.24 ± 0.09 vs 0.20 ± 0.07 mm, P = .008 and for maximum cup depth 0.69 ± 0.27 vs 0.60 ± 0.17 mm, P = .037) than control group eyes. Height variation contour also differed in the two groups (P = .007) but RNFL measurements did not. CONCLUSION: RNFL thickness between patients with keratoconus and healthy subjects seems to be more comparable than ONH parameters.

Ocular response analyzer to assess corneal biomechanical properties in exfoliation syndrome and exfoliative glaucoma.

BACKGROUND: The aim of this work was to investigate the differences in corneal biomechanical parameters between healthy and exfoliation syndrome (EXS) and exfoliative glaucoma (EXG) patients. METHODS: Two hundred and forty-four eyes of 102 healthy, 64 EXS, and 78 EXG patients were included in the study. Corneal biomechanical parameters were measured using an ocular response analyzer (ORA). Central corneal thickness (CCT) was measured with an ultrasonic pachymeter. The differences in ORA parameters between study and control group participants were analyzed using Student's t test. RESULTS: In healthy subjects, EXS and EXG eyes mean corneal hysteresis (CH) values were 9.4 ± 1.4 mmHg, 8.5 ± 1.5 mmHg and 6.9 ± 2.1 mmHg, respectively. The difference in mean CH between the EXG and the other two groups were statistically significant (p < 0.01 for both comparisons). CH was significantly lower in EXS patients than that of healthy eyes (p < 0.001). Mean corneal resistance factor (CRF) values were 9.8 ± 1.6 mmHg, 9.3 ± 1.8 mmHg and 9.5 ± 2.6 mmHg, respectively. Except for the difference between the control and EXS eyes (p = 0.004), no statistically significant difference was found between the groups in relation to mean CRF. There were no significant differences in CCT between the control eyes and exfoliative eyes with or without glaucoma. CONCLUSIONS: In this study, CH was found to be significantly lower in eyes with exfoliation. Further studies are needed to establish the relationships between exfoliation, ocular biomechanics, and glaucoma.

Topographic differences between large and normal optic discs: a confocal scanning laser ophthalmoscopy study.

PURPOSE: The aim of the study was to investigate the optic nerve head parameters of healthy macrodiscs to provide standard measurements for them to be the basis for future quantitative comparisons. METHODS: Sixty-nine subjects with macrodisc (disc area larger than 2.82 mm(2)) and 91 healthy controls (disc area between 1.16 and 2.82 mm(2)) were recruited. After a complete ophthalmic examination, confocal scanning laser ophthalmoscopy was performed in all participants. The stereometric parameters of confocal scanning laser ophthalmoscopy examination and the proportion of subjects classified as normal, borderline, and glaucomatous by the Moorfield Regression Analysis were compared between groups. RESULTS: A total of 160 subjects were included in the study. The average disc sizes in the control and macrodisc groups were 2.14 ± 0.33 mm(2) and 3.36 ± 0.36 mm(2), respectively. Cup area (p<0.001), rim area (p=0.01), cup volume (p<0.001), cup/disc area ratio (p<0.001), linear cup/disc ratio (p<0.001), mean cup depth (p<0.001), maximum cup depth (p<0.001), and cup shape measure (p<0.001) differed significantly between the 2 groups. The parameters of the optic nerve head which did not differ significantly between groups were rim volume (p=0.17) and height variation contour (p=0.88). A significantly higher number of eyes were erroneously identified as abnormal (15.1% vs 79.4%) by Moorfield Regression Analysis in the macrodisc group (p<0.001). CONCLUSIONS: Rim volume and height variation contour were the only optic nerve head topographic parameters that were similar in eyes with large and normal disc sizes. They seem to be promising parameters in the evaluation and comparison of the optic nerve head of subjects with macrodisc.

Comparison of the outcome of repeat trabeculectomy with adjunctive mitomycin C and initial trabeculectomy.

PURPOSE: To compare the efficacy and safety of repeat and initial trabeculectomy with mitomycine C (MMC). METHODS: Eighty seven patients, who had underwent repeat (repeat group) or initial (initial group) trabeculectomy with MMC, were enrolled in this prospective trial. Postoperative outcome measures included the amount of decrease in intraocular pressure (IOP), the number of anti-glaucoma medications, and the complications. The success of trabeculectomy was defined on the basis of three definitions which were: IOP ≤18 mmHg (definition 1), IOP ≤21 mmHg (definition 2), and the amount of decrease in IOP from baseline ≥30% (definition 3). Success was further defined as "complete" when these criteria were obtained without any anti-glaucoma medications and "qualified" with or without medical therapy and no further surgical procedures. RESULTS: Fifty nine eyes underwent initial and 28 eyes underwent repeat trabeculectomy. The mean follow-up period was 19.1 ± 5.9 months. Complete success rates were significantly greater in the initial trabeculectomy group (p = 0.02 for definition 1, p = 0.038 for definition 2, p = 0.003 for definition 3). A higher proportion of eyes in the initial group achieved qualified success relative to the group A eyes, but the differences were not statistically significant (p = 0.33 for definition 1, p = 0.99 for definition 2, p = 0.24 for definition 3). The mean number of antiglaucomatous medications at the last examination was 1.2 ± 1.2 in repeat group and 0.7 ± 1.1 in initial group (p = 0.01). The number of complications during the follow up period did not differ significantly between the two groups (p = 0.65). CONCLUSIONS: Repeat trabeculectomy with MMC has high success and low complication rates in patients with previously failed trabeculectomy in spite of the need of higher number of anti-glaucoma medications.