Comparison of cornea endothelial cell counts after combined phacovitrectomy versus pars plana vitrectomy with fragmentation

Background

To compare postoperative cornea endothelial cell loss between combined phacovitrectomy and pars plana vitrectomy (PPV) with fragmentation.

Methods

Eighty-eight consecutive patients (92 eyes) who underwent combined phacovitrectomy (53 eyes from 50 patients) or PPV with fragmentation (39 eyes from 38 patients) were enrolled in this retrospective study. Endothelial cell density (ECD) was calculated with specular microscopy at 1 and 3 months after surgery.

Results

At 3 months after surgery, the mean ECD decreased significantly from 2,646?±?296 cells/mm² to 2,422?±?347 cells/mm² in the combined phacovitrectomy group (P?<?0.001). However, the PPV with fragmentation group did not show any significant changes in ECD during the same period (from 2,123?±?628 cells/mm² to 2,073?±?574 cells/mm²). The mean endothelial cell loss in the combined phacovitrectomy group (7.9 and 9.5 %) was significantly higher than that in the PPV with fragmentation group (0.7 and 2.4 %) both at 1 and 3 months postoperatively (P?=?0.001 and P?=?0.001 respectively).

Conclusion

In this study, corneal endothelial cell loss during the early postoperative period was significantly higher after combined phacovitrectomy than after PPV with fragmentation.     

Properties of Corneas Reconstructed with Cultured Human Corneal Endothelial Cells and Human Corneal Stroma

Purpose

To examine the properties of corneas tissue-engineered with cultured human corneal endothelial cells (HCEC) and human corneal stroma.

Methods

Primary HCEC cultures were established from endothelial cell layer explants and propagated on culture dishes coated with bovine corneal endothelial extracellular matrix. A cell suspension of HCEC at the fifth passage was transferred onto human corneal stroma deprived of endothelial cells, and the corneas were gently centrifuged to enhance cell attachment. The cell density of the tissue-engineered corneas was examined after staining with alizarin red and trypan blue. The tissue-engineered corneas were histologically examined by light and electron microscopy. The pump function of the tissue-engineered corneas was measured using an Ussing chamber.

Results

The mean endothelial cell density of four tissue-engineered corneas was 2380 ± 264 cells/mm² (mean ± SD). HCEC on the tissue-engineered corneas had a morphology similar to HCEC in vivo. The pump function parameters of the tissue-engineered corneas were 55%–75% of those of normal corneas.

Conclusions

HCEC on the tissue-engineered corneas have morphology and cellular density similar to HCEC in vivo, whereas the pump function of the tissue-engineered corneas was lower than in normal corneas. Jpn J Ophthalmol 2005;49:448–452 © Japanese Ophthalmological Society 2005     

Subbasal nerve morphology, corneal sensation, and tear film evaluation after refractive femtosecond laser lenticule extraction

Background

The purpose of this study was to compare corneal subbasal nerve morphology, corneal sensation, and tear film parameters after femtosecond lenticule extraction (FLEX) and small-incision lenticule extraction (SMILE).

Methods

A prospective, randomized, single-masked, paired-eye design clinical trial of 35 patients treated for moderate to high myopia with FLEX in one eye and SMILE in the other. In both techniques, an intrastromal lenticule was cut by a femtosecond laser and manually extracted. In FLEX, a LASIK-like flap allowed removal of the lenticule, whereas in SMILE, it was removed through a small incision. In-vivo confocal microscopy was used to acquire images of the central corneal subbasal nerve plexus, from which nerve density, total nerve number, and nerve tortuosity were analyzed. Corneal sensation was measured using Cochet–Bonnet esthesiometry. A visual analog scale, tear osmolarity, non-invasive tear film break-up time (keratograph) tear meniscus height (anterior segment OCT), Schirmer's test, and fluorescein tear film break-up time were used to evaluate tear film and ocular surface symptoms. Patients were examined before and 6 months after surgery.

Results

There were no statistically significant differences in baseline parameters between FLEX and SMILE (p?>?0.050). With regard to changes from before to 6 months after surgery, mean reduction in subbasal nerve density was 14.22?±?6.24 mm/mm² in FLEX eyes, and 9.21?±?7.80 mm/mm² in SMILE eyes (p?<?0.05). The total number of nerves decreased more in FLEX eyes than in SMILE eyes (p?<?0.05). No change was found when comparing tortuosity (p?>?0.05). Corneal sensation was reduced with 0.38?±?0.49 cm in FLEX eyes, and 0.10?±?0.34 cm in SMILE eyes (p?<?0.01). No differences were found between FLEX and SMILE in tear film evaluation tests (p?>?0.05). Significantly more patients felt postoperative foreign body sensation in the FLEX eye within the first days after surgery, as compared to the SMILE eye.

Conclusions

Six months after surgery, the less invasive SMILE technique seemed better at sparing the central corneal nerves as compared to FLEX. Corneal sensation was only significantly reduced in FLEX eyes. There were no differences between FLEX and SMILE when comparing tear film evaluation tests 6 months after surgery.     

Comparison of keratocyte density after femtosecond laser vs mechanical microkeratome from 3 months up to 5 years after LASIK

Background

To compare keratocyte density after mechanical microkeratome LASIK (MK-LASIK) and femtosecond-laser assisted LASIK (FS-LASIK).

Methods

We performed a prospective study of myopic patients that underwent MK-LASIK or FS-LASIK. We measured keratocyte density 3 and 15 months, and 3–5 years after the surgery using confocal microscopy, and compared them with healthy, non-operated corneas.

Results

Thirty-one eyes were included in the FS-LASIK group, 30 in the MK-LASIK group and 28 in the control group. Three months postoperatively, there was an increase in the keratocyte population of the whole cornea, mainly due to the mid and posterior stromal layers, in both treatment groups. It was also increased in the stromal bed after MK-LASIK, but not after FS-LASIK. In both groups, this was followed by a normalisation and stabilisation of cell density in those deeper layers 15 months after the surgery. Keratocyte density in the flap and stromal bed was decreased 15 months after FS- and MK-LASIK compared to 3 months postoperatively and compared to controls. It seemed to remain stable thereafter. In spite of this decrease, the average cell density throughout the cornea was not decreased compared to controls at any time point.

Conclusion

We found a reorganization of keratocytes density after LASIK, with an initial increase, followed by a decrease in the stromal flap and stromal bed 15 months postoperatively, and stable from then onwards, but still maintaining normal average densities in the total cornea. There were no differences between MK- and FS-LASIK.     

In vivo corneal confocal microscopic analysis in patients with keratoconus

AIM:To quantify corneal ultrastructure using laser scanning in vivo confocal microscopy (IVCM) in patients with keratoconus and control subjects.METHODS: Unscarred corneas of 78 keratoconic subjects without a history of contact lens use and 36 age-matched control subjects were evaluated with slit-lamp examination (SLE), corneal topography and laser scanning IVCM. One eye was randomly chosen for analysis. Anterior and posterior stromal keratocyte, endothelial cell and basal epithelial cell densities and sub-basal nerve structure were evaluated.RESULTS: IVCM qualitatively demonstrated enlarged basal epithelial cells, structural changes in sub-basal and stromal nerve fibers, abnormal stromal keratocytes and keratocyte nuclei, and pleomorphism and enlargement of endothelial cells. Compared with control subjects, significant reductions in basal epithelial cell density (5817±306 cells/mm² vs 4802±508 cells/mm², P<0.001), anterior stromal keratocyte density (800±111 cells/mm² vs 555±115 cells/mm², P<0.001), posterior stromal keratocyte density (333±34 cells/mm² vs 270±47 cells/mm², P<0.001), endothelial cell density (2875±223 cells/mm² vs 2686±265 cells/mm², P<0.001), sub-basal nerve fiber density (31.2±8.4 nerves/mm² vs 18.1±9.2 nerves/mm², P<0.001), sub-basal nerve fiber length (21.4±3.4 mm/mm² vs 16.1±5.1 mm/mm², P<0.001), and sub-basal nerve branch density (median 50.0 (first quartile 31.2 - third quartile 68.7) nerve branches/mm² vs median 25.0 (first quartile 6.2 - third quartile 45.3) nerve branches/mm², P<0.001) were observed in patients with keratoconus.CONCLUSION: Significant microstructural abnormalities were identified in all corneal layers in the eyes of subjects with keratoconus using IVCM. This non-invasive in vivo technique provides an important means to define and follow progress of microstructural changes in patients with keratoconus.     

In vivo confocal corneal microscopy after keratoplasty

BACKGROUND: Seven eyes with clear grafts after penetrating keratoplasty were examined with in vivo confocal corneal microscopy in 1999. Our aim was the confocal microscopic investigation of the subclinical changes in clear grafts after long-term follow-up.METHODS: The preoperative diagnoses were keratoconus (two), granular corneal dystrophy (two), pseudophakic bullous keratopathy due to ACL (two), and corneal ulcer (one). The epithelium, corneal nerves, keratocytes of the anterior and posterior stroma, and endothelium were evaluated with confocal microscopy.RESULTS: Mean density of basal epithelial cells was 3928+/-378 cells/mm(2) at 15 months and 3284+/-565 cells/mm(2) at 66 months postoperatively. At 15 months the keratocyte density was 750+/-113 cells/mm(2) in the anterior stroma and 601+/-98 cells/mm(2) in the posterior stroma, at 66 months 383+/-53 cells/mm(2) in the anterior stroma and 411+/-98 cells/mm(2) in the posterior stroma. Endothelial cell density decreased from 1719+/-576 cells/mm(2) (15 months) to 965+/-272 cells/mm(2) (66 months).CONCLUSIONS: In the follow-up period a significant decrease of keratocyte and endothelial cell density was detectable with confocal microscopy. The clinical importance of our findings must be clarified with further examinations on more patients.     

Efficacy of self-retained cryopreserved amniotic membrane for treatment of neuropathic corneal pain

Purpose

Treatment of neuropathic corneal pain (NCP) remains intricate, and involves a long-term combined multistep approach. The self-retained cryopreserved amniotic membrane (PROKERA^®, Bio-Tissue, Miami,FL) has been utilized for multiple ocular surface disorders. We evaluate the efficacy, safety, and tolerability of ProKera^® Slim [PKS] and ProKera^® Clear [PKC] in the treatment of NCP.

Corneal nerve regeneration after herpes simplex keratitis: A longitudinal in vivo confocal microscopy study

Purpose

To evaluate the long-term alterations of corneal nerves in patients with herpes simplex virus (HSV) keratitis using in vivo confocal microscopy (IVCM).

Trans-conjunctival aqueous humor outflow in glaucomatous patients treated with prostaglandin analogues: an in vivo confocal microscopy study

Purpose

To analyze, using in vivo laser scanning confocal microscopy (LSCM), the conjunctival features in glaucomatous patients receiving prostaglandin analogues (PGA).

Methods

Eighty eyes of 80 consecutive glaucomatous patients naive for therapy were enrolled; 30 eyes of 30 healthy subjects served as a control. Patients were randomized to: preservative-free (PF) and preserved latanoprost (groups 1 and 2, respectively), PF and preserved timolol (groups 3 and 4), and controls to vehicle of latanoprost or physiological buffered saline solution (groups 5 and 6). All subjects underwent LSCM of bulbar conjunctiva at baseline and 3 months after initiating therapy. The main outcomes were: mean density (MMD: cysts/mm²) and mean area (MMA: cysts/mm²) of epithelial microcysts. The relations between MMA and MMD with intraocular pressure (IOP), age, and mean defect (MD), were analyzed.

Results

At baseline, microcysts were found in all subjects. At month three, MMD did not change in all groups (p?>?0.05). MMA significantly increased only in group 1 from 2,158.81?±?524.09 to 3,877.77?±?867.31, and in group 2 from 2,019.71?±?541.03 to 5,560.39?±?1,176.14, with values significantly higher in group 2 (p?p?>?0.05).

Conclusions

PGA increased MMA in therapy-naive glaucomatous patients, indicating a possible enhancement of the trans-conjunctival aqueous humor outflow. Therefore, conjunctiva seems an additional target tissue to evaluate the hydrodynamic pathways in glaucoma and modifications induced by medical therapy.     

Results of excimer laser penetrating keratoplasty in aphakic eyes

Background

Corneal grafting in aphakic eyes is often challenging. We report about the outcome of excimer laser trephination in aphakic eyes.

Methods

We examined 17 eyes of 17 patients. Diagnosis in 11 eyes was endothelial decompensation and in six, corneal scars. We performed an excimer laser keratoplasty with intraoperative “Flieringa ring” suturing. Follow-up ranged between 3 and 41 (17.6?±?11.7) months. Main outcome measures included: best-corrected visual acuity (BCVA), intraocular pressure (IOP), topographic astigmatism, corneal refractive power (CRP), central corneal thickness (CCT) and endothelial cell density (ECD).

Results

Preoperative BCVA was light perception in two eyes, hand motion in seven, finger counting in one eye, under 20/400 in six eyes and 20/200 in one eye. IOP ranged between 4 and 28 (13.6?±?5.1) mmHg. Topographic astigmatism ranged from 0.5 to 18.5 (7.0?±?6.9) dioptres. CRP was between 38 and 59 (46?±?9) dioptres. CCT was between 404 and 1069 (748?±?181) μm. Postoperative BCVA was hand motion in five eyes, under 20/400 in two and ranged between 20/200 and 20/20 in ten eyes. IOP ranged between 10 and 40 (18.3?±?8.5) mmHg. Topographic astigmatism ranged from 0.9 to 13 (5.5?±?3.2) dioptres. CRP was between 31.9 and 46.7 (42?±?4.1) dioptres. CCT was between 349 and 820 (552?±?115.57) μm. ECD was between 592 and 2319 (1674?±?553) cells/mm².

Conclusions

Excimer laser trephination can deliver beneficial visual outcomes in most of the aphakic eyes.     

Evaluation of corneal epithelial and stromal thickness in keratoconus using spectral-domain optical coherence tomography

Purpose

We sought to assess the corneal thickness of the epithelium and stroma in keratoconic and normal eyes by spectral-domain optical coherence tomography (SD-OCT).

Methods

Fifty-seven keratoconic and 20 normal eyes were studied. The eyes were examined by SD-OCT, and the keratoconic eyes were subdivided into 2 groups: those showing only smooth corneal thinning and corneal protrusion on the image (KC1 group) and those showing abnormalities in the Bowman layer or in the stroma, or in both (KC2 group). The thicknesses at the corneal vertex and at the superior, inferior, nasal, and temporal cornea 1.5 mm from the corneal vertex in the KC1 group were compared with those in the normal group. The OCT findings in the KC2 group were described.

Results

The epithelial thickness at the corneal vertex and at the inferior and temporal cornea, and the stromal thickness at all points were significantly thinner in the KC1 group than in the normal group (p < 0.05). The epithelial and stromal thicknesses at the corneal vertex were significantly correlated in the KC1 group and the normal group (r ²  = 0.427, p < 0.0001).The epithelial thickness in the KC2 group was not uniform owing to Bowman layer scarring, stromal scars, and secondary corneal amyloidosis.

Conclusions

Although epithelial thinning is associated with stromal thinning, when the cornea remains clear, the epithelial thickness may vary because of the irregularity of the stroma beneath the epithelium in patients with keratoconus.     

Biomechanical profile of the cornea in primary congenital glaucoma

Purpose: The aim of our study was to investigate the biomechanical properties of the cornea in primary congenital glaucoma (PCG) and to identify the potential ocular determinants, which affect the corneal biomechanical metrics. Methods: Corneal hysteresis (CH), corneal resistance factor (CRF) and central corneal thickness (CCT) were measured in 26 patients with PCG (40 eyes) with the aid of ocular response analyser. In vivo laser‐scanning confocal microscopy was used for the estimation of stromal keratocyte density (KD) and the evaluation of corneal endothelium. Twenty normal subjects (40 eyes) served as controls. Student’s t‐test and Pearson’s correlation coefficients were used for statistical analysis. p Values <0.05 were considered statistically significant. Results: Corneal hysteresis, CRF and CCT were significantly reduced in patients with PCG (all p < 0.05). Corneal hysteresis and CRF negatively correlated with the corneal diameter in both groups (r₁ = ?0.53, r₂ = ?0.66, p < 0.001 for CH and r₁ = ?0.61, r₂ = ?0.69, p < 0.001 for CRF). Moreover, we identified a significant correlation between CH and CRF with CCT in both groups (r₁ = 0.51, r₂ = 0.48, p < 0.001 for CH and r₁ = 0.45, r₂ = 0.44, p < 0.001 for CRF). Mean KD was significantly reduced both in the anterior and posterior corneal stroma in patients with PCG (764 ± 162 and 362 ± 112 cells/mm², respectively) compared with controls (979 ± 208 and 581 ± 131 cells/mm², respectively) (p < 0.001). There was no significant correlation between the keratocyte density in anterior and/or posterior stroma and CH or CRF in any group (r₁ = 0.29, r₂ = 0.31, p < 0.06). Mean endothelial cell density was also significantly reduced in PCG group (2920 ± 443 cells/mm²) compared with control group (3421 ± 360 cells/mm²) (p < 0.001). Pleomorphism and polymegalism were significantly increased in corneal endothelium of patients with PCG. Conclusions: Our results showed a significant reduction in CH and CRF in PCG. Both CH and CRF were negatively correlated with corneal diameter. A significant correlation of CH and CRF with CCT was identified in both groups. Keratocyte density was decreased in PCG, but did not have a significant impact on CH and CRF. Mean endothelial density was also decreased in PCG. Our results suggest that reduced CCT and increased corneal diameter are major ocular determinants for the modified corneal biomechanical profile in PCG, while cellular alterations in corneal stroma and endothelium have no significant biomechanical impact.     

Corneal crosslinking for keratoconus in Japanese populations: one year outcomes and a comparison between conventional and accelerated procedures

Purpose

We retrospectively investigated the efficacy of corneal crosslinking (CXL) on progressive keratoconus in a Japanese population and compared the outcomes of conventional and accelerated CXL.

Study design

A retrospective cohort study

Methods

A total of 108 consecutive eyes in 95 patients (75 men; 21.9 ± 6.2 years) with progressive keratoconus were enrolled. The epithelium was ablated in all eyes. After presoaking the corneal stroma in riboflavin, UV-A was irradiated at 3.0 mW/cm² (conventional CXL) for 30 min on 23 eyes and 18.0 mW/cm² for 5 min (accelerated CXL) on 85 eyes. Best spectacle-corrected visual acuity (BSCVA), manifest refraction, keratometric value, corneal thickness, corneal endothelial cell density (ECD), intraocular pressure, and complications were evaluated at 1, 3, 6, and 12 months after the procedure.

Results

BSCVA, manifest refraction, ECD, and corneal thickness did not change significantly after both procedures. The keratometric value was significantly decreased from the preoperative value at 12 months (p < 0.001). Progression to more than 1.0 D after CXL was observed in 10 eyes (9.3%). The ΔKmax was negatively associated with preoperative Kmax (p < 0.001) and positively associated with preoperative thinnest corneal thickness (p < 0.001). Both treatment modules showed no significant difference in all parameters.

Conclusion

CXL was as effective in treating keratoconus in Japanese patients as in individuals of other ethnicities. Overall, CXL could be performed using either the conventional or accelerated approach to halt the progression of keratoconus in Japanese populations.

     

Decreased retinal–choroidal blood flow in retinitis pigmentosa as measured by MRI

Purpose

To evaluate retinal and choroidal blood flow (BF) using high-resolution magnetic resonance imaging (MRI) as well as visual function measured by the electroretinogram (ERG) in patients with retinitis pigmentosa (RP).

Methods

MRI studies were performed in 6 RP patients (29–67 years) and 5 healthy volunteers (29–64 years) on a 3-Tesla scanner with a custom-made surface coil. Quantitative BF was measured using the pseudo-continuous arterial spin-labeling technique at 0.5 × 0.8 × 6.0 mm. Full-field ERGs of all patients were recorded. Amplitudes and implicit times of standard ERGs were analyzed.

Results

Basal BF in the posterior retinal-choroid was 142 ± 16 ml/100ml/min (or 1.14 ± 0.13 μl/mm²/min) in the control group and was 70 ±19 ml/100ml/min (or 0.56 ± 0.15 μl/mm²/min) in the RP group. Retinal–choroidal BF was significantly reduced by 52 ± 8 % in RP patients compared to controls (P<0.05). ERG a- and b-wave amplitudes of RP patients were reduced, and b-wave implicit times were delayed. There were statistically significant correlations between a-wave amplitude and BF value (r=0.9, P<0.05) but not between b-wave amplitude and BF value (r =0.7, P=0.2).

Conclusions

This study demonstrates a novel non-invasive MRI approach to measure quantitative retinal and choroidal BF in RP patients. We found that retinal–choroidal BF was markedly reduced and significantly correlated with reduced amplitudes of the a-wave of the standard combined ERG.     

Corneal biomechanics predict the outcome of selective laser trabeculoplasty in medically uncontrolled glaucoma

Purpose

To evaluate the predictive value of clinical parameters, including biomechanical properties on the outcome of selective laser trabeculoplasty (SLT) in medically uncontrolled open angle glaucoma (OAG).

Methods

Sixty-eight eyes from 68 patients with OAG and IOP insufficiently regulated by topical medications were enrolled. Patients’ follow-up occurred 6 and 12 months after the procedure. The recorded parameters intraocular pressure (IOP), angle characteristics, central corneal thickness (CCT) and biomechanical properties of the eyes, including corneal hysteresis CH and corneal resistance factor CRF measured with the Ocular Responses Analyzer (ORA, Reichert Ophthalmic Instruments) were tested on their predictive value of SLT-induced IOP lowering effect using correlation analyses and regression models.

Results

Mean IOP reduction 12 months after SLT was 4.2?±?5.7 mmHg (23.2 %, from baseline 18.1?±?5.2 mmHg). The preoperative IOP correlated significantly with IOP reduction (maximum Spearman’s correlation r?=?0.75, p?<?0.001). In linear regression analysis, the corneal biomechanical properties (CH and CRF) together with the baseline IOP revealed good modelling for the IOP lowering effect of SLT (R²?=?0.64, respectively).

Conclusions

In addition to the baseline IOP biomechanical properties (CH and CRF) are significant predictors of SLT induced IOP lowering effect in medically uncontrolled OAG.     

Novel use of 3T MRI in assessment of optic nerve volume in glaucoma

Purpose

To measure optic nerve (ON) volume using 3 T magnetic resonance imaging (MRI), to correlate ON volume with retinal nerve fiber layer (RNFL) thickness, and to determine the viability of MRI as an objective tool in distinguishing glaucoma severity.

Methods

In this cross-sectional study, 30 severe glaucoma patients, 30 mild glaucoma patients and 30 age-matched controls were recruited. All subjects underwent standard automated perimetry, RNFL analysis and 3 T MRI examinations. Glaucoma patients were classified according to the Hodapp–Anderson–Parish classification. Pearson’s correlation coefficient was used to correlate ON volume with RNFL, and receiver operating curve (ROC) analysis was performed to determine the sensitivity and specificity of ON volume in detecting glaucoma severity.

Results

Optic nerve volume was significantly lower in both the left and right eyes of the severe glaucoma group (168.70?±?46.28 mm³; 167.40?±?45.36 mm³) than in the mild glaucoma group (264.03?±?78.53 mm³; 264.76?±?78.88 mm³) and the control group (297.80?±?71.45 mm³; 296.56?±?71.02 mm³). Moderate correlation was observed between: RNFL thickness and ON volume (r?=?0.51, p <0.001), and in mean deviation of visual field and optic nerve volume (r?=?0.60, p?<?0.001). ON volume below 236 mm³ was 96 % sensitive and 80 % specific for the detection of severe glaucoma.

Conclusions

MRI measured optic nerve volume is a reliable method of assessing glaucomatous damage beyond the optic nerve head. A value of 236 mm³ and below can be used to define severe glaucoma.     

Retinal and optic nerve evaluation by optical coherence tomography in adults with obstructive sleep apnea–hypopnea syndrome (OSAHS)

Objective

To assess the peripapillary retinal nerve fiber layer (RNFL) thickness, optic nerve head (ONH) morphologic parameters, and macular thickness and volume in patients affected by obstructive sleep apnea–hypopnea syndrome (OSAHS).

Methods

This prospective, observational case-control study consisted of 96 eyes of 50 OSAHS patients (mean age of 50.9?±?12.4 years, best-corrected visual acuity ≥20/20, refractive error less than 3 spherocylindrical diopters, and intraocular pressure <21 mmHg) who were enrolled and compared with 64 eyes of 33 age-matched controls. Peripapillary RNFL thickness, ONH parameters, macular thickness and volume were measured by optical coherence tomography (OCT).

Results

OSAHS patients showed a significant reduction of the nasal quadrant RNFL thickness (74.7?±?15.8 μm) compared with those values observed in control patients (81.1?±?16.6 μm, p?=?0.047, Student's t-test). No differences in peripapillary RNFL thickness were observed when dividing the OSAHS group in accordance with disease severity. Vertical integrated rim area (VIRA) (0.67?±?0.41 mm³ in OSAHS vs 0.55?±?0.29 mm³ in controls; p?=?0.043, Student's t-test), horizontal integrated rim width (HIRW) (1.87?±?0.31 mm² in OSAHS vs 1.8?±?0.25 mm² in controls; p?=?0.039, Student's t-test) and disc area (2.74?±?0.62 mm² in OSAHS vs 2.48?±?0.42 mm² in controls; p?=?0.002, Student's t-test) showed significant differences, all of them being higher in the OSAHS group. Severe OSAHS had significant higher disc area (2.8?±?0.7 mm²) than controls (2.5?±?0.4 mm²; p?=?0.016, ANOVA test). Temporal inner macular thickness was significantly higher in mild–moderate OSAHS patients (270?±?12 μm) than in severe OSAHS patients (260?±?19 μm; p?=?0.021, ANOVA test).

Conclusions

OSAHS patients showed decreased peripapillary nasal RNFL thickness, and increased ONH area and volume parameters when they were evaluated by OCT. These findings suggest that neuronal degeneration might be present in the retina of OSAHS patients, as previously observed in some neurodegenerative disorders     

Protective effect of P7C3 on retinal ganglion cells from optic nerve injury

Purpose

To determine whether P7C3-A20, a proneurogenic neuroprotective agent, can protect the retinal ganglion cells (RGCs) of rats from optic nerve crushing.

Methods

The left optic nerve of 67 rats was crushed, and 5.0 mg/kg/day of P7C3-A20 (crush-P7C3) or its vehicle (crush-placebo) was injected intraperitoneally for 3 days from one day prior to the crushing. The protective effects were determined by the number of Tuj-1-stained RGCs and by the ratio of the mRNA levels of BAX/Bcl-2 on day 7. The levels of NAD and NAD-related genes were also determined.

Results

The density of RGCs was 2009.4 ± 57.7 cells/mm² in the sham controls; it was significantly lower in the crush-placebo group at 979.7 ± 144.3 cells/mm² (P < 0.0001). The neuroprotective effects of P7C3-A20 was demonstrated by the significantly higher density of 1266.0 ± 193.1 cells/mm² than in the crush-placebo group (P = 0.01, Scheffe). After crushing the optic nerve the BAX/Bcl-2 ratio was higher in the optic nerves and retina, application of P7C3-A20 significantly reduced this ratio. P7C3-A20 significantly increased the NAD level in the untouched optic nerves from 1.36 ± 0.05 to 1.59 ± 0.10 nmol/mg protein (P = 0.02, t test). Crushing the optic nerve decreased the level to 1.27 ± 0.21 nmol/mg protein and P7C3-A20 preserved the level at 1.43 ± 0.10 nmol/mg protein. Crushing the optic nerve decreased the mRNA levels of Nampt and Sirt-1 in the optic nerves, while P7C3-A20 significantly restored the levels.

Conclusions

P7C3-A20 can protect RGCs from optic nerve crushing possibly through preserving the NAD levels in the optic nerves.

     

Investigation of retinal nerve fiber layer thickness in patients with neurofibromatosis-1

Purpose

To compare the optical coherence tomography (OCT) findings of neurofibromatosis-1 (NF-1) patients with/without optic pathway glioma (OPG) with those of healthy controls.

Methods

Ten patients with NF-1, 17 patients with NF-1-associated OPGs, and 17 control subjects were included in the study. Retinal nerve fiber layer (RNFL) and macular thickness findings measured with Stratus OCT were compared between the groups.

Results

The average RNFL thickness was significantly lower in the OPG group (76.72 ± 22.16 μm) than in the controls (108.89 ± 9.92 μm) and NF-1 patients without OPGs (111.17 ± 12.13 μm) (p < 0.001). The macular volume was also found to be lower in NF-1 patients with OPG (6.41 ± 0.66 mm³) than in the healthy controls (7.19 ± 0.36 mm³; p = 0.001) and NF-1 patients without OPGs (7.25 ± 0.26 mm³; p = 0.005). Following this analysis the OPG group was further subdivided into two categories: OPG patients with normal visual acuity (VA) and OPG patients with decreased VA. The statistical analysis was repeated for these four subgroups, revealing that while the decrement in the average RNFL thickness was significant for both OPG groups that in the macular volume was only significant for OPG patients with decreased VA.

Conclusion

The results of our study suggest that RNFL thinning can be a helpful marker for the detection of OPGs in NF-1 patients. Larger studies with longitudinal data are required to confirm the role of OCT in the diagnosis and follow-up of these patients.     

Accelerated versus conventional corneal collagen cross-linking in patients with keratoconus: an intrapatient comparative study

Purpose

To compare the outcomes of the conventional and accelerated corneal collagen cross-linking (CXL) in patients with bilateral progressive keratoconus (KC).

Methods

Fifteen consecutive patients with bilateral progressive KC were enrolled. In each patient, the fellow eyes were randomly assigned to the conventional CXL (3 mW/cm² for 30 min) or accelerated CXL (ACXL) (9 mW/cm² for 10 min) groups. Manifest refraction; uncorrected and corrected distant visual acuity; maximum and mean keratometry; corneal hysteresis and corneal resistance factor; endothelial cell density and morphology; central corneal thickness; and wavefront aberrations were measured before and 12 months after the CXL.

Results

Manifest refraction spherical equivalent and refractive cylinder improved significantly only in conventional group. Uncorrected and corrected distant visual acuity did not change significantly in either group. Also there was no significant change in the maximum and mean keratometry after 12 months. There was significant decrease in central corneal thickness in both groups which was more prominent in conventional group. Endothelial cell density reduced only in the conventional group which was not statistically significant (P = 0.147). CH, CRF, and wavefront aberrations did not change significantly in either group. We did not observe any significant difference in the changes of the variables between the two groups.

Conclusions

Accelerated CXL with 9 mW/cm² irradiation for 10 min had similar refractive, visual, keratometric, and aberrometric results and less adverse effects on the corneal thickness and endothelial cells as compared with the conventional method after 12 months follow-up. However, randomized clinical trials with longer follow-ups and larger sample sizes are needed.