Cationic nanoemulsion vs. 0.15% sodium hyaluronate artificial tears in the healing process following modern surface keratorefractive surgery.

PURPOSE: The aim of this study was to investigate the influence of artificial tears containing either cationic nanoemulsion (CCN) or sodium hyaluronate artificial tears (SH) on early postoperative healing after modern surface refractive surgery. MATERIALS AND METHODS: In this multicenter, prospective, double-masked, parallel-group (1:1), comparative study, 129 patients (n = 255 eyes) were randomized to receive CCN (n = 128) or SH (n = 127) as an adjuvant treatment after either transepithelial photorefractive keratectomy (transPRK) or Epi-Bowman keratectomy (EBK). The patients' perspectives were gathered using the Ocular Surface Disease Index (OSDI) questionnaire, and uncorrected (UCVA), and corrected (BCVA) visual acuity were assessed before and one week and one month after the procedure. In addition, corneal epithelization and subjective assessment of visual blur and eye irritation on drop instillation were assessed at one week postoperatively. RESULTS: No statistically significant differences were found between two groups in age, spherical equivalent refractive error, UCVA, BCVA or OSDI scores before the procedure. There was also no difference between groups in UCVA one week and one month after the procedure. However, statistically significantly lower OSDI scores were found one week and one month after the procedure in the CCN group. Moreover, blurred vision after use of the eye drops was observed less frequently in the CCN group than in the SH group. CONCLUSIONS: The CCN and SH groups had similar postoperative UCVA. However the significantly lower OSDI scores and less frequently blurred vision after application of the eye drops in the CCN group suggest better subjective outcomes in this group.

Corneal Optical Densitometry in the Evaluation of 2-Year Graft Function Following Endothelial Keratoplasty.

This study aimed to assess clinical application of the Scheimpflug corneal tomography for objective evaluation of corneal optical density in eyes undergoing Descemet's stripping endothelial keratoplasty (DSEK). In this prospective study, 39 pseudophakic eyes with bullous keratopathy were enrolled. All eyes underwent primary DSEK. Ophthalmic examination included best corrected visual acuity (BCVA) measurement, biomicroscopy, Scheimpflug tomography, pachymetry, and endothelial cell count. All measurements were taken preoperatively and within a 2-year follow-up period. Gradual BCVA improvement was observed in all patients. After two years, the mean and median BCVA values were 0.18 logMAR. A decrease in central corneal thickness was noted only during the first 3 months postoperatively and was followed by a gradual increase. Corneal densitometry decreased constantly and most significantly in the first 3 months postoperatively. The consecutive decrease in endothelial cell count of the transplanted cornea was most significant during the first 6 months postoperatively. Six months postoperatively, the strongest correlation (Spearman's r = -0.41) with BCVA was found for densitometry. This tendency was maintained throughout the entire follow-up period. Corneal densitometry is applicable for objective monitoring of early and late outcomes of endothelial keratoplasty, showing a higher correlation with visual acuity than pachymetry and endothelial cell density.

Swept-source OCT for corneal graft quantitative evaluation in the eye bank and the correlation of the measurements to pre-excision values.

Quantitative evaluation of the human corneal grafts stored in the tissue banks is usually limited to endothelial cell density and central thickness. Swept-source OCT (SS-OCT) is capable of measuring the central curvatures of the corneal tissue prepared for transplantation without loss of sterileness, providing insights on its refractive state. The aim of the paper is to compare in vitro SS-OCT measurements with pre-excision values. Hand-held keratometry and ultrasound pachymetry was performed on 22 corneas before excision of corneoscleral button and insertion in the vial with Eusol-C solution (AlchimiaS.r.l, Nicolò, Italy). After 12 to 36 h of hypothermic storage the corneas were examined within the vials with custom built SS-OCT system maintaining a sterile environment. The anterior and posterior central curvatures, and central corneal thickness (CCT) were measured. Rotation of the corneoscleral button was controlled by making a 6-o'clock mark during excision. Mean pre-excision CCT was 626.45 ± 28.71 µm and 468.05 ± 52.96 µm when measured with SS OCT (r = 0.55; p < 0.001). Respective values for average keratometry were 7.74 ± 0.39 mm and 7.92 ± 0.57 mm (r = 0.6; p = 0.22). Although high differences were observed in corneal thickness, keratometric radius of curvature at the flat (r = 0.42; p < 0.001) and steep (r = 0.62; p = 0.014) meridian of the anterior corneal surface, as well as corneal anterior astigmatism (r = 0.3; p < 0.001), showed good correlation with pre-excision values. SS-OCT is capable of providing quantitative evaluation of the human corneal grafts in hypothermic storage. Good correlation between curvature measurements before excision and during banking in the vial indicates its clinical utility.

Methanol-induced optic neuropathy: a still-present problem.

Methanol-induced optic neuropathy (Me-ION) is a serious condition that may result in long-term or irreversible visual impairment or even blindness secondary to damage and loss of function of the optic nerve and retina. Me-ION shows a tendency to occur as mass poisonings around the world with a clear predilection for poor societies in developing countries. The main mechanism underlying the molecular basis of Me-ION is the inhibition of the mitochondrial oxidative phosphorylation process through the binding of the toxic metabolite of methanol-formic acid-with the key enzyme of this process-cytochrome c oxidase. However, other mechanisms, including damage to the eye tissues by oxidative stress causing the intensification of the oxidative peroxidation process with the formation of cytotoxic compounds, as well as an increase in the synthesis of pro-inflammatory cytokines and influence on the expression of key proteins responsible for maintaining cell homeostasis, also play an important role in the pathogenesis of Me-ION. Histopathological changes in the eye tissues are mainly manifested as the degeneration of axons and glial cells of the optic nerve, often with accompanying damage of the retina that may involve all its layers. Despite the development of therapeutic approaches, persistent visual sequelae are seen in 30-40% of survivors. Thus, Me-ION continues to be an important problem for healthcare systems worldwide.

Changes in the geometry of modern daily disposable soft contact lenses during wear.

The geometry of contact lenses can be altered by wear but determining the changes that occur in soft contact lenses (SCLs) is challenging. This study aimed to investigate the shape alterations of daily disposable SCLs after wear using swept-source optical coherence tomography (SS-OCT). Forty-five eyes with myopia of - 3.00 diopters (D) were enrolled. The participants wore three types of SCLs: hydrogel lens (nesofilcon A) and silicone hydrogel lenses (delefilcon A and stenfilcon A). The SCLs were scanned 3-6 min after lens removal. We found a significant decrease in the SCL anterior curvature: 0.24 ± 0.17 mm for nesofilcon A, 0.44 ± 0.21 mm for delefilcon A, and 0.53 ± 0.29 mm for stenfilcon A. The changes in the anterior curvature of SCLs correlated moderately with the mean corneal keratometry; Pearson's correlation coefficients for nesofilcon A and delefilcon A were 0.57 and 0.52, respectively (P < 0.001). A statistically significant change in the total diameter was observed in SCL made of stenfilcon A (0.39 mm, P < 0.001). To conclude, the central radii of curvature decreased after a wearing period for all three types of daily disposable SCLs to imitate the anterior corneal surface, however, the changes in other geometrical parameters measured with SS-OCT were lens-specific.

Evaluation of Blood Coagulation Parameters and ADMA, NO, IL-6, and IL-18 Serum Levels in Patients with Neovascular AMD before, during, and after the Initial Loading Phase of Intravitreal Aflibercept.

We evaluated the effect of intravitreal injections of aflibercept (IVA) on blood coagulation parameters including prothrombin time (PT), activated partial thromboplastin time (APTT), and thrombin time (TT), as well as asymmetric dimethylarginine (ADMA), nitric oxide (NO), interleukin 6 (IL-6), and interleukin 18 (IL-18) serum levels in patients with neovascular AMD (nAMD). Twenty-two eyes of 22 patients with nAMD were included. Parameters were evaluated before and 2-3 days after the first IVA injection, and then immediately before and 2-3 days after the third IVA injection. We revealed prolongation of the TT after the initial loading phase of IVA (p = 0.041) and a significant increase in IL-18 serum concentration immediately before the third IVA administration compared to baseline (p = 0.037). There were no statistically significant differences of other parameters and PT, APTT, ADMA, NO, and IL-6 values remained within the normal range at each of the time points of the study. Our results suggest that repeated IVA administration may affect the common blood coagulation pathway, which manifests as a prolongation of the TT value. Furthermore, we showed a significant increase in serum concentration of the pro-inflammatory cytokineIL-18during the initial loading phase of IVA.

Shape of the anterior surface of the cornea after extended wear of silicone hydrogel soft contact lenses.

PURPOSE: To measure geometrical changes in the anterior surface of the cornea after wearing silicon hydrogel (SiH) soft contact lenses continuously for 1 week. METHODS: Forty-three eyes with 3.0D of myopia and 22 eyes with 3.0D of hyperopia were enrolled in the prospective, interventional study. All subjects underwent a general eye examination, corneal tomography with wavefront aberration analysis, corneal thickness measurements and epithelial thickness mapping before and after wearing SiH lenses (Acuvue Oasys) for 7 days. RESULTS: No significant changes in average keratometry were observed in either refractive group. In the myopic group, keratometry findings for the flat meridian (K1) and central corneal thickness decreased significantly. After +3.0 D lens wear in the hyperopic group, a significant decrease in epithelial thickness up to 3.19 µm was observed in the central and paracentral cornea, (p < 0.001). In both refractive groups, the largest epithelial thickness increase was seen in the periphery. A decrease in spherical aberration was noted in myopic eyes, while an increase of both higher order corneal aberrations and coma was found in hyperopic subjects. CONCLUSION: Extended wear of SiH lenses results in a significant change in epithelial thickness leading to alteration in the geometry of the anterior surface of the cornea, particularly in hyperopic patients. These epithelial thickness variations lead to changes in the higher order aberrations of the cornea.

Three-year outcomes of mixed astigmatism correction with single-step transepithelial photorefractive keratectomy with a large ablation zone.

PURPOSE: To evaluate refractive and visual outcomes of single-step transepithelial photorefractive keratectomy (transPRK) in the treatment of mixed astigmatism with the use of an aberration-neutral profile and large ablation zone. SETTING: Nicolaus Copernicus University and Oftalmika Eye Hospital, Bydgoszcz, Poland. DESIGN: Retrospective, observational case series. METHODS: This study included patients who underwent transPRK to correct mixed astigmatism and completed the 3-year follow-up. Procedures were performed with an Amaris 750S excimer laser using an aberration-neutral profile and optical zone of 7.2 mm or more. RESULTS: A total 48 eyes of 39 patients were included. Preoperatively, mean spherical manifest refraction was +1.37 ± 0.98 diopter (D) (0.25 to 4.00 D), and astigmatism was -4.00 ± 0.76 D (-2.25 to -6.00 D). Three years postsurgery, it was -0.17 ± 0.26 D and -0.41 ± 0.44 D, respectively. Attempted spherical equivalent correction within ±0.50 D was achieved in 45 eyes (94%) and cylindrical correction in 34 (71%). Preoperative corrected distance visual acuity (CDVA) was 20/20 or better in 38 eyes (79%), and postoperative uncorrected was 20/20 or better in 29 eyes (60.0%). No eye had lost 2 or more Snellen lines of CDVA, whereas 3 eyes (6%) gained 2 or more lines. In 4 eyes (8%), haze of low intensity was observed at the periphery, with scores between 0.5 and 1.0, and only 1 eye getting a score of 2 in 0- to 4-degree scale. CONCLUSIONS: Mixed astigmatism correction with large-ablation-zone transPRK provided good results for efficacy, safety, predictability, and visual outcomes in a 3-year follow-up.

Change in the geometry of positive- and negative-powered soft contact lenses during wear.

Contact lens wear causes mutual interactions between the ocular surface and the lens, which may affect comfort as well as vision. The aim of this study was to examine deformations in modern positive- and negative-powered silicone hydrogel soft contact lenses (SiH SCLs) after 7 days of continuous wear. This pre-post interventional study included 64 eyes: 42 eyes with myopia of -3.00 D and 22 eyes with hyperopia of +3.00 D. All patients underwent general ophthalmic examination, corneal topography/tomography, total corneal and epithelial thickness mapping, and specular microscopy before and after the wearing period. SiH SCLs made of senofilcon A were worn continuously for 7 days on all eligible eyes. The geometry of the new and used lenses was measured 3 to 6 minutes after removal in two perpendicular planes using a custom-made swept source optical coherence tomography (SS-OCT) system for in vitro measurements. The anterior and posterior radii of curvature decreased in -3.00 D lenses in two perpendicular planes. This effect correlated significantly with average keratometry of the cornea. Sagittal lens height was lower in +3.00 D lens after wear, which correlated moderately with the corneal sagittal height. A significant decrease in central corneal epithelial thickness was observed after wearing +3.0 D lenses. In conclusion, SiH SCLs made of senofilcon A undergo minor deformations after 7-day continuous wear. Geometry modifications are different for -3.00 D and +3.00 D lenses, and they imitate the shape of the anterior eye surface. These geometric changes are accompanied by a decrease in the central thickness of corneal epithelium after +3.00 D lens wear.

High-speed OCT-based ocular biometer combined with an air-puff system for determination of induced retraction-free eye dynamics.

We demonstrate a swept source OCT-based ocular biometer integrated with an air-puff stimulus to study the reaction of the eye to mechanical stimulation in vivo. The system enables simultaneous measurement of the stimulus strength and high-speed imaging of the eye dynamics along the visual axis. We characterize the stimulus and perform optimization of the data acquisition for a proper interpretation of the results. Access to the dynamics of axial eye length allows for a determination of the eye retraction, which is used to correct the air-puff induced displacement of ocular structures. We define the parameters to quantify the reaction of the eye to the air puff and determine their reproducibility in a group of healthy subjects. We observe the corneal deformation process and axial wobbling of the crystalline lens. OCT biometer combined with the air puff is the first instrument with the potential to provide comprehensive information on the biomechanics of ocular components.

Air-Puff-Induced Dynamics of Ocular Components Measured with Optical Biometry.

Purpose: To analyze the dynamics of all optical components of the eye and the behavior of the eyeball under air-puff conditions in vivo. To determine the impact of the intraocular pressure (IOP) on the air-puff-induced deformation of the eye. Methods: Twenty eyes of 20 healthy subjects were included in this study. The dynamics of the ocular components, such as the cornea, the crystalline lens, and the retina, was measured by a prototype swept source optical coherence tomography biometer integrated with the air-puff system. The system allows to acquire a series of axial scans at the same location as a function of time with no transverse scanning. Several parameters were extracted from optical coherence tomography data. The IOP was measured using a Goldmann applanation tonometry. The measurements of the eyes were performed before and 2 hours after administration of IOP-reducing drops, namely, 0.2 % brimonidine tartrate. Results: There is a statistically significant correlation of corneal thickness, vitreous depth, and eye length with IOP. The deformation amplitudes of the cornea and the crystalline lens are inversely proportional to the IOP, but statistical significance is achieved only for the cornea. The crystalline lens is displaced without compression, and the return has the form of wobbling. The reduction of IOP level induces corresponding changes in the extracted parameters. Conclusions: Optical biometry combined with air puff provides comprehensive information on the in vivo behavior of all ocular components, including the crystalline lens. Measurement of the axial length dynamics of during deformation enables correcting the deformation for eye retraction.

Three-year outcomes after high hyperopia correction using photorefractive keratectomy with a large ablation zone.

AIM: To evaluate refractive and visual outcomes of photorefractive keratectomy (PRK) to treat high hyperopia using an aberration-neutral profile and large ablation zone. METHODS: This was a retrospective, consecutive observational case series at the Oftalmika Eye Hospital, Bydgoszcz, Poland. We included 51 consecutive eyes of 34 patients who underwent alcohol-assisted PRK to correct hyperopia within the range of +3.6 to +6.15 D (mean+4.61±0.67 D). Procedures were performed with an Amaris 750S excimer laser (Schwind eye-tech-solutions GmbH, Kleinostheim, Germany) using an aberration-neutral profile and a 10 mm total ablation zone. Refractive results, predictability, safety and efficacy were evaluated 3 years postoperatively. RESULTS: At 1-year postsurgery, the mean manifest refraction spherical equivalent (MRSE) was -0.002±0.43 D and mean cylinder was -0.181±0.31 D, while the values were +0.09±0.46 D and -0.15±0.26 D, respectively, at 2 years (MRSE p<0.001) and +0.15±0.44 D and -0.15±0.26 D, respectively, at 3 years (MRSE p<0.001). 78% of eyes were within ±0.50 D of the attempted spherical equivalent correction. Three years postoperatively, 22% of eyes lost one line of corrected distance visual acuity and 27% gained a line or two. The change in the mean corneal spherical aberrations for the 6 mm zone was from 0.27±0.07 to 0.08±0.13 µm. CONCLUSIONS: High hyperopia correction with PRK using an aberration-neutral profile and large ablation zone provides good efficacy, safety, predictability and visual outcomes. Relatively low change of corneal spherical aberrations and low increase of hyperopia in the first three postoperative years were observed.

Association between serotonin-norepinephrine reuptake inhibitors and acute angle closure: What is known?

Serotonin-norepinephrine reuptake inhibitors are widely used antidepressants with a relatively safe profile. One of the complications associated with this group of drugs is acute angle closure. The mechanisms linking serotonin-norepinephrine reuptake inhibitors and acute angle closure are complex and may be interlinked with the effects of the drug on the inhibition of serotonin and noradrenaline reuptake, as well as pseudo-anticholinergic effects, dopaminergic effects, and idiosyncratic reactions with the drug molecule in the eye. Individual characteristics, such as polymorphisms of the gene encoding the 2D6 subunit of cytochrome P450, may affect the metabolism of the serotonin-norepinephrine reuptake inhibitor, whereas the combination with other drugs may lead to an increased risk of iridocorneal angle closure and may further exacerbate other mechanisms. Improved knowledge of the mechanisms linking serotonin-norepinephrine reuptake inhibitors and acute angle closure and of the risk factors predisposing to patients to acute angle closure will reduce the number of patients affected by this dangerous complication.

Scheimpflug Camera Measurement of Optical Density of the Corneal Epithelium, Stroma, and Endothelium in Patients with Pseudoexfoliation Syndrome.

BACKGROUND The present study evaluated the optical density of particular layers of the cornea and anterior lens capsule in patients with pseudoexfoliation syndrome (PEX). MATERIAL AND METHODS Sixty patients with cataract and PEX (mean age 76.6±5.6 years, range 62-88 years) were compared to 55 controls with cataract without PEX syndrome (mean age 76.3±6.09 years, range 62-90 years; P>0.05). The anterior segment of one eye was examined in each patient using Pentacam HR by Oculus before the planned cataract surgery. RESULTS The average optical density of the corneal epithelium, stroma, and endothelium was 25.3±6.09% and 19.9±3.41% (P<0.001), 23.1±5.5% and 19.2±3.6% (P<0.0001), and 14.6±3.4% and 12.3±2.1% (P<0.0001) in the PEX and control groups, respectively. The optical density of the anterior lens capsule was 13.6±4.2% in the PEX group and 9.74± 2.23% in the control group (P<0.0001). The average thickness of the cornea was 555 µm and 556 µm and the average optical density of endothelial cells 2240/mm² and 2323/mm² in the PEX and control groups, respectively (P<0.05). CONCLUSIONS In patients with PEX, increased optical density was observed not only in the structures with pseudoexfoliative material detectable by a slit-lamp), but also in the corneal epithelium and stroma. The increased optical density was not associated with reduced endothelial cell density or increased central cornea thickness.

Single-Step Transepithelial PRK vs Alcohol-Assisted PRK in Myopia and Compound Myopic Astigmatism Correction.

Transepithelial photorefractive keratectomy (tPRK), where both the epithelium and stroma are removed in a single-step, is a relatively new procedure of laser refractive error correction. This study compares the 3-month results of myopia and compound myopic astigmatism correction by tPRK or conventional alcohol-assisted PRK (aaPRK).This prospective, nonrandomized, case-control study recruited 148 consecutive patients; 93 underwent tPRK (173 eyes) and 55 aaPRK (103 eyes). Refractive results, predictability, safety, and efficacy were evaluated during the 3-month follow-up. The main outcome measures were uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and mean refractive spherical equivalent (MRSE).Mean preoperative MRSE was -4.30 ±â€Š1.72 D and -4.33 ±â€Š1.96 D, respectively (P = 0.87). The 3-month follow-up rate was 82.1% in the tPRK group (n = 145) and 86.4% in aaPRK group (n = 90), P = 0.81. Postoperative UDVA was 20/20 or better in 97% and 94% of eyes, respectively (P = 0.45). In the tPRK and aaPRK groups, respectively, 13% and 21% of eyes lost 1 line of CDVA, and 30% and 31% gained 1 or 2 lines (P = 0.48). Mean postoperative MRSE was -0.14 ±â€Š0.26 D in the tPRK group and -0.12 ±â€Š0.20 D in the aaPRK group (P = 0.9). The correlation between attempted versus achieved MRSE was equally high in both groups.Single-step transepithelial PRK and conventional PRK provide very similar results 3 months postoperatively. These procedures are predictable, effective, and safe for correction of myopia and compound myopic astigmatism.

Photoreceptor Inner and Outer Segment Junction Reflectivity after Vitrectomy for Macula-Off Rhegmatogenous Retinal Detachment.

Purpose. To evaluate the spatial distribution of photoreceptor inner and outer segment junction (IS/OS) reflectivity changes after successful vitrectomy for macula-off retinal detachment (PPV-mOFF) using spectral domain optical coherence tomography (SdOCT). Methods. Twenty eyes after successful PPV-mOFF were included in the study. During a mean follow-up period of 15.3 months, SdOCT was performed four times. To evaluate the IS/OS reflectivity a four-grade scale was used. Results. At the first follow-up visit the IS/OS had very similar reflectivity in entire length of the central scan with total average value of 1,05. At the second visit the most significant increase of the reflectivity was observed in temporal and nasal parafovea with average values of 2,17 and 2,22, respectively. The third region of increased reflectivity of an average value of 2,33 appeared during the third follow-up visit and was located in the foveola. At the last follow-up visit in entire central cross section the IS/OS reflectivity exceeded grade 2 reaching the highest average values in nasal and temporal parafovea and foveola. Conclusions. A gradual increase of the IS/OS reflectivity was observed in eyes after PPV-mOFF. The process is not random and starts independently in the peripheral and central part of the macula which may be attributed to the variable regenerative potential of cones and rods.

Modified scleral suture fixation technique for foldable IOL with fenestrations in the proximal part of the haptics.

PURPOSE: To present a modified surgical technique for scleral suture fixation of a new foldable intraocular lens (IOL) design with fenestrations in the proximal part of the haptics. METHODS: An experimental model of a double continuous-loop 4-point scleral suture fixation of IOL with fenestrations in the proximal part of the haptics showed that with conventional techniques, the lens is located in a horizontal plane 90° to the expected iris plane. To achieve proper IOL positioning, we modified the technique so as to perform 2 needle passes through the sclera for each haptic in the same meridian, resulting in the external part of the suture being radial to the limbus. The technique was performed in 14 eyes. Mean follow-up time was 9.8 months. RESULTS: In all cases, the lens was successfully implanted through clear corneal tunnel incision and the scleral fixation, as mentioned above, was performed with the use of Hoffman scleral pockets. Good centration of the IOLs without signs of tilt was achieved. CONCLUSIONS: It is possible to decrease the risk of tilt of the IOL with fenestrations in the proximal part of the haptics by modifying the technique so that the 2 needle passes through the sclera for each haptic are done in the same meridian, resulting in a layout of the external part of the suture being radial to the limbus.

Spectral OCT with speckle contrast reduction for evaluation of the healing process after PRK and transepithelial PRK.

We evaluate Spectral OCT (SOCT) with a speckle contrast reduction technique using resonant scanner for assessment of corneal surface changes after excimer laser photorefractive keratectomy (PRK) and we compare healing process between conventional PRK and transepithelial PRK. The measurements were performed before and after the surgery. Obtained results show that SOCT with a resonant scanner speckle contrast reduction is capable of providing information regarding the healing process after PRK. The main difference between the healing processes of PRK and TransPRK, assessed by SOCT, was the time to cover the stroma with epithelium, which was shorter in the TransPRK group.

Intrascleral outflow after deep sclerectomy with absorbable and non-absorbable implants in the rabbit eye.

BACKGROUND: The purpose of the study is an analysis of intrascleral drainage vessels formed in rabbits' eyes after non-penetrating deep sclerectomy (NPDS) with absorbable and non-absorbable implants, and comparison to eyes in which surgery was performed without implanted material. MATERIAL/METHODS: NPDS was carried out in 12 rabbits, with implantation of non-absorbable methacrylic hydrogel (N=10 eyes) or absorbable cross-linked sodium hyaluronate (N=6 eyes), or without any implant (N=8 eyes). All the animals were euthanized 1 year after surgery. Twenty-one eyeballs were prepared for light microscopy and 3 were prepared for transmission electron microscope (TEM) analysis. Aqueous humour pathways were stained with ferritin in 6 eyeballs. RESULTS: By light microscopy, small vessels adjacent to the areas of scarring were the most common abnormality. Vessel density was significantly higher in operated sclera compared to normal, healthy tissue, regardless of the type of implant used. The average vessel densities were 2.18±1.48 vessels/mm2 in non-implanted sclera, 2.34±1.69 vessels/mm2 in eyes with absorbable implants, and 3.64±1.78 vessels/mm2 in eyes with non-absorbable implants. Analysis of iron distribution in ferritin-injected eyes showed a positive reaction inside new aqueous draining vessels in all groups. TEM analysis showed that the ultrastructure of new vessels matched the features of the small veins. CONCLUSIONS: Aqueous outflow after NPDS can be achieved through the newly formed network of small intrascleral veins. Use of non-absorbable implants significantly increases vessel density in the sclera adjacent to implanted material compared to eyes in which absorbable implants or no implants were used.

[Idiopathic juxtafoveolar teleangiectasia 2a in spectral domain optical coherence tomography (SdOCT)]. / Idiopatyczne teleangiektazje okolodoleczkowe typu 2a w obrazie spektralnej optycznej koherentnej tomografii (SOCT).

PURPOSE: The aim of the study was the evaluation of the changes characteristic for type 2a idiopathic juxtafoveal retinal telangiectasia in spectral domain optical coherence tomography images. MATERIAL AND METHODS: The study covered 23 eyes with diagnosed idiopathic juxtafoveal retinal telangiectasia of type 2a - 5 men and 7 women. Stage 2 was noticed in 9 eyes, stage 3 in 5 eyes, stage 4 in 8 eyes. Stage 5 was noticed in one eye. All the patients included in the study underwent the macula analysis by SdOCT technique. RESULTS: Stage 2 was characterized mainly by the occurrence of small hyporeflective microcysts (in 100% of cases), tiny hyperreflective deposits (in 90% of patients), focal retinal photoreceptor layer damage (in 80%) as well as large hyporeflective cysts (70%). Stage 3 in SdOCT scans showed dominating hyperreflective deposits, including both small ones (100%) and less frequent large shaded deposits (71%), and still numerous microcysts (86%) and larger hyporeflective compartments. Stage 4 was characterized by the occurrence of large spreaded areas of fading retinal photoreceptor layer (in 100% of examined eyes), accompanied by retina architecture disorders. We also noticed numerous tiny hyperreflective deposits (100% of examined eyes), as well as large hyperreflective deposits (80%). Microcysts occurred significantly less frequently than in other stages (60%). The average retina thickness in fovea in all eyes irrespective of the stage of disease amounted to 192.13 +/- 59.1 microm, on the other hand in the nasal and temporal parts of fovea 202.43 +/- 37.75 microm and 262.7 +/- 41.31 microm respectively (p< 0.05). CONCLUSIONS: Thanks to its high resolution, SdOCT examination depicts changes in retina in the course of idiopathic juxtafoveal telangiectasia in great detail. Our study shows certain permanent changes occurring in this disease, characteristic to subsequent stages which allow to make a highly probable diagnosis before fluorescein angiography is carried out.