Correlation of the OCT Double-Layer Sign with Type 1 Non-Exudative Neovascularization on OCT-A in Age-Related Macular Degeneration

Background and Objectives: Early diagnosis of the exudative form of age-related macular degeneration (AMD) is very important for a timely first treatment, which is directly related to the preservation of functional visual acuity over a long period. The goal of this paper was to examine the correlation between the double-layer sign (DLS) and the presence of non-exudative macular neovascularization (MNV). Materials and Methods: Our research included 60 patients with AMD, exudative in one eye and non-exudative in the other eye. We analyzed only the non-exudative form using optical coherence tomography (OCT) and optical coherence tomography angiography (OCT-A). The patients were classified into three groups, depending on the duration of the disease (<2 years, 2 to 5 years, >5 years). The onset of the disease was deemed the moment of establishing a diagnosis of exudative AMD in one eye. We defined the presence or absence of a DLS using OCT and the presence of non-exudative MNV using OCT-A, both on 3 × 3 mm and 6 × 6 mm sections. DLS was used as a projection biomarker for non-exudative MNV, with the aim of establishing a rapid diagnosis and achieving early treatment of the disease. Results: We found that there was a statistically significant correlation between the DLS diagnosed using OCT and non-exudative MNV diagnosed by OCT-A for both 3 × 3 mm (p < 0.001) and 6 × 6 mm (p < 0.001) imaging. There was a statistically significant difference between the frequencies of both DLS and MNV in Groups I and III on both 3 × 3 and 6 × 6 mm imaging. A statistically significant difference was also noted in the frequencies of DLS and MNV on 6 × 6 mm imaging, but not on 3 × 3 mm imaging, between Groups I and II. No differences were found between the frequencies of DLS and MNV between Groups II and III. Conclusions: The DLS on OCT can be used as a projection biomarker to assess the presence of a non-exudative MNV.

Interleukin 12 in the Acute Phase of the Immune Response after Excimer Laser Treatment

BACKGROUND AND OBJECTIVES

The aim of the research was to investigate the differences in the concentrations of IL-12, IL-4, IL-10, and IFN-γ in tears after LASIK and PRK procedures.

MATERIALS AND METHODS

The study included 68 myopic eyes up to -3.0 D refractive spherical equivalent, divided into two groups: Group 1 LASIK (n = 31) and Group 2 PRK (n = 37). Three tear samples were taken from each eye: immediately before the procedure (t₀), 1 h after the procedure (t₁), and 24 h after the procedure (t₂). The concentrations of IL-12p70, IL-4, IL-10, and IFN-γ in the tear samples were determined by flow cytometry. Participants were not taking anti-inflammatory therapy 24 h after the procedure.

RESULTS

IL-4 levels 1 h after treatment did not differ between LASIK and PRK (p = 0.990), while 24 h after PRK there was a significant decrease in IL-4 levels (p < 0.05), but not after LASIK (p = 0.476). In both the LASIK (p < 0.05) and PRK (p < 0.05) groups, there is an increase in IL-10 concentrations 1 h after treatment, which persists 24 h after LASIK (p < 0.05) but not after PRK (p = 0.081). There is an increase in IL-12p70 concentration 1 h after treatment in both the LASIK (p < 0.001) and PRK groups (p < 0.001). There is also an increase in IL-12p70 concentration 24 h after PRK (p < 0.005), but not after LASIK (p = 0.775).

CONCLUSIONS

IL-4 concentration shows a significantly higher value in the LASIK group than in the PRK group after 24 h. IL-10 and IL-12p70 levels increase one hour after surgery in both groups. After 24 h, the IL-10 levels remain elevated in the LASIK group, and the IL-12p70 levels remain elevated in the PRK group. Thus, LASIK and PRK procedures show different inflammatory dynamics.

Multifocal Femto-PresbyLASIK in Pseudophakic Eyes

BACKGROUND

Presbyopia treatment in pseudophakic patients with a monofocal IOL is challenging. This study investigates the refractive results of femto-PresbyLASIK and analyzes presbyopia treatment in pseudophakic eyes.

METHODS

14 patients with 28 pseudophakic eyes were treated with femto-PresbyLASIK. The dominant eye was targeted at a distance and the non-dominant eye at -0.5 D. The presbyopic algorithm creates a steepness in the cornea center by using an excimer laser that leads to corneal multifocality.

RESULTS

6 months after surgery a refraction of -0.11 ± 0.13 D (p = 0.001), an uncorrected distance visual acuity of 0.05 ± 1.0 logMAR (p < 0.001) and an uncorrected near visual acuity of 0.15 ± 0.89 logMAR (p = 0.001) were achieved in the dominant eye. For the non-dominant eye, the refraction was -0.28 ± 0.22 D (p = 0.002), the uncorrected distance of visual acuity was 0.1 ± 1.49 logMAR, and the uncorrected near visual acuity was 0.11 ± 0.80 logMAR (p < 0.001). Spherical aberrations (Z400) were reduced by 0.21-0.3 µm in 32% of eyes, and by 0.31-0.4 µm in 26% of eyes.

CONCLUSION

By steepening the central cornea while maintaining spherical aberrations within acceptable limits, PresbyLASIK created a corneal multifocality that safely improved near vision in both eyes. Thus, femto-PresbyLASIK can be used to treat presbyopia in pseudophakic eyes without performing intraocular surgery.

Steep keratometry and central pachymetry after corneal collagen cross-linking procedure in patients with keratoconus

Background/Aim. Keratoconus is a disorder of the eye which results in progressive thinning of the cornea. The cross-linking procedure (CXL) is applied in the treatment of initial progredient forms of keratoconus. It is aiming at increasing biomechanical stability of corneal stromal tissue to slow down or stop progressing the ectatic disorder. The aim of the study was to examine the effect of CXL procedure on values of steep keratometry (K2) and central pachymetry (CCT) six months after the intervention in keratoconusaffected patients. Methods. Clinical prospective cohort study included 30 eyes of 29 patients suffering from keratoconus. All patients were examined on Allegro-Oculyzer in order to diagnose and follow up keratoconus, thus obtaining corneal topography parameters and parameters important for this study: K2 and CCT, preoperatively and six months postoperatively. The CXL procedure was carried out by following the modified Dresden Protocol. Results. K2 mean value was 49.01 ? 3.99 diopter (Dpt) preoperatively and 48.06 ? 4.46 Dpt six months postoperatively. K2 decreased six months postoperatively by 0.95 Dpt, proportionally in all patients. Student's paired sample t test showed that average decrease of K2 (d? = 0.95 Dpt) was highly statistically significant (t = 3.381; p < 0.01). CCT mean value was 480.17 ? 36.62 ?m preoperatively and 444.37 ? 45.01 ?m six months postoperatively. CCT decreased six months postoperatively by 35.8 ?m, proportionally in all patients. Student's paired sample t test showed that average decrease of CCT (d? = 35.8 ?m) was highly statistically important (t = 6.40; p < 0.001)). Conclusion. Application of CXL procedure in the treatment of keratoconus with confirmed progression highly reduces steep keratometry and central pachymetry six months postoperatively. By steep keratometry reducing effect the CXL procedure is efficient in the treatment of keratoconus, especially its initial stages.

The acute phase of inflammatory response involved in the wound-healing process after excimer laser treatment

Purpose

To evaluate the participation of proinflammatory cytokines in the acute phase of corneal wound-healing response after excimer laser treatment.

Methods

The study included 68 myopic eyes up to −3.0 diopters divided into two groups: 1) eyes treated with laser in situ keratomileusis (LASIK) (n=31) and 2) eyes treated with photorefractive keratectomy (PRK) (n=37). Each group was then divided into three subgroups based on tear sampling times: before (0 hours), 1 hour after, and 24 hours after treatment. The tear fluid was sampled from lower lateral tear meniscus using a cellulose microsurgical sponge. The levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6, and IL-8 in tear fluid were determined by flow cytometry method.

Results

Statistical significance was observed in the concentrations of TNF-α (P=0.0421) and IL-1β (P=0.0225) between samples collected 1 and 24 hours after PRK treatment in favor of samples collected 1 hour after treatment. IL-6 concentration changes showed a significant increase in the PRK group in both time intervals following treatment compared to pretreatment (0 hour/1 hour, P=0.0031; 0 hour/24 hours, P=0.0059). For IL-8 concentrations, significant differences were observed between control and experimental groups in samples collected 1 hour after LASIK and 1 hour after PRK treatment (P<0.001 for both groups), and IL-8 concentrations between control and experimental groups in samples collected 24 hours after LASIK and 24 hours after PRK treatment were greater after PRK treatment (P=0.0005). Comparison of average concentration values of proinflammatory cytokines in all the tested samples between LASIK and PRK groups showed significantly higher levels of IL-1β in the LASIK group 24 hours after treatment (P=0.0134), and of IL-6 in the PRK group 24 hours after treatment (P=0.0031).

Conclusion

The acute phase of corneal wound healing after excimer laser treatment is defined by an intensive inflammatory response. After PRK treatment, there were increased concentrations of TNF-α and IL-1β in tear samples 1 hour after treatment, IL-6, 1 and 24 hours after treatment, and IL-8, 1 and 24 hours after treatment. After LASIK treatment, there were increased concentrations of IL-8 in tear samples 1 hour after treatment and IL-1β, 24 hours after treatment. Both PRK and LASIK methods are characterized with a significant inflammatory response. However, tear findings following PRK method showed more intensive inflammatory response than the findings after LASIK method.

Validation and cross-cultural adaptation of the National Eye Institute Visual Function Questionnaire (NEI VFQ-25) in Serbian patients

PURPOSE

To test the validity and reliability of the Serbian version of the interviewer-administered format of the National Eye Institute Visual Functioning Questionnaire (NEI VFQ-25).

METHODS

The Serbian version of NEI VFQ-25 was translated in accordance with standard methods that have been adopted internationally. In order to assess the reliability and validity of the translated NEI VFQ-25, we used a sample of 105 patients with four different chronic ocular diseases. Cronbach's alpha coefficient was used to assess internal consistency for each subscale. To assess test-retest reliability, intraclass correlation coefficients were used. The test-retest data were obtained from clinically stable patients with age-related cataracts, in surveys performed 2 weeks apart. Rasch analysis was also applied as a modern methods of psychometric assessment of the questionnaire.

RESULTS

Four groups of patients were studied and the most prevalent were patients with cataract 40 (38.1%), followed by diabetic retinopathy 31 (29.5%), age related macular degeneration 22 (21.0%) and glaucoma 12 (11.4%). The overall index score on the NEI VFQ-25 ranged from 65.3 to 67.8 with a mean of 67.4 ± 15.0. Cronbach's alpha coefficient (index of internal consistency reliability) ranged from 0.643 to 0.889 for the subscales. Evaluation of the validity of the Serbian version of NEI VFQ-25 is presented in the multi-trait-multi-method matrix and all items passed the convergent and discriminant validity tests. Rasch analysis showed a good measurement precision, but also demonstrated misfitting items and multidimensionality of the questionnaire.

CONCLUSION

Although traditional validation method indicates that the Serbian version of NEI VFQ-25 is a valid and reliable instrument for the assessment of vision specific QoL in Serbian populations aged 40 years or older, Rasch analysis revealed a substantial weakness of the questionnaire that should be taken into consideration when interpreting the results.

The prevalence of pseudoexfoliation syndrome and possible systemic associations in patients scheduled for cataract surgery at the Military Medical Academy in Belgrade

BACKGROUND/AIM

Pseudoexfoliation syndrome (PEX) is an age-related systemic degenerative disorder characterized by the production and progressive accumulation of extracellular fibrillar eosinophilic material in the anterior segment of the eye. The aim of the study was to evaluate several clinical aspects of PEX, such as frequency of PEX and pseudoexfoliation glaucoma (PEXG), intraocular pressure (IOP), the type of lens opacity, and the possible relationship of PEX and systemic diseases.

METHODS

All 674 cataract patients had a comprehensive eye examination, including slitlamp biomicroscopy before and after mydriasis, IOP measurement, and fundus examination. The patients were classified into two groups: the PEX and the non-PEX group.

RESULTS

The overall prevalence of PEX syndrome was found to be 17.5% (118 patients). The mean age of PEX patients (79.7 +/- 6.1 years) was significantly higher when compared with those without PEX (73.5 +/- 9.1 years) (p = 0.000). The prevalence of PEX syndrome was found to increase with age, from 7.3% in the 7th decade of life to 27% in patients older than 80 years (p < 0.001). The most common cataract type in the PEX patients was mature cataract observed in 40.7% of patients. The rest of the patients had mixed (30.5%), nuclear (25.4%), cortical (1.7%) and hypermature cataract (1.7%). Among the PEX patients 44 (37.2%) had glaucoma. Intraocular pressure was significantly higher in eyes with pseudoexfoliations than in eyes without it (17.8 +/- 3.2 mmHg and 15.8 +/- 2.8 mmHg, respectively; p = 0.001). Moreover, the prevalence of coronary heart disease was found to be higher in PEX patients.

CONCLUSION

PEX syndrome is a common problem among Serbian patients scheduled for cataract surgery. It represents one of the major glaucoma risk factors and probably associated with ischemic heart disease, intraoperative and postoperative problems in cataract surgery.

[Laser in situ keratomyleusis (LASIK) for correction of myopia and hypermetropia--our one year experience]

BACKGROUND/AIM

Laser in situ keratamileusis (LASIK) is the most commonly used refractive surgical method worldwide. The aim of this study was to examine the effectiveness and safety of LASIK in the correction of myopia and hyperopia.

METHODS

The study included myopic and hyperopic eyes with preoperative best corrected visual acuity (BCVA) = 1 (20/20), of the total number of 322 divided into 2 groups--1) myopic eyes (n = 241) which were divided into 4 subgroups according to the myopia strength: a) < or = -1.75 D (n = 23), b) from -2 to -3.75 D (n = 81), c) from -4 to -6.75 D (n = 113), d) > or = -7 D (n = 24); 2) hyperopic eyes (n = 81) which were divided into 3 subgroups according to the hyperopia strength: a) < or = +1.75D (n = 10), b) from +2 to +3.75 D (n = 46), c) > or = +4 D (n = 25). Myopic and hyperopic eyes with preoperative BCVA < or = 0.9 (eyes with ambliopia) were excluded from the study, as well as eyes with astigmatism > 1.5 D. To assess the effectiveness of LASIK we examined the percentage of eyes in the mentioned subgroups, which derived uncorrected visual acuity (UCVA) 6 month after the intervention to the following: a) UCVA = 1 (20/20) and b) UCVA > or = 0.5 (20/40). To assess the safety of LASIK we examined the frequency of intraoperative and postoperative complications. A prospective study was performed in a 6-months follow-up period. RESULTS. Refractive spherical equivalent (RSE) of myopic eyes was in the range from -0.75 D to -12 D. In the first subgroup preoperative mean value of RSE with standard deviation (mean RSE +/- SD) was -1.39 +/- 0.36 D, and 6 months after the LASIK 100% of the eyes had UCVA = 20/20. In the second subgroup preoperative mean RSE +/- SD was -2.85 +/- 0.50 D, and 6 months after LASIK 93% of the eyes had UCVA = 20/20, but 100% of the eyes had UCVA > or = 20/40. In the third subgroup preoperative mean RSE +/- SD was -5.03 +/- 0.75 D, and 6 months after the LASIK 90% of the eyes had UCVA = 20/20, but 100% of the eyes had UCVA > or = 20/40. In the fourth subgroup preoperative mean RSE +/- SD was -7.68 +/- 1.03 D, and 6 months after the LASIK 96% of the eyes had UCVA = 20/20, but 100% of eyes had UCVA > or = 20/40. Refractive spherical equivalent of hyperopic eyes was in the range from +1 D to +6 D. In the first subgroup preoperative mean RSE +/- SD was +1.50 +/- 0.30 D, and 6 months after the LASIK 90% of the eyes had UCVA = 20/20, but 100% of the eyes had UCVA > or = 20/40. In the second subgroup preoperative mean RSE +/- SD was +2.65 +/- 0.46 D, and 6 months after the LASIK 87% of the eyes had UCVA = 20/20, but 96% of the eyes had UCVA > or = 20/40. In the third subgroup preoperative mean RSE +/- SD was +4.62 +/- 0.68 D, and 6 months after the LASIK 64% of the eyes had UCVA = 20/20, but 100% of the eyes had UCVA > or = 20/40. In our study intraoperative complications appeared in 6 eyes (1.86%): thin flap in 2 eyes (0.62%) and epithelial defects in 4 eyes (1.24%), yet postoperative complications appeared in 10 eyes (3.10%): flap folds in 2 eyes (0.62%), epithelial ingrowth in 4 eyes (1.24%) and regression in 4 eyes (1.24%).

CONCLUSION

LASIK is effective and safe refractive surgical method for correcting myopia up to -12 D and hyperopia up to +6 D.

Anterior ischemic optic neuropathy associated with metabolic syndrome

PURPOSE

Metabolic syndrome denotes a common cluster of naturally connected risk factors including obesity, elevated blood pressure, insulin resistance, dyslipidemia, proinflammatory state and prothrombotic state. Anterior ischemic optic neuropathy is an acute ischaemic disorder of the optic nerve head and may lead to severe visual loss.

METHODS

We considered three patients with moderate degree of diabetic retinopathy and anterior ischemic optic neuropathy. They were submitted to endocrinological examination and the diagnosis of metabolic syndrome was established.

RESULTS

Cardiological examination revealed that blood pressure control was not optimal. The signs of left ventricular hypertrophy and diastolic dysfunction were confirmed by echocardiography. They are possible markers of preclinical cardiovascular disease.

CONCLUSION

We observed that a variety of well-known risk factors in metabolic syndrome may be involved in serious eye and cardiological complications. The early diagnosis and treatment of these patients can not only improve visual function but also prevent cardiovascular complications.