Application of smartphone-based infrared thermography devices for ocular surface thermal imaging.

Infrared thermography (IRT) is a well-known imaging technique that provides a non-invasive displaying of the ocular surface temperature distribution. Currently, compact smartphone-based IRT devices, as well as special software for processing thermal images, have become available. The study aimed to determine the possible use of smartphone-based IRT devices for real-time ocular surface thermal imaging. This study involved 32 healthy individuals (64 eyes); 10 patients (10 eyes) with proliferative diabetic retinopathy (PDR) and absolute glaucoma; 10 patients (10 eyes) with PDR, who underwent vitreoretinal surgery. In all cases, simultaneous ocular surface IRT of both eyes was performed. In healthy individuals, the ocular surface temperature (OST) averaged 34.6 ± 0.8 °C and did not differ substantially between the paired eyes, in different age groups, and after pupil dilation. In our study, high intraocular pressure was accompanied by a decrease in OST in all cases. After vitreoretinal surgery in cases with confirmed subclinical inflammation, the OST was higher than the baseline and differed from that of the paired eye by more than 1.0 °C. These results highlight that smartphone-based IRT imaging could be useful for the non-invasive detection of OST asymmetry between paired eyes due to increased intraocular pressure or subclinical inflammation.

Vitreoretinal Surgery with Temperature Management: A Preliminary Study in Rabbits.

The present study aimed to evaluate the structure of the rabbit retina after vitreoretinal surgery using prolonged irrigation with solutions of different temperatures. Thirty-six rabbits (72 eyes) were included in this study and randomly divided into 3 equal groups according to the temperature of the intraocular irrigating fluid they received during vitrectomy. Vitreoretinal surgery was performed with a 5°C irrigation solution in group 1 (12 rabbits, 24 eyes), a 22°C irrigation solution in group 2 (12 rabbits, 24 eyes), and a 36°C irrigation solution in group 3 (12 rabbits, 24 eyes). In each group of animals, the mean irrigation/aspiration time was 30 minutes for left eyes and 60 minutes for right eyes. Histological examination of the retina was performed 1, 7, and 30 days after surgery. During surgery, the temperature in the vitreous cavity of the eyes of rabbits of groups 1, 2, and 3 dropped by 26.0°C, 11.2°C (deep hypothermia), and 1.0°C (mild hypothermia), respectively. The highest rewarming rate was detected in group 1 (0.9°C/min) compared with group 2 (0.7°C/min) and group 3 (0.2°C/min). After 60 minutes of irrigation, retinal structural changes were detected in the animals of groups 1 and 2 (in contrast to the animals of group 3). After surgery with irrigation lasting 30 minutes, no retinal structural changes were observed. This study showed that temperature management, avoidance of intraoperative deep hypothermia, and prevention of rapid uncontrolled rewarming may protect the retinal morphology and increase the safety of prolonged vitreoretinal surgery.

Device Development for Ocular Surface Temperature and Heat Flux Density Measurement.

PURPOSE: Currently, much attention is paid to measuring the temperature of the ocular surface in various ophthalmic diseases. However, for a comprehensive assessment of heat transfer of the eye, it is advisable to measure both the ocular surface temperature and the heat flux (HF) density. This will expand our knowledge of the physiology of the eye and create new possibilities for diagnosing ocular pathology. The present study aimed to develop a thermoelectric device to study rabbits' ocular surface temperature and HF density. METHODS: The multichannel thermoelectric device was developed to measure the ocular surface temperature and HF density. This study included ten rabbits (20 eyes). In all animals, the temperature and the HF density were measured on the surface of the central cornea of both eyes. The measurement was repeated after pupils' dilation. RESULTS: The corneal surface temperature of rabbits was 33.1 ± 0.8 °C, and the HF density of the surface of the cornea was 8.3 ± 0.6 mW/cm2. Our results revealed a high degree of interocular symmetry in the surface HF density in healthy rabbits. After pupil dilation, an increase in the HF density on the surface of the rabbit cornea compared with the initial data and control eye was noted. CONCLUSIONS: The application of the developed device showed that it is safe and allows for the measurement of the ocular surface temperature and the HF density. We believe that further studies on the ocular surface HF density measurement in various eye diseases will allow us to evaluate the possibilities of this device and technique for diagnostic purposes.

Intraocular tumours imaging with transpalpebral near-infrared LED transillumination: Pilot study.

Purpose: To determine the possible use of near-infrared(NIR) light-emitting-diode (LED) radiation for imaging intraocular tumours by transpalpebral transillumination. Methods: This study was a pilot, open-label, prospective and non-interventional. Thirty patients (30 eyes; age 30-72 years) with uveal melanomas located in the iris, ciliary body, or choroid were under our observation. A biomicroscopy, ophthalmoscopy, transpalpebral NIR transillumination, and ultrasound examination were performed in all cases. Results: In all cases, NIR transillumination with transpalpebral approach enables visualization of the ciliary body and accurately estimates the projection of the pars plicata and ora serrata onto the sclera. In all patients, transpalpebral NIR transillumination made it possible to image the shadow of intraocular melanoma, estimate its dimensions and location concerning the ciliary body structures. Conclusions: We recommend the non-invasive transpalpebral NIR transillumination technique, together with traditional ultrasound imaging, to improve the accuracy of assessing the size and location of intraocular tumours.

Prospects of Temperature Management in Vitreoretinal Surgery.

Currently, there are no clear recommendations about the safety of certain temperature conditions for intraocular structures during vitreoretinal surgery; instructions on the safe rate of rewarming of the vitreous cavity; and the advisability of monitoring ocular temperature in the postoperative period. The purpose was to study the dynamics of epibulbar and intraocular temperature during vitreoretinal surgery. This study included 20 patients with rhegmatogenous retinal detachment (10 eyes) and retinal detachment associated with proliferative diabetic retinopathy (10 eyes). All patients underwent vitreoretinal surgery. In all cases, the ambient temperature, the patient's body temperature, the temperature of the irrigating solution, and temperature in the anterior, mid-, and posterior vitreous were recorded during surgery. Pre- and postoperative thermometry was also performed on the outer ocular surface. During vitreoretinal surgery with room temperature irrigation solution, a decrease in temperature (p < 0.001) versus the initial one was found in all segments of the vitreous cavity. In the absence of continuous irrigation, a rapid rewarming of the vitreous cavity was noted (an average of 0.18°C/min). Our study also demonstrated the presence of regional hyperthermia of the operated eye in a number of patients (25%) in the postoperative period. Current research shows that vitreoretinal surgery is performed under conditions of uncontrolled local ocular hypothermia and is characterized by a rapid uncontrolled rewarming of the vitreous cavity after cessation of cooling, and in the postoperative period local hyperthermia of the operated eye is observed in a number of patients.

Collagen-based scaffolds with infused anti-VEGF release system as potential cornea substitute for high-risk keratoplasty: A preliminary in vitro evaluation.

Currently the only widely accepted corneal blindness treatment is human donor cornea transplantation. However, increasing shortage of donor corneas as well as high risk of rejection in some corneal diseases remain two major problems, which limit the success of corneal transplantation. Corneal neovascularization is considered as one of the main risk factors of graft failure. Different cell-free biosynthetic scaffolds fabricated from collagens or collagen-like peptides are being tested as donor cornea substitutes (DCS). Here, we report for the first-time composite biosynthetic DCS with integrated sustained release system of anti-VEGF drug, bevacizumab and their preliminary in vitro validation. We have tethered gold nanoparticles with bevacizumab and integrated into a collagen-based cell-free hydrogel scaffold. Developed grafts preserved good optical properties and were confirmed not toxic to human corneal epithelial cells. Bevacizumab has been shown to constantly releasing from the DCS up to 3 weeks and preserved its anti-angiogenic properties. These results provide background for further use of infused composite biosynthetic DCS with integrated nanosystem of bevacizumab sustained release in corneal disease accompanied by neovascularisation where conventional corneal transplantation might fail.

[Imaging of Intraocular Foreign Bodies Located in the Projection of the Ciliary Body by Infrared Transillumination (Pilot Study)]. / Visualisierung von intraokularen Fremdkörpern im Ziliarkörperbereich mittels infraroter Transillumination (Pilotstudie).

BACKGROUND: Despite the improvement in diagnostic technologies, imaging of intraocular foreign bodies (IOFB) located in the projection of the ciliary body remains one of the current problems of ocular traumatology. PURPOSE: To study the possibilities of imaging intraocular foreign bodies in the projection of the ciliary body by infrared transpalpebral transillumination (IRTT). MATERIALS AND METHODS: 10 patients (10 eyes) with a penetrating eye wound and the presence of an IOFB were enrolled in the study. X-ray diagnostic testing, ultrasound examination of the eye and IRTT were performed in all patients. RESULTS: In all patients, the IRTT revealed the shadows of the Pars plana and Pars plicata of the ciliary body on the sclera as well as the shadow of an IOFB. CONCLUSION: The technique of IRTT in patients with penetrating eye injury allows non-invasive imaging of IOFB in the projection of the ciliary body and identification of their localisation.

Biomaterials-enabled cornea regeneration in patients at high risk for rejection of donor tissue transplantation.

The severe worldwide shortage of donor organs, and severe pathologies placing patients at high risk for rejecting conventional cornea transplantation, have left many corneal blind patients untreated. Following successful pre-clinical evaluation in mini-pigs, we tested a biomaterials-enabled pro-regeneration strategy to restore corneal integrity in an open-label observational study of six patients. Cell-free corneal implants comprising recombinant human collagen and phosphorylcholine were grafted by anterior lamellar keratoplasty into corneas of unilaterally blind patients diagnosed at high-risk for rejecting donor allografts. They were followed-up for a mean of 24 months. Patients with acute disease (ulceration) were relieved of pain and discomfort within 1-2 weeks post-operation. Patients with scarred or ulcerated corneas from severe infection showed better vision improvement, followed by corneas with burns. Corneas with immune or degenerative conditions transplanted for symptom relief only showed no vision improvement overall. However, grafting promoted nerve regeneration as observed by improved touch sensitivity to near normal levels in all patients tested, even for those with little/no sensitivity before treatment. Overall, three out of six patients showed significant vision improvement. Others were sufficiently stabilized to allow follow-on surgery to restore vision. Grafting outcomes in mini-pig corneas were superior to those in human subjects, emphasizing that animal models are only predictive for patients with non-severely pathological corneas; however, for establishing parameters such as stable corneal tissue and nerve regeneration, our pig model is satisfactory. While further testing is merited, we have nevertheless shown that cell-free implants are potentially safe, efficacious options for treating high-risk patients.

Intravitreal aflibercept for choroidal neovascularization associated with chorioretinitis: a pilot study.

PURPOSE: The purpose of this study was to evaluate the potential benefits of intravitreal aflibercept injections for the treatment of choroidal neovascularization (CNV) secondary to chorioretinitis. METHODS: In this uncontrolled, prospective cohort study, 15 eyes of 14 consecutive patients affected by CNV associated with ocular toxoplasmosis were treated with intravitreal aflibercept (2 mg) pro re nata and observed over a 12-month follow-up period. The primary outcome was the change in best-corrected visual acuity (BCVA) from baseline to month 12. Secondary outcomes included change in central retinal thickness (CRT) in the foveal area on optical coherence tomography (OCT) from baseline to month 12, the number of intravitreal aflibercept injections administered, and safety. RESULTS: Mean (standard deviation [SD]) BCVA improved significantly from 0.36 (0.23) at baseline to 0.64 (0.3) at month 12 (P=0.0002). Mean (SD) CRT on OCT showed a reduction from 317 (74) µm at baseline to 254 (43) µm (P=0.0002) at month 12. A mean (SD) of 1.7 (0.5) injections (range, 1-2 injections) were performed during the study period. No cases of endophthalmitis, uveitis, stroke, or retinal detachment were noted. No patient demonstrated an intraocular pressure >20 mmHg at any study visit. CONCLUSION: Intravitreal aflibercept showed a positive clinical effect and was well tolerated for the treatment of CNV associated with chorioretinitis. The results could be helpful for selecting a treatment for CNV secondary to chorioretinitis.

Intravitreal aflibercept for the treatment of choroidal neovascularization associated with pathologic myopia: a pilot study.

PURPOSE: To determine the efficacy of intravitreal aflibercept injections for the treatment of patients with choroidal neovascularization (CNV) associated with pathologic myopia. METHODS: In this uncontrolled, prospective cohort study, 31 eyes of 30 consecutive patients affected by CNV associated with pathologic myopia were treated with intravitreal aflibercept (2 mg) as needed following two initial monthly doses and observed over a 12-month follow-up period. The primary endpoint was change in best-corrected visual acuity (BCVA) at month 12, while central retinal thickness (CRT) on optical coherence tomography (OCT), neovascularization activity on fluorescein angiography, the number of aflibercept injections administered, and safety were examined as secondary endpoints. RESULTS: Patients received a mean of 2.6 intravitreal aflibercept injections over the 12-month study period. Compared with baseline, BCVA improved significantly at all time points (P<0.05). Mean (standard deviation [SD]) decimal BCVA was 0.2 (0.1) at baseline and 0.35 (0.16) at month 12. The greatest improvement in BCVA was seen within the first 2 months (P=0.01). Mean (SD) CRT on OCT decreased from 285 (62) µm at baseline to 227 (42) µm (P=0.01) at month 12. There was a continuous decrease in mean CRT on OCT over time. No cases of endophthalmitis, uveitis, stroke, or retinal detachment were noted. No patient demonstrated an intraocular pressure >20 mmHg during any study visit. CONCLUSION: The 12-month results of intravitreal aflibercept for myopic CNV using an as-needed regimen were positive, showing benefits in visual and anatomic outcomes and an acceptable tolerability profile.

Ciliary body imaging with transpalpebral near-infrared transillumination ­ a pilot study.

Background: Near-infrared light is known to pass through human tissues better than visible light. With invisible infrared light, the eye can be illuminated not only through the cornea or the sclera, but also through the eyelid, which can be beneficial in some cases. Purpose: To determine possible use of near-infrared radiation in visualizing ciliary body structures by transpalpebral transillumination. Material and methods: The study cohort included 15 people (30 eyes) with no visible lesions of the anterior segment of the eye; 20 patients (20 eyes) with absolute glaucoma before the laser transscleral cyclodestruction; and 15 patients (15 eyes) with intra­ocular tumours of the ciliary body. In all cases, a color photo of the anterior eye segment, infrared transillumination and ultrasound scan were performed. Results: In healthy individuals and in patients with absolute glaucoma prior to laser cyclodestruction, a ciliary body and its structures were imaged. In patients with intraocular tumours, near-infrared transillumination made it possible to visualize the tumour and to estimate its localization relative to the ciliary body structures. Conclusion: Transpalpebral near-infrared transillumination accurately estimates the projection of ciliary body structures to the sclera. Near-infrared transillumination can be used for ciliary body visualisation in patients with absolute glaucoma prior to laser cyclodestruction. Near-infrared transillumination helps visualize intraocular tumours and determine their projection to the sclera, which can be used for diagnostic purposes and during destruction of the tumour.

Bioengineered Corneas Grafted as Alternatives to Human Donor Corneas in Three High-Risk Patients.

Corneas with severe pathologies have a high risk of rejection when conventionally grafted with human donor tissues. In this early observational study, we grafted bioengineered corneal implants made from recombinant human collagen and synthetic phosphorylcholine polymer into three patients for whom donor cornea transplantation carried a high risk of transplant failure. These patients suffered from corneal ulcers and recurrent erosions preoperatively. The implants provided relief from pain and discomfort, restored corneal integrity by promoting endogenous regeneration of corneal tissues, and improved vision in two of three patients. Such implants could in the future be alternatives to donor corneas for high-risk patients, and therefore, merits further testing in a clinical trial.

Intravitreal ranibizumab for the treatment of choroidal neovascularizations associated with pathologic myopia: a prospective study.

PURPOSE: It was the aim of this study to determine the efficacy of intravitreal ranibizumab as treatment of choroidal neovascularizations associated with pathologic myopia. MATERIALS AND METHODS: In an uncontrolled, prospective time series cohort study, 65 eyes of 64 consecutive patients with choroidal neovascularization associated with pathologic myopia were treated with intravitreal ranibizumab and observed over 12 months. The change in best-corrected visual acuity (BCVA) at 6 and 12 months served as primary end point. Safety, central retinal thickness, neovascularization activity on fluorescein angiography and the number of ranibizumab injections were secondary end points. RESULTS: BCVA improved significantly throughout the follow-up (p = 0.001). The mean BCVA was 0.2 at baseline (SD 0.13) and 0.4 at 12 months (SD 0.21). Improvement was strongest within the first 3 months (p = 0.0001). The mean central retinal thickness showed a reduction from 313 µm (SD 82) to 243.5 µm (SD 31; p = 0.0001). CONCLUSION: Intravitreal ranibizumab offers a safe and effective treatment for choroidal neovascularizations in pathologic myopia.

Collagen-based bioengineered substitutes of donor corneal allograft implantation: assessment and hypotheses.

To fabricate donor corneal substitutes based on carbodiimide cross-linked porcine collagen, to study their in vitro and in vivo properties, and to elaborate new implantation techniques for the donor corneal collagen-based substitutes, this study had been performed. Bioengineered substitutes of corneal stroma (BSCS) were fabricated by cross-linking porcine type I collagen with 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide and N-hydroxysuccinimide, as previously described. Their refractive indices were measured using an Abbe refractometer. The mechanical properties were evaluated by their ability to tolerate interrupted stitches placed during deep lamellar keratoplasty performed on isolated rabbit eyes. BSCS were then implanted into one cornea of 8 rabbits and were followed-up for 12 months. Our BSCS had refractive indices of 1.24-1.3 (human cornea 1.37-1.38), and tolerated the placement of 12 interrupted stitches well. A new technique, the BSCS "stitchless" implantation, was developed. When implanted into rabbit corneas, BSCS remained stably integrated and clear during the 12 month follow-up. Non-intensive opacities within corneal layers (grade 1.5 on a scale of 0 to 4) were observed in 2/8 eyes during the 1st postoperative week, and in one eye the opacity resolved. In the 2nd eye a fine opacity (grade 1) remained. Light microscopy confirmed the integrity of the implants and the absence of inflammation in corneal stroma. The current data suggest that the BSCS fabricated in the Ukraine by cross-linking collagen is a good alternative to human donor corneas if medical grade porcine collagen is used. In addition, the new "stitchless" technique of BSCS implantation may decrease corneal substitute damage and accelerate its epithelialisation.

Serous pigment epithelium detachment associated with age-related macular degeneration: a possible treatment approach.

To evaluate the effects of intravitreal triamcinolone acetonide (TA) as a monotherapy of serous Pigment Epithelial Detachment (PED) associated with AMD (Age-Related Macular Degeneration), this study has been performed. Seventeen patients (19 eyes) with serous PED associated with AMD were observed. All patients received 0.1ml (4mg) of intravitreal TA. The mean follow-up period was 18 months. Re-attachment of serous PED was observed in 37% of cases to the end of follow-up. In other cases, the height and length of serous PED significantly decreased. Visual acuity remained stable in all cases. No evidence of RPE tear or CNV development were noted. Before TA administration, intraocular pressure (IOP) was 20.18 ± 2.58 mmHg however, after intravitreal TA, IOP increased gradually and reached its maximum of all period of observation (23.25±1.85mmHg) six months after injection (P=0.031). In 7 (37%) of the cases, progression to cataract was observed after treatment. After surgery, the visual acuity in all cases increased by 0.2 to 0.5. As a conclusion, intravitreal TA decreases of both the height and length of serous PED associated with AMD after 18 months follow-up in most cases. The presented data provides support for the hypothesis regarding the possibility of monotherapy of serous PED with intravitreal TA.

In vitro photodynamic properties of methylene blue in a combination with laser illumination at 630 nm concerning Candida albicans.

The study had to define influence of combined applications of laser radiation and methylene blue (MB) on pathogenic culture of Candida albicans in vitro. The experimental study was done at standard techniques of method of cultivations in a broth. The laser irradiation of cultures was done at once after addition of MB in concentration 0.05%, 0.1% and 0.2%. During studying action of MB in dark, influence of MB to the growth of test-shtam without laser radiation, were prepared fluid Gissa's broth with glucose without Andrede's indicator. Activation of MB was done by laser with wave length 630 nm during 3 or 5 min. All experiments were passed in 4 parallels and 3 repeats. Maximal suppression of growth of microorganisms was noted in group with using 0.1% MB with laser radiation 3 minutes without centrifugation after 24 hours. Maximal suppression of growth was noted in group after centrifugation with 0.05% MB with exposure of laser 3 min. after 48 hours. Sensitivity of pathogenic culture of Candida albicans to application of B and laser raises accordingly to increase of concentration of MB.

Digital imaging of the fundus with long-wave illumination.

PURPOSE: To increase the quality, diagnostic value and use of non-invasive fundus examination with transscleral or transpalpebral long-wave (red and near infrared) illumination. MATERIAL AND METHODS: For fundus visualization we used red light diode sources at 660 nm and near infrared light diode sources at 810, 940 nm. Light radiation from diode sources penetrates into the globe through eyelid skin and sclera. Fundus examination was performed without dye injection and local anesthesia. The technique was called "long-wave fundusgraphy" (LFG). RESULTS: Comparing with fluorescein angiography additional topographical information was received concerning CNV associated with hemorrhage or subretinal fluid, which masked the true borders of the neovascular component. If CNV is completely invisible under a layer of blood or pigment, on fluorescein angiography only a hypofluorescent area is registered. In such cases fluorescein angiography is insufficient for correct diagnosis. Examination of such patients with 940 nm excluded maximum masking property of blood or pigment deposits and permitted visualization of CNV. CONCLUSIONS: Non-invasive, consecutive long-wave imaging may be useful for CNV detecting and may obtain additional information about fundus structures in patients with dye intolerance, retinal hyperpigmentation, haemorrhage or fluid masking subretinal structures, miosis or in the presence of opaque media.