Preventing condensation of objective lens in noncontact wide-angle viewing systems during vitrectomy
| Autor: | Soonil Kwon, In Won Park, Jung Pil Lee, Ho Ra, Jinsoo Kim |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
genetic structures
medicine.medical_treatment vitrectomy Vitrectomy engineering.material 01 natural sciences 010104 statistics & probability 03 medical and health sciences 0302 clinical medicine lcsh:Ophthalmology Coating Clinical Research warm saline Cornea medicine wide-angle viewing systems Corneal surface 0101 mathematics Saline business.industry Condensation condensation Ophthalmology medicine.anatomical_structure lcsh:RE1-994 Lens (anatomy) 030221 ophthalmology & optometry engineering business Biomedical engineering |
| Zdroj: | International Journal of Ophthalmology, Vol 11, Iss 11, Pp 1809-1813 (2018) |
| ISSN: | 2227-4898 2222-3959 |
| DOI: | 10.18240/ijo.2018.11.12 |
| Popis: | Aim To assess the optimal conditions for preventing condensation of objective lens during vitrectomy with noncontact wide-angle viewing systems (WAVSs). Methods We explored the effectiveness of the coating with ophthalmic viscoelastic device (OVDs) on the corneal surface and the soaking the objective lens in warm-saline for preventing condensation of objective lens. First, to find the optimal soaking time to keep the objective lens warm, we measured the temperature of objective lens every minute after soaking in warm saline. Second, to find optimal distance between cornea and objective lens, which provide as wide a view as possible and less condensation at the same time, we measured the condensation time with different distances. With the obtained optimal soaking time and distance, we explored the effect of coating cornea with OVDs and soaking objective lens in warm saline on condensation time. Results One and 5min of soaking in warm saline was most effective for keeping the lens warm enough (45.1°C±2.1°C for 1min and 46.4°C ±1.0°C for 5min, P=0.109). The mean condensation times for the control group at 1, 3, and 5 mm from corneal surface to objective lens were 1±0.4, 4±1.4, 190±26.1s, respectively, thus 5 mm was most optimal distance for vitrectomy with WAVSs. For the OVD coating group, the mean condensation times were 1.5±0.3, 13±1.4, and 200±23.9s at 1, 3, and 5 mm distance and borderline significant compared with control group (P=0.068, 0.051, and 0.063, respectively). With the 1-minute warm saline soaking group, the mean condensation time were extended to 188±34.4, 416±65.7, and 600±121.3s at 1, 3, and 5 mm distance and statistically significant compared with control (P=0.043, 0.041 and 0.043, respectively). Conclusion OVD coating on corneal surface shows no difference on condensation time with control group. However, soaking the objective lens in warm saline revealed statistically significant extension of condensation time compared to control group. Therefore, keeping the objective lens warm with soaking in warm saline is a simple but effective to prevent condensation of objective lens during vitrectomy. The thermodynamics between objective lens and cornea during vitrectomy warrants further investigation. |
| Databáze: | OpenAIRE |
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