Prospects of using the TVGD-02 tonometer for assisted monitoring of intraocular pressure at home

Purpose: to evaluate the safety and convenience of self-using the intraocular pressure tonometer TVGD-02 at home with no participation of medical professionals. Material and methods. 42 people formed 30 pairs: a patient and an assistant. In 9 pairs, each person played both roles. The participants practiced the technique of transpalpebral measurement of intraocular pressure (IOP) at home, and, as assistants, measured IOP of their partner patients. All subjects were asked to fill in a questionnaire to evaluate the convenience and safety of the tonometer use by a 5-point system. Results. The assistant users, aged 22 to 83 (ave. 59.68 ± 17.20 years) had diverse educational levels. Of the patient users, aged 22 to 82 (ave. 60.64 ± 17.10 years), 82.14 % had ocular pathology, while 35.7 % had glaucoma with concomitant pathology. In 100 % of cases, the participants required no professional assistance to properly prepare the tonometer for operation and perform IOP measurement. The accuracy and reproducibility of measurement results significantly increased with the assistants’ gaining skills of operating the tonometer. On the 1st day, the data obtained in a series of measurements scattered for the control block within 2.07 ± 1.70 [7; 0] mm Hg, while the measured IOP of the patient scattered within 2.89 ± 19.10 [8; 0]. In contrast, on the 5th day, measurement accuracy increased significantly and the scatter dropped to 1.21 ± 0.72 [2; 0] and 0.85 ± 0.69 [2; 0] mm Hg, respectively. The users rated the ease of using the device at different staged from 4.21 ± 0.67 to 5.0 ± 0.0 points. Conclusion. Assisted transpalpebral tonometry with the TVGD-02 tonometer ensures an adequate assessment of IOP in patients at home. The principles of device operation and the technique can be learned and skills can be gained without the participation of medical personnel.

Transpalpebral tonometry after penetrating keratoplasty

Aim: to assess the efficacy and safety of EASYTON transpalpebral intraocular pressure (IOP) tonometer in the early postoperative period after penetrating keratoplasty (PK).Patients and Methods: 43 patients after unilateral PK were enrolled. IOP measurements with palpation and EASYTON transpalpebral IOP tonometer in the operated eye were performed daily for 7 days. In addition, IOP measurements with palpation, EASYTON, and the Goldmann applanation tonometer (GAT) in the fellow (non-operated) eye were performed.Results: Bland-Altman plots demonstrated a rather high degree of the similarity of IOP measurements with palpation, GAT, and EASYTON in the non-operated eyes. Therefore, IOP measurement by palpation is a rather informative technique and can be used to compare the accuracy of EASYTON in the operated eyes of the same patients. During the second step, a high degree of the similarity of IOP measurements with palpation and EASYTON was demonstrated in the operated eyes after PK. Mean IOP spread (as demonstrated by three consecutive IOP measurements with EASYTON) was 1.32 mm Hg thus showing a high degree of repeatability. The lack of the negative effects of IOP measurements with EASYTON supports its safety.Conclusion: EASYTON transpalpebral IOP tonometer prevents the subjectivity of IOP measurements after PK and makes tonometry available to the general public. The lack of the contact with the cornea, a rather high accuracy, a high repeatability, and the lack of negative effects allow for using this device after PK.Keywords: transpalpebral IOP tonometer, intraocular pressure, penetrating keratoplasty, instrumental tonometry, EASYTON, non-contact tonometry.For citation: Karlova E.V., Zolotarev A.V., Milyudin E.S., Pershakova A.E. Transpalpebral tonometry after penetrating keratoplasty. Russian Journal of Clinical Ophthalmology. 2020;20(4):175–179. DOI: 10.32364/2311-7729-2020-20-4-175-179.

Comparison of Intraocular Pressure before and after Laser In Situ Keratomileusis Refractive Surgery Measured with Perkins Tonometry, Noncontact Tonometry, and Transpalpebral Tonometry

Purpose. To compare the intraocular pressure (IOP) before and after Laser In Situ Keratomileusis (LASIK), measured by Diaton, Perkins, and noncontact air pulse tonometers.Methods. Fifty-seven patients with a mean age of 34.88 were scheduled for myopia LASIK treatment. Spherical equivalent refraction (SER), corneal curvature (K), and central corneal thickness (CCT) and superior corneal thickness (SCT) were obtained before and after LASIK surgery. IOP values before and after surgery were measured using Diaton, Perkins, and noncontact air pulse tonometers.Results. The IOP values before and after LASIK surgery using Perkins tonometer and air tonometers were statistically significant (p<0.05). However, no significant differences were found (p>0.05) for IOP values measured with Diaton tonometer. CCT decreases significantly after surgery (p<0.05) but no statistical differences were found in SCT (p=0.08). Correlations between pre- and postsurgery were found for all tonometers used, withp=0.001andr=0.434for the air pulse tonometer,p=0.008andr=0.355for Perkins, andp<0.001andr=0.637for Diaton.Conclusion. Transpalpebral tonometry may be useful for measuring postsurgery IOP after myopic LASIK ablation because this technique is not influenced by the treatment.