[Safety assessment of using collamer phakic implants in the correction of refractive errors].

BACKGROUND: An increasing number of patients with refractive visual impairments, in whom the correction using spectacles or contact lenses does not meet expectations, consider the possibility of undergoing refractive surgery. Phakic implants are an alternative for patients who are not eligible for laser correction. OBJECTIVES: The aim of the study is to assess the safety of using collamer phakic implants in the correction of vision defects during the annual follow-up. MATERIAL AND METHODS: The study included 24 eyes in 12 patients who were implanted with Visian ICL phakic posterior chamber lenses in order to correct myopia. The examinations carried out before the surgery were as follows: objective refractometry, the assessment of distant visual acuity with the best correction, intraocular pressure measurement, evaluation of the endothelium, corneal topography, and depth of the anterior chamber measurement. The final examinations included visual acuity, refraction, intraocular pressure, implant placement, endothelial microscopy, and funduscopic examination. RESULTS: Mean objective refraction was: sphere -7.77 ±3.55 diopters and cylinder 1.18 ±0.87 diopters. Spectacle correction produced the mean visual acuity of 0.91 ±0.20 (Snellen). During the period of 1-year follow-up, the mean spherical power was 0.475 ±0.39 diopters, cylinder 0.46 ±0.27 diopters and the visual acuity after the procedure 1.05 ±0.22 (Snellen). The results of the 12-month evaluation showed a statistically significant greater improvement in patients using phakic implants compared to those subjected to spectacle correction (p < 0.05). The preand post-operative evaluation demonstrated no significant differences in endothelial cell density (p < 0.05). No complications were reported both during the surgery and the entire follow-up period. CONCLUSIONS: The results of the safety assessment of using properly implanted ICL phakic lenses show good tolerance of collomer implants in the posterior chamber. They do not have a negative effect on the structures located in the anterior segment of the eye, including the corneal endothelium and the lens.

Horizontal and anterior chamber diameter for phakic intraocular lens sizing.

CLINICAL RELEVANCE: Proper selection of phakic intraocular lens diameter is necessary to avoid complications related with excessive vaulting after its implantation. BACKGROUND: Horizontal corneal diameter, measured as white-to-white distance, is one of the parameters used for phakic intraocular lens diameter calculation. Agreement was assessed between three parameters: white-to-white distance obtained with swept source optical coherence tomography, and white-to-white distance obtained with Scheimpflug camera and angle-to-angle parameter obtained with anterior segment optical coherence tomography. METHODS: This study included 55 eyes of 43 patients. The white-to-white distance was measured with two biometry techniques: swept source optical coherence tomography and Scheimpflug camera. The angle-to-angle was measured with anterior segment optical coherence tomography. Analysis of agreement was performed by the Bland-Altman method. For every patient, simulation of Visian Implantable Collamer Lens (ICL) sizing was performed using the Online Calculation and Ordering System with different white-to-white distance or angle-to-angle. RESULTS: Statistically significant differences were found between swept source optical coherence tomography biometer and anterior segment optical coherence tomography (p = 0.001) and between swept source optical coherence tomography and Scheimpflug camera (p < 0.001). However, there was a good correlation between swept source optical coherence tomography and Scheimpflug camera (intraclass correlation co-efficient = 0.623), with a shift toward higher white-to-white distance values on swept source optical coherence tomography. A relatively high correlation intraclass correlation co-efficient (0.772) and lack of statistically significant differences (p = 0.068) between anterior segment optical coherence tomography and Scheimpflug camera results were observed. Simulation of phakic intraocular lens sizing showed that swept source optical coherence tomography white-to-white distance should not be used interchangeably with Scheimpflug camera white-to-white distance or angle-to-angle. CONCLUSION: White-to-white distance measured with swept source optical coherence tomography was significantly different from values obtained with other methods. Angle-to-angle may support ICL sizing, helping in verification of white-to-white distance values obtained with other devices.

Application of a Partial Least Squares Regression Algorithm for Posterior Chamber Phakic Intraocular Lens Sizing and Postoperative Vault Prediction.

PURPOSE: To develop and validate a new algorithm for predicting the postoperative vault of the myopic EVO Visian Implantable Collamer Lens (ICL) V4c (STAAR Surgical AG). METHODS: This study included 81 eyes of 43 patients who had undergone ICL implantation. Preoperative data obtained by swept-source optical coherence tomography, Scheimpflug camera, and anterior segment optical coherence tomography were applied to develop a new partial least squares (PLS) regression algorithm. ICL sizing was performed using the standard white-to-white method with the online calculation and ordering system. The postoperative vault was assessed based on anterior segment optical coherence tomography. The PLS approach was applied to create the calibration model for predicting the postoperative vault. The new PLS model was cross-validated using the leave-one-out method and compared to a recently published linear regression model. Agreement between the actual and predicted vault values for the two methods was assessed by the Bland-Altman method. RESULTS: There was a statistically significant correlation (P < .001, r = 0.73) between the postoperative vault values and those predicted by the PLS algorithm. Validation of the PLS model yielded lower mean differences and limits of agreement (0 and 410 µm, respectively) than the linear regression method (400 and 750 µm, respectively). CONCLUSIONS: The PLS algorithm increases the precision of ICL vault prediction. However, it shows a tendency to overestimate small vault values and underestimate high vaults. [J Refract Surg. 2020;36(9):606-612.].

[Surgical treatment of giant retinal tear]. / Leczenie chirurgiczne otworów olbrzymich siatkówki.

PURPOSE: The purpose of the study was to evaluate anatomical and functional results of pars plana vitrectomy in giant retinal tears. MATERIALS AND METHODS: Ten eyes with giant retinal tears underwent pars plana vitrectomy. The time of observation after surgical intervention was 3 months to 2.5 years. RESULTS: Retinal reattachment was obtained in 9 eyes (90%). In one eye, despite second vitrectomy, there was no positive effect due to massive vitreo-retinal proliferation. CONCLUSIONS: Surgical treatment of giant retinal tear yields good anatomical and functional results. Rarely massive vitreo-retinal proliferation may cause the redetachment. Perfluorodecalin used during surgery facilitates unfolding and flattening of the retina.

[Treatment of subretinal macular hemorrhages with intravitreous injections of tissue plasminogen activator and SF6 gas]. / Leczenie krwotoków podsiatkówkowych w plamce doszklistkowym podawaniem tkankowego aktywatora plazminogenu oraz gazu SF6.

PURPOSE: Of our retrospective study was the estimation of the efficacy of recombinant tissue plasminogen activator (tPA) and intravitreal injections of SF6 gas in cases of subretinal macular haemorrhages. MATERIAL AND METHODS: In 20 patients aged 23-83 years, the subretinal macular haemorrhages were diagnosed, due to senile macular degeneration (9), hypertension (3), myopic retinochoroidal degeneration (3), other retinal heredodegeneration (2), retinal macroaneurysm (2) and trauma (1). We injected the solution of recombinant tissue plasminogen activator--Actilise (Boehringer Ingelheim) into vitreous cavity of these eyes. After lowering IOP, the intravitreous injections of 0.5 ccm SF6 gas were done, and following 24 hours down head positioning were carried out. RESULTS: The initial visual acuity before treatment was: HM or CF, from less then 1 meter in most of our cases (12 patients). The after treatment visual acuity ranged CF from 2 meters to 0.7. The early treatment conditioned better acuity. Even in cases of delayed treatment, the diminishing of central visual scotoma could be awaited. CONCLUSIONS: The new method of treatment in cases with subretinal macular haemorrhages despite of its symptomatic characters seems to be helpful in restoring the central vision in some cases.