Level of agreement of intraocular lens power measurements between an image-guided system and partial coherence interferometry.

PURPOSE: To evaluate the level of agreement of partial coherence interferometry (IOLMaster) and an image-guided system (Verion) in terms of keratometric values and intraocular lens (IOL) power calculation. SETTING: Department of Ophthalmology, University Hospital of Alexandroupolis, Greece. DESIGN: Prospective comparative study. METHODS: Keratometric (K) values and IOL power calculations were compared for 3 toric IOL models (SN6ATx, TFNTx0, and SV25Tx) using 4 formulas (SRK/T, Holladay 1, Hoffer Q, and Haigis) in patients who had cataract surgery in a consecutive-if-eligible way. RESULTS: Ninety-eight eyes from 54 patients were included in the study (mean age: 60.2 ± 9.2 years). Compared with the IOLMaster, the Verion measured significantly steeper K1, K2, and Km values (P < .05), but no significant difference was observed in astigmatism power and vectors J0 and J45 (P > .05). With the SRK/T formula, the SN6ATx IOL showed significant difference in the mean IOL power calculated by the 2 devices, whereas no significant difference was observed in the TFNTx0 IOL and the SV25Tx IOL. However, with the Holladay 1, Hoffer Q, and Haigis formulas, a significant difference was found in the mean IOL power of all 3 toric IOL models. Generally, the Verion calculated a significantly lower mean IOL power for almost all formulas and IOL models. For 35 toric implantations, the mean residual astigmatism power, 6 months postoperatively, was 0.29 ± 0.24 diopter. CONCLUSIONS: The IOLMaster and the Verion seemed to present differences in IOL calculation and surgical planning that could lead to unexpected residual refractive error. When discrepancy is detected in IOL calculation, using the IOLMaster as the primary biometry and the Verion as a digital marker alone could provide excellent outcomes in terms of astigmatism correction.

Image-guided lens extraction surgery: a systematic review.

A systematic review of the recent literature regarding the current image-guided systems used for cataract surgery or refractive lens exchange was performed based on the PubMed and Google Scholar databases in March 2018. Literature review returned 21 eligible studies. These studies compared image-guided systems with other keratometric devices regarding their accuracy, repeatability and reproducibility in measurement of keratometric values, astigmatism magnitude and axis, as well as in IOL power calculation. Additionally, the image-guided systems were compared with conventional manual ink-marking techniques for the alignment of toric IOLs. In conclusion, image-guided systems seem to be an accurate and reliable technology with measurements of high repeatability and reproducibility regarding the keratometry and IOL power calculation, but not yet interchangeable with the current established and validated keratometric devices. However, they are superior over the conventional manual ink-marking techniques for toric IOL alignment.

Lacrimal outflow mechanisms and the role of scintigraphy: current trends.

Lacrimal outflow can be compromised by anatomical obstructions or stenoses (nonfunctional epiphora) or by defective lacrimal "pump" function (functional epiphora). Although classic imaging modalities, such as X-ray dacryocystography, computed tomography, or magnetic resonance imaging can effectively evaluate the former, their success is much less in the evaluation of the latter. This is largely due to the fact that forced diagnostic injection of fluid into the canalicular system can overcome partial obstruction sites. On the other hand, lacrimal scintigraphy mimicks "physiological" lacrimal outflow, being performed under pressure gradients present in everyday life. This is why it is considered more suitable for the study of functional epiphora. Furthermore, quantitative lacrimal scintigraphy (with time-activity curves) enables the accurate measurement of lacrimal clearance from the conjunctival fornices and may be used to study the physiology of the lacrimal "pump." Data obtained from the scintigraphic study of lacrimal outflow may be used to design more effective procedures in the management of functional and nonfunctional epiphora. This is a review article, based on a literature search with emphasis on recent publications and on those supporting interdisciplinary cooperation between ophthalmology and nuclear medicine.

Ranibizumab for the treatment of degenerative ocular conditions.

Degenerative ocular conditions, such as age-related macular degeneration, diabetic retinopathy, retinal vein occlusions, and myopic degeneration, have become a major public health problem and a leading cause of blindness in developed countries. Anti-vascular endothelial growth factor (VEGF) drugs seem to be an effective and safe treatment for these conditions. Ranibizumab, a humanized monoclonal antibody antigen-binding fragment, which inhibits all biologically active isoforms of VEGF-A, is still the gold standard treatment for the majority of these pathological entities. In this review, we present the results of the most important clinical trials concerning the efficacy and safety of ranibizumab for the treatment of degenerative ocular conditions.

Monocanalicular intubation in external dacryocystorhinostomy.

PURPOSE: To examine the feasibility of monocanalicular intubation in external dacryocystorhinostomy (EX-DCR). METHODS: Monocanalicular intubation using the mini-Monoka tube (S1-1500u, FCI Ophthalmics, Marshfield Hills, MA, U.S.A.) was performed in 18 patients undergoing EX-DCR. The tube was placed at the superior canaliculus in 16 cases and at the inferior canaliculus in 2 cases and was removed 3 months postoperatively. All cases were followed for at least 6 months postoperatively. RESULTS: The mini-Monoka was well tolerated in all patients. One case of spontaneous tube dislocation and 2 cases of presumed tube migration were recorded on the 15-day interval. Success rates on the 6-month interval were 88.88% (16/18), 94.44% (17/18), and 66.66% (12/18), concerning patency upon irrigation, resolution of mucopurulent epiphora, and resolution of watery epiphora, respectively. CONCLUSIONS: Monocanalicular intubation using mini-Monoka in EX-DCR is safe and effective. The technique may have advantages over bicanalicular intubation, such as easier insertion and removal, easier probing and irrigation though the unintubated canaliculus and, more importantly, less risk of punctal or corneal damage.

Prolonged exposure of intraocular lens implant with preservation of globe integrity and visual function.

A 70-year-old woman had corneal ulcer and melting after complicated cataract surgery with polymethylmethacrylate lens implant insertion. A conjunctival flap was initially used to cover the defect with a plan to perform keratoplasty later. Fifteen months postoperatively, she presented with total absence of central corneal tissue and iris and exposure of the implant. The eye was not inflamed, painful, or hard on palpation and visual acuity was counting fingers at 3 m. The preservation of globe integrity despite exposure of the polymethylmethacrylate implant implies a stable adhesion between polymethylmethacrylate and residual corneal tissue and may prove useful in keratoprosthesis design.

Selective removal of sebaceous gland carcinoma of the lower eyelid with orbital infiltration.

A 74-year-old woman presented with a nodule on the right lower eyelid. An incisional biopsy was significant for sebaceous gland carcinoma, whereas magnetic resonance imaging revealed infiltration of the ipsilateral orbit, including the medial and lower rectus muscles. The lesion was selectively excised, including the infiltrated part of the lower lid and the intraorbital part of the tumor. Two years postoperatively, no recurrence or metastasis have been noted. Preoperative orbital imaging is mandatory in cases of sebaceous gland carcinoma because it can reveal clinically silent orbital invasion. In such cases, selective surgical excision may be used, avoiding orbital exenteration.

Late onset of acute angle-closure glaucoma following neodymium:YAG laser posterior capsulotomy.

Acute angle-closure glaucoma due to vitreous prolapse immediately following neodymium:YAG (Nd:YAG) laser posterior capsulotomy in eyes with posterior chamber intraocular lens implants is rare. Previously described cases were associated with advanced age, excessive amounts of laser energy, and a large-diameter capsular opening. The authors describe a case of acute angle-closure glaucoma occurring 21 days after Nd:YAG laser posterior capsulotomy in a young patient with a small-diameter capsule opening and a small amount of laser energy to stress the importance of close extended follow-up even in eyes with a theoretical low risk for this complication

Corneal topography in involutional ectropion of the lower eyelid: preoperative and postoperative evaluation.

PURPOSE: The shape and position of the eyelids affect corneal topography. This study evaluated preoperative and postoperative corneal topography in involutional ectropion of the lower eyelid. METHODS: Eighteen patients with unilateral involutional lower eyelid ectropion underwent ophthalmic examinations and corneal topography before surgical correction and at the 6-month postoperative interval. Corneal topographies were evaluated with the Holladay Diagnostic Summary package. The fellow eyes served as controls. Parameters evaluated included the regularity of astigmatism (RA), steep refractive power (SRP), flat refractive power (FRP), and total astigmatism (TA). RESULTS: Preoperatively, RA was found significantly decreased in the eyes with ectropion compared with the fellow eyes, whereas differences in other parameters were statistically nonsignificant. Postoperatively, RA was significantly increased, whereas SRP was significantly reduced. The percentage of eyes with with-the-rule astigmatism (WTRA) was increased postoperatively, although astigmatic axis changes were not systematic. CONCLUSIONS: Postoperative topographic changes may be related to either restoration of symmetry in the upper and lower lid apposition on the cornea or to rearrangement of the tear film. Further research will be required to assess whether corneal topographic findings could be used as an index of the severity of eyelid laxity and to evaluate the effects of topographic changes on corneal and total optical aberrations.

Processed fascia lata as an alternative implant material in evisceration.

PURPOSE: To examine the use of processed fascia lata strips as an implant material in evisceration. METHODS: This is a prospective, interventional, noncomparative case series. Eight patients underwent standard evisceration of an eye with subsequent primary insertion of processed fascia lata strips in the scleral shell. They were clinically examined at regular postoperative intervals (up to 20 months) and had computed tomography and magnetic resonance imaging scans of the orbits at the 12-month interval. The development of vascularity of the scleral shell contents was assessed with the intravenous administration of a contrast-enhancing agent. RESULTS: The fascia lata strips were incorporated without significant complications in all cases. The maintenance of adequate volume and position of the eviscerated globe was confirmed by both computed tomography and magnetic resonance imaging scans. T1-weighted magnetic resonance imaging studies with intravenous administration of contrast-enhancing agent and fat-saturation sequences revealed the development of vascularity of the scleral shell contents. CONCLUSIONS: Processed fascia lata may be a useful alternative implant material in evisceration. Possible advantages of its use may include protection against extrusion, custom volume selection and easy intraoperative manipulation.