Update on contraindications in laser corneal refractive surgery.

More than 25 years of experience with refractive surgery techniques (since the FDA [Food and Drug Administration] of the United States approved the use of the excimer laser in the remodeling of the cornea in 1995), added to the technological advances in ophthalmology (femtosecond laser, topography-guided ablation, anterior segment imaging systems) and increased understanding of refractive errors, higher order aberrations, and corneal biomechanics make corneal laser refractive surgery a safe method and effective for the correction of these defects. However, to date, there are still certain circumstances that represent a contraindication for its application, in addition to others that could be associated with complications, and that must be carefully analyzed. This review analyzes the current contraindications for laser corneal refractive surgery listed in the Preferred Practice Protocols (PPPs) of the American Academy of Ophthalmology and the Spanish Ophthalmology Society. These protocols are based on the best scientific evidence currently available and allow clear recommendations to be drawn, improving the safety profile of these techniques. Contraindications can be differentiated into relative or absolute; among the latter are: age less than 18 years, the absence of refractive stability and the existence of certain ocular pathologies (including certain corneal dystrophies, keratoconus, poorly controlled dry eye) or systemic pathologies (active autoimmune processes or poorly controlled diabetes mellitus). Other circumstances such as the use of certain drugs (amiodarone, isotretinoin), extreme values of mean central keratometry and pachymetry, history of previous uveitis or glaucoma, pregnancy and lactation, are considered relative contraindications according to the PPPs. However, there are studies that demonstrate the safety of refractive surgery in some of these cases.

Laser in situ keratomileusis and surface ablation in pregnancy.

PURPOSE: Although corneal refractive surgery is contraindicated during pregnancy, some patients are unaware that they are pregnant when they undergo surgery. Our objectives were to determine the functional outcomes of corneal refractive surgery during pregnancy and to compare the results with those of nonpregnant women. METHODS: We performed a multicenter, retrospective, interventional case series review of patients who were pregnant and who underwent laser in situ keratomileusis (LASIK) or surface ablation (photorefractive keratectomy, PRK) from September 11, 2002 to December 12, 2020 (group 1, n=82 eyes). Patients were included consecutively. Findings were compared with those of nonpregnant women (group 2, n=164 eyes). Functional (visual and refractive) outcomes are described. Follow-up was at least 550 days (control group, median [IQR], 990 days [715-1496]; study group, 895 days [709-1310]). The setting was Clínica Baviera, Spain, (AIER Eye Hospital Group). RESULTS: A statistically significant difference was found between the groups in terms of efficacy index (EI). No complications of pregnancy or labor were reported. Similarly, a search of medical records revealed no adverse effects in the infants. CONCLUSIONS: To the best of our knowledge, this is the first case series on pregnancy and refractive surgery. We do not recommend performing LASIK or surface ablation on pregnant women. Our objective in the present study was to present relevant scientific data obtained from women who underwent refractive surgery while unaware that they were pregnant.

Lens-based surgical correction of presbyopia. Where are we in 2020? / Corrección de la presbicia tras cirugía cristaliniana. ¿Dónde nos encontramos en 2020?

INTRODUCTION: Presbyopia is the progressive and irreversible loss of accommodation due to aging. It is one of the main causes of loss of quality of life in people from 45 years of age, due to the, often novel, dependence on spectacles. The eagerness to correct it by ophthalmologists impulsed by the desire of millions of people who suffer from it, has become one of the main drivers for the development of intraocular lens (IOL) technology over the last twenty years. MATERIAL AND METHODS: This review briefly presents the different alternatives that have allowed us to improve the crystalline lens surgical approach of presbyopia; from monofocal lenses and monovision technique, accommodative, refractive, and diffractive multifocal lenses, and finally the most recent extended depth of focus/field lenses known as EDOFs. RESULTS: Each IOL has its advantages, limitations and disadvantages. Furthermore, there is no single lens that suits the needs of all patients. CONCLUSIONS: It is necessary to know the variety of lenses available, and to have an in-depth understanding of their optical properties, as well as the impact that these will have later on their clinical performance and on the visual quality of the patients. This should help us to select the best alternative for each of them.

Visual outcomes, spectacle independence and satisfaction after diffractive trifocal intraocular lens implantation. / Resultados visuales, independencia de gafas e insatisfacción tras implante de una lente intraocular difractiva trifocal.

PURPOSE: To investigate visual outcomes, spectacle independence, and patient satisfaction after trifocal intraocular lens implantation. METHODS: A retrospective study conducted on 5,186 patients who underwent phacoemulsification and were implanted with a diffractive trifocal intraocular lens (FineVision Micro F, PhysIOL SA, Liège, Belgium). RESULTS: The mean pre-operative keratometry was 43.61±1.55 D, and mean keratometric cylinder was -0.86±0.66 D. At 3 months post-operatively, values changed to 43.59±1.56 and -0.71±0.46 D, respectively. Mean sphere varied from 2.04±2.60 to 0.14±0.38 D, and mean spherical equivalent from 1.64±2.61 to -0.05±0.36 D. More than 60% of the patients achieved better corrected distance visual acuity. The majority had a final residual refractive error (predictability) lower than 1 D (99.1%), with 14.3% needing optical adjustment (bioptics). Posterior capsulotomy was performed in 2.2%, and the lens was replaced in 5 patients. A high percentage of patients were satisfied in terms of vision and spectacle independence at all distances. Although 2% referred to worsening of night vision quality, only 2% were not very satisfied and 20 patients were dissatisfied. The causes were: blurred vision (7 cases), spectacle dependence (10), dysphotopsia (7), and dry eye (4). CONCLUSIONS: The implantation of this model provided good visual performance in all distances, as well as high levels of spectacle independence and satisfaction.

Comparison of 5468 retreatments after laser in situ keratomileusis by lifting the flap or performing photorefractive keratectomy on the flap. / Comparación de 5.468 retratamientos tras láser in situ queratomileusis levantando el lentículo o mediante queratectomía fotorrefractiva sobre el lentículo.

PURPOSE: To assess visual outcomes of retreatment after laser in situ keratomileusis (LASIK) by lifting the flap or performing photorefractive keratectomy (PRK) on the flap, as well as to establish whether there was an increased risk of epithelial ingrowth (EIG) when LASIK and lifting of the flap are separated by a long time interval and to determine the incidence of corneal haze after PRK. METHODS: Retrospective study of 4077 patients (5468 eyes) who underwent LASIK and subsequent retreatment were reviewed in order to study their visual results and identify cases of EIG and corneal haze. RESULTS: Enhancements included 5196 eyes from 3876 patients that were retreated by lifting the flap, and 272 eyes from 201 patients that were retreated by PRK on the flap. No statistically significant differences were found between the retreatments in terms of predictability, efficacy, and safety. A total of 704 cases of EIG were found after lifting the flap, for which surgical cleansing was necessary in 70. Surgical cleansing decreased the efficacy index when compared with patients with EIG who did not need cleansing (P=.01). Differences in terms of safety and predictability were not statistically significant. The incidence of corneal haze after ablation of the surface of the previous flap was 14.34%, although none of these cases were clinically relevant. CONCLUSIONS: Visual outcomes were similar between patients who were retreated by lifting the flap and those who underwent PRK. The incidence of EIG when the flap was lifted was 13.55%. The incidence of EIG increases with the time elapsed between the primary procedure and retreatment.

Non-lens-based surgical techniques for presbyopia correction. / Técnicas quirúrgicas no cristalinianas para la corrección de la presbicia.

INTRODUCTION: Presbyopia is the most prevalent refractive error. With a progressive aging population, its surgical correction is an important challenge for the ophthalmology community, as well as the millions of patients who suffer from it, and who are increasingly demanding alternatives to its correction with glasses or contact lenses. MATERIAL AND METHODS: A review is presented with a synthesised discussion on the pathophysiological theories of presbyopia and an updated and analytical description of the non-lens involvement surgical techniques used to treat presbyopia. RESULTS: Corneal procedures include various types of corneal implants and photo-ablative techniques that generate a multifocal cornea, or monovision. Scleral procedures exert a traction on supralenticular sclera that supposedly would improve the amplitude of accommodation. CONCLUSIONS: None of the techniques are able to completely eliminate the need for near -vision glasses, but many of them manage to improve the refractive status of the patients. More studies with rigorous and standardised methods and longer follow-up are needed to evaluate the changes in the near vision of the patients, in order to corroborate the real and practical usefulness of many of these techniques.

LASIK and surface ablation in patients treated with amiodarone. / LASIK y ablación de superficie en pacientes tratados con amiodarona.

OBJECTIVE: To determine the anatomical and functional outcomes of corneal refractive surgery in patients on amiodarone, a drug listed as being contraindicated in patients undergoing this procedure. MATERIAL AND METHODS: A retrospective observational study was conducted on all consecutive patients who took amiodarone and who underwent LASIK or surface ablation from January 2003 to December 2014. Functional (visual and refractive) outcomes are described. RESULTS: A total of 20 patients (33 eyes) were included. No significant intraoperative or postoperative complications were found. CONCLUSIONS: In our experience, LASIK and surface ablation did not produce significant clinical complications in selected patients taking amiodarone. The absolute exclusion of certain systemic medications should be reconsidered.

[Atypical presentation of ocular hypertension following myopic LASIK]. / Presentación atípica de la hipertensión ocular en los pacientes intervenidos de LASIK miópico.

OBJECTIVE: We present a masquerade syndrome recently described following uneventful laser in situ keratomileusis (LASIK). If misdiagnosed or left unattended, this condition can lead to severe visual loss. METHODS: Findings concerning ten patients who underwent uneventful myopic LASIK, but who presented with a granular haze in the interface in the early postoperative period, are described. Initially, some of the patients were treated for diffuse lamellar keratitis with an intensive course of topical steroids, but, rather than improving, the haziness of the interface worsened or remained the same, and was even accompanied by the development of epithelial edema. RESULTS: Tonometry led to the diagnosis of ocular hypertension induced by the steroid therapy. The clinical picture resolved completely with topical hypotensive treatment and with the cessation of steroid treatment. CONCLUSION: In the early postoperative period following LASIK an atypical presentation of ocular hypertension can occasionally be observed. A high index of suspicion of this diagnosis must be maintained due to the inaccuracy of tonometry after LASIK and the similarity of this clinical picture with diffuse lamellar keratitis. These cases emphasize the importance of taking into account underestimation of the intraocular pressure after myopic LASIK.

[Post-lasik corneal ectasia in patients with significant differences in keratometry readings between both eyes]. / Ectasia corneal post-LASIK en pacientes con diferencias significativas en las lecturas queratométricas de ambos ojos.

OBJECTIVES: A study is made on the incidence of corneal ectasia after laser in situ keratomileusis (LASIK) in patients with large differences in mean keratometry (MK) readings between both eyes (OU). Visual outcomes were also evaluated. METHODS: The medical records of 164,603 patients (315,259 eyes) who underwent LASIK from January 2003 to December 2011 were reviewed in order to identify patients with a difference in MK of ≥ 1.25 D between OU. The main outcome measures were incidence of ectasia after LASIK, and visual outcome. RESULTS: A total of 35 eyes that met the inclusion criteria were found. Functional and visual results were those expected for myopia studies. After a minimum follow-up of 2 years, no corneal ectasia was found in 3 eyes (2 patients). CONCLUSIONS: The possibility of finding a patient with an asymmetry in MK and normal topography is low (0.021%), and it does not seem to be a contraindication of LASIK. Although no corneal ectasia was found in this case series, and as it is a potentially sight-threatening complication, patients with very different MK between OU should be studied carefully before undergoing LASIK.

[Infectious keratitis in 266,191 laser in situ keratomileusis]. / Queratitis infecciosas en 262.191 láser in situ keratomileusis.

OBJECTIVE: To study the incidence of infectious keratitis (IK) after laser-assisted in situ keratomileusis (LASIK), along with its diagnosis, therapeutic action taken, its management and the results. MATERIAL AND METHOD: We carried out a retrospective study of 262,191 eyes intervened consecutively with LASIK, in our 20 centres, during the period from September 2002 and December 2009. All the cases susceptible to being diagnosed with IK, either clinically or due to the biological findings were analysed. RESULTS: A total of 82 cases were found with infectious keratitis, which assumed an incidence of 0.031%. Distributions are presented by gender, mean age of the patients, mean days since the surgery, the clinical signs and symptoms, predisposing factors, therapeutic action, complications, details of the causal germ, and the loss of lines of vision. CONCLUSIONS: Infectious keratitis after LASIK is a rare complication. The early diagnosis and management of the process are determining factors when establishing the prognosis. In our series all the cases were resolved without causing any other serious complications.

[Ophthalmological manifestations in Fabry's disease. Four clinical cases showing deficient alpha-galactosidase-A activity]. / Manifestaciones oftalmológicas en la enfermedad de Fabry. A propósito de 4 casos con actividad deficiente de a-galactosidasa A.

CASE REPORT: Fabry's disease is an illness produced by an alteration in the catabolism of the glycosphingolipids. We report ophthalmologic findings in 4 people, detected after 113 patient evaluations from an analytical, cardiological and genetic point of view. DISCUSSION: Fabry's disease is uncommon and shows variable ophthalmologic affectation. Some patients with Fabry's disease do not present ocular affectation, while, on the other hand, healthy carriers with important ocular alterations have been described. The deposit of glycosphingolipids produces affectation at the corneal, crystalline, vascular and retinal levels. The vascular alterations affect not only the veins but also the arteries, as we report in our patients.