LASIK Refractive Surgery Research Articles

Retrospective diagnosis of naked eye visual acuity (UCVA) variations in patients with refractive errors treated with SMILE, LASIK, and WF-LASIK refractive surgery

ABSTRACT A retrospective assessment of the visual acuity (UCVA) variations in bare eyes of the refractive error cases treated with SMILE, LASIK and WF-LASIK. A retrospective selection of 126 patients with refractive error treated by refractive surgery admitted to our hospital between January 2019 and December 2021 were divided into three separate sets of patients according to their surgical methods: the SMILE cohort, the LASIK cohort, and the WF-LASIK cohort, and the three sets of patients were analyzed for bare eye visual acuity, refraction, higher-order aberration, BUT, SIt index, and complications, and the recovery effects of patients with the three surgical procedures. All three types of refractive surgery, SMILE, LASIK and WF-LASIK, can yield good surgical results in the reduction of refractive error, and patients with SMILE have better postoperative tear film stability, while patients with WF-LASIK have the best postoperative visual quality.

Elevated intraocular pressure‐induced interlamellar keratitis in a patient with LASIK surgery 14 years ago

AbstractPurposeTo describe a case of interlamellar keratitis induced by elevated intraocular pressure (IOP) in a patient with a history of LASIK surgery and the importance of having a strong diagnostic suspicion for establishing adequate treatment.MethodsIntraocular pressure‐induced interlamellar keratitis is one of the potential complications of LASIK refractive surgery. The cases described generally occur a few months after surgery although there are some cases that have been described several years after surgery, usually in a context of uveitis and corticosteroid treatment or silent glaucoma. We present a case of 43‐year‐old woman who came to the emergency room with visual acuity (VA) impairment in the left eye in the setting of elevated intraocular pressure‐induced interlamellar keratitis secondary to the intravitreal corticosteroid implant in her left eye due to a diabetic retinopathy. She underwent LASIK surgery 14 years ago.ResultsThe treatment was based on lowering the intraocular pressure. Oral acetazolamide and topical timolol, bimatoprost and brinzolamide were used. The patient recovered her baseline VA and the IOP were properly controlled posteriorly.ConclusionsThis case shows the importance of considering this diagnosis in patients with corneal haze, elevated intraocular pressure and a history of LASIK surgery to establish an adequate treatment. A full recovery is expected.Bibliography1. Galal A, Artola A, Belda J, (2006) Interface corneal edema secondary to steroid‐induced elevation of intraocular pressure simulating diffuse lamellar keratitis. Journal of refractive surgery.2. Lee V, Sulewski M, Zaidi A (2010) Elevated Intraocular Pressure–Induced Interlamellar Stromal Keratitis Occurring 9 Years After Laser In Situ Keratomileusis. Corneal Journal.3. Lyle W, Jin G, Jin Y (2003) Interface fluid after laser in situ keratomileusis. Journal of refractive surgery.4. Tourtas T, Kopsachilis N, Meiller R, et al. (2010). Pressure‐Induced Interlamellar Stromal Keratitis After Laser In Situ Keratomileusis. Corneal Journal.

The Prevalence and Risk Factors for Symptomatic Dry Eye in Adults in Riyadh, Saudi Arabia

Objectives: The objective of this study is to estimate the prevalence of symptomatic suspected dry eye, diagnosed dry eye syndrome (DES), and associated risk factors; in Riyadh, Saudi Arabia. Methods: A cross-sectional study of 654 participants was employed using a self-administered semi-structured questionnaire that included demographic characteristics like age, gender, and risk factors (smoking, using contact lenses, chronic comorbidities, etc.). Results: There were 266 (40.7%) previously diagnosed DES participants and 388 (59.3%) non-diagnosed DES, of which 497 were female and 157 were male. Females had a significantly higher rate of diagnosed DES than males (p<0.001), with a significant increase in the rate of DES diagnosis with age (p<0.001). There was also a significant increase in DES in participants with diabetes mellitus, allergic eye, thyroid eye, and skin diseases, as well as having undergone laser surgery or using contact lenses. There was no significant increase in DES in cases of smoking, daily use of electronic devices, or duration of sleep. Conclusion: The prevalence of dry eye among adults in Riyadh was 46.6%, with the most important risk factors being female gender, increasing age, Lasik refractive surgery, skin disease around the eye, and thyroid eye disease.

Wave front aberrations induced from biomechanical effects after customized myopic laser refractive surgery in finite element model.

A customized myopic refractive surgery was simulated by establishing a finite element model of the human eye, after which we studied the wave front aberrations induced by biomechanical effects and ablation profile after wave front-guided LASIK surgery. Thirty myopia patients (i.e., 60 eyes) without other eye diseases were selected. Their ages, preoperative spherical equivalent, astigmatism, and wave front aberration were then obtained, in addition to the mean spherical equivalent error range - 4 to - 8D. Afterward, wave front-guided customized LASIK surgery was simulated by establishing a finite element eye model, followed by the analysis of the wave front aberrations induced by the surface displacement from corneal biomechanical effects, as well as customized ablation profile. Finally, the preoperative and induced aberrations were statistically analyzed. Comatic aberrations were the main wave front abnormality induced by biomechanical effects, and the wave front aberrations induced by the ablation profile mainly included coma and secondary coma, as well as sphere and secondary-sphere aberrations. Overall, the total high-order aberrations (tHOAs), total coma (C31), and sphere ([Formula: see text]) increased after wave front-guided customized LASIK surgery. According to our correlation analyses, coma, sphere, and tHOAs were significantly correlated with decentration. Additionally, the material parameters of ocular tissue were found to affect the postoperative wave front aberrations. When the material parameters of the sclera remained constant but those of cornea increased, the induced wave front aberrations were reduced. All biomechanical effects of cornea and ablation profile had significant effects on postoperative wave front aberrations after customized LASIK refractive surgery; however, the effects of the ablation profile were more notorious. Additionally, the characteristics of biomechanical materials have influence on the clinical correction effect.

The corneal biomechanical changes after SMILE and LASIK refractive surgery were compared based on finite element analysis

The three-dimensional (3D) finite element model of human eye was established, and the intraocular pressure (IOP) was loaded to simulate refractive surgery. The biomechanical properties of human cornea after SMILE and LASIK surgery were studied from the stress, strain and induced wavefront aberration. Our results showed that SMILE had less impact on the biomechanics, having less stress and strain changes than LASIK. However, the stress and strain of the cornea increased with the increase of the diopter and were concentrated in the central region. We also investigated the changes in wavefront aberrations of the cornea after surgery, and the results indicated that the defocus and vertical commotion were significantly affected by SMILE and LASIK surgery, while the remaining aberrations were approximately unchanged. In conclusion, both SMILE and LASIK sergury procedures changed the postoperative corneal biomechanics, but SMILE had less impact on the biomechanics of corneal.

A porous collagen-based hydrogel and implantation method for corneal stromal regeneration and sustained local drug delivery

Biomaterials designed to replace the diseased cornea could be used to treat corneal blindness where human donor tissue is in short supply, but challenges are the integration of biomaterials with host tissue and cells, avoiding a rapid material degradation and maintaining corneal transparency. Additionally, implantation surgery often triggers an aggressive wound healing response that can lead to corneal thinning and opacity. Here, we report a collagen-based hydrogel with transparency and mechanical properties suitable for replacing a substantial portion of a damaged or diseased corneal stroma. The porous hydrogel permitted migration and population by host cells while maintaining transparency and thickness six months after surgical implantation in an in vivo model of human corneal surgery. With a novel hybrid surgical implantation technique inspired by LASIK refractive surgery, rapid wound healing occurred around implants to maintain biomaterial integrity, transparency and function. Host stromal cell repopulation and regeneration of host epithelium and nerves were observed, as necessary steps towards corneal regeneration. Finally, as a proof-of-principle, the hydrogel loaded with a neuroregenerative drug achieved sustained slow-release drug delivery in vitro. The proposed hydrogel and novel implantation technique together represent a therapeutic approach with translational potential for replacing and regenerating diseased corneal stromal tissue.

Anatomical and Visual Outcomes after LASIK Performed in Myopic Eyes with the WaveLight® Refractive Suite (Alcon® Laboratories Inc., USA).

Purpose To evaluate changes in corneal anatomy and quality of vision following LASIK refractive surgery for mild to high myopia using the WaveLight® Refractive Suite (Alcon® Laboratories Inc., USA). Setting. Rothschild Foundation, Paris, France. Design Prospective interventional case series. Methods We examined 60 myopic eyes (average SE −4.5 D, from −9.3 to −0.75 D) of 30 patients from 21.3 to 38.7 years old. Pachymetry, keratometry, Q factor, corneal aberrations, visual acuity (VA), contrast sensitivity, dry eye assessment, and quality of vision were measured preoperatively, one day (D1), and 1, 3, and 6 months postoperatively. Results 6 months postoperatively, keratometry became flatter, and the Q factor became more oblate (from −0.18 ± 0.08 to +0.19 ± 0.06). Pachymetry decreased by 117.9 ± 62.2 µm at D1 and increased by 37.87 ± 32.6 µm between D1 and M6. Refraction was emmetropic at D1 and remained stable thereafter. Six months after surgery, VA was slightly but nonsignificantly improved (<0.05 log MAR), whereas contrast sensitivity remained unchanged. Quality of vision was not affected by surgery and was more related to dry eye symptoms than to corneal HOAs (r2 = 0.49; p < 0.001 vs. r2 = 0.03; p < 0.001). Conclusions LASIK surgery for moderate to high myopia, performed with the WaveLight® Refractive Suite, showed good postoperative outcomes, with demonstrated safety, predictability, efficiency, and stability. This is probably due to well-controlled spherical aberration and the use of large optical zones. Besides, we can assume that the patients' quality of vision depends more on the postoperative dry eye disease generated by the laser than on the induced HOAs.

Effects of the LASIK flap thickness on corneal biomechanical behavior: a finite element analysis

BackgroundIt is well known that the biomechanical properties change after LASIK refractive surgery. One reason is the impact of flap creation on the residual stroma. The results have revealed that the change is closely related with the flap thickness in several studies. However, the quantitative relationships between the distributions of displacement and stress on the corneal surface and flap thickness have not been studied. The aim of the study was to quantify evaluate the biomechanical change caused by the LASIK flap.MethodsBy building a finite element model of the cornea, the displacement, the stress and the strain on the corneal surface were analyzed.ResultsThe results showed that the corneal flap could obviously cause the deformation of the anterior corneal surface. For example, the displacement of the corneal vertex achieved 15 μm more than that without corneal flap, when the thickness of corneal flap was 120 μm thick. This displacement was enough to cause the change of aberrations in the human eyes. In the central part of the cornea, the stress on the anterior corneal surface increased with flap thickness. But the change in the stress on the posterior corneal surface was significantly less than that on the anterior surface. In addition, the stress in the central part of the anterior corneal surface increased significantly as the intra-ocular pressure (IOP) increase. Furthermore the increase of IOP had a clearly less effect on stress distribution at the edge of the cornea. Distributions of strain on the corneal surface were similar to those of stress.ConclusionsThe changes in the biomechanical properties of cornea after refractive surgery should not be ignored.

Clinical and Functional Outcomes of Lens-Iris Diaphragm Implantation with Simultaneous Subtotal Penetrating Keratoplasty: a 15-Year Follow-Up Case Report

Combined traumatic injuries of the anterior eye segment are attributed to the severe consequences of the injured organ of vision. Iris defects result in spherical and chromatic aberrations, diplopia, flares, severe photophobia, cosmetic defects, and significantly reduced visual acuity after the injury. The literature describes various methods to restore visual functions impaired as a result of aniridia. Use of an artificial iris together with an intraocular lens pathology results in optimal reconstruction and recovery of normal anterior segment anatomy and topography. In this paper, we provide a report on a patient followed up for 15 years after combined reconstruction eye surgery for an off-the-job penetrating eye injury sustained in 2003. A complex intervention was required due to the involvement of the cornea, iris, and lens. In 2004, the patient underwent a lens-iris diaphragm implantation combined with penetrating keratoplasty. The diaphragm implantation was followed by an improvement in visual acuity and elimination of photophobia and flares. There were no intra- or postoperative complications. Two years later, LASIK refractive surgery was performed on the corneal transplant to eliminate induced ametropia. The patient retained good eye function, with a stable position of the lens-iris diaphragm, for many years after the diaphragm implantation, keratoplasty, and refractive surgery. In 2018, he had an intravitreal implant impregnated with dexamethasone, as changes in the retina had developed. The long-term follow-up in this case demonstrates that the implantation of a lens-iris diaphragm resulted in an elimination of undesirable optical events associated with aniridia and produced an optimal functional result, while also improving the patient’s quality of life with a good aesthetic effect.

Descripción del estado acomodativo en pacientes con astigmatismos antes y después de cirugía refractiva con la técnica Lasik

Objective: To describe accommodative function in astigmatics who took Lasik refractive surgery. Methodos: 30 patients diagnosed with myopic astigmatism, hyperopic and mixed, candidates for Lasik, which amplitude of accommodation was assessed with the methods of Sheard and modified Donders, accommodation flexibility, lag of accommodation with Nott dynamic retinoscopy, positive relative accommodation and negative relative accommodation, measure of the refractive data through static and dynamic refraction before and after surgery. These measurements were performed before surgery refractive optical correction and a month thereafter with new refractive conditions. Were considered as inclusion criteria: astigmatism greater than 0.75 and those for the refractive surgery procedure and any pre surgical accommodative state. Within the exclusion criteria were considered patients with severe ocular and/or systemic pathologies, no cognitive or mental depress, no permanent strabismus diagnosis, contraindications for refractive surgery, myopia, hyperopia and presbyopic before the refractive surgery. Results: Neither variable corresponding to the accommodative state components do not show discrepancies between the pre and post. By comparing the amplitude of accommodation with the reference values given by Donders, Duane and Hofstteter, it appears that there was statistical difference and Duane Hofstetter (p ≤ 0.05), clinically, the difference was relevant towards Duane (1.86D), and Donders minor. The most common accommodative impairment after refractive surgery was excessive accommodation by 13% (4 / 30) of patients, given that the dates did not change between the time before and after surgery and 10% (3 / 30) had no obvious pre accommodative inertia surgically. Conclusions: accommodative components are not affected by the performance of Lasik refractive surgery. The normal values handled by Duane, are clinical differences with those of Hofstetter and Donders.

Corneal morphology and visual outcomes in LASIK patients after orthokeratology: A pilot study.

For the first time, this study shows that corneas that previous undergone orthokeratology treatment do not respond differently to LASIK compared with previous soft contact lens wear experience. To evaluate and compare the corneal morphology and visual outcomes of long-term soft and orthokeratology (OK) contact lens fitting in wearers undergoing corneal refractive surgery (LASIK) for myopia correction. Sixteen (16) myopic patients wearing hydrophilic soft contact lens (SCL, n = 8 subjects, control group) and OK (n = 8 subjects, OK group) lenses who undergone LASIK were retrospectively evaluated. Preoperative fitting of contact lenses and one year postoperative were studied using Pentacam (Oculus, Inc. GmbH, Wetzlar, Germany). Corneal pachymetry and volume, corneal topography, anterior and posterior surface elevation data and the anterior surface aberrometry of the cornea were recorded and used for fitting. Age, refractive error and topographic parameters before LASIK did not showed statistically significant differences between the two study groups. LASIK post-treatment results showed identical changes in both control and OK groups and did not show significant differences in all the parameters evaluated. The changes on corneal parameters and HOA due to refractive surgery intervention were not different between Control and OK group (p > 0.050). Corneal changes due to OK treatment are reversible after its discontinuation. The present study gives an overview of how OK does not impair future LASIK surgery for the correction of myopia and does not influence the success/results of such intervention. These findings suggest that OK CL wear does not change corneal biomechanics and does not compromise a possible LASIK refractive surgery. Although this is a pilot study and there is a need of evaluate this results/changes in future studies.

TCH-017 Eye Drops Made from Platelet-Rich Plasma: Development and Use of a New Master Formula

Background Eye drops made from platelet-rich plasma are used in the treatment of ocular surface dysfunctions after LASIK refractive surgery, severe dry eye and corneal ulcers.Purpose To describe the process...

Necrotizing scleritis as a complication of cosmetic eye whitening procedure

BackgroundWe report necrotizing scleritis as a serious complication of a cosmetic eye whitening procedure that involves the use of intraoperative and postoperative topical mitomycin C.FindingsThis is a single case report. A 59-year-old Caucasian male with a history of blepharitis status post uncomplicated LASIK refractive surgery reported chronic conjunctival hyperemia for 15 years prior to undergoing a cosmetic eye whitening procedure. He presented to our clinic 12 months after the cosmetic eye whitening procedure with progressive bilateral necrotizing scleritis and scleral calcification.ConclusionsChronic conjunctival hyperemia may prompt patients to seek surgical correction with cosmetic eye whitening procedures. However, conjunctival hyperemia secondary to tear deficiency and evaporative dry eye may predispose to poor wound healing. Serious complications including necrotizing scleritis may result from cosmetic eye whitening procedures and the use of topical mitomycin C.

FK962 induces neurite elongation in cultured monkey trigeminal ganglion cells

LASIK refractive surgery is widely accepted for correcting myopia. Creation of the corneal flap in LASIK surgery can lead to dry eye due to amputation of corneal sensory nerves. Previous studies in the hippocampus showed that a substituted fluorobenzamide drug, FK962, caused release of neurotrophic peptides that stimulate and control nerve activity. Our studies in rabbits also showed that FK962 accelerated extension of neuronal processes and recovery of corneal sensitivity. The purposes of the present study were to 1) determine if FK962 induces spouting and elongation of neurites in cultured monkey trigeminal ganglion (TG) cells, and 2) investigate involvement of the neurotrophic peptide GDNF in FK‐induced neurite elongation. Dissociated, cultured TG cells, containing neuronal cells and Schwann cells, were cultured for 48 hours with or without FK962. Neuronal length and elongation were evaluated by staining with antibody for neurofilament specific to neurons. Culture with GDNF, or with antibody against GDNF, was used to determine the role of GDNF in neurite elongation. Our results showed that FK962, or GDNF alone, significantly induced neurite elongation. GDNF antibody significantly inhibited neurite elongation induced by FK962 or GDNF. Our data suggested that GDNF was a mediator of FK962‐induced neurite elongation. FK962 might be a candidate drug for treatment of complications after LASIK.Dr. Shearer receives consulting fees from, and Drs. Azuma and Nakajima are employees of, Senju Pharmaceutical Co. Ltd.

PACAP induces axonal elongation in cultured monkey trigeminal ganglion cells

LASIK refractive surgery is widely accepted for correcting myopia. However, flap creation during LASIK surgery leads to complications including dry eye, caused by degeneration of sensory nerves. Our previous studies in rabbits showed that PACAP accelerated the extension of neuronal processes and recovered corneal sensitivity. The purposes of the present study were to 1) establish a cell culture system for monkey trigeminal nerve (TgN), whose fibers innervate cornea, and 2) determine if PACAP induces sprouting and elongation of axons. Expression of mRNA and cellular distribution for the PACAP receptor, PAC1, were determined by qPCR and immunostaining. Axonal length in cultured TgN ganglion cells was evaluated by staining with antibody for neurofilament. Our results showed that dissociated, cultured TgN ganglion cells contained neuronal and Schwann cells. The bioactive N‐terminal peptide PACAP27 significantly induced axonal elongation which was inhibited by the PAC1 antagonist PACAP 6–27. Downstream inhibitors of the PAC1 signaling pathway, AC and PKC, also inhibited axonal elongation. Together with positive PAC1 staining in neuronal cells, our data suggested involvement of PAC1 activation in axonal elongation. PACAP might be a candidate drug for treatment of complications after LASIK.Dr. Shearer receives consulting fees from, and Drs. Azuma and Nakajima are employees of, Senju Pharmaceutical Co. Ltd.

Cone directionality from laser ray tracing in normal and LASIK patients

Laser ray tracing, a technique originally developed to measure ocular aberrations from the deviations of the local ray aberrations as a function of entry pupil, was used to assess cone directionality in 29 normal eyes (seven of which underwent LASIK surgery) and seven eyes after LASIK corneal refractive surgery for myopia. The total intensity of the retinal aerial images was computed as a function of the entry location of the illuminated beam. The measured intensity distribution was fit to a two-dimensional Gaussian function plus a constant background. The maximum of the distribution represents the pupillary location toward which the cone photoreceptors are oriented (peak of the optical Stiles–Crawford, SCE, function). We found the average SCE peak location was located mm nasally and mm inferiorly to the center of the pupil. In general, there was not a relation between the pupillary area of best quality and SCE peak location, either pre-operatively or post-operatively. The cone directionality shape factor was also unchanged by surgery. However, in two eyes, pre- and post-operative SCE peak location changed significantly. LASIK refractive surgery decreased the MTF in all eyes, even when the actual SCE directionality of the subject is considered. In the two eyes that showed significantly different SCE peak location, the apodized post-operative MTF with the post-operative SCE peak exceeded the simulated post-operative MTF assuming no shift in the SCE peak. However, the statistical power of these two cases is low, and the general findings are consistent with the hypothesis that differences in optical quality are not a major driving mechanism for cone orientation.

Traumatic Corneal Flap Dislocation One to Six Years After LASIK in Nine Eyes With a Favorable Outcome

To report our experience treating eye trauma after LASIK refractive surgery. Nine eyes of eight patients (one woman and seven men) were treated for ocular trauma: blunt trauma (n=5), sharp instrument trauma (n=2,) and trauma from inflation of automobile air bags during a traffic accident (n=2). The time from LASIK varied between 3 months and 6 years. All patients were hospitalized as a result of severe decrease in visual acuity and pain. Seven of nine LASIK flaps had some degree of dislocation and were lifted, irrigated, and repositioned. Two flaps were edematous without dislocation. Intensive topical steroids and antibiotics were used in all patients up to 3 weeks after trauma. Three months after trauma, five eyes regained their pre-trauma visual acuity (between 20/20 and 20/40), and three eyes lost one line of best spectacle-corrected visual acuity. Trauma occurring several months or years after LASIK may cause flap injury. Adequate and prompt treatment usually is successful.

Comparison of the Retinal Image Quality with a Hartmann-Shack Wavefront Sensor and a Double-Pass Instrument

Wavefront sensors provide quite useful information on the optical quality of the eye. However, in eyes where very high-order aberrations and scattered light are prominent, wavefront sensors may overestimate retinal image quality. This study showed that, in those cases, the double-pass technique is a complementary tool for better estimation of ocular optical quality. A double-pass (DP) instrument was used, based on recording images of a point source in near-infrared light after reflection in the retina and double-pass through the ocular media. The aberrations were also measured with a prototype of near-infrared Hartmann-Shack (HS) wavefront sensor adapted to the clinical environment. From the wave aberrations, the modulation transfer function (MTF) was calculated (MTF_HS). The MTF was also obtained from the double-pass images (MTF_DP). Both techniques were applied in normal young subjects as the control and in three other groups of eyes: older subjects, after LASIK refractive surgery, and after IOL implantation. The MTFs obtained from DP and HS techniques were compared. In the group of normal eyes with low levels of intraocular scattering, these estimates were quite similar, indicating that both techniques captured well most of the optical degradation. However, in eyes where scatter was more predominant (e.g., early cataract, posterior capsular opacification after IOL implantation) the MTF provided by the HS sensor was always higher than the MTF obtained from DP. A single parameter was used to indicate the differences. In eyes with low scattering, DP and HS techniques provided similar estimates of the retinal image quality. However, in a patient's eye with mild to severe amount of scatter, wavefront sensors might overestimate image quality, whereas the DP technique produces a more accurate description of the optical quality, better correlated with the quality of vision.

Corneal polarimetry after LASIK refractive surgery

Imaging polarimetry provides spatially resolved information on the polarization properties of a system. In the case of the living human eye, polarization could be related to the corneal biomechanical properties, which vary from the normal state as a result of surgery or pathologies. We have used an aberro-polariscope, which we recently developed, to determine and to compare the spatially resolved maps of polarization parameters across the pupil between normal healthy and post-LASIK eyes. The depolarization distribution is not uniform across the pupil, with post-surgery eyes presenting larger levels of depolarization. While retardation increases along the radius in normal eyes, this pattern becomes irregular after LASIK refractive surgery. The maps of slow axis also differ in normal and post-surgery eyes, with a larger disorder in post-LASIK eyes. Since these changes in polarization indicate subtle structural modifications of the cornea, this approach can be useful in a clinical environment to follow the biomechanical and optical changes of the cornea after refractive surgery or for the early diagnosis of different corneal pathologies.

Refractive surgery and strabismus

Aim: To evaluate the orthoptic outcome of patients with a pre-existing ocular motility defect who presented for Lasik refractive surgery. Method: The case notes were reviewed of 59 patients who had presented to two centres for Lasik refractive surgery and were judged to be at risk of post­operative symptoms because of a pre-existing ocular motility defect. All patients had undergone a com­prehensive orthoptic assessment. Factors examined in the analysis were the type of refractive error, the type of deviation, change in binocular status, change in the angle of deviation, and incidence of symptoms/diplopia after refractive surgery. Results: Forty-four patients were considered suitable for refractive surgery. Of these, 39 proceeded to surgery; data were incomplete for 12 cases, leaving 27 cases for analysis. No patient experienced diplopia or a change in binocular status after refractive surgery. Five patients with an accommodative-type esotropia had a reduction in the angle of deviation of between 9Δ and 20Δ. There was a small reduction in angle of 5Δ to 6Δ in 3 patients with exo deviations and a reduction of 12Δ base-out and 15Δ base-in for 2 patients with myopic anisometropia. Conclusion: Full orthoptic assessment of binocular status prior to refractive surgery is essential for patients with a pre-existing ocular motility defect, in order to identify those who are at risk of post­operative symptoms/diplopia and provide advice on the possible consequences of proceeding with the surgery.