Myopic Error Research Articles

Postoperative Pain Comparison Between Alcohol-Assisted and Transepithelial Photorefractive Keratectomy Using Nepafenac Treatment: A Novel Study.

The study aimed to compare postoperative pain between alcohol-assisted and transepithelial photorefractive keratectomy in patients who received the novel analgesic preoperative nepafenac treatment 2days preoperatively and 3days postoperatively. Pain, stinging, tearing, light sensitivity, and stress levels were evaluated. The study included a retrospective analysis of 55 patients divided into two groups: bilateral alcohol-assisted photorefractive keratectomy (aa-PRK) and transepithelial photorefractive keratectomy (transepithelial-PRK). Nepafenac was administered for pain control for all patients, with patients receiving four drops for 2 days before the surgery and 3 days postoperatively per clinical instructions. Patients completed questionnaires on the day of the surgery and for the first 5 days postoperatively. Statistical analysis was performed using XLSTAT (version 2023.1.2). t-Test was used to analyze and compare pain and symptom levels and Fisher's exact test for categorical data. p-Values less than 0.05 were considered statistically significant. The study examined 55 patients (49% female) with a mean age of 25.11 ± 6.81years who had undergone bilateral surface refractive surgery to correct myopic errors. The mean baseline standard error (SE) was -3.16 ± 2.20 D. Among these patients, 27 patients underwent aa-PRK and 28 patients underwent transepithelial-PRK. Higher levels of pain were significant in the aa-PRK group (p = 0.003). However, there was no significant difference between the groups in the average levels of stinging, tearing, or light sensation. Additionally, stress levels decreased over time in both groups, with levels becoming almost equal after 5 days, and there was no significant difference in the average stress levels between the two groups. The study found that patients who underwent the transepithelial-PRK procedure had significantly lower pain levels compared with those who underwent aa-PRK after being treated with nepafenac per protocol. However, there was no significant difference between the two groups in terms of stinging, tearing, light sensation, and stress levels.

A Possible Reciprocal Relationship Between Myopia and Dry Eye Disease in Japanese Teenagers.

To investigate the relationship between dry eye disease (DED) and myopia in Japanese teenagers. This clinic-based, retrospective, cross-sectional study assessed DED condition in 10- to 19-year-old teenagers presenting at Japanese eye clinics. They included 106 high myopic patients (HM; mean age, 16.4 ± 2.2 years), 494 mild myopic patients (15.0 ± 2.6 years) and 82 non-myopic teenagers (NM; 13.8 ± 2.6 years). Subjective refraction and anisometropia were measured. Myopia grade was classified as HM (≤ -6.00 D), MM (> -6.00 D, < -0.50 D), or NM (≥ -0.5 D). The presence of DED-related symptoms including dryness, irritation, pain, fatigue, blurring and photophobia were assessed through a questionnaire. Tear film break-up time (BUT) and fluorescein corneal staining were investigated. Comparison among three groups and regression analysis of myopic error and other variables were conducted. Anisometropia and astigmatic error were greatest in the HM group compared with the other groups (p < 0.001). The HM group reported less photophobia (p < 0.001) and less pain (p = 0.039) compared with the NM group. Regression analysis revealed that myopic error was correlated with astigmatic error (β = -0.231, p <0.001), anisometropia (β = -0.191, p <0.001), short BUT (β = -0.086, p = 0.028) and the presence of diagnosed DED (β = -0.112, p = 0.003). Dryness (β = -0.127 p = 0.004), photophobia (β = 0.117, p = 0.002) and pain (β = 0.084, p = 0.034) correlated with myopic error. This study associated clinical findings of DED in HM teenagers. The present results suggest DED might be associated with myopia, possibly in a reciprocal relationship.

Method comparison and overview of refractive measurements in children: implications for myopia management

ObjectiveThis study investigated the agreement between objective wavefront-based refraction and subjective refraction in myopic children. It also assessed the impact of cyclopentolate and refraction levels on the agreement.MethodsA total of...

Low-dose atropine 0.01% for the treatment of childhood myopia: a pan-India multicentric retrospective study

ObjectiveThe objective of this study was to assess the efficacy of low-dose atropine 0.01% in controlling myopia progression among Indian children over a 2-year period.MethodsThis retrospective study, conducted across 20...

Clinical History Method versus Corneal Tomographers in Estimating Corneal Power after.

To investigate the concordance between the corneal power determined by various approaches with two tomographers (MS-39® and Galilei G6®) and the clinical history method (CHM) in patients undergoing photorefractive surgery with excimer laser for myopic errors. Prospective cohort study. Patients undergoing keratorefractive surgery, and having pre- and postoperative keratometries, and tomographies, were included. In 90 eyes, the differences in the power estimated by the CHM and the one determined by four approaches with the corneal tomographers, which included measurements of the posterior cornea, did not show statistically significant differences in their averages. However, the 95% limits of agreement were very wide. After obtaining regression formulas to adjust the values of these four variables, the results of the agreement analysis were similar. Although certain values either directly determined or derived from measurements with the Galilei® and MS-39®corneal tomographers, approximated the estimated value of postoperative corneal power according to the CHM, due to the amplitude of their limits of agreement, these calculations must be taken with care, because they may not be accurate in a given eye.

Comparing myopic error in patients with basic and convergence insufficiency intermittent exotropia in China

PurposeTo compare the degree of myopia between the dominant and non-dominant eyes in teenagers with intermittent exotropia (IXT) in China.MethodsA total of 199 IXT patients with myopia were included in this retrospective study and were divided into two groups according to the difference between near and distance exodeviation: basic IXT and convergence insufficiency (CI) IXT. Refractive errors were analyzed by spherical equivalent (SE) values. Patients were further stratified into anisometropia group and non-anisometropia group based on binocular SE values difference greater than 1.0D or not.ResultsThere were 127 patients in the CI IXT group, with a near deviation of 46.94 ± 20.53 prism diopters (PD) and a distance deviation of 28.36 ± 14.34 PD, and there were 72 (36.2%) patients in the basic IXT group, with a near deviation of 37.68 ± 22.21 PD and a distance deviation angle of 33.21 ± 23.96 PD. The near exodeviation was significantly larger in the CI group than in the basic IXT group(P < 0.001). In the CI IXT group, the mean SE was − 2.09 ± 1.45 diopters (D) in the dominant eye and − 2.53 ± 1.44D in the non-dominant eye, while in the basic IXT group, the mean SE was − 2.46 ± 1.56D in the dominant eye and − 2.89 ± 1.37D in the non-dominant eye. The anisometropia group included 43 patients, while non-anisometropia group included 156 patients. The near and distance exodeviation in the anisometropia group were 45.26 ± 24.41 PD and 33.53 ± 23.31 PD, respectively, and those in the non-anisometropia group were 43.42 ± 20.69 PD and 29.07 ± 16.84 PD, respectively. There were no significant differences in near and distance deviation (P = 0.78 and P = 0.73 respectively) between the two groups. The SE of the dominant eye was less myopic than of the non-dominant eyes in both the CI and anisometropia groups (P = 0.002 and P < 0.001, respectively).ConclusionsOur study revealed that convergence insufficiency IXT is more common than the basic type in pediatric myopic population and is characterized by higher inter-eye differences of myopia. The dominant eye was found to be less myopic in IXT patients, particularly in those with convergence insufficiency and anisometropia.

Comparing the AC/A Ratio with spectacles and soft contact lenses in Myopes

Purpose: To compare accommodative convergence over accommodation (AC/A) ratio when Myopic patient changes from Spectacles to Contact lenses. Methods: A prospective, cross-sectional study group of 50 subjects and Myopic error from -0.75DS to -6.00DS. The AC/A ratio was measured by two methods; the heterophoria method and the gradient method. Gradient method was measured by plus and minus Lenses technique. Heterophoria in near and distance was measured to calculate heterophoria method. Wilcoxon Signed Ranks Test was used to compare between two methods p value < 0.05. Results: The mean AC/A ratio in Gradient method when using Soft Contact Lenses in comparison to Spectacles was: with+3(2.21,2.24), and with-3(1.51,150) respectively. Although the AC/A ratio was less in amount with +3D lens in near and more in distance with -3D lens as compared to Spectacles, there were no significant differences found between the two (P:0.285 and P:0.317 respectively). The means of AC/A ratio as calculated by Heterophoria method was increased with soft contact lenses (5.97) as compared to spectacles (5.96) with no significant difference p: 0.317 Conclusion: No significant difference has been found for myope when changing from spectacles to contact lenses.

Flapless and Conjunctiva-Sparing Technique for Transscleral Fixation of Intraocular Lens to Correct Refractive Errors in Eyes without Adequate Capsular Support.

To evaluate refractive outcomes, intraocular lens (IOL) power calculation, and IOL position following a novel conjunctiva-sparing transscleral fixation technique. Forty-one eyes of 40 patients managed with a flapless transscleral-sutured technique were included. Preoperative and postoperative refractive errors (spherical equivalents, SE) were compared. IOL position was assessed on the Scheimpflug images. IOL power was calculated by SRK/T, Holladay 1, and Hoffer Q formulas. The mean age was 57.39 ± 14.83 years (range: 26 to 79 years), and the mean follow-up was 7.46 ± 6.42 months (range: 1 to 24 months). Surgical indications were aphakia (n = 14), subluxated lenses (n = 3), and IOL dislocation (n = 24). The SE was 4.50 ± 6.38 diopter (D) (range: -3.75 to 13.75 D) preoperatively and -1.68 ± 1.57 D (range: -5.50 to 1.13 D) postoperatively (P < 0.001). The mean tilt angle and decentration were 2.90° ± 1.93° (range: 0.39° to 9.10°) and 0.23 ± 0.19 mm (range: 0.02 to 0.94 mm) vertically, and 1.75° ± 1.41° (range: 0.24° to 7.65°) and 0.18 ± 0.19 mm (range: 0.02 to 1.06 mm) horizontally, which were clinically insignificant. All three IOL formulas produced myopic errors (range: -0.29 to -0.50 D). The SRK/T had the lowest median absolute error (0.55 D), followed by the Holladay 1 (0.70 D) and the Hoffer Q (0.74 D). The three formulas had the same percentage of prediction errors (PEs) within ±0.5 D (43.48%), while the Hoffer Q had the highest percentage of PEs within ±1.0 D (82.61%). The present technique can serve as an alternative approach for transscleral IOL fixation and refractive correction in eyes with compromised capsular support, ensuring the stability of IOLs and reasonable IOL power calculation accuracy.

DETERMINATION OF FACTORS ASSOCIATED WITH LONG-TERM ENDOTHELIAL LOSS AND REFRACTIVE RESULT IN PATIENTS WITH ARTISAN PHAKIC LENS.

To determine the changes in endothelial cell density, refractive results, and risk factors associated with endothelial loss in patients with irisclaw phakic intraocular lenses for myopia/myopic astigmatism (Artisan). Data collection was obtained from an existing database with information on patients with a phakic Artisan lens implant between 1998 and 2011 at the Virgilio Galvis Ophthalmology Centre, with at least 5 years of follow-up. As a second stage, an analysis was carried out to identify the change in endothelial cell density and its potential associated factors. A total of 80 eyes with myopic errors were included with a follow-up of 11.9 + 3.48 years. The percentage of total loss of endothelial cells was greater than 25% of the preoperative density in 43.8% of the eyes. A postoperative annual loss &gt; 1.6% was found in 47.0% of the eyes with that information available. 41 eyes (51%) had final endothelial density &lt; 2000 cells/mm2, and 7 (8.8%) eyes had endothelial cell density &lt; 1000 cells/mm2. Among the variables studied, no associated factors for long-term endothelial loss were found. During the course of the study, 8 (10%) phakic intraocular lenses were explanted, including 3 with accelerated endothelial loss, and another 2 with cataract associated and a significantly low endothelial density. The last mean spherical equivalent was -0.81 (±1.01 D), and the final uncorrected distance visual acuity was 0.45 logMar (Snellen 20/56). Artisan-type phakic lenses are a good alternative for the correction of high myopic defects, with predictable refractive results in the long term. However, there is an increased loss of endothelial cells in the long term in a high percentage of patients. Strict postoperative follow-up, including endothelial evaluation, is required, and further studies are warranted.

Effect of refractive status on retinal nerve fiber layer thickness in Chinese Population.

To evaluate the relationship between retinal nerve fiber layer (RNFL) thickness and other related parameters measured by spectral-domain optical coherence tomography and the refractive error of eyes. A total of 5394 subjects were enrolled in this population-based cohort study, who were divided into three groups by refractive state after they underwent a standardized ophthalmic examination: emmetropia (the absolute value should range from 0 to 0.5 D), low-moderate myopia (the absolute value of myopic error should range from 0.5 to 6 D), and high myopia (the absolute value of myopic error should be over than 6 D). R 3.6.1 software was adopted for statistical analysis. Two thousand five hundred fifty-two subjects (4548 eyes) were collected in this study, with an average age of 53.14 ± 10.64years. There were significant differences among groups in average central corneal curvature, spherical equivalent, and axial length (P < 0.001). The measurements of average retinal nerve fiber layer (RNFL) were 113.95 ± 10.62μm, 112.97 ± 11.59μm, and 101.88 ± 15.67μm, respectively, in the emmetropia, low-moderate, and high myopia groups (P < 0.001). Meanwhile, there was a decreasing trend of cup area, cup volume, disc area, and rim area in the high myopia group compared with the emmetropia group (P < 0.001). The measurements of RNFL thickness vary greatly with refractive error, and this study indicated that it is of great significance for the accurate diagnosis of glaucoma to establish an individualized RNFL thickness database.

Steep increase in myopia among public school-going children in South India after COVID-19 home confinement

Novel coronavirus has brought huge changes in lifestyle, especially among children. Reports indicate that the prevalence of refractive errors among children has increased due to home confinement. Hence, this study was done to understand the current status of refractive errors among children from public schools in southern India. This cross-sectional study was conducted as part of school eye screening conducted between September and October 2021. Children between 14 and 17 years of age from public schools underwent a three-phased comprehensive eye examination. Children identified with refractive errors and an equal proportion of children without any refractive errors underwent a survey on outdoor activities. Prevalence estimates and 95% confidence interval were calculated. Chi-square tests and regression analysis were used to understand the association between refractive error and other variables. From the data of 3,850 (90.69%) children, the prevalence of vision impairment, refractive errors, and myopia in at least one eye was found to be 12.83% (n = 494), 21.51% (n = 828), and 19.53% (n = 752), respectively. The average myopic spherical equivalent error was found to be -2.17 ± 1.11D (range:-0.50 D to -14.00 D). Almost 96.82% of girls had less than 3 h of outdoor activities. Refractive errors were 7.42 and 2.77 times more (95% CI: 3.51-15.70), P < 0.001) among children who had outdoor activities less than 3 h per day and sleep less than 7 h per day. Comparing to previous studies from North Indian and South Indian public schools, this study reports a three- to six-fold rise in myopia post-home confinement among public school children from India.

Determining Association of Myopia and Primary Open Angle Glaucoma

Objective: To determine the association between myopia and primary open-angle glaucoma.&#x0D; Study Design: Comparative cross-sectional study.&#x0D; Place and Duration of Study: Department of Ophthalmology, Liaquat University Hospital Jamshoro from Jan to Jun 2015.&#x0D; Methodology: A sample of 170 diagnosed cases of myopia and 170 subjects without myopia were selected. Inclusion criteria were age 35-60 years, both genders, cases with myopia &gt;1.0 D and controls - without myopic error. Visual status was determined by the Huwitz autorefractor (model 8800) machine. Retinoscopy, Goldmann's Applanation tonometry, gonioscopy, vertical cup to disc (VCD) ratio and visual field defects were detected.&#x0D; Results: Age of group – 1 and–2 was 55.7 ± 8.6 and 52.3 ± 7.3 years respectively (p=0.071). VCD ratio in group-1 was 0.6 ± 0.13 compared to 0.5 ± 0.02 in group-2 (p&lt;0.001). Normal and abnormal VCD ratio in cases and control was noted as 161 (94.7%) vs. 168 (98.8%) and 9 (5.2%) vs. 2 (1.1%) respectively (p&lt;0.03). 23 (13.5%) of group–1 show visual field defects compared to 6 (3.5%) in group–2. Intraocular pressure was found elevated in group-1 16.8 ± 2.3 mmHg compared to 14.0 ± 2.7 in group-2 (p&lt;0.001). POAG was observed in 9 (5.2%) myopes group–1 compared to 2 (1.1%) in group–2 (p&lt;0.003).&#x0D; Conclusion: The present study concludes that myopia is associated with primary open-angle glaucoma, and the risk of glaucoma is high in these patients.

The influence of corneal ablation patterns on prediction error after cataract surgery in post-myopic-LASIK eyes

PurposeTo evaluate the influence of corneal ablation patterns on the prediction error after cataract surgery in post-myopic-LASIK eyes.MethodsEighty-three post-myopic-LASIK eyes of 83 patients that underwent uneventful cataract surgery were retrospectively included. Predicted postoperative spherical equivalence (SE) was calculated for the implanted lens using the Haigis-L and Barrett True-K formula. Prediction error at one month postsurgery was calculated as actual SE minus predicted SE. For each eye, area and decentration of the ablation zone was measured using the tangential curvature map. The associations between prediction errors and corneal ablation patterns were investigated.ResultsThe mean prediction error was − 0.83 ± 1.00 D with the Haigis-L formula and − 1.00 ± 0.99 D with the Barrett True-K formula. Prediction error was positively correlated with keratometry (K) value and negatively correlated with ablation zone area using either formula, and negatively correlated with decentration of the ablation zone using the Barrett True-K formula (all P < 0.05). In the K < 37.08 D group, prediction error was negatively correlated with decentration of the ablation zone with both formulas (all P < 0.05). Multivariate analysis showed that with the Haigis-L formula, prediction error was associated with axial length (AL), K value and decentration, and with the Barrett True-K formula, prediction error was associated with AL and decentration (all P < 0.05).ConclusionA flatter cornea, larger corneal ablation zone and greater decentration will lead to more myopic prediction error after cataract surgery in post-myopic-LASIK eyes.

Importance of Axial Length Measurement in Routine Clinical Practice

When the refractive components of the eye namely cornea and lens do not adapt for axial lengthening during growth, it results in refractive errors like myopia and hyperopia. High myopia associated with axial elongation of the eye results in structural changes, increasing the risk of severe irreversible vision loss. Myopia is becoming more incident in the world, with recent research estimating that 30 percent of the world's population is myopic now and nearly 50 percent by 2050. Risk factors for predicting future myopia was previously found to be family history with one parent being myopic when children had axial length to a certain value at the age of six. It was also researched that longer axial length in the third grade was a risk factor to turn myopic in grade eight. Axial length measurements could be for purpose of predicting future myopia, assessing the pathological risk of current myopic error, and for baseline record to monitor myopia progression and control. This present paper proposes that axial length should be measured during routine eye examination.

Efficacy of atropine for myopia control in children: A meta-analysis of randomized controlled trials.

To conduct a meta-analysis of randomized controlled trials (RCTs) on the effects of atropine eye drop in slowing myopia progression. A systematic search of relevant articles was done through a computerized search on PubMed, Medline, Cochrane Library, and Google Scholar on June 16, 2022. A supplementary search was done on ClinicalTrials.gov on the same date. After thorough search and analysis, seven relevant RCTs, double-masked with atropine eye drop as intervention arm and placebo as control arm, were selected for meta-analysis. Jadad scoring was used to evaluate the quality of RCTs. The outcome measurements included in the present meta-analysis are mean changes in the spherical equivalent (SE) of myopic error, and mean changes in axial length (AL) during the study period. Pooled summary effect size, calculated by random effect model, for SE of myopia progression was 1.08 with 95% confidence interval (CI) (0.31-1.86) which was statistically significant (P-value = 0.006). Pooled summary effect size, calculated by random effect model, for axial length was - 0.89 with 95% CI (-1.48 to - 0.30) which was statistically significant (P-value = 0.003). In summary, atropine was demonstrated to be effective in controlling myopia progression in children. Both outcome measures, mean SE changes and mean AL elongation responded to atropine intervention compared to placebo.

Eight-Year Outcomes of Implantation of Posterior Chamber Phakic Intraocular Lens With a Central Port for Moderate to High Ametropia.

Purpose: To assess the 8-year clinical outcomes of implantation of an implantable collamer lens (ICL) with a central port (KS-Aquaport; EVO-ICL) for moderate to high myopia and myopic astigmatism.Methods: This retrospective study comprised a total of 177 eyes of 106 patients with spherical equivalents of −7.99 ± 3.33 D [mean ± standard deviation], who underwent EVO-ICL implantation. We evaluated the safety, efficacy, predictability, stability, and adverse events of the surgery, at 1 month, and 1, 2, 4, 6, and 8 years postoperatively.Results: The logarithm of the minimal angle of resolution (LogMAR) uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA) were −0.07 ± 0.17 and −0.20 ± 0.09, respectively, at 8 years postoperatively. The safety and efficacy indices were 1.18 ± 0.24 and 0.89 ± 0.28, respectively. At 8 years, 83 and 93% eyes were within ± 0.5 D and ± 1.0 D of the targeted correction, respectively. Change in manifest refraction from 1 month to 8 years postoperatively was −0.13 ± 0.30 D. Three eyes (1.7%) that developed cataracts had a slight pre-existing peripheral anterior subcapsular cataract formation required simultaneous ICL extraction and cataract surgery at 2 or 3 years or ICL size change (1 size up) at 7 years postoperatively. We found that neither significant intraocular pressure (IOP) rise (including pupillary block) nor significant endothelial cell loss occurred in any case throughout the 8-year observation period.Conclusions: Current ICL implantation with central port technology offered good continuous outcomes for all measures of safety, efficacy, predictability, and stability for correcting moderate to high myopic errors over a long period, thereby suggesting its long-term viability as a surgical approach for the treatment of such eyes.

Surgeon effects on cataract refractive outcomes are minimal compared with patient comorbidity and gender: an analysis of 490 987 cases

AimTo investigate effect of patient age, gender, comorbidities and surgeon on refractive outcomes following cataract surgery.MethodsStudy population: patients on UK national ophthalmic cataract database on cataract operations undertaken between 1...

Scleral buckling surgery for stage 4A and 4B retinopathy of prematurity in critically ill neonates.

To determine the efficacy of scleral buckling in eyes with stage 4A and 4B retinopathy of prematurity (ROP). Seven eyes of five premature infants underwent scleral buckling for stage 4 ROP in zone II. Five eyes had stage 4A ROP, and two eyes had stage 4B ROP. Six eyes had previous diode laser photocoagulation, and one eye had received an intravitreal ranibizumab injection. Scleral buckling was the procedure of choice due to lack of access to specialized pediatric vitrectomy instrumentation. Average age at surgery was 3.4months. Postoperative anatomic retinal status, visual acuity outcome and refractive error were assessed. The scleral buckle was removed on average 8months after surgery. Retinal reattachment was achieved in all seven eyes. At final follow-up one eye had macular ectopia and disc dragging, one eye had a macular traction fold and two eyes had optic disc pallor. Average myopic error after buckle removal was -7.5 D. Scleral buckling can be performed safely and effectively in 4A and 4B stage ROP in critically ill infants, when access to specialized pediatric vitrectomy instrumentation is limited. This surgical technique may provide adequate relief of vitreoretinal traction with improved visual potential.

Assessment of types of phorias in myopic patients before and after refractive correction

Purpose: To assess the types of phorias in different degrees of myopic patients and different age groups before and after refractive correction. Study design: Descriptive cross-sectional study. Material and methods: This was a comparative cross-sectional study that included 100 patients. Types of phorias in myopic patients were assessed before and after refractive correction. Patients involved are 15-35 years of age groups. Data was collected from the University of Lahore Teaching Hospital. Results: A total of 100 subjects were participated out of which 52% were males and 48% were females. 38% were 15-20 years, 42% were 21-25 years, 9% were 26-30 years, and 11% of participants were31-35 years of age. Visual acuity before the correction of refractive error was also recorded 42% of participants were observed with 6/6-6/12 visual acuity, 6/18-6/36 visual acuity was reported in 42% subjects and 16% subjects had &lt;6/60 visual acuity. After the correction of myopic error 87% subjects had 6/6-6/12 and 13% subjects had 6/18-6/36 best corrected visual acuity. Degree of myopia was recorded mild in 42% participants, moderate in 42% subjects and severe in 16% subjects. Before the correction of myopia 21% participants were observed with esophoria, 54% had exophoria and 25% subjects were orthophoric. After refractive correction 13% participants were esophoric, 28% were exophoric and 59% were orthophoric while measuring horizontal phoria at distance. In vertical phoria before correction 14% participants were hyperphoria, 1% were hypophoria and 85% were orthophoric. After best correction 5% participants were recorded as hyperphoria, 1% were hypophoria and 94% were orthophoric. Conclusion: Horizontal and vertical phorias were evaluated at distance with Maddox rod. It is concluded that after correction the frequency of horizontal phorias is high than vertical phorias. In horizontal phorias exophoric pattern has significant frequency. Exophoria can also result due to weak fusional reserves. Fusional convergence eliminates the disparity of retinal images and maintain exophoria in myopic patients. So, convergence weakness and excess of divergence leads to exophoria in myopic patients. Mostly exophoric participants are reported from age range of 15 to 20 years. After refraction if patient still have asthenopia symptoms proper evaluation and management should be made for latent squint. By treating and managing the latent squint the chances of phorias to convert in manifest squint will be minimize.

Comparison of Planned Versus Achieved Central Stromal Thickness Reduction in LASIK Versus SMILE: A Contralateral Eye Study.

To compare attempted versus achieved corneal stromal thickness reduction in a consecutive case series of patients undergoing laser in situ keratomileusis (LASIK) in one eye and small incision lenticule extraction (SMILE) in the other eye. This prospective, randomized, contralateral eye study included 22 consecutive patients (44 eyes), one eye randomized to have myopic LASIK and the contralateral eye to have SMILE. Anterior segment optical coherence tomography was performed preoperatively and at 3 months postoperatively. For each of the treatment groups, the achieved maximum stromal thickness reduction was compared to the planned/attempted thickness. The deviation of planned versus achieved stromal thickness reduction was then compared between the two groups. At 3 months postoperatively, LASIK had a lower difference between planned versus attempted stromal thickness reduction compared to SMILE (13.72 ± 14.45 vs 24.00 ± 19.45 µm, P = .03). Graphical analysis revealed this deviation to be exaggerated in higher myopic errors, when a higher maximum stromal reduction was planned. The mean stromal reduction thickness was 83.40 ± 29.52 µm achieved versus 97.13 ± 25.69 µm mean planned ablation depth in the LASIK group (P < .001) compared to 76.45 ± 29.69 µm achieved versus 100.45 ± 26.56 µm planned ablation depth in the SMILE group (P < .001). LASIK had a significantly lower difference between planned versus achieved stromal thickness reduction when compared to SMILE (P = .03). This difference was more apparent in higher myopic corrections. [J Refract Surg. 2021;37(7):454-459.].