Sensory exotropia versus sensory esotropia: A comparative clinical features study

PURPOSE

This study aimed to compare the preoperative clinical features of patients with sensory esotropia (ET) and sensory exotropia (XT).

METHODS

In a retrospective study, the medical records of 13,252 patients who underwent strabismus surgery were reviewed at the Farabi Eye Hospital, Iran, from 2012 to March 2022. There were 1017 patients with sensory horizontal strabismus whose, in their worse eye, had corrected distance visual acuity (CDVA) equal to or <20/160 tested with the Snellen chart.

RESULTS

The mean age of patients was 29.0 ± 12.4 years [574 (56.4%) males and 443 (43.6%) females]. Sensory XT and ET were observed in 717 (70.5%) and 300 (29.5%) patients, respectively (P<.001). The mean CDVA in the strabismic and non-strabismic eyes was 1.40 ± 0.75 and 0.05 ± 0.13, respectively (P<.001). Also, the CDVA in the strabismic eyes was significantly worse in the patients with sensory XT than in the patients with sensory ET (P<.001). Sphere and spherical equivalent (SE) components were more hyperopic in both eyes of patients with sensory ET than sensory XT (P<.001). In sensory ET group, the mean horizontal deviation at far and near was significantly higher than the sensory XT group (both P<.001). The prevalence of moderate and severe amblyopia among all patients with sensory strabismus was 274 (26.9%) and 727 (71.5%), respectively (P<.001). There were 398 (39.1%) patients who needed more than one surgery.

CONCLUSION

The frequency of sensory XT was about 2.5 times more than the sensory ET. Most patients with sensory ET were operated at a younger age, had better CDVA, more hyperopic spherical and SE, and higher angle of deviation compared with patients with sensory XT. The chance of reoperation in patients with sensory strabismus was about 40%.

Strabismus management in retinoblastoma survivors

PURPOSE

To report the result of strabismus surgery in eye-salvaged retinoblastoma (Rb) patients.

METHODS

A retrospective case series including 18 patients with Rb and strabismus who underwent strabismus surgery after completing tumor treatment by a single pediatric ophthalmologist.

RESULTS

A total of 18 patients (10 females and 8 males) were included with a mean age of 13.3 ± 3.0 (range, 2-39) months at the time tumor presentation and 6.0 ± 1.5 (range, 4-9) years at the time of strabismus surgery. Ten (56%) patients had unilateral and 8(44%) had bilateral involvement and the most common worse eye tumor's group was D (n = 11), C (n = 4), B (n = 2) and E (n = 1). Macula was involved by the tumors in 12 (67%) patients. The tumors were managed by intravenous chemotherapy (n = 8, 47%), intra-arterial chemotherapy (n = 7, 41%) and both (n = 3, 17%). After complete treatment, the average time to strabismus surgery was 29.9 ± 20.5 (range, 12-84) months. Except for one, visual acuity was equal or less than 1.0 logMAR (≤ 20/200) in the affected eye. Seven (39%) patients had exotropia, 11(61%) had esotropia (P = 0.346) and vertical deviation was found in 8 (48%) cases. The angle of deviation was 42.0 ± 10.4 (range, 30-60) prism diopter (PD) for esotropic and 35.7 ± 7.9 (range, 25-50) PD for exotropic patients (P = 0.32) that after surgery significantly decreased to 8.5 ± 5.3 PD in esotropic cases and 5.9 ± 6.7 PD in exotropic cases (P < 0.001). The mean follow-up after surgery was 15.2 ± 2.0 (range, 10-24) months, in which, 3 (17%) patients needed a second surgery.

CONCLUSION

Strabismus surgery in treated Rb is safe and results of the surgeries are acceptable and close to the general population. There was not associated with tumor recurrence or metastasis.

Refractive error and vision related quality of life

BACKGROUND

To investigate and compare the vision-related quality of life (QOL) in different types of refractive error (RE).

METHODS

This cross-sectional study was performed on 200 subjects, categorized into four groups of 50 each, consisting of subjects with myopia, hyperopia, astigmatism, and emmetropia, the latter being the control group. The mean age of the participants was 23.88 ± 5.87 (range, 15 to 38: 110 females and 90 males). RE was defined as myopia, spherical equivalent (SE) < -0.25 diopters (D), hyperopia, SE > + 0.25 D, astigmatism, cylinder < -0.25 D, and emmetropia (-0.25 ≤ SE(D) ≤ + 0.25, cylinder ≥ -0.25). Groups are subdivided into very low magnitudes of RE (0.50 and 0.75) and significant RE (1.00 ≤). Vision-related QOL was assessed using the Persian version of the 25-item National Eye Institute Visual Functioning Questionnaire (NEI-VFQ-25). The NEI-VFQ was scored as visual function and socioemotional scales using Rasch analysis.

RESULTS

Corrected myopia, astigmatism, uncorrected myopia, and hyperopia had a lower vision-related QOL than emmetropes. (P < 0.001). Vision-related QOL in myopic subjects was lower than that in astigmatic participants. Very low myopes, who often do not use correction, had a significantly lower QOL than other groups.

CONCLUSION

Individuals with refractive errors experience a lower QOL score than those without. Notably, the adverse impact on QOL score is significantly greater in myopic cases, particularly very low myopia, compared to other refractive errors. Therefore, it is strongly recommended not to neglect managing very low myopia since it may improve participants' QOL.

Refractive features and amblyopia in Duane's Retraction Syndrome: A review of the 582 patients

PURPOSE

To report the visual and refractive characteristics and the prevalence of amblyopia in patients with different types of Duane's Retraction Syndrome (DRS).

METHOD

This retrospective study was performed on hospital records of 582 DRS patients at Farabi Hospital, Iran, from 2012 to March 2022.

RESULTS

The mean age of patients was 19.4 ± 11.9 (range, 3-70) years [335 (57.6 %) females and 247 (42.4 %) males (P < .001)]. DRS type I, II, III, and IV were presented in 347 (59.6 %), 148 (25.4 %), 82 (14.1 %), and 5 (0.9 %) patients, respectively. There were 530 (91.1 %) patients with unilateral and 52 (8.9 %) with bilateral involvement. In the unilateral patients, the DRS eyes' corrected distance visual acuity (CDVA) and astigmatism were significantly worse than the Non-DRS Eyes (P < .001). The mean amount of all refractive and visual parameters in bilateral patients' right or left eyes was significantly lower than in unilateral patients' non-DRS eyes (all P < .05). Anisometropia was observed in 75(12.9 %) of the patients. Amblyopia was observed in 18.5 % (98 patients) and 36.5 % (19 patients) of unilateral and bilateral DRS patients, respectively (P < .001). In unilateral patients, amblyopia was found in 57 (16.4 %) patients with Type I, 22 (14.9 %) patients with Type II, 16 (19.5 %) patients with Type III, and 3 (60 %) patients with Type IV. Forty-four (37.6 %) of patients with amblyopia had anisometropia.

CONCLUSION

This large-scale study indicates that DRS types differ in terms of refractive error, visual acuity, and the prevalence of amblyopia and anisometropia. Clinicians should be aware of the clinical features associated with different types of DRS.

Evaluation of the effect of artificial tears on corneal epithelial thickness changes after photorefractive keratectomy

PURPOSE

This study aimed to evaluate the corneal epithelial thickness changes after photorefractive keratectomy (PRK) and the impact of long-term artificial tear usage on epithelial thickness changes in these patients.

METHODS

This study was performed on 71 patients (142 eyes) without dry eye disease who received PRK for myopic refractive correction. The corneal epithelial thickness profile was obtained before, one, three, and six months after surgery using anterior segment optical coherence tomography. Patients were randomly divided into two groups: group A, who received preservative-free artificial tears post-surgery, and group B, who did not receive artificial tears.

RESULTS

The epithelial thickness decreased universally in the first month and then increased in the 3- and 6-month follow-ups. Group A had a significantly thicker epithelium in central, paracentral, and midperipheral zones compared with group B in the 3-month follow-up. In the 6-month follow-up, no significant differences were detected between groups. At the last follow-up, the central, paracentral, and midperipheral zone epithelial thicknesses in all patients were significantly higher than preoperative values, but peripheral zone thickness only increased to preoperative values.

CONCLUSIONS

Patients using artificial tears showed a faster thickening, especially in the central and paracentral zones, but there were no significant differences between the two groups in the final follow-up. Artificial tear usage may increase the rate of the epithelial remodeling process in post-PRK patients without significantly altering the final epithelial thickness profile. Further studies are warranted to evaluate the influence of different factors on epithelial remodeling.

Comparison of two different 360-degree intrastromal corneal rings combined with simultaneous accelerated-corneal cross-linking

PURPOSE

to compare five-year outcomes of two complete intracorneal implants (MyoRing versus annular-shaped intracorneal implant [AICI]) combined with accelerated corneal cross-linking (A-CXL) in progressive KCN.

METHODS

In this historical cohort study, preoperative and postoperative visual, refractive, tomographic, biomechanical, and aberrometric parameters of 27 eyes of 27 patients who underwent implantation of two complete rings (13 AICI and 14 MyoRing) combined with A-CXL were recorded.

RESULTS

The mean age of patients in "AICI plus A-CXL" and "MyoRing plus A-CXL" groups were 28.1 ± 4.6 and 26.3 ± 3.8 years, respectively. All pre- and postoperative visual and refractive parameters between the two groups were not significantly different (p > 0.05). Comparing pre- and postoperative tomographic measurements showed that anterior corneal surface (ACS) flat-K and corneal thickness at pachymetric apex significantly improved for MyoRing plus A-CXL group after five years (p < 0.05). On the other hand, ACS K-max and mean-K values were significantly improved for AICI plus A-CXL group after five years (p < 0.05). Both groups revealed significant improvements in ACS steep-K and corneal astigmatism (p < 0.05). Five years after surgery, the high order aberration in the AICI group (2.60 ± 0.83) was significantly better than the MyoRing group (1.70 ± 0.43) (p = 0.007).

CONCLUSIONS

Both complete intrastromal rings (MyoRing or AICI) combined with A-CXL significantly Improved visual, refractive, and corneal aberrometric, biomechanical, and tomographic parameters and halt the progression of KCN with comparable long-term outcomes.

Sensory Strabismus; A Literature Review

Persistent unilateral or bilateral visual deprivation at any age, particularly in children, can compromise sensory fusion and result in a type of strabismus known as sensory or secondary strabismus. There are several pathologies that can induce visual impairment, such as severe anisometropia, congenital unilateral cataract, corneal opacity, retinal diseases, and optic nerve anomalies. Sensory strabismus may be horizontal or vertical or a combination of them; however, most reports indicate the development of horizontal deviation as sensory strabismus. Regardless of the direction of the sensory strabismus, early diagnosis and management of the underlying pathology are important before strabismus treatment. The primary treatment approach for patients with sensory strabismus is surgery to correct ocular misalignment and straighten the eyes. This can help to improve the patients' symptoms and diminish the negative psychosocial impacts. In this article, we review the underlying etiologies and background pathologies associated with sensory strabismus. In addition, we investigate the determinant factors of the direction of sensory strabismus and its management strategies.

Brown syndrome: a literature review

The current data on various aspects of Brown syndrome are limited and sporadic. This review provides a coherent and comprehensive review of basic features, etiology, classification, differential diagnosis, and different management strategies of patients with Brown syndrome. In this topical review, PubMed, Scopus, and Google Scholar search engines were searched for papers, published between 1950 and January 2023 based on the keywords of this article. The related articles were collected, summarized, categorized, assessed, concluded, and presented. Brown syndrome is identified by restricted passive and active elevation of the eye in adduction. The condition is divided into congenital and acquired causes. The clinical features result from a restricted motion of the superior oblique tendon sheath through the trochlea while trying to look up in adduction. The newest explanation of the underlying pathophysiology has been explained as the presence of a fibrotic strand in the superior oblique muscle tendon with variable insertion sites which creates various elevation deficits seen in Brown syndrome. The most common clinical features include the presence of an abnormal head posture, V-pattern strabismus, and hypotropia in the primary position. Management of Brown syndrome includes watchful observation, surgical, and non-surgical procedures. Some cases might resolve spontaneously without any intervention; however, some acquired cases might require systemic and/or intra-trochlear steroid administration to treat the underlying causes. Surgical procedures such as superior oblique tenectomy and using a silicon tendon expander are indicated in the presence of hypotropia and significant abnormal head posture in the primary position.

The Frequency and Manifestations of Ocular Causes of Abnormal Head Posture

PURPOSE

To determine the frequency and manifestations of different ocular causes of abnormal head posture (AHP).

METHOD

This prospective, consecutive case series study was performed on 149 patients with ocular AHP at Farabi hospital, Iran, from February 2020 to June 2021. All patients underwent routine ophthalmic examinations. The manifestation of AHP was determined by direct observation from three viewing angles, while the patient read the smallest line on the vision chart that they could see. In front, above, and lateral gazes, observations were performed to find head tilt, head turn, and chin abnormal position, respectively. A picture with habitual AHP was taken from all patients. The amount of head tilt was measured by calculating the angle between the line that connects the lips center to the center of the eyebrows and the vertical line using the Corel Draw X7 computer software.

RESULTS

The mean age of 149 patients with ocular AHP [101 (67.8%) males and 48 (32.2%) females] was 16.2 ± 12.2 (range, 2-57) years. The most common ocular sources of AHP were found to be superior oblique palsy (SOP) in 66 (44.3%) patients, 54 (36.2%) cases with Duane's retraction syndrome (DRS), and 12 (8.1%) patients with nystagmus. Other frequent causes of ocular AHP were dissociated vertical deviation (DVD) in 5 (3.4%), A and V pattern strabismus in 3 (2.0%), and 2 cases (1.3%) in each of Brown syndrome, inferior rectus (IR) palsy, and congenital fibrosis of the extraocular muscles (CFEOM). The most common manifestations of AHP in all cases were "pure head turn" (48.3%), followed by "pure head tilt" (24.8%), "simultaneous head tilt and head turn" (20.8%), and "chin up" (6.0%). The mean head tilt among all patients with head tilt was 10.4° ± 8.9° (range, 5.0°-31.7°).

CONCLUSION

The most frequent ocular sources of AHP were SOP, DRS, and nystagmus, followed by DVD, A and V pattern strabismus, IR palsy, CFEOM, and Brown syndrome. In addition, pure head turn and pure head tilt were the most common manifestations of ocular AHP but were not always seen in the same direction or combination as previously reported with these etiologies.

Pediatric ocular melanoma: a collaborative multicenter study and meta-analysis

PURPOSE

To investigate clinical manifestations and prognoses in pediatric patients (≤12 years old) with ocular melanoma.

METHODS

This was a retrospective, multicenter cohort study with individual participant data (IPD) meta-analysis pooling available published cases, and unpublished cases from an international collaboration of seven ocular oncology centers.

RESULTS

There were 133 eyes of 133 pediatric patients with choroidal or ciliary body (n = 66 [50%]), iris (n = 33 [25%]), conjunctival (n = 26 [19%]), and eyelid (n = 8 [6%]) melanoma. Overall, the mean patient age at presentation was 7 years (median, 8; range, 1-12 years), with 63 males (49%). The mean age by tumor site was 6.50 ± 3.90, 7.44 ± 3.57, 9.12 ± 2.61, and 5.63 ± 2.38 years, for choroid/ciliary body, iris, conjunctiva, and eyelid melanoma, respectively (P = 0.001). Association with ocular melanocytosis was seen in 15%, 11%, 4%, and 0%, respectively (P = 0.01). Frequency of ocular melanoma family history did not vary by tumor site (7%, 17%, 9% and 12%, resp. [P = 0.26]). After mean follow-up of 74, 85, 50, and 105 months (P = 0.65), metastasis was seen in 12%, 9%, 19%, and 13% of choroid/ciliary body, iris, conjunctiva, and eyelid melanoma, respectively. Death was reported in 5%, 3%, 8%, and 0%, respectively, with survival analysis indicating higher mortality in choroidal/ciliary body and conjunctival melanoma patients.

CONCLUSIONS

Ocular melanoma in the pediatric population is rare, with unique clinical features and outcomes. Iris melanoma accounts for about one-third of pediatric uveal melanoma cases.

The effect of online visual games on visual perception, oculomotor, and balance skills of children with developmental dyslexia during the COVID-19 pandemic

PURPOSE

To evaluate the effect of online visual games on the balance, visual perception, and oculomotor skills of children with developmental dyslexia during the COVID-19 pandemic.

METHODS

In this single-blind randomized clinical trial, 50 children with developmental dyslexia, aged 7 to 11 years, were recruited from rehabilitation centers in Tehran, Iran, using a convenience sampling strategy. Participants were randomly divided into two groups: intervention (25) and control (25), with close matching based on sex, age, IQ, and type of disease. The interventions consisted of web-based online computer games focusing on visual perception and oculomotor skills. Outcome measures included the Test of Visual Perception Skills-Revised, the Pediatric Balance Scale, and videonystagmography. The Wechsler Intelligence Scale for Children-IV and the Reading and Dyslexia Test were used to evaluate IQ and reading skills, respectively.

RESULTS

The intervention group exhibited significant post-intervention improvements in the Test of Visual Perception Skills-Revised, tracking gain, saccade latency, and saccade velocity scores (all P < 0.001). In contrast, the control group showed no significant differences in these tests in pre- and post-intervention (all P > 0.05). Notably, post-intervention comparisons between the groups revealed significant differences in smooth pursuit eye movements (P < 0.001), saccade latency (P = 0.027), and saccade velocity (P < 0.001). The Pediatric Balance Scale scores remained unchanged in both groups post-intervention (intervention: P = 0.317; control: P = 0.999). Game face validity was affirmed with impact scores above 1.5 for all items, suggesting that the games were straightforward, clear, and relevant.

CONCLUSION

Online visual games enhanced oculomotor and visual perception skills in children with dyslexia but did not influence balance skills.

Basic acquired nonaccommodative esotropia patients managed with surgery; a study of 2102 patients

INTRODUCTION

Several studies investigated preoperative clinical features of patients with basic-acquired nonaccommodative esotropia (BANAET); however, their sample sizes were small, and they did not compare the clinical features among cases that needed different surgery times. The main purpose of this study is to compare the preoperative clinical features of patients with BANAET managed with one surgery with patients who underwent two or more strabismus surgery over 10 years.

METHODS

This historical cohort study was performed on the hospital records of 13,252 Iranian strabismic patients who underwent surgery at Farabi eye hospital, Tehran, Iran, from 2012 to September 2022. Of those, 2102 cases with BANAET were selected as the sample size. Data collected included sex, age at the time of first surgery, corrected distance visual acuity (CDVA), refractive error, presence of amblyopia, angle of deviation, and times of surgery.

RESULTS

The mean age was 18.9 ± 15.6 [1200 (57.1%) males and 902 (42.9%) females] and the median age was 14 years. In 1599 (76.1%) patients, esotropia was managed with one surgery; however, 342 (16.3%) cases were managed with two surgeries and 161 (7.6%) patients underwent three or more surgeries. The mean angle of horizontal deviation at distance and near in patients managed with two and ≥3 surgeries was significantly higher than in cases managed with one surgery (P < .001). Amblyopia was observed in 289 (18.1%) patients who were managed with one surgery, 69 (20.2%) patients with two surgeries and 43 (26.7%) patients with three or more surgeries (P < .001). Patients with BANAET managed successfully with only one surgery were younger, had better CDVA, lower astigmatism and less horizontal angle of deviation at distance and near than those who underwent two or more surgeries (all P < .001).

DISCUSSION

The higher astigmatism, lower CDVA, greater angle of horizontal deviation, and higher frequency of amblyopia were found in the preoperative examinations of BANAET patients managed with two or more surgeries compared with cases managed with only one surgery.

Comparison of the ocular ultrasonic and optical biometry devices in the different quality measurements

PURPOSE

To compare the reliability and agreement of axial length (AL), anterior chamber depth (ACD), and lens thickness (LT) measurements obtained with optical biometry based on swept-source optical coherence tomography (IOLMaster 700; Carl Zeiss, Germany) and an ultrasound biometry device (Nidek; US-4000 Echoscan, Japan) in different qualities of AL measurement.

METHODS

A total of 239 consecutive eyes of 239 cataract surgery candidates with a mean age of 56 ± 14 years were included. The quality measurements were grouped according to the quartiles of SD of the measured AL by IOLMaster 700. The first and fourth quartile's SD are defined as high and low-quality measurement, respectively, and the second and third quartiles' SD is defined as moderate-quality.

RESULTS

The reliability of AL and ACD between the two devices in all patients and in different quality measurement groups was excellent with highly statistically significant (AL: all ICC=0.999 and P<0.001, ACD: all ICC>0.920 and P<0.001). AL and ACD in all quality measurements showed a very strong correlation between devices with highly statistically significant. However, there was poor (ICC=0.305), moderate (ICC=0.742), and good (ICC=0.843) reliability in measuring LT in low-, moderate-, and high-quality measurements, respectively. LT showed a very strong correlation (r = 0.854) with highly statistically significant (P<0.001) between devices only in patients with high-quality measurements.

CONCLUSIONS

AL and ACD of the IOLMaster700 had outstanding agreements with the US-4000 ultrasound in different quality measurements of AL and can be used interchangeably. But LT should be used interchangeably cautiously only in the high-quality measurements group.

Clinical features and refractive profile of Brown syndrome

CLINICAL SIGNIFICANCE

Understanding the refractive profile, amblyopia prevalence, binocular status, and head position in patients with Brown syndrome help clinicians become more familiar with this syndrome.

BACKGROUND

Brown syndrome is identified as an active and passive restricted elevation of the eye in adduction. There is little information on clinical features, including refractive status, amblyopia, abnormal head posture (AHP), and types of deviation in these patients.

METHODS

This study retrospectively evaluated records of 100 Brown syndrome patients from 2015 to 2022 at Farabi Eye Hospital, Iran.

RESULTS

The mean age was 6.99 ± 6.33 years, including 48 (48%) males. A congenital source was found in 74 (74%) and 96 (96%) patients had unilateral involvement. The mean CDVA for the affected and non-affected eyes were 0.05 ± 0.11 and 0.03 ± 0.06 logMAR, respectively (P = 0.31). In unilateral cases, hyperopia, myopia, and emmetropia were observed in 55 (57.29%), 2 (2.08%), and 39 (40.63%) affected eyes, respectively. The most common type of deviation was pure hypotropia, which was found in 53 (53%) cases, followed by 'combined exotropia and hypotropia' observed in 26 (26%) patients. The mean angle of hypotropia and horizontal deviation in the primary position at distance was 12.10 ± 8.50 and 8 ± 13.20 prism dioptre, respectively. A V-pattern was found in 76 (76%) patients. Amblyopia was observed in 13 (21.67%) of 60 cooperative patients, and AHP was noticed in 66 (66%) patients, in which "combined chin up and contralateral face turn" was the most common type.

CONCLUSION

About 75% of cases were congenital, 50% had pure hypotropia, 75% showed V-pattern, 20% had amblyopia, and AHP was observed in 67% of patients. The remarkable prevalence of amblyopia alongside the high occurrence of AHP should alert clinicians to carefully assess patients with Brown syndrome for sensory fusion and amblyopia.

Modified big bubble technique for deep anterior lamellar keratoplasty in keratoconus

We describe a modified technique for deep anterior lamellar keratoplasty with three modifications in big bubble pneumodissection technique; including two staged stromal trephination to avoid inadvertent full-thickness trephination, deep bevel-up needle air injection for better visualization and deeper air injection and, vicoseperation by refilling the pre-Descemet space with a viscoelastic after removing the air bubble for safe removal of the deep stromal layers. Patients with advanced keratoconus underwent deep anterior lamellar keratoplasty with pneumodissection by two-staged trephination followed by bevel-up needle deep air injection and viscoseperation. The big bubble was successfully formed in all cases and there was no case with the rupture of the Descemet's membrane (DM) during air injection or baring of DM.

Does Head Tilt Influence Facial Appearance More Than Head Turn?

Purpose

To evaluate the frequency of facial asymmetry parameters in patients with head tilt versus those with head turn.

Methods

This cross-sectional comparative study was performed on 155 cases, including 58 patients with congenital pure head turn due to Duane retraction syndrome (DRS), 33 patients with congenital pure head tilt due to upshoot in adduction or DRS, and 64 orthotropic subjects as the control group. The facial appearance was evaluated by computerized analysis of digital photographs of patients' faces. Relative facial size (the ratio of the distance between the external canthus and the corner of the lips of both face sides) and facial angle (the angular difference between a line that connects two external canthi and another line that connects the two corners of the lips) measured as quantitative facial parameters. Qualitative parameters were evaluated by the presence of one-sided face, cheek, and nostril compression; and columella deviation.

Results

The facial asymmetry frequency in patients with head tilt, head turn, and orthotropic subjects was observed in 32 (97%), 50 (86.2%), and 22 (34.3%), respectively (P < 0.001). In patients with head tilt and head turn, the mean facial angle was 1.78º ± 1.01º and 1.19º ± 0.84º, respectively (P = 0.004) and the mean relative facial size was 1.027 ± 0.018 and 1.018 ± 0.014, respectively (P = 0.018). The frequencies of one-sided nostril compression, cheek compression, face compression, and columella deviation in patients with pure head tilt were found in 19 (58%), 21 (64%), 19 (58%), and 19 (58%) patients, respectively, and in patients with pure head turn the frequencies were observed in 42 (72%), 37 (63%), 27 (47%), and 43 (74%), respectively. All quantitative and qualitative facial asymmetry parameters and facial asymmetry frequencies were significantly higher in head tilt and head turn patients as compared to the control group (P < 0.001).

Conclusion

All facial asymmetry parameters in patients with head tilt and head turn were significantly higher than orthotropic subjects. The quantitative parameters such as relative facial size and facial angle were significantly higher in patients with pure head tilt than pure head turn. The results revealed that pure head tilt was associated with a higher prevalence of facial asymmetry than pure head turn.

Seven-year follow-up of a novel 360-degree implant (annular intracorneal inlay) plus accelerated corneal cross-linking: A case study

AIM

to report late visual, refractive, and tomographic findings of a patient with progressive keratoconus (KCN) over 7-year follow-up examinations after treatment with an advanced intrastromal implant known as annular intracorneal inlay (AICI) combined with accelerated corneal cross-linking (ACXL).

METHODS

Slit-lamp photography of anterior segment, corneal tomography maps, and manifest refractions were recorded.

RESULTS

A 30-year-old female presented with the complaint of gradual decreased visual acuity in recent years that was remarkable in her left eye (LE). After clinical examinations, she underwent AICI implantation plus ACXL on her LE. Seven years later, notable improvements were observed in some visual, refractive, and tomographic parameters. The most obvious change was ascribed to the uncorrected distance visual acuity (UDVA) that was 1.3logMAR and 0.4logMAR, before and 7 years after the operation, respectively. However, the preoperative corrected distance visual acuity (CDVA) improved slightly from 0.3logMAR to 0.22logMAR after 7 years. The values of anterior K-max, mean-K, flat-K, and steep-K were flattened by 1.80 D, 1.10 D, 1.00 D, and 1.30 D, respectively. Most visual, refractive, and tomographic data improved or remained stable after 7 years and no remarkable ocular complication was observed at the end of the 7^th year.

CONCLUSION

AICI implantation plus ACXL could be considered as a safe and effective strategy in halting the KCN progression and improving the visual and tomographic properties of the KCN patients. However, future prospective studies with more participants are needed to evaluate the potential effect of AICI implantation on KCN progression.

Topical Minoxidil Solution-Induced Central Toxic Keratopathy following Photorefractive Keratectomy: A Case Study

Purpose

To report the clinical findings of unilateral central toxic keratopathy (CTK) associated with inadvertent exposure to topical minoxidil 5% solution 1 day after bilateral photorefractive keratectomy (PRK).

Methods

Anterior segment slit-lamp photography, anterior segment optical coherence tomography (AS-OCT), pachymetry map, epithelial map, and manifest refractions were recorded.

Results

This is a case of a 27-year-old male who underwent bilateral PRK and presented 5 days after surgery with the complaint of acute decreased visual acuity in the left eye (LE). His LE was reportedly exposed to topical ethanol-based minoxidil 5% on postoperative day 1, which he was using as a posthair transplant treatment. Clinical examination showed hyperopic shift, poor visual acuity, central corneal opacity, epithelial irregularity, central corneal thinning, and flattening on AS-OCT. These findings were consistent with a diagnosis of CTK. The patient was monitored with conservative treatment and demonstrated full recovery after 6 months.

Conclusion

It is recommended to warn patients who have undergone refractive surgery concerning the use of ethanol-containing agents, such as minoxidil solution, because of the possible risk of CTK, a complication not formally recognized.

Binocular contrast sensitivity in patients with intermittent exotropia in relation to angle of strabismus and level of compensation

Intermittent exotropia (IXT) causes photophobia, and photophobia has been studied by measurement of contrast sensitivity (CS). CS was reduced in children with IXT. We compared binocular CS (BCS) in patients with IXT and normal subjects in relation to the angle of strabismus and control of IXT. This case-control study was performed on 40 patients with IXT and 40 normal subjects who were examined with the CSV1000 CS device in mesopic (3 cd/m2) and photopic (85 cd/m2) conditions with and without a glare stimulus at 3, 6, 12, and 18 cycle/degree (cpd) spatial frequencies. The angle of strabismus and near stereoacuity were also measured. The patient's IXT compensation was graded based on the office control scale. The mean age for IXT and normal participants were 12.30 ± 0.60 (range, 6-18) and 11.00 ± 0.78 (range, 6-18) years, respectively (P = .34). The IXT patients had lower binocular CS than controls at all spatial frequencies (P < .001). The largest decrease in CS occurred at 6 cpd spatial frequency under mesopic condition (1.61 ± 0.07 vs 1.38 ± 0.15, P < .001) and photopic condition with glare (2.03 ± 0.06 vs 1.77 ± 0.13, P < .001). Patients with better control scores had higher levels of BCS; also, the score of BCS showed a significant decrease in patients with a deviation of 25 prism diopter or more, compared to those with less deviation. BCS correlated at 3 and 6 cpd with near stereoacuity (r = -0.652, P < .001 and r = -0.613, P < .001). Binocular CS in patients with IXT correlates with the angle of strabismus and level of compensation.

Updates on Optical Strategies of Myopia Control

Myopia has become a pandemic disease in the past few years and its sight-threatening consequences associated with high myopia have been a challenging issue for most public health societies. Controlling myopia progression has also become a global concern for many people particularly, parents of myopic children. Accordingly, a large body of work has been devoted to considering different optical and non-optical methods to prevent   or retard myopia progression. Different optical strategies such as sunder correction, monofocal spectacles or contact lenses, bifocal or progressive spectacle lenses, multifocal contact lenses, gas-permeable (GP) contact lenses, and orthokeratology (ortho-K) have been proposed to slow down the myopia progression. Although the effectiveness of these treatment strategies has been vastly studied, there are some debates concerning the most efficient method in controlling myopia progression. The present study reviewed the current optical therapies to control the progression of myopia. A literature review revealed that optical strategies, such as myopic under correction, monofocal spectacles or contact lenses, GP contact lenses, and bifocal and multifocal spectacle lenses did not provide a clinically significant reduction in myopia progression. In contrast, ortho-K and newly introduced multifocal soft contact lenses may significantly slow myopia progression.

Latest Updates on Pharmacological Management of Myopia Control: A Review Study

Introduction: Concerns about the increasing prevalence of myopia are because of its rising ocular complications, which in some cases could lead to blindness. Therefore, all practitioners should know the latest updates on myopia control in routine practice. Materials and Methods: PubMed, Science Direct, and Google Scholar databases were searched for related scientific articles using search keywords. In this regard, the books and articles published from 2016 to June 2021 were included. The selected articles and valid scientific resources were collected, summarized, classified, evaluated, and finally concluded by the authors. Results: The results of the latest published papers for the prevention of myopia progression can be summarized as follows: choroidal blood supply as a potential “rapid predictor indicator” for the axial elongation, periocular injection of salidroside and formononetin, hyperopic defocus reduction using MiSight contact lenses, the chemical effect of 7-methylxanthine, and the suppressive effect of crocetin dietary supplement. Conclusion: Using the latest methods of myopia control alongside conventional strategies has a synergistic effect.

Clinical characteristics and surgical approach in Duane retraction syndrome: a study of 691 patients

PURPOSE

To evaluate the clinical findings of different types of Duane retraction syndrome (DRS).

STUDY DESIGN

Retrospective.

METHODS

This study was performed on 691 patients with DRS who underwent surgery. Clinical examinations included laterality, abnormal head posture (AHP), corrected distance visual acuity (CDVA), refractive error, amblyopia, deviation, overshoots, and type of surgery.

RESULTS

The mean age of patients with DRS was 16.7 ± 12.5 (range 1.0-73) years. The patients included 396 (57.3%) women and 295 (42.7%) men (P < 0.001). DRS type I, was observed in 429 (62.1%), II in 168 (24.3%), III in 88 (12.7%) and IV in 6 (0.9%) patients. Unilateral DRS was observed OS in 628 (90.9%) [471 (%78.9) and OD in 157 (21.1%) eyes (P < 0.001)]. O ther clinical findings were AHP (n = 522, 78.1%), overshoot (n = 236, 34.2%) and amblyopia (n = 118, 17.1%). The prevalence of overshoot in types I, II, and III was 17.5% (75/429), 60.7% (102/168) and 64.8% (57/88), respectively (P < 0.001). The prevalence of amblyopia was significantly lower in patients with AHP (80/522, 15.3%) compared to patients with normal head posture (38/169, 22.5%) (P = 0.023). The mean angle of deviation in the primary position (PP) at distance was 21.7 ± 11.5 △ for esotropic group and 17.8 ± 12.4 △ for exotropic group. Sixty-two (9.0%) patients required second surgery for resolving residual misalignment (1.1 surgeries for each patient).

CONCLUSIONS

About two-thirds of DRS patients had AHP, one-third had overshoots, and one-sixth had amblyopia. The results show that different types of DRS are associated with different epidemiological and clinical characteristics.

Interocular Axial Length Difference and Treatment Outcomes of Anisometropic Amblyopia

Purpose

To evaluate the effect of interocular axial length (AL) difference on outcomes of treatment for anisometropic amblyopia in comparison with normal participants.

Methods

In this historical cohort study, 83 patients with anisometropic amblyopia were divided into two age groups, 70 children (mean, 7.86 ± 1.56 and range, 5–15 years) and 13 adults (mean, 26.46 ± 10.87 and range, 16–45 years). The control group consisted of 43 non-amblyopic children and 17 non-amblyopic adults. Treatment outcomes after a period of one year were defined as successful or unsuccessful when posttreatment amblyopic corrected distance visual acuity (CDVA) was reported as ≤0.9 versus CDVA ≤ 0.8, respectively. AL was measured using a Lenstar LS900 (Haag-Streit AG, Switzerland).

Results

Fifty-nine patients showed satisfactory treatment outcomes (55 children and 4 adults), while unsuccessful treatment outcomes were observed in 24 patients (15 children and 9 adults). The mean of amblyopia treatment duration was 1.24 ± 0.76 years. The mean of interocular AL difference in all patients, control, successful and unsuccessful treatment outcome groups were 0.49 ± 0.70mm (range, 0.00–3.89 mm), 0.12 ± 0.07 mm (range, 0.02–0.41), 0.33 ± 0.23 mm (range, 0.00–0.99 mm), and 1.81 ± 0.80 mm (range, 1.14–3.89 mm), respectively. In both age groups, the mean of interocular AL difference in patients with unsuccessful treatment outcomes was greater than those with successful treatment outcomes and that of the control group (P< 0.001).

Conclusion

The results of this study suggest that the outcome of anisometropic amblyopia treatment may depend on the interocular AL difference.

Is there any connection between choroidal thickness and obesity?

Obesity is a health-threatening and epidemic medical condition that can affect individuals of different ages and is potentially associated with an increased risk of systemic and ocular disorders. Despite the well-documented adverse effects of obesity on different parts of the body vasculature, less published data are available concerning obesity-related consequences on the ocular vasculature. As the human choroid is a highly vascularized tissue, its morphology and function might be altered in obese individuals. The micro-structural changes within the choroid could also trigger development of subsequent functional abnormalities of the eye. Previous population-based studies have asserted an association between obesity and choroidal thickness; however, they reported conflicting patterns of association between obesity and changes in choroidal thickness. Therefore, to enhance our understanding of the changes in choroidal morphology secondary to obesity, we reviewed studies describing the micro-structural consequences of obesity on the choroidal thickness profile and its underlying physiological and anatomical basis. This review includes all original publications related to the association between choroidal thickness and obesity published until mid-2021 that were indexed in PubMed, Google Scholar, ScienceDirect, or Scopus.

The link between Keratoconus and posterior segment parameters: An updated, comprehensive review

Keratoconus (KCN) has been typically known as a disorder with effects limited to the cornea. Because of this viewpoint, less attention has been devoted to its effects on the posterior segment structures. We aimed to provide a comprehensive review of the literature to understand the potential link between KCN and posterior segment structures and their functions. It is clear from the extensive evidence in the literature that KCN can be associated with morphological and functional changes in different parts of the posterior segment. It is worth noting that anatomical changes have been not only noted in several layers of the retina but also in the optic nerve head and the choroid. Several mechanisms have been proposed to explain this observation, including incidents induced by oxidative stress in keratoconic corneas and retinal adaptions to the distorted image that lands on the retina. Consequently, when KCN has been diagnosed, it seems practical to consider assessing the retinal and choroidal profile using optical coherence tomography and potentially functional abnormalities through electrophysiology procedures.

Comparison of Postoperative Symptoms of Alcohol-Assisted Versus Mechanical Epithelial Removal in Photorefractive Keratectomy: A Contralateral Double Blind Clinical Trial

PURPOSE

To compare the short-term complaints of postoperative pain, and other ocular discomfort symptoms in patients who underwent photorefractive keratectomy (PRK) with alcohol-assisted epithelial removal in one eye versus mechanical debridement in the other eye.

METHOD

A prospective, interventional, contralateral double blind clinical trial was performed on 164 eyes of 82 candidates of PRK surgery. The patients were divided into two groups. The first group was alcohol-assisted PRK group in which the epithelial removal was performed on their right eye. The second group was mechanical PRK group in which epithelial removal was performed on their left eye. A numerical rating scale was given to the patients to describe the severity of postoperative pain on the first day following PRK. Postoperative discomfort symptoms including the complaints of light sensitivity, tearing, blurring, and foreign body sensation was also provided by the survey form.

RESULTS

One day following PRK, the mean pain score of the alcohol-assisted PRK group and the mechanical PRK group was 3.4±3.1 and 4.1±3.3, respectively (P=0.019). The highest scores recorded for alcohol-assisted and mechanical treated groups were burning (5.22) and light sensitivity (5.46), respectively. Sixty-eight (82.9%) of all patients experienced postoperative pain, and in 52 (76.5%) of them, the time of pain onset was less than 2 hrs.

CONCLUSION

We found less pain and discomfort using alcohol-assisted technique compared with mechanical epithelial removal that was provided by a detailed pain and ocular discomfort symptoms assessment one day following PRK surgery.

The Correlation between Hypertropia and Head Tilt in Congenital Unilateral Superior Oblique Muscle Palsy

Purpose:

To evaluate the correlation between the angle of deviation in different gazes and the amount of head tilt in patients with congenital unilateral superior oblique muscle palsy (SOP).

Methods:

This case series study was performed on 20 consecutive SOP patients with head tilt. Based on the Bielschowsky three-step test, the angle of deviation was measured in different gazes. Furthermore, the hypertropia difference between the two lateral gazes (gaze difference) and the two head tilt sides (bilateral head tilt difference) was calculated. For measuring head tilt, close-up pictures from 40 cm with a habitual abnormal head position were captured and analyzed by the Corel Draw X7 software.

Results:

The mean age of patients was 13 ± 9 years (range, 2.5–31 years). The mean angle of hypertropia in ipsilateral and contralateral head tilt was 24.5 Δ ± 7.1 Δ and 6.5 Δ ± 4.2 Δ, respectively (P < 0.001), and in ipsilateral and contralateral lateral gaze positions, it was 8.2 Δ ± 5.5 Δ and 22.5 Δ ± 6.1 Δ, respectively (P < 0.001). The mean of bilateral head tilt hypertropia difference was 18 Δ ± 5.3 Δ and gaze hypertropia difference was 14.3 Δ ± 6.16 Δ. There was a positive correlation between bilateral head tilt hypertropia difference and the amount of head tilt (R = 0.609, R² = 0.371, P = 0.004, the amount of head tilt = 0.39 × [Bilateral head tilt hypertropia difference] +1.77). The amount of head tilt also had a positive correlation with the gaze hypertropia difference (R = 0.492, R² = 0.242, P = 0.028, the amount of head tilt = 0.27 × [gaze hypertropia difference] +4.81).

Conclusion:

In SOP patients, the amount of head tilt had a positive correlation with bilateral head tilt hypertropia difference and also gaze hypertropia difference.

Update on Pain Management After Advanced Surface Ablation

PURPOSE

To provide an update for postoperative pain control strategies to help ophthalmic surgeons establish a more effective management plan for patients who underwent advanced surface ablation surgeries.

METHODS

Google Scholar, Scopus, ScienceDirect, and PubMed were the main resources used to search the medical literature.

RESULTS

The postoperative cornea's healing process is accompanied by intense pain as the chief complaint in the first days after the operation. Several strategies were developed to relieve postoperative pain after surface ablation procedures. These strategies included different preoperative, intraoperative, and postoperative methods. Considering the preoperative demographic and emotional factors, underlying dry eye, alternative epithelial removal techniques, bandage contact lenses, and topical or oral therapeutic agents are some examples of postoperative pain treatments after surface ablation procedures.

CONCLUSIONS

The current review revealed that despite the development of numerous protocols to relieve postoperative pain following surface ablations, the best approach could be a combination of different strategies. In practice, no validated and standardized strategy is available for total elimination of postoperative pain following advanced surface ablation surgeries. [J Refract Surg. 2021;37(11):782-790.].

Facial Asymmetry in Unilateral Congenital Superior Oblique Muscle Palsy

SIGNIFICANCE

This study was conducted to evaluate facial asymmetry in unilateral congenital superior oblique muscle palsy (SOP). The results showed that all facial asymmetry parameters had a higher frequency in SOP patients compared with orthotropic individuals.

PURPOSE

This study aimed to evaluate the characteristics of facial asymmetry in unilateral congenital SOP and compare with orthotropic individuals.

METHODS

This cross-sectional comparative case series was conducted in 58 patients with ocular torticollis caused by SOP (mean ± standard deviation age, 18 ± 12 years) and 58 orthotropic individuals (mean ± standard deviation age, 19 ± 13 years). The exact form of torticollis was determined by direct observation from yaw, roll, and pitch axes. Four photographs were taken from patients: (1) with torticollis to calculate the amount of head tilt; (2) with the head in the straight position to calculate the facial angle and relative facial size (RFS); and (3 and 4) with the head positioned downward (to compare the cheek size) and upward (to assess columella deviation and nostril asymmetry).

RESULTS

Twenty-nine patients (50%) had a head tilt, 23 (39.66%) had combined head tilt and a face turn, and 6 (10.44%) had a pure face turn. The mean ± standard deviation of head tilt, facial angle, and RFS was 10.11 ± 6.31°, 1.11 ± 1.67°, and 1.003 ± 0.126 in SOP patients, respectively, and the mean RFS and facial angle were significantly higher in SOP patients compared with orthotropic individuals (both P < .001). Facial hemihypoplasia, unilateral cheek compression, nostril asymmetry, and columella deviation were observed in 43 (74.1%), 31 (53.4%), 39 (67.2%), and 38 patients (65.5%), respectively, which were all significantly more common compared orthotropic individuals (P < .001). Facial asymmetry was seen in 52 patients (91.2%) and 17 orthotropic subjects (29.3%), respectively (P < .001).

CONCLUSIONS

All quantitative and qualitative facial asymmetry parameters had a higher frequency in SOP patients compared with orthotropic subjects.

Long-term comparison of the outcomes of Ahmed Glaucoma Valve surgery between glaucoma surgeons and cornea trained surgeons

PURPOSE

To compare the long-term outcomes obtained by glaucoma surgeons versus cornea trained surgeons performing Ahmed glaucoma valve (AGV) surgery.

METHODS

Of the total 376 patients (3 month to 83 year) conducted in this retrospective study, 130 patients with refractory glaucoma were evaluated who had been followed up for at least six months during ten years period. The primary outcome measure was the surgical success of AGV surgery that was categorized in two groups: (A5 ≤ IOP ≤ 21 mmHg and at least 20% reduction in IOP without any glaucoma medications (complete success) and reduction by using one or more glaucoma medications (qualified success) (B) similar to previous criteria but the cutoff for higher IOP at 16 mmHg without vision loss and the need for medication or re-surgery.

RESULTS

Mean age of the patients was 32.99 ± 24.20 years in the glaucoma surgeon group and 25.18 ± 24.33 years in the cornea trained surgeons group (P = 0.07). The overall success of both methods at the end of four years were 66.7% and 41.7% for the group of glaucoma surgeons and cornea trained surgeons, respectively (p = 0.661). The cumulative success according to criterion A and B was 66.7% in the glaucoma surgeon group and 47.1% in the others surgeon group (P = 0.661). Repeated glaucoma surgery was required in 33.3% and 52.9% of the patients in the glaucoma surgeon and cornea trained surgeons groups, respectively (P = 0.661). Although there was a significant difference for IOP among various follow-up periods (p = 0.004), this difference was not significant between the two groups (p = 0.374).Visual Acuity did not have a signifiant difference between various follow-up periods and surgeons groups (p = 0.419 and P = 0. 690, respectively).

CONCLUSION

There were comparable outcomes with regard to complications and success rates between glaucoma surgeons and cornea trained surgeons performing AGV surgery.

Role of artificial tears with and without hyaluronic acid in controlling ocular discomfort following PRK: a randomized clinical trial

AIM

To compare outcomes of applying preservative free artificial tears (PFAT) with and without hyaluronic acid (HA) in early postoperative course following photorefractive keratectomy (PRK).

METHODS

In this triple-blinded randomized clinical trial, PRK procedure was performed on both eyes of 230 patients. Following PRK, patients were divided into three groups: the HA⁺ group, 44 patients PFAT containing HA; the HA^- group, 71 patients PFAT without HA were administered 5 times per day (every 4h); the third group, 115 patients received no PFAT before lens removal. On the 1^st and 4^th postoperative day, Visual Analogue Score (VAS) was utilized to evaluate patient's level of pain. Participants were asked to complete a questionnaire about the severity of eye discomfort ranked from 0 to 10 (0=no complaint; 10=most severe complaint experienced).

RESULTS

In eyes receiving PFAT with or without HA (Drop group), mean scores for epiphora, foreign body sensation, and blurred vision on the 1^st postoperative day were statistically lower (P<0.05). Filamentous keratitis (FK) was detected in 11 (4.7%) eyes, and recurrent corneal erosion (RCE) was observed in 5 (2.1%) eyes. In the control group, FK was noted in 16 (6.9%) eyes while 13 (5.6%) eyes had RCE and 5 (2.1%) eyes had corneal haze. The rate of complications was statistically lower in Drop group (P=0.009). However, the aforementioned scores were not statically different between HA⁺ and HA^- group one and two (P=0.29).

CONCLUSION

Following PRK, applying PFAT with and without HA yields faster visual recovery, decreases postoperative ocular discomfort and haze formation; however there is no additive effect for HA.

Quantitative real-time polymerase chain reaction analysis in herpes simplex virus keratitis with and without epithelial involvement

PURPOSE

To evaluate the quantitative real-time polymerase chain reaction (qRT-PCR) analysis in herpes simplex virus (HSV) keratitis with and without epithelial involvement.

METHODS

This cross-sectional study was performed on 70 patients with different HSV types and an active ocular lesion in Farabi Eye Hospital, Tehran, Iran. From these 70 patients, 171 samples were collected, including seventy tear samples and 33 scraping samples from involved eyes; and 68 samples from uninvolved fellow eyes. Samples were frozen at - 70 °C until DNA extraction was performed. Quantity of HSV was measured using qRT-PCR in all three samples.

RESULTS

The mean age of HSV patients was 52.19 ± 20.42 years (range, 4-85 years). Forty-one (58.6%) HSV patients had epithelial involvement, and 29 (41.4%) patients did not have epithelial involvement. In PCR-positive cases, the mean number of viruses in affected eyes' tears (8,831,234 ± 4,051,979) was significantly higher than uninvolved eyes' tears (182,603 ± 69,141) (P = 0.02). The mean of PCR in HSV patients with and without epithelial involvement was 10,320,269 ± 5,329,800 and 1,469,419 ± 1,070,396, respectively (P = 0.04). The qRT-PCR of involved tears in both groups (with and without epithelial involvement) was significantly higher than unaffected eyes' tears (P < 0.0001 and P = 0.01, respectively). In cases with and without epithelial involvement, the cutoff points of viral load in involved eyes' tears were 281,000 and 126,000 copies, respectively.

CONCLUSION

The results indicated that qRT-PCR is an excellent method for the detection of herpes simplex keratitis.

Long-term results of MyoRing implantation in patients with keratoconus

Clinical relevance: This study was conducted to evaluate five-year outcomes of MyoRing implantation in patients with keratoconus. The results showed that MyoRing implantation is a minimally invasive procedure and is safe and effective for improving visual acuity and refraction in most patients with keratoconus.Background: The long-term effects of MyoRing implantation on corneal features were studied.Methods: A total of 48 keratoconic eyes of 43 consecutive patients who had undergone MyoRing implantation using the Pocket Maker microkeratome (Dioptex, gmbh, Linz, Austria) and who had completed five years of follow‑ups were included in this retrospective study. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), refraction and keratometry (K) readings were measured and assessed pre-operation, and five years post-operatively. As well, post-operation satisfaction was assessed using a validated questionnaire.Results: Five years post-operatively, there was a significant improvement in UDVA, CDVA, K readings, spherical equivalent (SE), and manifest sphere and cylinder (p < 0.001). Mean UDVA was 1.20 logMAR before the surgery and 0.42 after the surgery (p < 0.001). Mean CDVA was 0.63 logMAR before the surgery and 0.20 logMAR after the surgery (p < 0.001). SE was improved from -6.53 dioptres (D) before the surgery to -2.23 D after the surgery (p < 0.001). Moreover, the results show that the mean K was reduced by 2.82 D after the surgery (p = 0.001). Overall, 81% of patients were moderately to highly satisfied five years after surgery.Conclusion: MyoRing implantation was found to be a minimally invasive procedure, and is safe and effective for improving visual acuity and refraction in most patients with keratoconus.

Effect of axial length and anterior chamber depth on the peripheral refraction profile

AIM

To evaluate the effect of axial length (AL) and anterior chamber depth (ACD) on peripheral refractive profile in myopic patients compared to emmetropic participants.

METHODS

This cross-sectional study was conducted in right eyes of 58 participants of whom 38 were emmetropic and 20 were myopic. Central and peripheral refraction were measured at 10°, 20°, and 30° eccentricities in nasal and temporal fields using an open-field autorefractor. The Lenstar LS900 was used to measure ACD and AL. The participants were divided into three groups of short (<22.5 mm), normal (22.5-24.5 mm), and long eye (>24.5 mm) according to AL and three groups of low ACD (<3.00 mm), normal ACD (3.00-3.60 mm), and high ACD (>3.60 mm) according to ACD.

RESULTS

The mean age of the participants was 22.26±3.09y (range 18-30y). The peripheral mean spherical refractive error showed a hypermetropic shift in myopic and emmetropic groups although this shift was more pronounced in the myopic group. The results showed significant changes in the spherical equivalent, J0, and J45 astigmatism in all gazes with an increase in eccentricity (P<0.001). The pattern of refractive error changes was more noticeable in long and short eyes versus normal AL eyes. Moreover, the pattern of peripheral refractive changes was much more prominent in the high ACD group versus the normal ACD group and in the normal ACD group versus the low ACD group.

CONCLUSION

Peripheral refraction changes are greater in participants with AL values outside the normal range and deeper ACD values compared to participants with normal AL and ACD.

Ocular abnormal head posture: A literature review

Purpose:

Methods:

Results:

Conclusion:

Post-LASIK keratectasia in the context of a thicker than intended flap detected by anterior segment optical coherence tomography

The corneal flap created in LASIK is responsible for most of its advantages in comparison with surface ablation. However, lamellar dissection of the corneal layers in LASIK can also result in serious complications such as corneal ectasia. A 23-year-old man underwent LASIK for correction of −4.75 −2.00@15 in the right eye and −4.50 −2.00@160 in the left eye with a preoperative thinnest corneal thickness of 518 µm/right eye and 513 µm/left eye in 2009. An intended flap thickness and ablation depth in both eyes were 160 µm and 94 µm, respectively, and subsequently, residual stromal bed thickness was 264 µm/right eye and 259 µm/left eye. Several years after surgery, he was referred for the decreased vision. His corrected-distance visual acuity was 0.50 in both eyes. A scissoring reflex was found in retinoscopy. Orbscan imaging was compatible with keratoconus. Anterior segment optical coherence tomography was performed to measure the LASIK flap. It was much thicker (200 µm) than intended (160 µm), and therefore, the residual stromal bed thickness was much thinner. In summary, keratectasia may develop in cases where thicker than expected flaps result in excessive thinning of the residual stromal bed. The obtained results from this case emphasize and remind the importance of intraoperative measurement of flap thickness and using femtosecond and new criteria for patient selection to avoid post-LASIK keratectasia.

Abnormal Head Posture in Unilateral Superior Oblique Palsy

Purpose: To evaluate the manifestations and severity of abnormal head posture (AHP) in unilateral congenital and acquired superior oblique palsy (SOP) patients and to assess the effect of AHP on facial appearance. Patients and methods: This case series study was performed on 60 consecutive SOP patients, which consisted of 47 patients with congenital SOP and 13 patients with the acquired source. The exact type of AHP in congenital and acquired cases was determined based on direct observation. In addition, a close-up picture from 40 cm with habitual AHP was captured from all patients. For evaluation of the severity of AHP and measurement of head tilt, these pictures were analyzed by the Corel Draw X7 software (Corel Corp, Canada). Besides, qualitative and quantitative facial asymmetry parameters were evaluated by the assessment of pictures of patients, which were taken in different gazes. Results: Five different manifestations of AHP were observed to the contralateral side of the palsy; 1 - pure head tilt, 2 - simultaneous head tilt and turn, 3 - pure head turn, 4 - head tilt and chin down, and 5 - head tilt and turn with chin down. The frequency of these five manifestations of AHP in the congenital group were 23 (48.9%), 10 (21.3%), 4 (8.5%), 5 (10.6%), and 5 (10.6%) patients, respectively (P <.001) and in acquired patients, were 1 (7.7%), 8 (61.5%), 2 (15.4%), 2 (15.4%), and 0 (0%), respectively (P =.024). In all SOP patients, the most common manifestations of AHP were pure head tilt (40%), simultaneous head tilt and turn (30%), and head tilt with chin down (11.7%), respectively. The mean degrees of head tilt in congenital and acquired patients were 15.10° ± 9.34° and 9.61° ± 5.84°, respectively (P =.022). Conclusion: The most common type of AHP in congenital SOP patients was contralateral head tilt, but in acquired cases was simultaneous head tilt and turn. The mean amount of head tilt in the acquired group was significantly higher than congenital patients; in contrast, the frequency of facial asymmetry was higher in the congenital group compared with the acquired patients.

Evaluating the Ectasia Risk Score System in Cancelled Laser In Situ Keratomileusis Candidates

Purpose

To evaluate the ectasia risk score system in cancelled laser in situ keratomileusis (LASIK) candidates at an academic hospital.

Methods

LASIK candidates who had been cancelled by a surgeon considering the patient age, preoperative central corneal thickness, residual stromal bed thickness, or preoperative manifest refraction spherical equivalent were retrospectively reviewed, and their Randleman ectasia risk score system score was calculated.

Results

The mean ectasia score of 194 eyes (97 patients) was 4.5 ± 2.67; 40 (20.6%), 46 (23.7%), and 108 (55.7%) eyes were classified as low-, moderate-, and high-risk eyes, respectively. The topography was abnormal in 69% of the patients. The mean manifest refraction spherical equivalent, central corneal thickness, and estimated residual stromal bed thickness were 4 (+0.50 to –15.50) diopters, 520 (439 to 608) µm, and 312.38 (61.5 to 424.12) µm, respectively. The main cause of cancellation in low- and moderate-risk patients (86 eyes) was the presence of unstable refractive error in the past year.

Conclusion

Although promising, some other criteria, such as stable refraction, should be added to this scoring system to achieve greater practicality since a main cause of cancelling LASIK candidates in this study was the presence of unstable refraction.

Anterior Uveitis with Posterior Synechia and Iris Atrophy Following Implantation of a Phakic Intraocular Lens

Purpose

To describe a case with acute postoperative uveitis, posterior synechia and iris atrophy following iris-claw phakic intraocular lens (pIOL) implantation.

Methods

A case report.

Results

A 26-year-old man with high myopia had implantation of a −14.0 diopter, foldable, iris-claw Artiflex (model 401) anterior chamber pIOL (Ophtec B.V.) in both eyes. On the third postoperative day, the patient had significant postoperative inflammation in the left eye and received topical steroids and mydriatic eye drops. On the fifth postoperative day, the right eye had a round pupil and centered pIOL, but the left eye had an atrophic iris and dilated pupil with significant posterior synechias over the inferior half of the pupil. Despite intensive topical steroid application, the synechias remained one year after surgery.

Conclusion

Severe uveitis with posterior synechia can occur after iris-claw pIOL implantation. We hypothesized that excessive iris tissue enclavation in the pIOLs haptics and large iridotomies may be an associated factor.

Stop and Flip: A Simple and Safe Phacoemulsification Technique

We introduce a simple, easy to learn, fast and safe technique to facilitate nucleus management in patients with zonular weakening in uncomplicated cases. The surgery begins with a temporal 3.2 mm clear corneal incision under topical anesthesia. Two side-port incisions are made on the inferior and superior sides. Anterior continuous curvilinear 5-6 mm diameter capsulorhexis and hydrodissection are performed to loosen capsule cortical attachments. The nucleus is not rotated, and an appropriated groove (80-90% depth) is sculpted using phaco machine. The groove is cracked into two hemispheres; lateral pressure and a side port manipulator. Then, 15-30 degree phaco tip is introduced and embedded into one hemisphere of nucleus beside the capsulorhexis edge at temporal or nasal part. After complete removal of the first hemisphere, the second is flipped again from bag into iris plane and phacoemulsified in the same manner.

Behcet's Disease Presenting With Bilateral Hypopyon Masquerading Post Cataract Surgery Endophthalmitis

Purpose

To report a case of Behcet’s disease presented with bilateral hypopyon after sequential cataract surgery masquerading delayed onset post-operative endophthalmitis.

Methods

A 53-year-old man with a history of sequential uneventful cataract surgeries came to our clinic with decreased vision (0.3 LogMAR) since 2 days ago and bilateral hypopyon in his both eyes. The primary diagnosis was chronic late-onset endophthalmitis.

Results

There was no lid edema or chemosis on the external examination. On slit-lamp examination, the cornea was clear, the pupil was well reactive with no posterior synechia, the intraocular lens was centered with good red reflex, however, bilateral hypopyon was detected in his both eyes which was more prominent in the left eye. The eyes were fairly calm and absence of vitreous reaction on slit-lamp examination, there was no pain and photophobia. Further, on physical examination, oral mucosal ulcerations were detected. His systemic workup revealed Behcet’s disease with HLA-B5 positive serology.

Conclusion

In cases with delayed onset hypopyon following cataract surgery, inflammatory diseases such as Behcet’s disease should be considered. Appropriate history taking and physical examinations in the context of serologic laboratory investigations may lead to the proper diagnosis.

Changes in Corneal Asphericity after MyoRing Implantation in Moderate and Severe Keratoconus

PURPOSE

To evaluate the effect of MyoRing implantation on corneal asphericity in moderate and severe keratoconus (KCN).

METHODS

This cross-sectional observational study comprised 32 eyes of 28 patients with KCN, who had femtosecond-assisted MyoRing corneal implantation. The primary outcome measures were preoperative and six-month postoperative corneal asphericity in 6-, 7-, 8-, 9-, and 10-mm optical zones in the superior, inferior, nasal, temporal, and central areas. The secondary outcome measures included uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction, thinnest location value, and keratometry readings.

RESULTS

A significant improvement in the UDVA and CDVA was observed six months after the surgery (P < 0.001) with a significant reduction in the spherical (4.67 diopters (D)) and cylindrical (2.19 D) refractive errors. A significant reduction in the corneal asphericity in all the optical zones and in the superior, inferior, nasal, temporal, and central areas was noted (P < 0.001). The mean thickness at the thinnest location of the cornea decreased from 437.15 ± 30.69 to 422.81 ± 36.91 μm. A significant corneal flattening was seen. The K1, K2, and Km changes were 5.32 D, 7 D, and 6.17 D, respectively (P < 0.001).

CONCLUSION

MyoRing implantation is effective for improving corneal asphericity in patients with KCN. It allows successful corneal remodeling and provides a significant improvement in UDVA, CDVA, and refractive errors.

Posterior corneal astigmatism: a review article

Most human eyes show at least a small degree of corneal astigmatism and it can arise from both surfaces of the cornea. The shape of the anterior corneal surface provides no definitive basis for knowing the toricity of the posterior surface. In the previous studies, average astigmatism of the posterior corneal surface was -0.26 to -0.78 diopter. The radius of the posterior corneal surface is less than the radius of the anterior corneal surface. Most studies have found a clear correlation between the anterior and posterior corneal asphericities and the asphericity of the posterior surface is independent of the vertex radius of curvature, refractive error and gender. In contrast to the anterior corneal surface, the asphericity of the posterior corneal surface varies significantly between meridians. The anterior and posterior corneal surface would have approximately parallel principal meridians and both of these surfaces are often flatter in the horizontal meridian than the vertical one. This is especially true in the higher degrees of corneal astigmatism, and then about 10% of any anterior corneal astigmatism is neutralized by an astigmatism arising from the posterior corneal surface. Although the second corneal surface only contributes to about 10% of the total refractive power of the eye, a precise knowledge of its morphology is needed for the correct diagnosis and monitoring the corneal diseases or the surgical interventions and in many eyes neglecting the posterior corneal surface measurement may lead to significant deviations from the corneal astigmatism estimation. In this article, we have reviewed the shape and the toricity of the posterior corneal surface and also the effect of age on it. We investigated the contribution of posterior corneal astigmatism to the total corneal astigmatism and evaluated the accuracy of corneal astigmatism estimation by neglecting the posterior corneal surface measurement.

The effect of tea tree oil on dry eye treatment after phacoemulsification cataract surgery: A randomized clinical trial

PURPOSE

To evaluate the effect of eyelid scrubbing with eye shampoo containing tea tree oil on dry eye disease following phacoemulsification cataract surgery.

METHODS

This prospective triple-blinded randomized clinical trial was performed on 62 eyes of 62 patients. Patients were randomly assigned to two groups-(1) treatment group: for 33 patients in the treatment group, artificial tears, topical steroid drops, and eye shampoos with tea tree oil and (2) for 29 patients in the control group, artificial tears, topical steroids, and eye shampoos without tea tree oil were used. In the first and second (after 1 month) follow-up visits, microscopic Demodex examination, refraction, corrected distance visual acuity, the ocular surface disease index score (by the questionnaire), Schirmer test, tear break-up time test, and osmolarity of tears (by TearLab) were recorded in treatment and control groups.

RESULTS

The mean age of patients was 66.37 ± 8.83 (range: 37-82) years, of which 49 (79%) were female and 13 (21%) were male. The results showed a significant improvement in tear break-up time test, corrected distance visual acuity, osmolarity, and ocular surface disease index score in both groups (p < 0.05). However, the number of Demodex decreases significantly only in the treatment group after treatment (p <0.001). Tear break-up time, osmolarity, and ocular surface disease index scores in the treatment group were significantly better than the control group (p < 0.05). However, there was no significant difference between the two groups in the pre- and post-Schirmer test results (p > 0.05).

CONCLUSION

Eyelid scrubbing with eye shampoo containing tea tree oil is recommended for dry eye treatment after cataract surgery, especially decrease in the number of Demodex.

Central serous chorioretinopathy following ingestion of sildenafil citrate

INTRODUCTION

We report a case of a 35-year-old man who presented with headache followed by decreased vision, metamorphopsia, and altered color perception in his left eye, after repeated intake of sildenafil citrate (four times; 100 mg) in a limited period (3 days).

METHODS

On the first ocular examination, best-corrected distance visual acuity (CDVA) was 20/80 in his left eye and 20/20 in his right eye. On fundus examination, loss of foveal reflex and serous retinal detachment in the foveal region were detected. Fluorescein angiography of the left eye was compatible with a leakage area with determined borders. The patient was advised to stop sildenafil intake.

RESULTS

After 4 weeks, CDVA increased to 20/25, and the fundus examination revealed significant improvement of the macular edema. Optical coherence tomography showed increased foveal thickness to 350 μm.

CONCLUSION

Advising patients with central serous chorioretinopathy to stop sildenafil intake should be considered.