Comparison of corneal flap thickness predictability and architecture between femtosecond laser and sub-Bowman keratomileusis microkeratome in laser in situ keratomileusis.

PURPOSE OF THE STUDY: The purpose of the study is to assess and compare the corneal flap thickness predictability and uniformity between Visumax femtosecond laser and Moria sub-Bowman keratomileusis microkeratome in laser in situ keratomileusis procedure to correct myopic and myopic astigmatism refractive errors. METHODS: One hundred eyes from 100 patients were enrolled in this study. Only one eye (right eye) of each patient was chosen for this study. They were divided into two groups of equal size (50 each). Target flap thickness was 90 µm. Flap thickness was measured by anterior segment optical coherence tomography in 7 specified positions at 3 months postoperative. RESULTS: For femtosecond laser group, the average central flap thickness (CFT) was 91.35 µm ± 4.97. There was no statistically significant difference between the target flap thickness and the resultant flap thickness (p = 0.12). When the central, nasal and temporal thicknesses in the same flap were compared, there was no statistically significant difference among these measurements (p = 0.9). For the microkeratome group, CFT was 102.18 µm ± 5.63. There was statistically significant difference between the target flap thickness and the resultant flap thickness (p = 0.001). The central, nasal and temporal thicknesses were compared and there was a statistically significant difference (p = 0.000). CONCLUSIONS: Our study is among few studies in the literature comparing femtosecond laser flap to SBK microkeratome flap. Femtosecond laser creates more predictable flap thickness and more uniform flap architecture. Trial registration Trial registration number: NCT04684888. Trial Registration date: December 2020. Registered at www. CLINICALTRIALS: gov .

Blunt scissors stromal dissection technique for deep anterior lamellar keratoplasty.

OBJECTIVE: We describe a modified technique for performing lamellar dissection in deep anterior lamellar keratoplasty after failure to achieve a "big bubble" detachment of Descemet's membrane (DM) with deep intrastromal pneumatic injection. METHODS: The technique utilizes blunt lamellar dissection with blunt-tipped corneal mini scissors as an alternative to a crescent blade, which can be difficult for surgeons to master and is associated with a high risk of perforation. RESULTS: Other techniques of blunt dissection, such as the Melles technique, cannot be utilized after failure to achieve a big bubble, as emphysema in the stroma prevents visualization of the spatula. In contrast, our blunt scissors lamellar dissection technique takes advantage of the emphysema and microdetachments of DM created by the pneumatic injection. CONCLUSION: This technique provides deep anterior lamellar keratoplasty surgeons with a simple, alternative method of baring DM or achieving a pre-DM plane with minimal residual stroma, after failure to achieve a big bubble.

Fusion can mask the relationships between fundus torsion, oblique muscle overaction/underaction, and A- and V-pattern strabismus.

PURPOSE: To evaluate relationships between fundus torsion, A- or V-pattern strabismus, and oblique muscle over- or underaction, and to explore the influence of stereopsis on these relationships. METHODS: The medical records of patients with A or V patterns and/or abnormal ocular torsion seen at a single institution over nearly 30 years were retrospectively reviewed. Data collected were age, objective fundus torsion (estimated by indirect ophthalmoscopy), horizontal deviations in up- and downgaze, oblique muscle over- or underaction, and stereopsis. RESULTS: A total of 396 patients were included. A patterns were observed in 121 patients (30.6%); V patterns in 90 (22.7%). Of the A-pattern patients, 73.6% had superior oblique muscle overaction, whereas 71.1% of the V-pattern patients had inferior oblique muscle overaction (P < 0.0001, r = 0.71), increasing to 78.6% and 86.3%, respectively, for patients without stereopsis (r = 0.78). Of the patients with fundus intorsion, 78.7% had superior oblique muscle overaction, whereas 74.4% of those with fundus extorsion had inferior oblique muscle overaction (P < 0.0001, r = 0.79), increasing to 83.5% and 82.8%, respectively, for patients without stereopsis (r = 0.82). Fundus intorsion occurred in 76% of the A-pattern patients, whereas fundus extorsion occurred in 71.1% of the V-pattern patients (P < 0.0001, r = 0.73), increasing to 78.6% and 86.3%, respectively, for patients without stereopsis (r = 0.79). CONCLUSIONS: Strong correlations were found between fundus intorsion, superior oblique muscle overaction, and A patterns, and between fundus extorsion, inferior oblique muscle overaction, and V patterns. These correlations increased in patients without stereopsis, suggesting that the presence of binocular fusion can partially interfere with the close correlation of these parameters.

Features of Urrets-Zavalia syndrome after descemet stripping automated endothelial keratoplasty.

PURPOSE: To report a case series of pupil abnormalities consistent with features of Urrets-Zavalia syndrome (UZS) after Descemet stripping automated endothelial keratoplasty (DSAEK) for corneal edema secondary to corneal endothelial cell dysfunction. METHODS: Retrospective chart analysis of subjects who developed UZS after DSAEK at the University of Texas Southwestern Medical Center. RESULTS: We present a series of 7 eyes with features consistent with UZS, after undergoing DSAEK. Elevated intraocular pressures (IOP) were noted in the early postoperative period in all cases. Five of 7 had graft dislocation in the postoperative period and required rebubbling or repeat DSAEK to obtain a well-apposed graft. Patients were followed for 3 to 14 months and showed improvement in visual acuity and IOP, but fixed dilated pupils persisted. CONCLUSION: A fixed irregular or dilated pupil is a rare complication that can be associated with DSAEK surgery. Patients with an elevated IOP and complicated postoperative course seem to be at greater risk for developing iris ischemia and pupil abnormalities consistent with the diagnosis of UZS.

Incidence of esotropia developing in subjects previously diagnosed with pseudoesotropia: a pilot study.

PURPOSE: To assess the rate of development of esotropia following the diagnosis of pseudoesotropia among young children. METHODS: Retrospective records review of children diagnosed during an eye examination with pseudoesotropia prior to age 5 years with a reassessment for strabismus completed after age 5 years. RESULTS: Thirty-one patients met the inclusion criteria. The median age at diagnosis of pseudoesotropia was 1.3 years. Fourteen were boys (45%). Six (19.4%) children were subsequently diagnosed with esotropia (95% confidence interval: 7.5 to 37.5%). CONCLUSION: Even when experienced examiners find no misalignment in young children, a small number will later be found with esotropia. Serial examinations and parent education about this possibility need to be considered.