Strabismus after retinal detachment surgery: etiology, diagnosis, and treatment

Between 5% and 25% of patients may experience persistent diplopia after surgery for retinal detachment. The complexity of the presentation poses a distinct challenge to both the retinal and the strabismus surgeon. Careful evaluation to determine factors contributing to the strabismus and assessment of fusional capabilities are essential before treatment. A combination of the appropriate surgical approach with nonsurgical adjuncts such as prisms or botulinum toxin is often successful in relieving symptoms.     

Keratoreformation by contact lenses after radial keratotomy: a re-analysis

A recent paper analysed change in refraction and corneal curvature associated with contact lens wear in patients who had had radial keratotomy at least a year beforehand. Conventional methods of analysis were used. This paper applies methods that have only recently become available. The results are clearer and less ambiguous. Formally, the analysis shows that there are significant mean changes in refraction (estimated to be +1.69/-0.50 x 105) and corneal power (-0.66/-0.25 x 155). In spite of the difference between these two mean changes, the analysis shows that the change in refraction may be associated with change in the corneal power alone. There is no reason to believe that any other change is occurring in the eye. Care needs to be executed in assigning a causative role to contact lenses in changing refraction and corneal curvature. Almost certainly the lenses do have such a role but the analysis does not formally allow an unequivocal conclusion concerning that role.     

Corneal biomechanical properties after LASIK,ReLEx flex,and ReLEx smile by Scheimpflug-based dynamic tonometry

Purpose

To evaluate corneal biomechanical properties after LASIK, ReLEx flex, and the flap-free procedure ReLEx smile by Scheimpflug-based dynamic tonometry (Corvis ST) and non-contact differential tonometry (Ocular Response Analyzer, ORA).

Methods

Patients treated for high myopia (?10.5 to ?5.5 diopters, spherical equivalent refraction) more than one year previously at Aarhus University Hospital were included. Treatments comprised LASIK (35 eyes), ReLEx flex (31 eyes), and ReLEx smile (29 eyes). A control group included 31 healthy eyes. Cornea-compensated IOP (IOPcc), corneal hysteresis (CH), and corneal resistance factor (CRF) were measured with ORA. Corneal applanation and deformation were registered with Corvis ST during an air-pulse.

Results

Multiple linear regression analysis showed that CH and CRF were significantly lower after all keratorefractive procedures compared to healthy controls (p?<?0.05). No significant differences were observed in CH or CRF between the keratorefractive groups. Corvis ST showed no differences in radius at highest concavity (HC radius), time until first applanation (A1 Time), time until second applanation (A2 Time), and deflection length at highest concavity (HC deflection length) between groups. LASIK treated eyes had significantly shorter time until highest concavity than eyes treated with ReLEx smile (HC Time, p?=?0.01). The A1 deflection length was significantly shorter in the keratorefractive groups compared to the healthy controls (p?<?0.05).

Conclusions

Keratorefrative procedures alter the corneal biomechanical properties with regard to corneal hysteresis and corneal resistant factor. The flap-based LASIK and ReLEx flex and the flap-free ReLEx smile result in similar reduction in corneal biomechanics when evaluated by Corvis ST and ORA.     

Acute-onset endophthalmitis after cataract surgery (2000-2004): incidence, clinical settings, and visual acuity outcomes after treatment

PURPOSE: To report the incidence, clinical settings, and visual acuity outcomes of acute-onset endophthalmitis after cataract surgery. DESIGN: Retrospective, observational case series. METHODS: Annual cataract surgery statistics were determined by review of electronic surgical records. The clinical and microbiologic records were reviewed of all patients with clinically diagnosed endophthalmitis within 6 weeks after cataract surgery at a single university-affiliated hospital between January 2000 and November 2004. main outcome measures: Operative technique, intraoperative complications, and visual acuity. RESULTS: The incidence of acute-onset endophthalmitis after cataract surgery was 0.04% (7/15,920) for cataract surgeries of all methods, 0.05% (6/11,462) for cataract surgery by clear cornea phacoemulsification, and 0.02% (1/4,458) for cataract surgery by methods other than clear cornea phacoemulsification (P = .681, Fisher's exact test). Six of seven (86%) cases occurred in the right eye, and all cases were performed by right-handed surgeons through temporal incisions. Five of seven (71%) patients had relative immune compromise. Four of seven (57%) patients had an intraoperative complication: vitreous loss in three patients and iris prolapse in one patient. Two patients had topical placement of lidocaine 2% gel before povidone-iodine preparation. The visual acuity at final follow up was 20/25 or better in four patients and count fingers or worse in three patients. CONCLUSIONS: The incidence of acute-onset endophthalmitis after temporal clear cornea incision phacoemulsification is low (0.05%). Potential risk factors for endophthalmitis may include intraoperative complications, relative immune compromise, application of lidocaine 2% gel before povidone-iodine preparation, and inferior incision location.     

Central corneal thickness measurements by ultrasound, Orbscan II, and Visante OCT after LASIK for myopia

PURPOSE: To compare central corneal thickness measurements obtained with Orbscan II scanning slit topography, Visante optical coherence tomography (OCT), and ultrasound pachymetry in myopic eyes after LASIK. METHODS: This retrospective study included 34 consecutive patients (68 eyes) who underwent LASIK for the correction of myopia. Six months after surgery, central corneal thickness measurements were obtained using ultrasound pachymetry, Orbscan scanning slit topography, and Visante OCT. Data were analyzed using paired sample t test, Bland and Altman plot, and linear regression. RESULTS: Average postoperative central corneal thickness was 436.65+/-43.82 microm for ultrasound pachymetry, 422.84+/-51.04 microm for Orbscan (0.89 acoustic equivalent correction factor), and 422.26+/-42.46 microm for Visante. Compared to the ultrasound measurement, Orbscan and Visante measurements significantly underestimated the corneal thickness by 13.81+/-17.34 microm (P<.01) and 14.38+/-10.13 microm (P<.01), respectively. CONCLUSIONS: Both Orbscan and Visante OCT underestimated central corneal thickness compared to ultrasound pachymetry 6 months after LASIK, although measurements obtained with Visante OCT had better agreement and correlation with ultrasound pachymetry than with Orbscan.     

Efficacy, safety, predictability, aberrations and corneal biomechnical parameters after SMILE and FLEx: Meta-analysis

AIM: To identify possible differences of efficacy, safety, predictability, higher-order aberrations and corneal biomechnical parameters after small-incision lenticule extraction (SMILE) and femtosecond lenticule extraction (FLEx). METHODS: A systematic literature retrieval was conducted in Medline,Embase and the Cochrane Library, up to October, 2015. The included studies were subject to a Meta-analysis. Comparison between SMILE and FLEx was measured as pooled odds ratio (OR) or weighted mean differences (WMD). Of 95% confidence intervals (CI) were used to analyze data. RESULTS: A total of seven studies were included. Firstly, there were no differences in uncorrected distance visual acuity (UDVA) 20/20 or better (OR, 1.37; 95% CI, 0.69 to 2.69; P=0.37) and logMAR UDVA (WMD, -0.02; 95% CI, -0.05 to 0.01; P=0.17) after SMILE versus FLEx. We found no differences in corrected distance visual acuity (CDVA) unchanged (OR, 0.98; 95% CI, 0.46 to 2.11; P=0.97) and logMAR CDVA (WMD, -0.00; 95% CI, -0.01 to 0.01; P=0.90) either. Secondly, we found no differences in refraction within ±1.00 D (OR, 0.98; 95% CI, 0.13 to 7.28; P=0.99) and ±0.50 D (OR, 1.62; 95% CI, 0.62 to 4.28; P=0.33) of target postoperatively. Thirdly, for higher-order aberrations, we found no differences in the total higher-order aberrations (WMD, -0.04; 95% CI, -0.09 to 0.01; P=0.14), coma (WMD, -0.04; 95% CI, -0.09 to 0.01; P=0.11), spherical (WMD, 0.01; 95% CI, -0.02 to 0.03; P=0.60) and trefoil (WMD, -0.00; 95% CI, -0.04 to 0.03; P=0.76). Furthermore, for corneal biomechanical parameters, we also found no differences (WMD, 0.08; 95% CI, -0.17 to 0.33; P=0.54) after SMILE versus FLEx. CONCLUSION: There are no statistically differences in efficacy, safety, predictability, higher-order aberrations and corneal biomechnical parameters postoperative between SMILE and FLEx.     

Paracentral retinal holes occurring after macular surgery: incidence, clinical features, and evolution

Aim

To describe the incidence, clinical features, and evolution of paracentral retinal holes occurring after macular surgery.

Methods

A retrospective non-randomized study of 909 patients operated on for either a macular hole (MH, n?=?400 patients) or an epiretinal membrane (ERM, n?=?509 patients) between 2004 and 2009. Six patients (0.6%) developed a paracentral macular hole after surgery. Their clinical, auto-fluorescence, and optical coherence tomography (OCT) characteristics as well as their visual outcomes were studied.

Results

The mean age of patients was 70?years. Paracentral holes occurred approximately 5?weeks after surgery (with a range of 2–12?weeks). All patients were asymptomatic. Five patients underwent ILM peeling during initial surgery. Paracentral retinal holes were located superiorly to the fovea in three cases and temporally in the other three cases. Mean pre-operative BCVA was 20/200 and mean post-operative BCVA was 20/40. The eye where the eccentric MHs were closest to the fovea (inferior to 1 optic disc area) had the poorest final visual acuity. Autofluorescence imaging showed a bright fluorescence in paramacular holes. On OCT images, they were shown to be flat full-thickness holes. No treatment was attempted. No rhegmatogenous complications or choroidal neovascularization occurred in any of the patients. Mean follow-up was 2?years.

Conclusions

In summary, paracentral MHs are uncommon complications which can occur at the site where ILM peeling has been initiated or completed. Except for the closest holes to fovea, they have good visual prognosis and do not require any treatment underlining the importance of initiating the ILM peeling as far as possible from the fovea.     

Endophthalmitis after pars plana vitrectomy: Incidence, causative organisms, and visual acuity outcomes

PURPOSE: To investigate the incidence, causative organisms, and visual acuity outcomes associated with endophthalmitis after pars plana vitrectomy. DESIGN: Retrospective, noncomparative, consecutive case series. METHODS: The medical records were reviewed of all patients who developed acute-onset postoperative endophthalmitis (within 6 weeks of surgery) after pars plana vitrectomy at Bascom Palmer Eye Institute between January 1, 1984 and December 31, 2003. RESULTS: During the 20-year study interval, the overall incidence rate of postvitrectomy endophthalmitis was 0.039% (6/15,326). Cultured organisms were Staphylococcus aureus (n = 3), Proteus mirabilus (n = 1), and Staphylococcus epidermidis/Pseudomonas aeruginosa (n = 1); one case was culture-negative. Visual acuity after treatment for endophthalmitis ranged from 2/200 to no light perception, with a final vision of light perception or no light perception in four of six (67%) eyes. CONCLUSION: The incidence of endophthalmitis after pars plana vitrectomy is low but the visual acuity outcomes after treatment are generally poor.     

Effect of optic aberrations, caused by ablation pattern decentration after laser vision correction, on visual acuity

The aim of this work was to study the effects of subclinical ablation pattern decentration on the quality of vision after photorefractive laser surgery. Optical high order spherical and coma-like aberrations of 30 eyes were evaluated before, 1 and 3 months after photorefractive surgery (PRK and LASIK). Relationship between the size and shape of the light spot on the retina during transmission of paraxial beams through the eye and the ablation zone decentrations was estimated. The results are presented for pupil diameters of 1 and 6 mm both at the center of the retina along the optical axis and at a distance of 0.5 mm from the center. Decentration of ablation zone by less than 1 mm makes the principal contribution to induction of higher order aberrations. The relative increase factor is 3.9 and 5.1 for the coma-like and spherical aberrations, respectively. At such decentrations spatial resolution of the eye decreases as the pupil size increases, which is most pronounced even at a slight distance from the visual axis but inside the fovea.