In a unique case of drug-induced transient myopia, researchers from Sydney, Australia, sought to describe the case of a patient being treated with zolmitriptan for migraines.
A 42-year-old woman who had been using increasing amounts of zolmitriptan over the previous 12 months presented with an acute myopic shift and increased intraocular pressures with anterior chamber shallowing. The researchers reviewed clinical examination findings at presentation and at follow-up visits.
Initial examination revealed unaided visual acuities of 20/100 in the right eye and 20/125 in the left, with IOPs of 34 mmHg bilaterally. Zolmitriptan was ceased and the patient was started on glaucoma drops. Within two weeks, IOP had normalized, with deepening of the anterior chamber and complete resolution of her myopia. Her final recorded unaided visual acuities were 20/12.5 in the right eye and 20/16 in the left. When the glaucoma medication was ceased the patient developed pressure-related headaches and surgeons performed selective laser trabeculoplasty to minimize the need for long-term topical medication use.
The researchers say that idiosyncratic drug reactions resulting in ciliochoroidal effusion, secondary angle closure and transient myopia are well described, but haven’t been previously reported with zolmitriptan use. They add that awareness of the various potential causative agents is important, as findings are generally reversible if recognized early and if the offending drug is discontinued.
J Glaucoma 2017;26:954-956
Lee JTL, Skalicky SE, Lin ML.
Optimized Keratometry for Toric IOL Calculation
Researchers at the G. B. Bietti Foundation IRCCS in Rome conducted a prospective case series to compare keratometric astigmatism and different modalities of measuring total corneal astigmatism for toric intraocular lens calculation, and to optimize corneal measurements in order to eliminate residual refractive astigmatism after cataract surgery.
The researchers enrolled 62 patients (64 eyes) who had a toric IOL. Preoperatively, the study measured TCA through ray tracing. They compared different combinations of measurements at a 3-mm diameter, centered on the pupil or the corneal vertex and performed along a ring or within it. Keratometric astigmatism was measured using the same Scheimpflug camera and a corneal topographer. Astigmatism was analyzed with Næser’s polar value method. The optimized preoperative corneal astigmatism was back-calculated from the postoperative refractive astigmatism.
With both devices, KA produced an overcorrection of with-the-rule astigmatism by 0.6 D and an undercorrection of against-the-rule astigmatism by 0.3 D. The lowest meridional error in refractive astigmatism was achieved by the TCA pupil/zone measurement in WTR eyes (0.27-D overcorrection) and the TCA apex/zone measurement in ATR eyes (0.07-D undercorrection). In the whole sample, no measurement allowed more than 43.75 percent of eyes to yield an absolute error in astigmatism magnitude lower than 0.5 D. Optimized astigmatism values increased the percentage of eyes with this error up to 57.81 percent, with no difference compared with the Barrett calculator and the Abulafia-Koch calculator. Compared with KA, TCA improved calculations for toric IOLs; however, optimization of corneal astigmatism measurements led to more accurate results.
J Cataract Refract Surg 2017;43:1140-1148
Savini G, Næser K, Schiano-Lomoriello D, Ducoli P.
Learning Curve of SMILE
In an effort to evaluate the surgically challenging learning curve of small incision lenticule extraction, researchers from India described the intraoperative complications observed during the initial learning curve of SMILE and their management.
The surgeons performed a prospective evaluation of 100 consecutive eyes (50 patients) undergoing SMILE at an apex tertiary-care ophthalmic center. Patients older than 18 years with a stable refractive error ranging from -1 to -10 D myopia and up to 3 D astigmatism were included. Any intraoperative complications and their management were noted. Postoperative examination including visual acuity was performed on day one, one week and one month.
Intraoperative difficulties observed in the initial 100 eyes included suction loss (2 percent), black spots (11 percent), opaque bubble layer (19 percent), epithelial defect (2 percent) and difficult lenticule extraction (9 percent). Lenticule dissection and extraction was the most surgically challenging step and resulted in posterior stromal damage, as well as anterior cap tear (1 percent), side-cut tears (4 percent), a partially retained lenticule (1 percent) and completely retained lenticules (2 percent). Difficulties with dissection/extraction incidence decreased from 16 percent (8/50) in the initial 50 cases to 2 percent (1/50) in the next 50. Two eyes with completely retained lenticules were retreated with flap-based excimer laser ablation after three months. Optimal visual and anatomical outcomes could be achieved, the surgeons say, and no sight-threatening complication was observed in any case.
According to these results, lenticule dissection and extraction is the most difficult step, leading to a multitude of SMILE complications. However, most complications that result in delayed visual recovery are observed in the initial 50 cases.
Cornea 2017;36:1377-1382
Titiyal J, Kaur M, Rathi A, et al.
Optimizing the Number of Postop Visits
In a prospective case series conducted at the Eye Clinic of Sweden’s Sunderby Hospital, researchers sought to evaluate safety issues that might arise if there were no planned postoperative visits after cataract surgery.
Composed of 1,249 patients (1,115 in the study group and 134 in the control group), the study examined all cataract surgery cases during a one-year period. The study group had the standard routine at the clinic, that is, no planned postoperative visit for patients without comorbidity and uneventful surgery. For the control group, patients who had surgery during one month of the one-year period were chosen. All these patients had a planned postoperative visit. The outcome measures were any planned postoperative visit, any complication and/or adverse event, postoperative corrected distance visual acuity and any postoperative control/contact initiated by the patient.
No significant differences in demographics, postoperative CDVA, frequency of planned visits because of ocular comorbidity or postoperative patient-initiated contacts were found between the two groups. Of the 1,249 patients, 9 percent (117 patients) initiated a postoperative contact, of whom 26 percent (30 patients) also had a scheduled visit. The reasons for the patient-initiated contacts were visual disturbance, redness and/or chafing, pain and anxiety. An evaluation of all medical records two years postoperatively found no reports of missed adverse events.
Based on these results, the researchers concluded it is possible to refrain from planned postoperative visits for patients having uncomplicated cataract surgery. However, they say, preoperatively, patients with comorbidities should be provided with individual planning of their postoperative follow-up. They note that preoperative counseling is important, and the clinic must have resources to answer questions from patients and be prepared for additional unplanned postoperative visits.
J Cataract Refract Surg 2017;43:1184-1189
Westborg I, Monestam E.
IOP Responses: Influence of Fitness Level
Researchers from the University of Granada, Spain, conducted a study to investigate the acute effect of different levels of resistance on intraocular pressure depending on participants’ fitness level when performing cycling sprints.
In total, 26 physically active collegiate men performed five cycling sprints against different resistances in a randomized order, and IOP was measured immediately before and after each sprint. Participants were divided into two subgroups (low- and high-fitness) according to their maximum power output relative to body weight to assess the influence of fitness level. Two identical testing sessions were performed to assess the repeatability of IOP values.
Researchers found that IOP decreases with the lightest resistance (p<0.01), whereas IOP increases with heavier resistances (p<0.01), and it showed a positive linear tendency (r=0.99). They say that their results suggest that participants’ fitness level seems to influence IOP responses, with a more stable response in the high-fitness group. A strong intersession repeatability of IOP values was observed (intraclass correlation coefficient range: 0.82 to 0.98; coefficients of variations range: 1.76 percent to 6.23 percent).
Based on the study, the researchers drew three conclusions: IOP is sensitive to cycling resistance in all-out sprints, with a lowering effect on the lightest resistance and an increasing effect with medium and heavy resistances; high fitness level is beneficial for avoiding IOP fluctuations during sprints; and these changes are comparable when measured on two different days under the same experimental conditions. Future studies are needed to clarify the consequences of exercise in glaucoma patients, the researchers say.
J Glaucoma 2017;26:881-887
Vera J, Redondo B, Garcia-Ramos A, et al.
