The spectrum of iatrogenic intraocular injuries caused by inadvertent cannula release during anterior segment surgery.

OBJECTIVE: To evaluate the causes of inadvertent intraocular injuries resulting from the use of cannulas during anterior segment surgery. Method Retrospective review of all cases with inadvertent release of irrigation and viscoelastic cannulas during anterior segment surgery in 15 years. RESULTS: Inadvertent release of cannulas occurred in 9 of 10 230 cases of anterior segment surgery during a 15-year period. The incidence of cannula release was 0.88 per 1000 procedures per year. Twenty percent of the surgeons who performed anterior segment surgery in this period were involved in this unfortunate event. Six cases occurred during cataract extraction and 3 during penetrating keratoplasty or replacement of corneal graft. The latter 3 cases included posterior capsule rupture and vitreous loss. Macular scar in 2 (22%) of the 9 cases was associated with poor visual outcome of counting fingers at 2.1 to 3.0 m (P = .03). In all other surgeries, the cannula caused iris or anterior chamber angle injury without consequences. CONCLUSIONS: Inadvertent release of cannulas during anterior segment surgery is a rare, memorable, and unfortunate event. The severity of the injury may be related to the type of the surgical wound. In most cases, visual outcome is not compromised unless the cannula causes retinal disruption.

Visual functions following recovery from non-arteritic central retinal artery occlusion.

BACKGROUND AND OBJECTIVE: Visual acuity and other visual functions may improve following treatment of central retinal artery occlusion (CRAO). A prospective, noncomparative case series study was conducted to investigate patients' visual functions after treatment of non-arteritic CRAO. PATIENTS AND METHODS: Eight consecutive patients whose visual acuity improved following successful systematic treatment protocol for non-arteritic CRAO of less than 48 hours (one of them with patent cilioretinal artery) were evaluated for visual functions. The visual acuity in seven patients ranged from no light perception to counting fingers at 3 feet on presentation and improved to 20/100 to 20/20 following treatment. The visual tests included: blue-yellow (Farnsworth D-15) and green-red (pseudoisochromatic Ishihara color plates) color discrimination, contrast sensitivity, and visual fields. The patients were also evaluated for subjective daily function following treatment. All tests were also performed in the fellow uninvolved eye as a control. RESULTS: The visual acuity following treatment improved from no light perception to counting fingers at 3 feet to an average of 20/65 (range, 20/20 to 20/100). Despite this improvement, six patients had dyschromatopsia to blue, green, or red whereas only two patients with a final visual acuity of 20/20 preserved their full color discrimination. All patients had decreased contrast sensitivity at mid-spatial frequency (6 cycles/min) or a more generalized decrease and visual field defects. All of the patients except one were satisfied with the visual outcome and daily function after treatment. CONCLUSION: Despite improvement in visual acuity after treatment for CRAO, all patients had residual visual function abnormalities. These abnormalities may be attributed to partial recanalization, conversion of CRAO to multiple branch retinal artery occlusions, or different retinal susceptibility for ischemia.

Diode laser thermal keratoplasty to correct hyperopia.

PURPOSE: We investigated long-term efficacy, predictability, stability, and safety of diode laser thermal keratoplasty (DTK) to correct hyperopia. METHODS: DTK was performed on 24 eyes (18 patients). Eight eyes with high hyperopia (mean +4.75 +/- 0.63 D; range +3.50 to +5.50 D) received 12 pairs of coagulation spots at 6-mm and 7-mm treatment zone diameters; eight eyes with low hyperopia (mean +2.25 +/- 0.40 D; range +1.50 to +2.75 D) received eight coagulation spots at 8 mm, and eight eyes with low hyperopia (mean +1.50 +/- 0.46 D; range +1.25 to +2.25 D) were treated to induce mild myopia (-1.50 D) in the non-dominant eye for monovision using eight pairs of spots at 7 and 8-mm diameters. Minimum follow-up was 18 months. RESULTS: Mean decrease in cycloplegic refraction at 18 months was 5.00 +/- 0.38 D in the high hyperopia group, 1.75 +/- 0.19 D in the low hyperopia group, and 3.25 +/- 0.27 D in the presbyopia group. Mean increase in uncorrected visual acuity (UCVA) at 18 months was 8.125 +/- 2.1 Snellen lines in the high hyperopia group, 6.625 +/- 0.744 lines for low hyperopia; decrease of 1.00 +/- 1.85 line occurred in the presbyopia group. Near UCVA in the presbyopia group improved by 3.875 +/- 0.83 Jaeger lines. Best spectacle-corrected visual acuity (BSCVA) was restored by 3 months in all eyes. CONCLUSION: DTK was an effective and fairly safe procedure, with reasonable predictability and stability. Nomograms for laser energy level, treatment zone diameter, and number of spots need improvement.