[Pseudoexfoliation syndrome and cataract surgery. Avoidance and treatment of complications]

Short-term fluctuation of lens corneal distance and clinical correlation with phacodonesis

BACKGROUND

To analyze the role of short-term lens-corneal distance (LCD) fluctuation in quantifying preoperative phacodonesis and predicting intraoperative zonular weakness.

METHODS

Patients were divided into control (lens without clinical phacodonesis) and study (lens with suspicious and clinical phacodonesis) groups for evaluation. Slit-lamp examination followed by IOLMaster (Carl Zeiss) for LCD assessment was performed. Five readings were taken at five time points (0 s, 15 s, 30 s, 45 s & 60 s) continuously over a minute (short term) for the LCD fluctuation calculation.

RESULTS

A total of 135 eyes (82 controls and 53 study) were assessed. Study group included 32 (60.3%) suspicious and 21 (39.6%) moderate to severe phacodonesis. There was difference between the control and study eyes (p = 0.000) in short-term LCD fluctuation. Twenty-one study eyes (39.6%) showed LCD difference > 1 mm, including 11 eyes (52.3%) with > 2 mm. There was a difference in LCD with respect to severity of phacodonesis (p = 0.000). In the study eyes, 13 eyes underwent glued IOL implantation (clinical phacodonesis - ten, suspicious phacodonesis - three), and two eyes (suspicious phacodonesis) had glued capsular hook. Thirteen eyes (clinical phacodonesis - ten, suspicious phacodonesis - three) required intraoperative vitrectomy due to vitreous ingress. Intraoperative zonular weakness in 62.5% of eyes with suspicious donesis and association (Chi-square = 0.000) of weakness with preoperative LCD fluctuation was noted.

CONCLUSIONS

Short-term lens-corneal distance fluctuation can be used as a parameter for quantifying lens stability and as an aid in assessing the intraoperative risk.

Intraoperative intracameral pilocarpine after capsular tension ring and capsule/iris hook insertion in pediatric eyes with subluxated cataract

Capsular tension rings and iris hooks have proved to be useful devices in cataract surgery in cases of zonular weakness and dialysis. We describe the use of intracameral pilocarpine-induced pupillary miosis to couple the iris and the capsulorhexis edge with iris hooks during phacoemulsification in pediatric cases with posttraumatic subluxated cataractous lens. The coupled iris and capsule act as a single unit, eliminating the space between them and significantly reducing the possibility of vitreous or ophthalmic viscosurgical device passing through the zonular defect.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.

[Femtosecond laser in cataract surgery. A critical appraisal]

BACKGROUND

The use of femtosecond lasers (FSL) is increasingly spreading in cataract surgery. Potential advantages over standard manual cataract surgery are the superior precision of corneal incisions and capsular openings as well as the reduction of ultrasound energy for lens nucleus work-up. Exact positioning and dimensioning of the anterior capsular opening should help reduce decentration and tilt of the intraocular lens (IOL) optics and thus achieve better target refraction. Together with the possibility to correct low-grade corneal astigmatism by precise arcuate incision, FSL technology is expected to convert cataract surgery from a purely curative into a refractive procedure.

METHODS

Apart from own experiences this review article critically analyses the pertinent literature published so far as well as congress presentations and personal reports of other FSL surgeons. The advantages and disadvantages are scrutinized with regard to their impact on the surgical and refractive results and compared with those experienced by the authors with manual cataract surgery over several decades. Economic and healthcare political aspects are also addressed.

RESULTS

The use of FSL surgery improves the precision and reproducibility of corneal incisions and the capsular opening and reduces the amount of ultrasound energy required for lens nucleus work-up. However, the clinical benefits must be put into perspective due to the subsequent surgical manipulation of the incisions (during lens emulsification, aspiration and IOL injection), the lacking possibility to visualize the crystalline lens equator as the reference for correct capsulotomy centration and the relativity of ultrasound energy consumption on the corneal endothelial trauma. This is of particular relevance against the background of the significantly higher costs. Conversely, tears of the anterior capsule edge which, apart from interfering with correct IOL positioning, may entail serious complications presently occur more frequently with all FSL instruments. From the economic and healthcare political viewpoint, thought should be given to the possible acquisition of the cataract surgical business by the industry or investors, as cataract surgery is a high-volume standardized procedure with enormous future potential. This could fundamentally change our currently decentralized and individualized structures and subsequently the steam of patient and make surgeons largely dependent or superfluous.