Effect of cooled intraocular irrigating solution on the blood-aqueous barrier after cataract surgery

Using continuous intraoperative optical coherence tomography to classify swirling lens fragments during cataract surgery and to predict their impact on corneal endothelial cell damage

PURPOSE

To quantify and classify swirling lens fragments during cataract surgery and record their impact on the corneal endothelium using continuous intraoperative optical coherence tomography (OCT).

SETTING

Vienna Institute for Ocular Surgery, Hanusch Hospital, Vienna, Austria.

DESIGN

Prospective case series.

METHODS

Patients scheduled for cataract surgery without other ophthalmologic comorbidities were included. During surgery, continuous OCT recordings were performed to measure and score swirling lens fragments that came into contact with the corneal endothelium. Endothelial cell density (ECD) was measured preoperatively and 1 month postoperatively. In addition, the central corneal thickness and aqueous flare were measured preoperatively and 1 hour, 1 day, and 1 month postoperatively.

RESULTS

Continuous intraoperative OCT video recordings showed 104 swirling lens fragments in 40 eyes that came into contact with the corneal endothelium. A mean of 2.6 lens fragments (range 0 to 6) that came into contact were observed per eye. Small fragments and fragments touching the center of the endothelium had a significantly greater effect on postoperative ECD than other fragment parameters. The predictive power of the fragment score on ECD was found to be moderate (r(2) = 0.6).

CONCLUSIONS

Small swirling lens fragments touching the center of the corneal endothelium had a significant influence on ECD. With the newly developed fragment score, it was possible to predict the operative endothelial cell loss.

FINANCIAL DISCLOSURE

None of the authors has a financial or proprietary interest in any material or method mentioned.

Laser flare-cell photometer: principle and significance in clinical and basic ophthalmology

A slit-lamp examination is an indispensable and essential clinical evaluation method in ophthalmology, but, it is qualitative subjective. To complement its weaknesses in making a quantitative evaluation of flare intensity and number of cells in the aqueous humor in the eye, we invented the laser flare-cell photometer in 1988. The instrument enables a non-invasive quantitative evaluation of flare intensity and number of cells in the aqueous with good accuracy and repeatability as well as maneuverability equal to slit-lamp microscopy. The instrument can elucidate the pathophysiology in the blood-aqueous barrier (BAB) function in a variety of ocular disorders. The accuracy of the instrument makes it possible to investigate not only the pathophysiology of intraocular disorders but also the effects of various drugs and surgical procedures in BAB. The instrument does not only lighten the burden on patients in clinical examinations and study but it also helps minimize the sacrifice of experimental animals and improves the reliability of the results by minimizing inter-individual variations through its good repeatability. Here I shall relate how the instrument has been applied to clinical and basic studies in ophthalmology and what novel knowledge its application contributed to pathophysiology in ophthalmology.

Intraindividual aqueous flare comparison after implantation of hydrophobic intraocular lenses with or without a heparin-coated surface

PURPOSE

To assess the efficacy of a heparin-surface-modified (HSM) hydrophobic acrylic intraocular lens (IOL) (EC-1YH PAL) and the same IOL without heparin coating (EC-1Y-PAL) by the flare and cell intensity in the anterior chamber after uneventful cataract surgery.

SETTING

Department of Ophthalmology, Paracelsus Medical University Salzburg, Austria.

DESIGN

Comparative case series.

METHODS

Routine phacoemulsification with randomized implantation of an HSM IOL in 1 eye (HSM IOL group) and an uncoated IOL (uncoated IOL group) in the fellow eye was performed. Postoperative inflammation was assessed objectively using a laser flare-cell meter (FM-600) preoperatively as well as 1 day and 1 and 3 months postoperatively. Aqueous cells in the anterior chamber, distance visual acuities, and subjective manifest refraction were also evaluated at each visit.

RESULTS

One hundred eyes (50 patients) were enrolled. In both groups, the mean flare values increased significantly from preoperatively to 1 day postoperatively (P<.001) and nearly reached preoperative values by 3 months postoperatively. One day postoperatively, the mean flare value was statistically significantly lower in the HSM IOL group (14.92 photons per millisecond [ph/ms] ± 7.47 [SD]) than in the uncoated IOL group (mean 16.73 ± 7.81 ph/ms) (P=.04); there was no statistically significant difference between groups 1 and 3 months postoperatively (both P>.58). The HSM IOL group had a greater and quicker decrease in aqueous cells, reaching statistical significance 1 month postoperatively (P=.01).

CONCLUSION

The HSM IOL showed a significant lower inflammatory reaction in the early postoperative stage with a faster disappearance of inflammatory signs.

FINANCIAL DISCLOSURE

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

Effect of heparin coating of a foldable intraocular lens on inflammation and capsular bag performance after cataract surgery

PURPOSE

To evaluate the effect of a heparin-coated foldable intraocular lens (IOL) on postoperative flare in high-risk patients.

SETTING

Vienna Institute for Research in Ocular Surgery, Department of Ophthalmology, Hanusch Hospital, Vienna, Austria.

DESIGN

Randomized clinical trial.

METHODS

This study included patients with diabetes mellitus (DM), pseudoexfoliation syndrome (PXF), or both scheduled for cataract surgery in both eyes. One eye received a coated IOL (Polylens EC-1YH PAL) and the other eye, an uncoated control IOL (Polylens EC-1Y PAL). Aqueous flare measurements were taken using a laser flare meter (FM-600, Kowa) preoperatively and 1 hour, 1 day, 3 weeks, and 3 months postoperatively. Visual acuity and anterior (ACO) and posterior (PCO) capsule opacification were assessed, and IOL centration and tilt were measured with a Purkinje meter.

RESULTS

Eighty eyes of 40 patients were included in the study; 64 eyes of 32 patients completed the study. The mean flare values (photons/ms) preoperatively and 1 hour, 1 day, 3 weeks, and 3 months postoperatively were 6.98 ± 3.71 (SD), 19.14 ± 18.90, 16.62 ± 25.33, 10.33 ± 9.70, 8.74 ± 4.64, respectively, with the coated IOL and 8.65 ± 5.73, 22.08 ± 16.23, 13.44 ± 13.71, 7.50 ± 4.11, and 7.03 ± 3.70, respectively, with the control IOL. No significant differences were found in flare, visual acuity, ACO, PCO, tilt, or centration between the coated IOL and the control IOL at any timepoint.

CONCLUSION

No significant differences in flare or capsule performance were found between the coated IOL and control IOL.

Cryoirrigation in phacoemulsification facilitates a quicker cornea endothelia recovery

OBJECTIVE

To compare the recovery of cornea endothelia after phacoemulsification (phaco) with anterior chamber irrigation at different temperatures.

STUDY DESIGN

A between-group design was used.

PARTICIPANTS

Thirty-eight patients with cataract.

METHODS

Phaco was done on 40 eyes in these patients with exactly the same procedure except for the temperature of the anterior chamber: cryoirrigation at 12 masculine C for group 1 and at room temperature (25 masculine C) for group 2, 20 eyes in each group, randomly distributed. The cornea edema, keratic precipitate (KP), and anterior chamber flare were observed with micro-slit lamp and graded on a 4-point scale at 1, 3, and 7 days after surgery and compared between groups.

RESULTS

The corneas in group 1 were found to be clearer than those in group 2 at 1 and 3 days after surgery. The difference was statistically significant (p < 0.05) in favour of group 1, suggesting a lighter reaction of cornea endothelia and a quicker recovery in group 1 after the surgery with cryoirrigation. Corresponding recovery in group 2 was found to occur latterly between day 3 and day 7. However, the recovery in both groups was complete, yielding no difference between groups, at day 7 after surgery. In addition, no significant difference was found in Tyndall phenomenon and KP between groups.

CONCLUSIONS

Cryoirrigation during phaco could reduce postoperative cornea edema and promote recovery. The result advocates the use of cryoirrigation in clinic.

Comparison between Ringer's lactate and balanced salt solution on postoperative outcomes after phacoemulsfication: a randomized clinical trial

Aim:

To compare the effects of balanced salt solution (BSS) and Ringer's lactate (RL) on corneal thickness, endothelial morphology, and postoperative anterior chamber inflammation in eyes undergoing phacoemulsification.

Setting:

Iladevi cataract and IOL research center, Ahmedabad, India.

Materials and Methods:

This prospective randomized study comprised 90 consecutive patients with age-related cataract who were randomly assigned to either Group 1 (n = 45) with BSS or Group 2 (n = 45) with RL. Observations made included measurement of central corneal thickness (CCT), presence of anterior chamber flare and cells, endothelial cell loss, and change in coefficient of variation (CV). Data was analyzed using Mann Whitney test and test of proportion.

Results:

Mean increase in CCT on postoperative Day 1 was 58 µm and 97 µm in Groups 1 and 2 respectively (P = 0.01). Increase in CCT at one month was 10µm and 11µm in Groups 1 and 2 respectively (P = 0.99); increase in CCT at three months was 3 µm and 6 µm in Groups 1 and 2 respectively (P = 0.86). Number of eyes with flare grades in a range of 0 to 3 was statistically higher in Group 2 on postoperative Day 1 (P = 0.004, 0.016, <0.001, 0.047 for Grade 0, 1, 2 and 3 respectively). Number of eyes with cells of Grade 3 on first postoperative day was significantly higher in Group 2 as compared to Group 1 (P = 0.004). Three months postoperatively, endothelial cell loss was 5.5% and 7.8% in Groups 1 and 2 (P = 0.21) and change in CV was 3 and 5.4 in Groups 1 and 2 (P = 0.20) respectively.

Conclusion:

BSS offers a significant advantage over RL in terms of increase in corneal thickness and postoperative inflammation on the first postoperative day in patients undergoing phacoemulsification.

Quantitative thermographic analysis of viscoelastic substances in an experimental study in rabbits

PURPOSE

To measure the temperature parameters on the corneal surface during the delivery of standardized ultrasound energy assisted with ophthalmic viscosurgical devices (OVDs) or different temperatures of irrigating solutions in an experimental animal model.

SETTING

Department of Ophthalmology and Visual Rehabilitation, Medical University of Lodz, and Central Institute for Labor Protection, National Research Institute, Warsaw, Poland.

METHODS

Thirty rabbits (60 eyes) were randomly divided into 6 groups in which different OVD or balanced salt solutions (BSS) were used: group 1: Viscoat (sodium hyaluronate 3%-chondroitin sulfate); group 2: Provisc (sodium hyaluronate 1%); group 3: soft-shell technique; group 4: Celoftal (hydroxypropyl methylcellulose 2%); group 5: BSS 22 degrees C; and group 6: BSS 4 degrees C. After the nucleus and lens cortex were removed, the anterior chamber was filled with OVD or BSS and a phaco tip was introduced into the pupillary plane and switched on. The same phaco tip parameters were used in all groups. For thermographic measurements (ie, maximal temperature [MT], dynamic rise in temperature [DRT], and time when the maximal level of temperature [TMLT] was achieved), a thermocamera was used.

RESULTS

Mean preoperative temperature on the rabbit corneal surface was 22.76 degrees C +/- 1.48 degrees C (SD). Working with a phaco tip increased the temperature in each group. A significantly higher MT was observed in group 5 (27.85 degrees C +/- 0.52 degrees C), followed by group 2 (27.75 degrees C +/- 0.54 degrees C), group 3 (27.74 degrees C +/- 0.46 degrees C), and group 4 (27.25 degrees C +/- 0.60 degrees C), than in group 6 (26.81 degrees C +/- 0.34 degrees C) and group 1 (26.52 degrees C +/- 0.48 degrees C) (P<.05). Significantly higher values of DRT and shorter TMLT values were observed in group 5 (1.16 degrees C/s +/- 0.42 degrees C/s, 4 seconds) and group 6 (0.91 degrees C/s +/- 0.13 degrees C/s, 5 seconds) than in groups 2, 3, 1, and 4 (0.09 degrees C/s +/- 0.07 degrees C/s, 30 seconds; 0.08 degrees C/s +/- 0.04 degrees C/s, 40 seconds; 0.07 degrees C/s +/- 0.03 degrees C/s, 45 seconds; 0.06 degrees C/s +/- 0.02 degrees C/s, 50 seconds, respectively) (P<.0001).

CONCLUSIONS

Currently used OVDs potentially offer different levels of protection against the increase in temperature that occurs during phacoemulsification. Therefore, the surgeon should consider this aspect when choosing an OVD, particularly in difficult cases (ie, hard nucleus, shallow anterior chamber, endothelial abnormalities).

Early objective assessment of intraocular inflammation after phacoemulsification cataract surgery

PURPOSE

To evaluate the time course of blood-aqueous barrier (BAB) disturbance in the early period after small-incision cataract surgery.

SETTING

Department of Ophthalmology, Vienna University, Vienna, Austria.

METHODS

In a prospective study, 15 eyes of 15 patients with age-related cataract had small-incision cataract surgery by phacoemulsification with intraocular lens implantation. Care was taken to minimize trauma to the uvea during surgery. Postoperative inflammation was assessed by measuring aqueous flare and cell count with a laser flare-cell meter. Postoperative measurements were performed hourly for the first 6 hours, every 2 hours until 12 hours, every 4 hours until 40 hours, and every 8 hours until 56 hours.

RESULTS

The time course of aqueous flare and cell count differed significantly among patients. The peak inflammatory response in most cases was 1 hour after surgery, with the response decreasing thereafter. The pattern of the time course was classified into subgroups defined by the presence and size of an initial spike immediately after surgery and the intensity of the subsequent inflammatory reaction. A slight increase in flare and cells was seen in the morning hours of the first postoperative day.

CONCLUSIONS

Acute BAB disturbance within the first 48 hours after small-incision cataract surgery showed high interpatient variability. However, many differences were not detectable 1 day after surgery.