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November consultation #7
1934
CONSULTATION SECTION
If measurement of the posterior astigmatism is not possible, I would use the Baylor nomogram1 or the new Barrett calculator available at the American Society of Cataract and Refractive Surgery web site.A If the surgery can be completed without fixation of the iridodialysis, it would be the time to close it as detailed above. Anterior vitrectomy, if necessary, should be completed at this time. Postoperatively the patient would be treated with antibiotic and steroid topical drops, similar to regular cataract extraction surgery. However, NSAID topical drops would also be prescribed for an extended period (approximately 2 months). Guy Kleinmann, MD Rehovot, Israel
REFERENCE 1. Koch DD, Jenkins RB, Weikert MP, Yeu E, Wang L. Correcting astigmatism with toric intraocular lenses: effect of posterior corneal astigmatism. J Cataract Refract Surg 2013; 39:1803– 1809
OTHER CITED MATERIAL A. Barrett toric calculator. Available at: http://www.ascrs.org/barretttoric-calculator. Accessed September 3, 2014
- This case in which the patient’s main complaint is photophobia in the right eye requires consideration of several issues; that is, the hard cataract, temporal iridodialysis, and zonular dehiscence with localized vitreous prolapse. It seems as though the lens is not wobbling, and the normal ECC is reassuring. The first question is whether and how to extract the dense cataract considering that the pupil does not dilate well and there is vitreous prolapse. In cases like this, it is advantageous to have several optional plans. I would start by preparing a sclerocorneal tunnel superiorly away from the iridodialysis that can easily be enlarged if conversion to an extracapsular cataract extraction (ECCE) becomes necessary. The use of trypan blue to stain the anterior capsule and of a dispersive OVD to protect the endothelium seems necessary, as does the additional use of a cohesive OVD to slightly push back and block the vitreous prolapse. Although nowadays I prefer a Malyugin ring, an iris retractor from the temporal side should be used for enlargement of the pupil in this case. The retractor could also be used later to suspend the temporal capsulotomy to stabilize the lens during phacoemulsification and irrigation/aspiration. Additional retractors might be necessary to further enlarge the pupil (eg, when converting to ECCE). A regular-sized
curvilinear capsulorhexis of the trypan blue–stained capsule should be feasible. Care should be taken during hydrodissection not to overfill the anterior chamber and luxate the lens. For phacoemulsification, I would use a horizontal chop technique with the Lieberman microfinger to lift the entire lens from the posterior capsule and stabilize the nucleus during phacoemulsification with the aim of not straining the remaining zonular fibers. This is initially performed with a high vacuum setting (400 mm Hg venturi pump) and relatively low pressure (bottle height 85 cm) while the lens behavior, particularly on the temporal side, is observed. Initially, the US energy should be set at approximately 50% in the burst mode to reduce the total amount of power delivered. With the use of the microfinger/chopper, the nucleus can be stabilized and rotated. After the nucleus is chopped in little segments over 360 degrees (care should be taken not to injure the capsule with sharp nucleus fragments), I would switch to pulse to remove the chopped segments. I would implant a regular CTR before placing the IOL in the bag. Should more pronounced subluxation of the lens become evident during surgery, a Cionni ring with a suspension eyelet could be used alternatively. I would not expect the vitreous to cause too much trouble; however, if it did, careful anterior vitrectomy could be necessary at any stage during surgery. Because the patient’s main complaint is photophobia, the last question would be how to address the temporal iridodialysis. I would try to refixate the iris transsclerally. Alternatively, McCannel–Siepser knots could be placed to reduce the pseudopupil. Or, a cut-to-size segment of an artificial silicone iris could be implanted later after a trial of iris-printed contact lenses if the patient still reports photophobia. David Goldblum, MD Basel, Switzerland
- The patient’s eye was injured at the age of 12 years, which means the eye might have become amblyopic. Furthermore, the patient might have lost stereopsis. It is surprising that the glare is worse now than the year before. The temporal iridodialysis might explain these symptoms, although the glare has been present since the injury occurred. The case description says this may be due to the progressive shrinkage of the lens and the consecutive extension of the coloboma.
J CATARACT REFRACT SURG - VOL 40, NOVEMBER 2014
CONSULTATION SECTION
If measurement of the posterior astigmatism is not possible, I would use the Baylor nomogram1 or the new Barrett calculator available at the American Society of Cataract and Refractive Surgery web site.A If the surgery can be completed without fixation of the iridodialysis, it would be the time to close it as detailed above. Anterior vitrectomy, if necessary, should be completed at this time. Postoperatively the patient would be treated with antibiotic and steroid topical drops, similar to regular cataract extraction surgery. However, NSAID topical drops would also be prescribed for an extended period (approximately 2 months). Guy Kleinmann, MD Rehovot, Israel
REFERENCE 1. Koch DD, Jenkins RB, Weikert MP, Yeu E, Wang L. Correcting astigmatism with toric intraocular lenses: effect of posterior corneal astigmatism. J Cataract Refract Surg 2013; 39:1803– 1809
OTHER CITED MATERIAL A. Barrett toric calculator. Available at: http://www.ascrs.org/barretttoric-calculator. Accessed September 3, 2014
- This case in which the patient’s main complaint is photophobia in the right eye requires consideration of several issues; that is, the hard cataract, temporal iridodialysis, and zonular dehiscence with localized vitreous prolapse. It seems as though the lens is not wobbling, and the normal ECC is reassuring. The first question is whether and how to extract the dense cataract considering that the pupil does not dilate well and there is vitreous prolapse. In cases like this, it is advantageous to have several optional plans. I would start by preparing a sclerocorneal tunnel superiorly away from the iridodialysis that can easily be enlarged if conversion to an extracapsular cataract extraction (ECCE) becomes necessary. The use of trypan blue to stain the anterior capsule and of a dispersive OVD to protect the endothelium seems necessary, as does the additional use of a cohesive OVD to slightly push back and block the vitreous prolapse. Although nowadays I prefer a Malyugin ring, an iris retractor from the temporal side should be used for enlargement of the pupil in this case. The retractor could also be used later to suspend the temporal capsulotomy to stabilize the lens during phacoemulsification and irrigation/aspiration. Additional retractors might be necessary to further enlarge the pupil (eg, when converting to ECCE). A regular-sized
curvilinear capsulorhexis of the trypan blue–stained capsule should be feasible. Care should be taken during hydrodissection not to overfill the anterior chamber and luxate the lens. For phacoemulsification, I would use a horizontal chop technique with the Lieberman microfinger to lift the entire lens from the posterior capsule and stabilize the nucleus during phacoemulsification with the aim of not straining the remaining zonular fibers. This is initially performed with a high vacuum setting (400 mm Hg venturi pump) and relatively low pressure (bottle height 85 cm) while the lens behavior, particularly on the temporal side, is observed. Initially, the US energy should be set at approximately 50% in the burst mode to reduce the total amount of power delivered. With the use of the microfinger/chopper, the nucleus can be stabilized and rotated. After the nucleus is chopped in little segments over 360 degrees (care should be taken not to injure the capsule with sharp nucleus fragments), I would switch to pulse to remove the chopped segments. I would implant a regular CTR before placing the IOL in the bag. Should more pronounced subluxation of the lens become evident during surgery, a Cionni ring with a suspension eyelet could be used alternatively. I would not expect the vitreous to cause too much trouble; however, if it did, careful anterior vitrectomy could be necessary at any stage during surgery. Because the patient’s main complaint is photophobia, the last question would be how to address the temporal iridodialysis. I would try to refixate the iris transsclerally. Alternatively, McCannel–Siepser knots could be placed to reduce the pseudopupil. Or, a cut-to-size segment of an artificial silicone iris could be implanted later after a trial of iris-printed contact lenses if the patient still reports photophobia. David Goldblum, MD Basel, Switzerland
- The patient’s eye was injured at the age of 12 years, which means the eye might have become amblyopic. Furthermore, the patient might have lost stereopsis. It is surprising that the glare is worse now than the year before. The temporal iridodialysis might explain these symptoms, although the glare has been present since the injury occurred. The case description says this may be due to the progressive shrinkage of the lens and the consecutive extension of the coloboma.
J CATARACT REFRACT SURG - VOL 40, NOVEMBER 2014