Peter Senn

Combined Pars Plana Vitrectomy, Phacoemulsification, and Intraocular Lens Implantation in the Capsular Bag: A Comparison to Vitrectomy and Subsequent Cataract Surgery as a Two-Step Procedure

BACKGROUND AND OBJECTIVE To evaluate the effectiveness and safety of combined surgery. PATIENTS AND METHODS Combined surgery (CS) consisting of pars plana vitrectomy (PPV), phacoemulsification, and implantation of a posterior chamber intraocular lens (PC IOL) in the capsular bag was performed on 26 patients. Another 26 had phacoemulsification with PC IOL insertion one to 84 months (mean 17.3) after PPV (sequential surgery, SS). Mean follow-up was 21.9 months after CS and 19.5 months after the cataract surgery in the SS group. The data were analyzed in a prospective, nonrandomized fashion. RESULTS Visual acuity and refraction, astigmatism, accuracy of biometry, intraocular pressure, intraoperative, postoperative and long-term complications, and medical treatment were comparable in the two groups. Among the four uveitis patients in each group, transient fibrin formation was more frequent with CS (100%) than with SS (25%). The advantages of CS are that only one operation is needed, intraoperative working conditions are good, macular recovery is not masked by postvitrectomy cataract formation, and ideal lens centration is achievable. Potential disadvantages of CS include a longer operative time and increased technical demand, shrinkage of the anterior capsular opening, which may interfere with fundus view, and increased inflammation may be seen in patients with preexisting uveitis. CONCLUSION Combined surgery in selected patients is a safe and effective approach, and outcomes are comparable to sequential surgery.

Glare sensitivity and visual acuity after excimer laser photorefractive keratectomy for myopia

BACKGROUND Following excimer laser photorefractive keratectomy (PRK), an increase in glare sensitivity and a reduction in contrast sensitivity can occur owing to changes in the cornea (structure and topography). In this study, an attempt was made to quantify and document objectively a change in those subjective perceptual factors. METHODS Snellen visual acuity and disability glare were measured with the Berkeley glare test preoperatively as well as 1, 3, 6, 9, and 12 months postoperatively, after excimer laser photorefractive keratectomy (PRK) on 32 myopic patients (46 eyes). During the postoperative progress checks, haze was graded and contrast sensitivity was measured with the Vistech chart. All the data were statistically analysed by multiple regression. RESULTS One year after PRK, a reduction in visual acuity (VA) measured with the low acuity contrast chart (10%) with and without glare could still be found, despite the fact that acuity measurements with a high contrast Snellen chart showed the same VA 6 months postoperatively as well as before the treatment. The lowest VA could be measured 1 month postoperatively; thereafter, the acuity increased despite the increase in haze that occurred during the first 3 months. CONCLUSION Disability glare and a reduction in contrast sensitivity could be observed in most patients after PRK treatment with the Meditec laser system with its scanning slit. The future will show if new technology and a broader flattening area of 6 to 7 mm can minimise these postoperative complications.

Central and peripheral pressure measurements with the Goldmann tonometer and Tono-Pen after photorefractive keratectomy for myopia.

Purpose: To compare the accuracy of Goldmann tonometry with that of the Tono‐Pen® in measuring intraocular pressure (IOP) after photorefractive keratectomy (PRK). Setting: Eye Clinic, Cantonal Hospital, Lucerne, Switzerland. Methods: Thirty‐five eyes (25 patients) had PRK for a mean myopia of −6.2 diopters ± 2.6 (SD). Intraocular pressure (IOP) measurements were performed first with the Goldmann tonometer and then with the Tono‐Pen in 2 corneal locations: centrally in the usual manner and temporally. For the temporal measurements, the patient was directed to gaze nasally as the tonometer was placed perpendicular to the temporal portion of the cornea and with the rim of the tonometer positioned just inside the limbus of the cornea. Subsequently, similar measurements were made with the Tono‐Pen. Measurements were performed before and 1 and 3 months after PRK. Results: Preoperative IOPs measured centrally and temporally were similar. After PRK, the central pressure readings with the Goldmann tonometer and the Tono‐Pen were between 1.8 and 2.3 mm Hg lower than those measured temporally. The differences were statistically significant (P < .0001). Conclusion: Central corneal pressure readings obtained with either the Goldmann tonometer or the Tono‐Pen after myopic PRK are inaccurate. Measurements over the temporal part of the cornea are likely more reliable.

Glare sensitivity and optical side effects 1 year after photorefractive keratectomy and laser in situ keratomileusis

Purpose: To compare the outcome of low‐contrast visual acuity and glare sensitivity after photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK). Setting: Department of Ophthalmology, Cantonal Hospital of Lucerne, Lucerne, Switzerland. Methods: In this prospective study, patients selected PRK or LASIK after the advantages and disadvantages of both had been described. Snellen visual acuity and disability glare were measured with the Berkeley glare test preoperatively and 1 year postoperatively. At the 1‐year follow‐up, haze was graded and patients had to assess their quality of vision subjectively. Results: One‐year follow‐up of 58 patients in the PRK group and 64 patients in the LASIK group was achieved. In both groups, the mean uncorrected visual acuity was 20/32 (P = .63) and the mean best corrected visual acuity, 20/20 with no statistically significant difference (P = .20). There were no preoperative or postoperative differences between the 2 groups in low‐contrast visual acuity under 4 glare conditions. At 1 year, LASIK eyes had significantly lower postoperative haze scores than PRK eyes (P = .0013). The number of eyes with visually moderate and disturbing halos or disturbances in night vision did not differ considerably between the groups (P = .88). Conclusions: Efficacy outcomes were generally similar in the PRK and LASIK groups. Both achieved good objective and subjective results after treatment with a second‐generation excimer laser.

Interaction Between Silicone Oil and Silicone Intraocular Lenses: An In Vitro Study

The objective of this study was to examine the interaction between silicone oil and silicone intraocular lenses (IOLs) in vitro. Six types of silicone IOLs were placed in silicone oil (1000 or 5000 centistokes) for 1 minute, 7 days, and 420 days. Slit-lamp examination, target photographs, and opacity measurements were performed. Optical measurements were repeated in a balanced salt solution after removal from the oil. The IOL surface was examined through scanning electron microscopy, and surface irregularities underwent x-ray spectroscopy. No changes were observed while the IOLs were stored in silicone oil, but in the balanced salt solution, the IOLs were observed to have a layer of silicone oil droplets that reduced the optical quality. Scanning electron microscopy showed that oil-coated foreign body particles were simulating IOL surface defects. After ultrasonic cleaning with ethanol, the oil layer was broken, and no damage to the IOL surface could be detected. The length of exposure to silicone oil, the type of oil, and the type of IOL were found to have no bearing on the interaction between silicone oil and silicone IOLs. Although no surface damage is incurred by silicone IOLs from silicone oil, the reduction in optical quality and fundus view due to remnant oil droplets seems to indicate that complex cases requiring silicone oil injection may contraindicate IOLs made of silicone.

Bubbles in the Bleb-Troubles in the Bleb? Molteno Implant and Intraocular Tamponade With Silicone Oil in an Aphakic Patient

A 14-year-old aphakic girl who had had previous bilateral glaucoma surgery with a Molteno implant underwent pars plana vitrectomy and silicone-oil tamponade for proliferative-vitreoretinopathy retinal detachment in both eyes. The filtering bleb of the left eye was functional for 5 months before becoming available for histologic examination. We found numerous foreign-body granulomas coating the inner surface of the bleb, as well as intracellular and extracellular deposits of emulsified silicone oil in the wall of the bleb. In the fellow eye, the filtering bleb remained functional despite repeated vitreous surgery with silicone oil. Filtration in aphakic eyes with previous Molteno surgery and silicone-oil tamponade after vitrectomy may continue normally for a prolonged period of time, although emulsified oil droplets likely will have accumulated in the bleb and become incorporated in its fibrous capsule.

Photoastigmatic refractive keratectomy for primary treatment and revision of myopic astigmatism

Purpose: To evaluate the results in 43 eyes treated with a rotating mask for myopic astigmatism and followed for up to 1 year. Setting: Lucerne Eye Clinic, Cantonal Hospital, Lucerne, Switzerland. Methods: Thirty‐two patients (42 eyes) were selected to have photoastigmatic refractive keratectomy (PARK). In 33% (14 eyes), this treatment was the second or third ablation. The Aesculap Meditec MEL 60 excimer laser was operated in the scanning slit mode, and a rotating mask was used. To evaluate cylindrical shaping, vector analysis was performed. Results: One year after PARK, mean uncorrected visual acuity in all patients (26 eyes) improved from 20/160 preoperatively to 20/40. Surgically induced astigmatism in 20 of 26 eyes (77%) was within ±1.00 diopter (D) of the targeted induced astigmatism. At 1 year, 81% of patients who had primary excimer laser treatment for myopic astigmatism equivalent to −10.00 D or less were within ±1.00 D of target refraction compared with 44% of re‐treated eyes. Conclusion: The result of PARK in eyes with low to moderate degrees of myopic astigmatism was satisfactory. However, in eyes with extensive scarring and wound healing activity after the first ablation, re‐treatment was less predictable.

Combined pars plana vitrectomy and phacoemulsification with intraocular lens implantation in severe proliferative diabetic retinopathy.

The authors report a case of acute development of an extensive retrobulbar abscess 3 weeks after an orbital floor fracture. Urgent drainage of the abscess was performed by an anterior transconjunctival approach. A dramatic recovery was observed a few days following the operation. The visual acuity increased from hand motions to 0.7 to 0.8 in the early postoperative period and to 1.0 shortly thereafter. The severity of infection, the importance of antibiotic prophylaxis for blowout fractures, and the efficacy of the transconjunctival approach on the final visual and functional outcome are described.A 38-year-old man with human immunodeficiency virus was referred for evaluation of retinal lesions in both eyes. Optical coherence tomography was performed after dilating the pupils. Biomicroscopy of the retina showed an atypical, solitary, yellowish-white lesion in the macula of both eyes with no inflammation of the vitreous. Optical coherence tomography of the lesions showed an area of extremely low reflectivity with well-defined but irregular borders in the outer retina. The surrounding retina showed normal reflectivity and was of normal thickness. Optical coherence tomography showed selective necrosis of the outer layers due to progressive outer retinal necrosis. Optical coherence tomography may serve as a useful tool for the early diagnosis of progressive outer retinal necrosis.

Diagnosis and management of bilateral posterior lenticonus in 7 members of the same family.

PURPOSE: To report on the occurrence of monosymptomatic bilateral posterior lenticonus in 7 members of the same family and discuss the diagnoses and methods of management. SETTING: Eye Clinic, Cantonal Hospital, Lucerne, Switzerland. METHODS: Two sisters were found to suffer from bilateral posterior lenticonus. The 3 sons of the elder sister and the 2 daughters of the younger sister all presented with bilateral posterior lenticonus. A cataract operation or a clear lens extraction with intraocular lens implantation was performed in 4 of the 7 patients. RESULTS: The disorder was found to be inherited and to follow a pattern of autosomal dominance. Visual acuity improved to 20/20 in all operated eyes. CONCLUSION: This may be the largest group in 1 family presenting with bilateral posterior lenticonus described to date. Treatment of posterior lenticonus, if necessary, can be successfully managed as an ordinary cataract.

Correction of astigmatism with Excimer laser transverse keratectomy

Abstract. Transverse keratectomies with the Excimer laser were performed on seven eyes of 4 patients with a mean, naturally occurring astigmatism of 5.32D (sd 1.0), range 4.25 to 7.0D. One month later mean astigmatism was 3.46D (sd 1.35), 3 months later 3.8D (sd 1.35), rising to 4.3D (sd 1.6) after 6 months, and to 4.68 (sd 1.4) after 1 year. The refractive cylinder was reduced from a mean of 5.8D to 4.5D and the mean unconnected visual acuity rose from 0.16 to 0.3. No serious complications occurred, and uncorrected visual acuity could be improved slightly. Excimer laser transverse keratectomy cannot be recommended as a good method to treat high degrees of naturally occurring astigmatism.