Survival and success rates of soft-milled cobalt-chromium-ceramic full-arch screw-retained implant-supported prostheses: a 2- to 7-year follow-up retrospective study

OBJECTIVES

To retrospectively assess implant and prosthesis survival and success and patient satisfaction in edentulous patients treated with soft-milled cobalt-chromium-ceramic full-arch screw-retained implant-supported prostheses (SCCSIPs) over a mean clinical follow-up period of 4 years.

MATERIALS AND METHODS

Twenty-one edentulous patients, aged 47-80 years, underwent restoration with 27 SCCSIPs (210 implants, 349 crown units). After definitive prosthesis insertion, patients participated in a yearly dental check-up recall program, including clinical and radiographic examinations. All supporting implants were examined for biological and technical complications, and the restorations were evaluated using modified California Dental Association (CDA) criteria. Life table and Kaplan-Meier survival analyses were performed. Patient satisfaction regarding chewing, esthetics, comfort, and phonetics was evaluated using a visual analog scale (VAS).

RESULTS

After a mean of 4 years, two implants (3.8%) failed, with no effect on prosthesis survival. The cumulative survival rate was 98.6% and 100% for implants and prostheses, respectively. The most frequent minor biological complication was soft tissue recession (11%). Porcelain fracture was the only major technical complication (0.6% of crown units), while the only minor technical complication was porcelain chipping (4% of crown units), which required only polishing. Overall, 66.7% of the prostheses were free of technical complications. Patient satisfaction was high to very high. Less satisfaction was noted with comfort due to soft tissue recession and food impaction.

CONCLUSIONS

Within the limitations of this study, we conclude that the survival and success rates of SCCSIPs in edentulous patients were excellent.

CLINICAL RELEVANCE

SCCSIPs should be considered when planning metal-ceramic implant-supported restorations.

Complete rehabilitation of patients with bruxism by veneered and non-veneered zirconia restorations with an increased vertical dimension of occlusion: an observational case-series study

PURPOSE

To assess the clinical performance of the complete rehabilitation of a series of patients with bruxism treated by teeth- and implant-supported veneered and non-veneered zirconia restorations with an increased vertical dimension of occlusion (VDO).

METHODS

Ten patients with bruxism, aged 62-70 years, were treated with 108 veneered and 142 non-veneered zirconia restorations and attended the recall appointment. The mean observation period was 28.2 (±16.8) months. The patients were identified from records, and clinical details were retrieved from their files. In the recall appointment, the restorations were evaluated using modified California Dental Association (CDA) criteria. The periodontal probing depth, bleeding index, presence of caries and implant survival and success rate were recorded.

RESULTS

No biological complications were recorded for any restorations. The success and survival rate of all implants was 100%. The overall mean survival and success rate of all restorations was 99.6%. In the veneered group, the predominant complication was minor veneer chipping (13.9%) on the incisal edge, which required only polishing (grade 1); in the non-veneered group, the predominant failure was open proximal contacts between the implant restoration and adjacent teeth (9%); only one implant restoration needed repair. One restoration was replaced due to a horizontal tooth fracture.

CONCLUSIONS

Within the limitations of this study, we conclude that the survival and success rate of monolithic zirconia restorations installed in patients with bruxism was excellent, although the veneered zirconia restorations showed a high rate of minor veneer chipping, which required only polishing.

Marginal Fit and Retention Strength of Zirconia Crowns Cemented by Self-adhesive Resin Cements

The absolute marginal gap (AMG) precementation and postcementation and the retention of zirconia crowns cemented to standardized molar preparations (4×10) by self-adhesive resin cements (SARCs) were evaluated. The following SARCs were used: RelyX U-200 (RXU200; 3M ESPE, Seefeld, Germany), SmartCem 2 (SC2; Dentsply, Milford, DE, USA), and G-Cem Automix (GCA; GC, Alsip, IL, USA). The control adhesive resin cement was Panavia 21 (PAN; Kuraray Dental Co Ltd, Osaka, Japan). Twenty measuring locations at a constant interval along the margins were marked, and the AMG was measured by an image analysis system connected to a stereomicroscope (20×). The cemented copings were aged 270 days at 100% humidity and 37°C and then underwent 10,000 thermal cycles, 5°C-55°C. After aging, the crowns were tested for retention, and the debonded surfaces were examined at 3× magnification. The mean marginal gaps precementation and postcementation were 34.8 ± 17.4 μm and 72.1 ± 31 μm, respectively, with no statistically significant differences between the cements. A significant difference ( p≤0.001) in retention between the cements was found. The highest values were obtained for SC2 and GCA (1385 Pa and 1229 Pa, respectively), but these presented no statistically significant differences. The lowest values were found for PAN and RXU200 (738 Pa and 489 Pa, respectively), but these showed no statistically significant differences. The predominant mode of failure in all of the groups was mixed, and no correlations were found between marginal gap and retention.

The effect of enriching denture adhesives with chlorhexidine diacetate on the proliferation of Candida albicans: an in vitro analysis

Denture adhesives are widely used in dentistry. The growth of Candida albicans on the denture base is common on both jaws, particularly in elderly patients. A strong correlation has been found between the growth of Candida albicans and dentures, potentially leading to denture stomatitis. Recent studies show that the addition of chlorhexidine diacetate (CHDA) to denture adhesives can have a protective effect against denture stomatitis. The aim of this research is to examine the antifungal properties of three denture adhesives when CHDA is added. We hypothesize that the addition of CHDA to denture adhesives will result in antifungal activity against Candida albicans. Three denture adhesive materials (Corega, Protefix and Kukident) were prepared with and without the addition of CHDA in order to measure whether CHDA increased the resistance of the adhesives to the growth of Candida albicans. Dynamic and static intercellular changes were assessed through direct contact test (DCT) and confocal microscopy. The tested materials were evaluated immediately after setting and at 14 days post-setting. When combined with CHDA, all three denture adhesive materials decreased Candida albicans growth compared to the control (p less than 0.0001). This inhibition of growth was more prominent in the first 24 h. The confocal microscopy results supported the DCT findings. The addition of CHDA to denture adhesive pastes inhibits growth of Candida albicans, and may potentially reduce the incidence of denture stomatitis. Further studies are warranted.

The association between dental wear and reduced vertical dimension of the face: a morphologic study on human skulls

OBJECTIVE

The aim of this study was to explore the relationship between dental wear and facial morphology, with particular reference to the occlusal vertical dimension, in modern human skulls.

DESIGN

One hundred and three skulls (52 men and 51 women) between the ages of 20 and 50+ years old were studied. The selected skulls were from a modern period (the 17th and the 18th centuries) and included at least one entire condyle and had at least 3 posterior teeth (premolar or molar) in each quadrant to allow for dental articulation. Occlusal wear was evaluated using ordinal scale (0-4) and vertical occlusal dimension was evaluated by measuring upper facial height (UFH), lower facial height (LFH), LFH-to-UFH ratio (L-U-R) and dental wear. Based on the occlusal wear score, two groups were defined: with and without significant wear.

RESULTS

Significant relation was observed between age and dental wear (P<0.01). No significant differences were found in the LFH (P=0.847) or UFH (P=0.108) between the two wear groups. In addition, no significant difference (P=0.132) was demonstrated in the LFH-to-UFH ratio between the groups. No difference was observed in the dental wear score between genders (P=0.321).

CONCLUSION

Within its limitations, this study demonstrated that dental wear does not influence the vertical dimension of occlusion. Our assumption is that the dento-facial complex fully compensates for the dental effects of wear throughout life.

[Impressions techniques--Part 2]

A dental impression is a positive replica of the teeth, the surrounding gingiva and the border between them; the purpose of which is to create an accurate master model. Two major techniques for impressions exist today: The conventional and the digital impressions. The current article describes both techniques. In the conventional impressions, it is important to choose a proper tray, stock or custom, and to mix the material properly. The commonly used impression techniques for making a conventional impression are described with a review on the effect of the technique on its accuracy. The effect of the wash bulk on the accuracy of the stone dies and/or the restoration is discussed, as well. The digital impressions with their advantages and disadvantages are described in comparison to the conventional impressions. Although, digital impressions eliminate some of the negative characteristics of conventional impressions, proper soft-tissue management and isolation of tooth preparation margins is still mandatory.

[Tissue displacement and impression techniques--part 1]

In order to create an accurate model of the soft and hard tissues of the mouth, a complete control of the gingiva around the prepared teeth is needed. This gingiva must be displaced and bleeding must be avoided. This article describes the three techniques for tissue displacement: mechanical, chemicomechanical and surgical. Mechanical displacing the gingiva can be done by either the use of copper bands or with plain retraction cord. By combining chemical action with packing of a retraction cord a chemicomechanical displacement of the tissue can take place. The surgical retraction is possible by Laser, Electro surgery or Rotatory curettage. The advantages, disadvantages, and limitations of each of the different techniques are discussed. In addition, the different hemostatic agents are described with their mechanism of action, indications and contra-indications of each one of them.

[Elastomeric impression materials]

Elastomeric impression materials are in common use. The impression taken should be highly precise, thus, requiring specific care when manipulatingthese materials. There are 4 groups of elastomers; polysulfide, condensation silicone, addition silicone and polyether; each differ in their setting mechanism and their physical and chemical properties. This review elaborates the major properties of elastomers and its implications on their use. The impression material is inserted into the patient's mouth in a viscous state and transforms into viscoelastic state, upon withdrawal, influencing the residual deformation. The requirements are minimal residual deformation or maximal elastic recovery. As the mouth is a wet environment a major consideration is hydrophilicity. The wettability which is estimated by measuring either the contact angle of a droplet of water and the substrate post setting or the contact angle of a droplet of impression material and the wet tooth pre setting, determines the interaction of the material with both mouth fluids and gypsum. As the primary end target is to obtain a model depicting accurately the oral details, an attention to the impressions' compatibility with gypsum should also be given. Many studies were conducted to get a thorough understanding of the hydrophilic properties of each material, and the mechanism utilized, such as surfactants in hydrophilic PVS. Polyether is the only material that is truly hydrophilic; it exhibits the lowest contact angle, during and after setting. Recent studies show that during setting the Polyether hydrophilicity is increased compared to the condition after setting. Dimensional stability, a crucial property of the impression, is affected by the physical and chemical attributes of the material, such as its tear strength. Polysulfide has the highest tear strength. Tear Strength is affected by two major parameters, viscosity, a built-in property, and how fast the impression is pulled out of the mouth, the faster the impression is loaded and pulled out, the higher the tear strength is. The clinical use is dictated from the properties of each impression material, and the understanding of those enables the practitioner to minimize failures.

Is cataract associated with cardiovascular morbidity?

AIMS

To evaluate the prevalence of cardiovascular disease (CVD) and its risk factors among patients undergoing cataract surgery.

METHODS

A retrospective observational case-control study of all the members older than 50 years who underwent cataract surgery in the Central District of Clalit Health Services in Israel (years 2000-2007) (n=12,984) and 25, 968 age- and gender-matched controls. We calculated the prevalence of CVDs' and their risk factors, including carotid artery disease (CAD), peripheral vascular disease (PVD), systemic arterial hypertension (HTN), chronic renal failure (CRF), ischaemic heart disease (IHD), congestive heart failure, diabetes, smoking, alcohol abuse, and hyperlipidaemia. The main outcome measures were the odds ratio of having CVDs among cataract patients undergoing surgery compared with controls.

RESULTS

No difference was found in demographics (age, gender, marriage status, socioeconomic class, and living place) between the study and control groups. All CVDs' risk factors were significantly more prevalent in cataract patients in univariate analysis. Multivariate logistic regression analysis revealed a significant association of the following with cataractogenesis: diabetes, CAD, HTN, PVD, smoking, IHD, CRF, hyperlipidaemia, and Ashkenazi origin.

CONCLUSIONS

CVDs and their risk factors are more prevalent among cataract patients undergoing cataract surgery.

Long term effect on IOP of a stainless steel glaucoma drainage implant (Ex-PRESS) in combined surgery with phacoemulsification

AIM

To evaluate the efficacy and safety of a stainless steel miniature glaucoma drainage device (Ex-PRESS R50) for the surgical treatment of primary open angle glaucoma (POAG) and cataract when combined with phacoemulsification.

METHODS

Clinical, prospective, multicentre, single treatment arm, non-randomised, non-masked study. The Ex-PRESS device was implanted at the limbus under a conjunctival flap. Phacoemulsification cataract extraction and in the bag IOL implantation were performed through clear cornea temporally.

PRIMARY OUTCOME

IOP change; secondary outcomes: side effects and VA changes.

RESULTS

26 eyes of 25 patients were implanted with the device. The mean (SD) follow up was 23.9 (10.4) months and the mean age was 75.1 (7.1) years. 17/26 eyes have more than 3 years of follow up. One case was discontinued because of device removal, one because of death, and three were lost to follow up.

EFFICACY

preoperative IOP was 21 (4) mm Hg; at 1, 2, and 3 years IOP was 15.3 (3.1) mm Hg (35% reduction), 16.6 (2.7) mm Hg (29% reduction), and 16 (2.6) mm Hg (22% reduction) respectively. Kaplan-Meyer determined overall success rate (IOP < or = 21 mm Hg at the last visit with or without medications) as 76.9%. The number of antiglaucoma medications was reduced by 95% at year 1. Only six patients (23%) were taking IOP lowering treatment at their last visit, five with one medication and one with two medications. Side effects: early postoperative complications were clinically mild and included six cases of hypotony (IOP <5 mm Hg), three cases of hyphaema (<2 mm) with no clinically significant further effects. Long term complications were two cases (7.7%) of device rotation (one treated by reposition) and three cases (11.5%) of conjunctival erosion at 2 and 3 years.

CONCLUSIONS

The Ex-PRESS implant, combined with phacoemulsification cataract extraction, is clinically safe and effective, maintaining in the long term a large reduction in IOP and in the number of antiglaucoma medications.

Long-term follow-up of occlusion therapy in amblyopia

OBJECTIVE

To determine whether the results of occlusion therapy for amblyopia are maintained into adulthood.

DESIGN

Prospective, observational case series.

PARTICIPANTS

Fifty-four patients, who were successfully treated in childhood for unilateral amblyopia by occlusion, were followed up to the age of 9 years, were evaluated in 1984 for long-term results 6.4 years on average after cessation of treatment, and accepted our invitation for reevaluation in 1999.

METHODS

All patients were given a complete eye examination. The visual acuity (VA) was measured.

RESULTS

The average period of follow-up was 21.5 years (range, 17.2-25.1 years). The mean age at the most recent examination was 29.0 +/- 2.1 years (range, 25.1-34). At this examination, a best-corrected visual acuity (BCVA) of 20/40 or better was achieved by 72.3% of the patients. The mean BCVA was 20/35 (20/25-20/70) at the end of occlusion therapy, 20/45 (20/20-20/300) in 1984, and 20/34 (20/15-20/100) at the present examination. Relative to the results at the end of therapy, BCVA at the present examination was maintained or improved in 66.7% of the patients. Relative to 1984, the BCVA in 1999 was maintained or improved in 87% of the patients.

MAIN OUTCOME MEASURE

Visual acuity.

CONCLUSION

Comparative evaluation of BCVA at a long-term follow-up examination, performed 21.5 years on average after cessation of occlusion therapy, showed that VA was maintained or improved in two thirds of patients who had been successfully treated by occlusion for unilateral amblyopia in childhood.

Bacterial keratitis after [correction of following] laser in situ keratomileusis

PURPOSE

The development of bacterial keratitis after laser in situ keratomileusis (LASIK) has been described in only a few isolated cases. We report the development of bacterial keratitis as a postoperative complication of LASIK in three subjects.

DESIGN

A retrospective interventional small case series.

PARTICIPANTS

Three patients who underwent LASIK for correction of myopia during July and August 1998 and had bacterial keratitis develop after surgery.

METHODS

Bacterial keratitis was encountered in the operated eyes between 1 and 22 days after surgery. Topical antibiotic therapy was administered. In one eye, which had significant opacification and irregularity of the flap was developed, lamellar keratoplasty was performed.

MAIN OUTCOME MEASURES

Postoperative inflammation was followed clinically and photographically until it resolved. Visual acuity was measured at intervals throughout the follow-up period.

RESULTS

Keratitis resolved within 3 to 16 days of starting antibiotic therapy. The final best-corrected visual acuities were 20/30, 20/15, and 20/25.

CONCLUSIONS

Although infectious keratitis after LASIK is an infrequently reported event, it should be discussed preoperatively with patients as a possible complication.

[Toxic optic neuropathy caused by methanol poisoning]

A 40-year-old woman attempted suicide by drinking methanol. Her visual acuity began to deteriorate 36 hours later and was found to be 6/60 in her right eye with no light perception in the left. No systemic manifestations other than the eye symptoms were found. In the following months visual acuity improved without specific therapy. 2 months following the methanol, visual acuity was 6/6 in the right eye and finger-counting at 1 meter in the left eye. There was pronounced optic atrophy in the left eye, as well as a central defect in the left visual field due to the methanol toxicity.

Long-term effect of hypermetropic anisometropia on the visual acuity of treated amblyopic eyes

AIM

To evaluate the effect of the extent of hypermetropic anisometropia on the long term visual acuity results in amblyopic eyes following their treatment by occlusion.

METHODS

The visual acuity of 86 patients, who had been treated for unilateral amblyopia by occlusion of the fellow eye and followed up at least to the age of 9 years, was examined 6.4 years, on average, after cessation of treatment. Patients were divided into two groups--those with a small amount of hypermetropic anisometropia, where the spherical equivalent difference between the eyes ranged between 0 and +1.50 dioptres, and those with a large amount of hypermetropic anisometropia, where the difference was +1.75 dioptres or greater.

RESULTS

Deterioration of visual acuity after cessation of occlusion treatment occurred in 51% of the patients in the group with a small amount of anisometropia and in 75% of the patients in the group with a large amount. At cessation of treatment, the average visual acuity in both groups was 20/40+. At the long term follow up examination, however, the average visual acuity was 20/40- and 20/70, respectively. This difference was statistically significant.

CONCLUSIONS

Hypermetropic anisometropia greater than 1.50 dioptres appears to be a risk factor for deterioration of visual acuity in the long term, following treatment of amblyopic eyes by occlusion of the fellow eye.

Shear bond strength of several new core materials

This study compared the shear bond strengths of three core materials: a light activated glass-ionomer cement (VariGlass VLC), a fluoride-release dual cure composite resin (Fluoro Core), and a conventional silver-reinforced glass-ionomer cement (Miracle Mix) when cured to dentin. Fifty-four noncarious molar teeth were extracted, cleaned, mounted in acrylic resin, and sectioned horizontally to expose the dentin surface. Each material was mixed according to manufacturer's instructions, applied in a premade mold to the exposed dentin, and then cured. The specimens were randomized into three group (six teeth from each material) and stored (37 degrees C, 100% humidity) for 15 minutes, 24 hours, and 24 hours and were then thermocycled (5 degrees to 55 degrees C) for 125 cycles. The specimens were tested for shear bond strength with the Instron universal testing machine. The differences among time groups were not statistically significant except for Miracle Mix and VariGlass VLC cements, which showed a greater improvement with thermocycling. This study indicated that the FluoroCore resin exhibited the greatest shear bond strength of the core materials and that VariGlass VLC cement had greater bond strength than Miracle Mix cement except after thermocycling, when VariGlass VLC cement and FluoroCore resin were not significantly different.

Results of treatment with topical mitomycin C 0.02% following excision of primary pterygium

AIMS

The effectiveness of instillation of mitomycin C eyedrops on the recurrence rate of pterygium was assessed in patients undergoing primary pterygium surgery. Any side effects were also noted.

METHODS

Primary pterygia in 38 consecutive patients were surgically excised during July to December 1992. After surgery, mitomycin C 0.02% eyedrops twice daily for 5 days as well as dexamethasone 0.1% four times tapered for the next 6 weeks were instilled. Postoperative follow up ranged from 6 to 11 months.

RESULTS

In one patient the pterygium recurred after 3 months (recurrence rate 2.6%). The side effects encountered were: avascularised sclera in 13 cases between 1-10 months postoperatively; ocular discomfort and lacrimation in five cases; superficial punctate keratitis during the first month in three cases; pyogenic granuloma in two cases. In one patient steroid induced increased intraocular pressure was found 4 weeks after surgery. The adverse side effects were all mild, self limiting, and easily treated.

CONCLUSION

This study suggests that postoperative instillation of mitomycin C 0.02% eyedrops twice daily for 5 days following excision of primary pterygium is an effective and safe treatment to obviate pterygium recurrence.

Factors affecting long term results of successfully treated amblyopia: initial visual acuity and type of amblyopia

AIMS

The study aimed to assess the effect of initial visual acuity and type of amblyopia on the long term results of successfully treated amblyopia.

METHODS

The visual acuity of 94 patients, who had been successfully treated for unilateral amblyopia by occlusion of the good eye and followed up to the age of 9 years, was examined 6.4 years, on average, after cessation of treatment. Patients were divided into two groups according to the depth of amblyopia before occlusion therapy was started: those with visual acuity between 20/60 and 20/100 and those with visual acuity of 20/100 or worse.

RESULTS

Deterioration of visual acuity was observed in 42% of patients in the first group and in 63% of patients in the second group. Their average deterioration, as measured by the Snellen chart, was 0.58 and 1.54 lines, respectively. The results were also assessed by the division of patients into three groups according to the type of amblyopia: strabismic, strabismic anisometropic, and anisometropic. Deterioration of visual acuity occurred in 46%, 79%, and 36% of patients in these three groups, with an average deterioration on the Snellen chart of 0.70, 2.04, and 0.64 lines, respectively.

CONCLUSION

It is concluded that low initial visual acuity and strabismic anisometropic amblyopia are risk factors for deterioration of visual acuity in the long term, following the successful earlier treatment of eyes with amblyopia.

A comparison of the diametral tensile strength, the flexural strength, and the compressive strength of two new core materials to a silver alloy-reinforced glass-ionomer material

This study compared three mechanical properties of two recently introduced core materials, a light-activated glass ionomer cement (VariGlass VLC) and a fluoride-release dual cure composite resin (FluoroCore), with those of a conventional silver-reinforced glass-ionomer cement (Miracle Mix). Seventy-two samples (eight per product for each property) were prepared for testing diametral tensile strength, flexural strength, and compressive strength. The specimens were cured, stored for 24 hours at 37 degrees C in 100% humidity, and tested with the use of an Instron universal testing machine. The results of this study indicate that the diametral tensile strength, flexural strength, and compressive strength of the FluoroCore and VariGlass VLC materials were significantly higher than those of the conventional Miracle Mix. The values obtained with FluoroCore material were consistently higher than those obtained with VariGlass VLC material.

An unusual presentation of adenoid cystic carcinoma of the lacrimal gland

Adenoid cystic carcinoma of the lacrimal gland is a highly malignant tumor usually characterized by symptoms of less than 1 year's duration. Computed tomographic (CT) findings of adjacent bony erosion or focal tumor sclerosis are also suggestive. We present a 57-year-old female patient who manifested symptoms of an enlarging mass in the right lacrimal fossa for almost 3 years prior to the establishment of the diagnosis of adenoid cystic carcinoma. CT findings during those years were not supportive for malignancy. The treatment included en bloc resection of the mass and adjacent bone and radiotherapy.

Factors affecting long-term results of successfully treated amblyopia: age at beginning of treatment and age at cessation of monitoring

The visual acuity of 104 patients who had previously been successfully treated for unilateral amblyopia by occlusion of the good eye was examined 6.4 years, on average, after cessation of treatment. Three age groups were defined, according to the age at which treatment was started: younger (2 to 5.5 years), middle (5.5 to 8 years) and older (above 8 years). In 55% of the patients, the long-term follow-up examination revealed deterioration of the visual acuity. In patients in whom amblyopia had been monitored at least up to the age of 9 years, the age at which treatment was started did not significantly affect the mean amount of deterioration or the mean visual acuity noted at the long-term follow-up examination.

Management of lower-lid retraction with hard-palate mucosa grafting

Lower eyelid retraction is frequently managed by recession of the lower-lid retractors and interposition of a "spacer graft." We have used hard-palate mucosa as our spacer material in 25 eyelids of 18 patients. A graft twice the height of the measured amount of lid retraction was used and resulted in predictable, satisfactory results. The hard-palate mucosa was easily obtained and the donor site healed well in all patients, with minimal care.

The value of intranasal surgery in assuring the success of a conjunctivodacryocystorhinostomy

Conjunctivodacryocystorhinostomy is a much maligned procedure, and there are widely varying opinions about its efficacy and long-term success. We present our modification of the procedure used in 38 eyes of 29 patients over 10 years, with an average follow-up of 2.5 years, which has resulted in a very high rate of success.

Visual thresholds in aphakia and pseudophakia

Following extracapsular senile cataract extraction, visual thresholds were measured in 15 aphakic eyes corrected with glasses and compared with an appropriately matched group of 23 eyes with poly (methyl methacrylate) posterior chamber lenses. All subjects were six months to three years postoperative and had 20/30 or better visual acuity. The paramacular dark adapted threshold, the foveal luminance threshold, and the glare effect on both thresholds were not significantly different in the two groups despite the optical differences between aphakic and pseudophakic correction.

Visual thresholds following posterior chamber lens implants

The dark-adapted threshold for a 2 degree white test imaged 10 degrees parafoveal and the foveal threshold luminance for Landolt ring gap discrimination were measured on 23 pseudophakic eyes with 6/9 or better visual acuity, 6 months to 3 years following posterior chamber lens implantation, and on 15 phakic eyes from an appropriately matched control group. Both scotopic and photopic thresholds were higher for the pseudophakic than for the control group by 0.3 and 0.6 log, respectively. These parafoveal and foveal thresholds, when measured under the influence of glare, were likewise significantly higher for the pseudophakic group.

Anterior vitrectomy for shallow anterior chamber after cataract extraction

Pars plana anterior vitrectomy was performed in 9 patients with shallow anterior chamber after cataract extraction. Five patients had choroidal and/or ciliary body effusion (CCBE), and 4 had aphakic pupillary block (APB). Vitrectomy was performed only after medical treatment failed to restore a normal anterior chamber depth. In all patients the anterior chamber restored during surgery and remained so thereafter, although in patients with CCBE, the fundal pathology subsided days or even months later. The only surgical complication was a longstanding cystoid macular oedema in one patient. Pars plana vitrectomy would appear to have advantages over other surgical techniques, in similar circumstances.